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1. delay unsigned intvalue value 50 gt lt delay gt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF scenario lt disturbance gt H12 QVM Pedal Sensor Disturbance 10 11 XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset removes pedal signal 10 out of 11 rounds cluster cycle sent on both channels repeated 2500 times gt lt definition name const_signal gt 145 Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 740 gt lt duration gt lt signal_low gt lt source gt lt definition gt lt lt KKEKKKK KKK KKK KKK KKK CC CK CC CK CK CI CI CC CC C CK CI CI CIC CC A Ck CK CK CI CI CC Ck Ck CK Ck Ck A S Ck Ck Ck Sk A Sk x A A X M x Configures all the settings needed to run the disturbance relay MEDL etc gt lt scenario name set_to_run gt lt Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66f 6a3900080018c000403200104000 9388500c
2. Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF scenario Runs the disturbance scenario gt scenario name no_disturb gt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt delay unsigned intvalue value 50 delay Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF gt scenario lt disturbance gt H11 QVM Pedal Sensor Disturbance 5 6 XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset removes pedal signal 5 out of 6 rounds cluster cycle sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A source channel BOTH 143 lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt
3. 43 A1 The Time Triggered Protocol sosetan a a EEKE rca nennen nnne nnn nne 43 A2 Developing Applications for the TTTech Cluster sesssseeeee 46 Appendix B DemoCluster Application Quick Start Guide sss 48 Appendix D TTTech TTP Build Quick Start Guide ooocooccconoccconococoncccconnnonananannc cnn cc narra nann canaria 78 Appendix E TTTech TTP Load Quick Start Guide sse 101 Appendix F TTTech TTP View Quick Start Guide 107 Appendix G MATLAB Quick Start Guide Appendix H Experimental Disturbance Node XML Scenarios H1 QVM Node 1 Disturbance XML sseeesss H2 QVM Node 2 Disturbance XML useesss H3 QVM Node 3 Disturbance XML sesesss H4 QVM Node 4 Disturbance XML eeeesss H5 QVM Pedal Sensor Disturbance 1 5 XML H6 QVM Pedal Sensor Disturbance 1 4 XML H7 QVM Pedal Sensor Disturbance 1 3 H8 QVM Pedal Sensor Disturbance 1 2 XML H9 QVM Pedal Sensor Disturbance 3 4 XML H10 QVM Pedal Sensor Disturbance 4 5 XML H11 QVM Pedal Sensor Disturbance 5 6 XML H12 QVM Pedal Sensor Disturbance 10 11 XML H13 QVM Pedal Sensor Disturbance 20 21 XML H14 QVM Pedal Sensor D
4. Runs the disturbance scenario gt scenario name disturb the slot where the disturbance 1 Specifies wait for roundslot roundslot 6 offs Output trigger for oscilloscope trigger name TRIGGER 1 switch 0N Starts the disturbance gt run definition name const signal lt Resets the output trigger signal trigger name TRIGGER_1 switch OFF starts gt Bp ET que gt to low gt gt 129 lt scenario gt lt disturbance gt H4 QVM Node 4 Disturbance XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs round 7 of qvm pedal sensor 790 us low voltage signal 5 us offset sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 790 gt duration signal low lt source gt lt definition gt Ses CK Ck Ck CK CK CIC CC CK KKK KKK KKK KKK KKK KKK C CK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK A o ko gt Configures all the settings needed to run the disturbance relay MEDL etc gt
5. Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON delay unsigned intvalue value 50 delay lt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt lt scenario gt lt disturbance gt H15 QVM Pedal Sensor Disturbance Channel A XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation Distu XML Schema xsd 152 disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset every fourth cluster cycle sent on chan A repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel CH_A gt Sends a constant differential high signal on both channels for 100 microseconds gt duration unsigned intvalue value 780 duration signal low lt source gt lt definition gt sios CK Ck Ck CK C CC CC CK CC CI CI CI CC CC CC CK CI CI CIC CK CC CK CI CIC CC C Ck CK CK CK CCS Ck Ck CK Ck S S S A M kx Sk Sk ko kx A A X X X gt Configures all the settings needed to run the disturbance rela MEDL etc gt lt scenario name set_to_run gt lt Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 5b4d008c018c00040
6. Round 2 Message 1 Message 1 Round 3 Message 1 d Message 1 Message 2 Round 4 Message 1 eee Message 1 Message 3 Fig A1 Example Schedule of a Time Triggered System Please Note A new version of Message 1 is not sent twice during each round Think of the message from Node 2 as a backup of Node 1 s message Each node could be connected to 45 sensors place at nearly the identical location to ensure that data from that location be received even in the event of hardware failure of a single sensor The primary structure of a TTP application follows an object model The entire system is comprised of nodes Each node will communicate across the bus via messages Each node will be running one or more than one subsystem that produces and consumes these messages Each subsystem is comprised of one or more than one task Each task contains the user generated applications reading sensors making calculations and so on Keep this object model in mind while we discuss the applications used during development A2 Developing Applications for the TTTech Cluster There are three primary means of developing applications for a TTTech system The first method which is the most commonly employed uses the tools provided by TTTech to create a cluster database and schedule then develops node databases for each node in the system Next the developer gener
7. gt scenario name do gt 1 destroy to consecutive rounds to trigger ack failure gt lt repeat_scenario name disturb loop 2500 gt lt scenario gt Runs the disturbance scenario gt scenario name disturb gt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt Starts the disturbance gt run definition name const signal Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt scenario lt disturbance gt H5 QVM Pedal Sensor Disturbance 1 5 XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xSi noNamespaceSchemaLocation Distu_XML_Schema xsd gt lt l disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset every fourth cluster cycle sent on both channels repeated 2500 times gt 131 lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 740 gt duration signal low lt source gt lt definition gt sce CK Ck Ck CK CIC CC CC CK C CC CIC CC CK CK
8. QVM Interval 5 6 Wheel Speed vs Round 99 a o m C a o o o No o o E 91 o A e o a o o T 200 400 600 800 1000 1200 Round o Figure 4 15 Disturbance Interval of 5 6 31 QVM Interval 10 11 Wheel Speed vs Round Wheel Speed m s 3 g 91 o o 0 200 400 600 800 1000 1200 1400 Round Figure 4 16 Disturbance Interval of 10 11 QVM Interval 20 21 Wheel Speed vs Round A o o Wheel Speed m s 8 91 o o T T T T T T T T O 200 400 600 800 1000 12001400 1600 1800 Round Figure 4 17 Disturbance Interval of 20 21 32 QVM Interval 40 41 Wheel Speed vs Round ao a o m C a o o o m e o Wheel Speed m s a 100 50 0 T T 0 500 1000 1500 2000 Round Figure 4 18 Disturbance Interval of 40 41 4 1 4 Experiment D Disruption of Bus Channel Finally the last QVM scenario demonstrates the ability of the TTTech development cluster to handle signal disruption on one of the two bus channels The results are shown in Figure 4 19 This test confirms a feature of the TTP protocol that handles all message passing across the the channels of the bus without requiring intervention from the application to handle the error Once received by the TTP communication layer at the node the messages from each channel are compared and a final version of the
9. run definition name const signal lt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt lt scenario gt lt disturbance gt H2 QVM Node 2 Disturbance XML disturbance start scenario set to run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs round 5 of qvm 760 us low voltage signal brake calc node 2 5 us offset sent on both channels repeated 2500 times 126 lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 760 duration signal low lt source gt lt definition gt See CK C Ck CK CK C KKK KKK KKK KKK KKK KKK KKK KKK C CK CK KKK KKK KKK KKK KK KKK KKK AA AAA Ck Sk AAA AAA x x gt Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 5b4d008c018c000403200104000 334c00b7018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 800400038 60225c52f ed98c1dd400000000
10. 25 The required fields are length and type cat more information for required values can be found on page 52 optional values page 72 length specifies the size of these messages in bits you can also specify bytes or 68 combinations of the two Please see the manual for the formatting type cat is either INT for integer values that can be negative UINT for integer values that are always positive and REAL for all real values 26 Once you have completed the required fields click Commit Then Close the previous dialogue box once you ve added all of your needed message types Finally click Next on the Guide to continue to the TTA Message page 27 On the TTA Message Guide page Click the Edit button You are now given the option to set preferences for the messages you previously created see Fig C15 69 TI Tech Object Editor for test TA Message Select filter A TTA Message sg2 sg New Copy Rename Reload soe pu msgl init value max prd max psd validity span Figure C15 Message object list 70 28 Highlight each message and click the Edit button TI Tech Object Editor for test T TA Message SEE TTA Message msq1 Required attributes Optional attributes agreement P E description A e ishsselno 4avJ max prd iuc a max psd A 0 sender_status RA validity span AAA JE More Help App
11. 80a500987bae0c110011c00000008080c0a50099F5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f medl reboot 1 Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt blackout detection roundslot 0 repeat scenario name do loop 2500 gt lt scenario gt lt l Ck CK CK Ck CK Ck Ck Ck Ck Ck CK Ck CK Ck Ck KC Ck CK KKK C CK Ck Ck Ck C CK CI Ck CK Ck Ck CK CI Ck CK Ck Ck kx KK x KG KG Kk ko ko ko ko gt Runs the disturbance scenario gt scenario name do gt lt destroy to consecutive rounds to trigger ack failure run scenario name disturb gt run scenario name disturb gt run scenario name disturb gt run scenario name disturb run scenario name disturb gt run scenario name disturb run scenario name disturb gt run scenario name disturb gt run scenario name disturb gt run scenario name disturb gt run scenario name disturb gt run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run
12. Figure 1 1 Global time triggered schedule The time triggered architecture TTA consists of a number of distributed nodes that model a system and are connected to one another across a real time communication network 1 Each node will consist of three components the host controller that contains the system of interest a communication controller that serves as the interface between the host and the third element the communications network interface CNI referred to here as the bus TTA specifies a dual channel bus for fault tolerance and the specification allows for the replication of nodes to ensure data integrity 1 TTA also specifies methods for generating agreement amongst multiple copies of redundant data This process known as replica determinism allows for communication controllers to handle data validation or pass the responsibility up to the host controller 4 A key principle of time triggered systems is the notion of composability A time triggered system being a series of autonomous nodes connected across the CNI allows the separation of system level architecture and node level design At each level of the design process for a time triggered system testing and certification can be performed without fear that future integration will create incompatibilities assuming each component is designed to specification Initially system level architecture will specify the exact data and time intervals passed across the CNI At this point
13. Fluid Pressure Figure 2 3 ABS control schema 13 3 Solution Models 3 1 Quarter Vehicle Model The quarter vehicle model QVM is adapted from a model provided by TTTech TTTech provides the model to mimic a real world application running on the development cluster and demonstrate principles of redundancy and application load distribution The QVM is divided into three modules brake force calculation wheel speed braking model and pedal position sensor The wheel speed braking module and pedal sensor are each operating in a single node while the brake force calculations are redundantly performed on three nodes Every 3 4 ms pedal position and wheel speed are updated and new braking force is applied to the wheel Results from that rounds braking are calculated and the ensuing wheel speed is derived for the following round Fig 3 1 Wheel Speed Brake Force Braking Model Pedal Position Figure 3 1 TTTech ABS Simulation Model The algorithm for the brake force calculation is itself composed of two modules the raw brake force calculation and the ABS control module Brake force is determined as a simple ratio of the wheel speed which creates a rough approximation of the necessary brake force in Newtons Fig 3 2 Product comp_brake_force Product pedal_pos uint32 50 cst Figure 3 2 MATLAB representation of brake force model The ABS logic is also straightforward as brake force is r
14. Monitoring node C2NF mon IP address 0 0 0 0 TTP Plan User Script py Add from journal file TTTech Ready Figure G8 TTP main object properties dialog 13 If it isn t already selected please select the Cluster tab highlighted in red The following fields will need to be completed Round Duration the length of your TDMA round in microseconds Transmission Speed the transmission speed of your TTP bus in kbits s A value of 2000 will suffice for the development cluster Byte order on TTP bus this value depends on your application A value of big 32 endian should suffice as a starting point For more information on endianness see the TTP Plan documentation page 6 or for more general information http en wikipedia org wiki Endianness Monitoring node The monitoring node for the development cluster is the C2NF mon IP address The IP address of the monitoring node is 192 168 47 11 119 14 Once you ve completed these fields click OK to close the dialog 15 A small application developed in MATLINK for the development cluster will look like Fig C9 s aces File Edit View Simulation Format Tools Help D e Hg Bieo ft el a fi Normal 8 TTP Matlink Main Dialog Counter1 Send Counter2A Send Counter2A Rec Counter2_A_sub Display1 Counter2B Rec Counter2B Send Counter2_B_sub Display2 Counter1 Rec3 Counter2A Rec2
15. TOOTHED RING Figure 2 1 Quarter Vehicle Components 9 At any given wheel speed sensors will monitor the deceleration rate of the wheel If the deceleration occurs too quickly and passes a designated threshold the embedded ABS controller will reduce the braking force on that wheel This is accomplished with the use of values at the brake caliper that either close the intake valve of the break master cylinder to maintain steady pressure or open the outlet valve to reduce pressure and allow the wheel to accelerate out of wheel lock 7 Through the duration of the stop the ABS controller sends a series of signals to the brake master cylinder and pump to either increase or decrease the fluid pressure at that brake as needed The driver of the vehicle will feel a series of strong pulses through the brake pedal To an external viewer a car undergoing active ABS breaking will appear to have its wheels fluctuate in speed or occasionally stop as the system modifies the breaking force needed to keep the wheels spinning in relation to the road surface At a minimum an ABS system requires two additional components that work in tandem with a vehicles brakes the wheel speed sensors and the ABS controller that monitors the speed sensor and modulates the breaking A single quarter vehicle model of a car consisting of a single wheel brake caliper wheel rotor speed sensor and controller is adequate to exam the basic functioning of the abs controller progr
16. gt scenario name do gt 1 destroy to consecutive rounds to trigger ack failure gt lt repeat_scenario name disturb loop 2500 gt lt scenario gt Runs the disturbance scenario gt scenario name disturb 1 Specifies the slot where the disturbance starts wait for slot slot 0 offset 5 155 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF gt lt scenario gt lt disturbance gt H17 FVM Node 2 Disturbance XML disturbance start scenario set to run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd mh disturbs node 2 of fvm 750 us low voltage signal wheel 2 5 us offset sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt duration unsigned intvalue value 750 lt duration gt lt signal_low gt lt source gt lt definition gt lt CK C Ck CK CK KKK KKK KKK KKK KKK KKK KKK KKK C CK KKK KKK KKK CK CK CK KKK AAA C Ck
17. gt lt scenario gt Runs the disturbance scenario gt scenario name disturb gt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF lt scenario gt lt disturbance gt H16 FVM Node 1 Disturbance XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs node 2 of fvm 750 us low voltage signal wheel 1 5 us offset sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 750 duration signal low 154 lt source gt lt definition gt edo KKKKKKK CK CI CC CC CC Ck CK CK C CC CK Ck CK CK CI CIC CC CK CK C Ck CI CI CI CC CK CC C CK CI CI CI CC C Ck Ck C S S E AAA Kk Kk kA AAA oM gt Configures all the settings needed to run the disturbance relay MEDL etc
18. node level designers have the opportunity to meet the specification required while testing the node level implementation to ensure safety and reliability 4 Integrating nodes must maintain stability of prior services as each node will only communicate across the CNI as dictated by the globally shared schedule In this way nodes are easily replaceable in instances of single point failure Absolutely vital to the functioning of time triggered systems is the notion of a global clock Given that time triggered systems are intended for safety critical systems single points of failure such as a single global external clock would present significant problems The TTA specifies that each node contain a local clock along with the global schedule of communication 1 Each node then generates a functional global clock as it receives messages according to the global schedule by comparing known signal times and times listed in the global schedule Discrepancies between a node s local clock and the global schedule are corrected such that a de facto global clock is created So long as each node possesses the same global schedule agreement amongst all nodes in the system about a global time can occur The TTA specification allows for scalability via the introduction of bridge nodes If a single application becomes too computationally intensive to continue running on a node and still provide its data within the deadline that node can be expanded with little
19. scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 5b4d008c018c000403200104000 334c00b7018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 800d00038 60225c52fed98c1dd400000000 a3a0aaaba0a9a2aabef2e6f4beala3a3aa933aa7d2d5a6aa aba7aaa9a0d5d5d730333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 2020202020202020982 0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000808080a50099 2640411 130 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099F5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f medl reboot lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt run scenario name do scenario pes XC CC CK Ck Ck Ck CK C CC CC Ck Ck CK CK CC CC CK CK CC CK CI CI CC CK CC CK CK CI CI CIC CC CK CI CI CI CIC Ck Ck CK C S AAA x Kk Sk Sk Sk ko A Ax X X Runs the disturbance scenario
20. unsigned intvalue value 740 gt duration signal low lt source gt lt definition gt cem Ck Ck Ck CK C C CC CK C CC CIC CC CK CK CC CK CI CI CIC CC C CK CI CI CCS C Ck CK CK CK CIC Ck Ck CK CK CI S C Ck Ck Ck Sk Sk x x A M x kx x RA Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 6a3900080018c000403200104000 938500c6018c00040320 0104000 000000c80000006001800554002c000400030004 000000000005001400024000000300000004000301be09ab 00000000003 4a7100038427c95alccad98c1dd400000000 90939998939a91998dc1d5c78492909099a03a94e1e69894 597939a95e1e59230333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 20202020202020209adc0004000000000002fffffff f0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000 ffff ffffffffeb000011001100000000828280850098f 7c70411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6bP0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f lt medl gt lt reboot gt lt Specifies the time slot where the protocol performs the cli
21. 2 When you create your plan in TTP Plan you should save the cluster database file cdb extension into the root release cdb directory During TTP Plan when you create the schedule a new subdirectory will be created in the cdb folder This folder will be named lt application gt ddb where application is the name of your cluster For example the following structure is created when you save a plan for a cluster named test see Fig B2 48 6 5 build Ltest ddb 5 release J E test bak a0 El test cdb C3 test ddb i test vdb C3 nodet E test jsgittin cdt journal C3 node2 C3 node3 5 node4 Figure B2 Cluster File Structure 4 As you can see the test ddb folder is present and was created by TTP Plan We also have the cluster database file for the test cluster test cdb 5 As for the rest of the file structure your individual node database filed created in TTP Build will be saved to their respective node folders under the release directory So Node1 would be saved to root release node1 When you generated the FT COM code at the end of the TTP Build process for a node it will place the header and source files in the same directory of the node database file see Fig B3 iG build Elimain c 2 473 release Node1 bak B cdb t Node1 ndb C3 test ddb ttpc_ftl c O nodet ttpc msg h C3 node2 ttpos conf c C3 nodes E ttpos_func c C3 node4 Figure B3 Node file structure 6
22. 7 of qvm 780 us low voltage signal pedal sensor 147 5 us offset removes pedal signal 10 out of 11 rounds cluster cycle sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt lt unsigned_intvalue value 740 gt lt duration gt lt signal_low gt lt source gt lt definition gt eres CK Ck Ck CK C C CC CK CC CK CI CI CC CK CC CK CK CI CIC CK CC CK CI CI CC CC Ck CK CK CK CIC CC C Ck CK Ck Ck C Ck Ck Ck Sk Sk x x A A X oo gt Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 6a3900080018c000403200104000 9238500c6018c00040320 0104000 000000c80000006001800554002c000400030004 000000000005001400024000000300000004000301be09ab 00000000003 4a7100038427c95alccad98c1dd400000000 90939998939a91998dc1d5c78d92909099a03a94e1e69894 597939a95e1e59230333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 20202020202020209adc0004000000000002fffffff f0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a081110110000000080
23. CK Ck Ck Ck C CK CK CIC CK CC CK CI CK CC CK C CC CK C Ck Ck Ck Ck CK kk Ck Sk Ck CK kk Ck Sk Ck Sk Sk Kk Sk ke kx Kk k ko X ko kx gt Runs the disturbance scenario gt scenario name do gt lt destroy to consecutive rounds to trigger ack failure gt lt run_scenario name disturb gt lt run_scenario name no_disturb gt 136 lt run_scenario name no_disturb gt lt scenario gt Runs the disturbance scenario gt scenario name disturb lt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt Starts the disturbance run definition name const signal lt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF scenario Runs the disturbance scenario gt scenario name no disturb Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt delay unsigned intvalue value 50 delay Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt scenario lt disturbance gt H8 QVM Pedal Sensor Disturbance 1 2 XML disturbance start
24. CRC encoding embedded in the message nodes that agree in memberships can decode their groups data So long as other nodes receive and agree with this listing that node is included in the global membership If at any time a node finds itself as part of a membership that contains less than half of the total nodes the node restarts in an attempt to rejoin the system 4 The time triggered architecture began development in 1979 at the Technical University of Berlin as part of the MARS project In 1982 Hemann Kopetz began working on variations of the MARS architecture at the Vienna University of Technology examining the critical need for hardware supported fault tolerant clock synchronization in the time triggered architecture 1 Development continued through the 1980 s and early 1990 s The University commercialized the protocol in 1998 and created the TTTech corporation which focuses on safe reliable real time systems for use in transportation industries Currently TTTech systems are used in the Airbus A380 Boeing 787 Dreamliner and the next generation of Audi A8 5 2 Problem Description Anti lock Breaking System Anti lock brakes have been around for decades finding wide use in commercial aircraft in the 1950 s 6 In 1936 Robert Bosch filed the patent for Apparatus for preventing lockbraking of wheels in a motor vehicle 7 During the next 40 years Bosch would work on modifying his ABS system to produce a commercially viable product
25. Counter1 Stat ReceiveA Faunterl Rer Figure G9 Example model 16 Messages into and out of subsystems are the yellow polygons red highlight Subsystems are the blue rectangles blue highlight and output is show in the display boxes highlighted green Any of these objects can be double clicked to open property dialog boxes for further configuration Note that subsystems when double clicked will display the tasks within that 120 subsystem 17 For example double clicking the Counter1_sub box will open that subsystems task Fig C10 demoapp_powernode Counter1_sub File Edit View Simulation Format Tools Help Diag ae mucus a f Normal 7 gi Navigate back b Counter1 in Counterf out task ont Figure G10 Subsystem task window 18 Double clicking the any task will open the its grouped objects For example double clicking on task cnt1 will reveal Fig C11 121 1 demoapp powernode Counter1 sub task cnt1 File Edit View Simulation Format Tools Help ODISHS BB gt T TypeConv2 Constant output signal LED YELLOW 4 LED YELLOW 4 Figure G11 Task example 19 You will know where you are in the object hierarchy by looking at the title of the model window 20 When you have completed your model and are ready to test it You can click the Run Simulation button to run the program and view its output via the display boxes assuming you have them as shown in Fi
26. HN 103 4 Your window should now look like Fig E4 ITTech TIP Load for cluster demo_app ddb lt unsaved gt Fie Edit Check TTP Reports Windows Scripts Help eh IP Addr 192 168 47 11 f Load YPilot Errors Report Node Num All Hosts DDB Short Info Nodet 5 J MEDL Node2 T 5 v MEDL Node3 T do v MEDL Node4 E Iv MEDL 65278 C2NF_mon T MEDL Figure E4 Example of loaded cluster 5 If any of the check boxes are grayed out it means that those node databases need to be rebuilt against the loaded cluster database see Fig E5 Rebuild the grayed out nodes in TTP Load v MEDL APPL S MEDE RPPL JE MEDIE IRPPL bl IF ve APPL MEDL LH 104 Figure E5 Out of sync MEDLs 6 Next check the box next to the C2NF_mon MEDL This represents the monitoring node It will need a current copy of the MEDL as well if you intend to view the activity of the development cluster with TTP View 7 Next verify that you are connecting to the correct IP address of the monitoring node Your window should resemble Fig E6 Tl Tech TIP Load for cluster test ddb lt unsaved gt File Edit Check TTP Reports Windows Scripts Help Node Num All P DDB Short Info Figure E6 Monitoring node IP address 8 Please note that the monitoring node has been configured to listen at the 192 168 47 11 IP address 9 Finally s
27. Kk Ck CK Ck Ck CK CC CK C Ck CK CK CI CC Ck CK CIC CC CK C C CC CC Ck Ck Ck KK Ck Ck KK KK A kx kx A A kx Mk AAA Runs the disturbance scenario gt scenario name do gt 1 destroy to consecutive rounds to trigger ack failure gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name no_disturb gt lt scenario gt 140 Runs the disturbance scenario gt scenario name disturb lt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF scenario Runs the disturbance scenario gt scenario name no_disturb gt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt delay unsigned intvalue value 50 gt lt delay gt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt scenario lt disturbance gt H10 QVM Pedal Sensor Disturbance 4 5 XML
28. Object Editor for test TTA Host Ea tx I Select filter not Ir zs 1 kz or TTA Host 2_mon C2NF mon sv Edit Delete Figure C5 Host list The C2NF_mon is the configuration information for the monitoring node included in with the development cluster To add a new node enter a name for the node in the highlighted textfield and click New 57 11 Once you ve clicked new the node will appear in the upper list below the C2_Mon entry Highlight your node in the list and click the edit button see Fig C6 TI Tech Object Editor for test T TA Host Select filter not and ot TTA Host 2NF_mon 2_mon Figure C6 Host list with use created node 58 12 A new dialogue box will open and you will be allowed to enter values for this node see Fig C7 TI Tech Object Editor for test TTA Host TTA Host Node1 Required attributes Optional attributes allow active role yes 4Y e asynchronous preamble cutoff ns p e c state round spec Ea clock accuracy 100000 o coid statta i svje controller type sv e description A external_rate_correction_allowed no ay is_optional no avj medtet mux period Da mux_round 1 receiver arm delay ns h e rpv startup logic fe a d serial number Number to address this node for download must be unique in the cluster cuen AAA E Figure C7 Host propert
29. On the TTA Host page you will be configuring an individual node in the cluster Click Edit and you will open the window shown in Fig D4 TT Tech Object Editor for test Node1 TTA Host TTA Host Node1 Required attributes E node_config VF 3x 0 startup type Synchronous_Startup 2 e Optional attributes L asynchronous _preemble_cutof _ns o matt message_initialization_hook receiver_arm_delay_ns ft code name ftpeetme E gt msg_header_include fe msg_header_name ftipozmsgh E o os_config_name Beescotc os func name fitpostuncc E node config amp specific node configuration hardware target on which the host software is executed Figure D4 Host property editor There are two required fields node config and startup type more information on page 7 of the TTP Build documentation For the node config field select MPC555 AS8202NF as this is the 80 chipset of all four nodes in the development cluster For startup_type select either Synchronous_Startup or Asynchronous_Startup based on the requirements of your application See page 58 of the TTP OS manual for more details Click Commit when finished 6 Click Close on the Object Editor Window notice that you can only view the other Nodes in your cluster because TTP Build can only work on one Node at a time during this process Click Next in the Guide and continue to the TTA Node Su
30. Task message link property editor 16 The three required fields are see page 11 for required fields page 57 for optional fields access_type determines how the values this task recieves are handled raw states that all messages in are directly passed to task whereas agreed waits for the messages to be processed by the agreement functions to determine message validity receives set to yes if this task receives this message no if it does not sends set to yes if this task sends this message no if it does not 87 17 Click Commit when finished and then Edit each of your links before closing the link editor window Click Next in the Guide to continue to the TTA Node IO Message page 88 18 The TTA Node IO_Message page lets you create links between task and messages that do not travel over the TTP bus For example if you task depended on a sensor reading that entered into the system from outside of the Node this is where you specify to TTP that this message must be used and accounted for in the timing of the code Click Edit to bring up the link editor window as shown in Fig D11 TTTech Object Editor for test Node1 TTA Node lO Message AE Select filter not and r TTA Node lO Message Figure D11 Message list editor 89 19 Enter the name of the lO message into the red highlighted field and then click the New button Once the message is in the Node IO Message box select it and then cl
31. Vehicle ABS Diagram 9 Balancing the needs of safety and the market present interesting challenges As noted previously time triggered systems that implement the time triggered protocol focus on composability which leads to cost savings and parts standardization While not the focus of this study it would be interesting to examine the safety gains and cost increases of utilizing a hybrid speed sensor with an embedded abs controller system that distributed the abs calculations to four independent nodes within the automobile Would it be possible to justify the increased costs with the gains achieved in safety and composability Another area for exploration and the focus of this study is fault tolerance within the time triggered system Given that the worst case execution 11 time remains constant within the time triggered architecture system designers are presented with some unique opportunities when testing fault tolerance and simulating failures of the system Certain failures can be examined using the quarter vehicle model Failure at the speed sensor and bus need not be total to cause significant problems within the ABS Significant disruption of the speed sensor may prevent it from meeting deadlines updating the wheel speed which causes anomalous results in the ABS calculations at the controller At what threshold must the speed sensor provide updates for the ABS controller to maintain adequate and correct brake force for the wheel Is
32. it possible to fail gracefully and still utilize data from the sensor at a less than optimal frequency and at what point is the data infrequent enough to consider the sensor failed Once the sensor has failed the four wheel model can then examine the viability of the vehicle s ABS system with the loss of a single node wheel and later examine at what point the system fails entirely after the lost of two or three nodes The TTTech development cluster provides tools that can examine these various fail states Through the use of a disturbance node connected to the cluster it is possible to knock out or disrupt individual messages such as wheel speed as they are being sent across the bus These disruptions are configurable and allow for the testing of both intermittent both irregular and regular patterns and total disruption of a node What s more these disruptions can also be targeted at the signals relayed from the ABS controller simulating failure at the application level Fig 2 3 At what minimum frequency are brake updates required to maintain safe control of the vehicle under potential wheel lock conditions Thus the quarter vehicle and complete vehicle models can be implemented on the TTTech development cluster and then tested in various states of failure Wheel Speed Pedal Position ABS System Brake Pressure State Increase Decrease Maintain p m a SF a SS a Se eS ee um E E mo um E
33. lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset removes pedal signal 4 out of 5 rounds cluster cycle sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt 141 lt duration gt relay unsigned intvalue value 740 gt duration signal low lt source gt lt definition gt Ss CK Ck Ck Ck CK C CC CC CC CC CI CI C CC CK CC CI CIC CIC CK KKK KKK A Ck Ck KKK KKK KKK CK AAA AAA AAA Sk Sk A AAA AAA Configures all the settings needed to run the disturbance MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66f 6a3900080018c000403200104000 9238500c6018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 4a7100038427c95alccad98c1dd400000000 90939998939a91998dc1d5c78492909099a303a94e1e69894 597939a95e1e59230333938343a31392d6175672d323030 392020202020202020202020202020206a736
34. message is passed to the application without any intervention required As Figure 4 19 shows there is no functional disruption of the pedal sensor and the curve mirrors that of the undisturbed nodes in section 4 1 1 33 QVM Channel A Disturbance Wheel Speed vs Round 99 a o m C a o o o m e eo A e o Wheel Speed m s g a o o O 100 200 300 400 500 600 700 800 Round Figure 4 19 Disturbance of pedal sensor channel A 4 2 FVM Development of the FVM builds on the modified version of the QVM from section 4 1 The same cyclical single wheel model is present in four separate instances to simulate the four wheels of a standard passenger vehicle To determine the speed of the entire vehicle the speed from each of the four wheels is averaged during each TDMA round Again as in the QVM model the TTTech model is modified in order reset to the beginning state once the wheel speed has reached zero The 4 QVM models run Node 1 contains wheel 1 Node 2 contains wheel 2 and Node 3 generates wheels 3 and 4 and calculates the average during the last round of the TDMA cluster on Node 4 This average attempts to handle the disturbance of a single node s output by substituting the previous cluster round s value for averages wheel speed in the absence of input In this way the system should adapt to failure of a single wheel without failure of the entire system Each node is disturbed to test t
35. representation of your variable based on its type definition To begin 110 monitoring the variable through the monitoring node click the blue highlighted button Start Online Monitoring This will begin collecting data from the monitoring node and store it in memory 8 To stop monitoring your variables and begin analyzing them click the stop button highlighted in red as shown in Fig F5 e Update Period 200 E Online Step Figure F5 Stop recording button 9 Once you have stopped recording you can then step or scan through your output using the vcr type controls see Fig F6 E ok O ol 2 Cd EN Update Period 200 Memory Buffer Step 1 j Roundincc f Figure F6 VCR controls 10 You can step a single frame at a time forward or back by clicking on the 1 lt or gt 1 buttons You can also quickly scan along the process by clicking anywhere within the blue timeline bar Finally to save your output click on the disk icon 111 Appendix G MATLAB Quick Start Guide 1 Start MATLAB Start Button gt All Programs gt MATLAB gt R2008a gt MATLAB R2008a 2 MATLAB will start with the desktop open and the command window ready to accept input as seen in Fig G1 MATLAB 7 6 0 R2008a DER Fie Edit Debug Desktop Window Help t a amp Ha a r Current Directory C Documents and Settings jsgittin My Documents MATLAB VIE E Shortcuts 12 How to Ad
36. scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb gt run scenario name disturb run scenario name disturb run scenario name disturb gt run scenario name disturb gt 151 lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name no_disturb gt lt scenario gt Runs the disturbance scenario gt scenario name disturb 1 Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch 0N gt Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF gt scenario Runs the disturbance scenario gt scenario name no_disturb gt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5
37. the Real Time Workbench TTTech has provided a number of tools that allow an experienced MATLAB user to develop a model and then output the necessary cluster database node databases FT COM layers and application code all from within MATLAB The advantages to this approach are quicker application development and greater flexibility when creating and testing your application model However this approach does not allow the degree of fine tuning needed on some systems in order to achieve peak performance It should be noted that the two processes are performing the same operations The tools within MATLAB add another layer of automation to decrease development time The description of the third method SCADE is left for a later date 47 Appendix B DemoCluster Application Quick Start Guide The goal of this documentation is to assist in getting an application created from scratch that will run on the TTTech Development cluster Please note that this does not go into depth regarding the API available in TTP OS but illustrates the minimum necessary code needed to get a program to compile link and load into the Development Cluster 1 Please unpack the included zip file root zip into your project directory It will unpack with the following structure see Fig B1 root B build 3 nodet 3 node2 5 node3 5 node4 B release O cdb 5 node1 5 node2 C3 node3 3 node4 Figure B1 Directory Structure of Build Tree
38. up a dialog box where you input the cluster name Enter a name for your cluster and click OK see Fig C2 53 Tttech cluster name Cancel Figure C2 Cluster name dialog 5 Once you ve clicked OK another dialogue box will open see Fig C3 TlTech Object Editor for test TTA Cluster TTA Cluster test Required DI E mewe E e tr_period 0 transmission_speed 1000 Optional attributes alternate_channels yes 3Y application id f0 application version 0 c_state_length e clock sync clock Sync Stander 2 coldstart iframes 20 controller type TTTech_CanF J e description a E edge jiter tolerance ns 1000 lt gt controller_type clo max frame size controller type protocol m max membership failure 5 di may_mix_frame_types yes 4 e byte order Byte order used for the transmitting of data on the TTP bus Figure C3 Object editor for cluster 54 6 Three values are required to continue byte_order tr_period and transmission_speed See page 6 of the TTP Plan Documentation for more information Byte_order for the purposes of creating a test cluster 32bit big endian big_32_endian is sufficient but your application may require an alternative byte ordering For a brief overview of endianness see the following http en wikipedia org wiki Endianness tr_period TDMA round period The value you p
39. value PN312 External If it does not select PN312 External in the dropdown box highlighted in red and then click the load button highlighted in blue NCO Node Config MPCS55 AS8202NF Board Figure D19 MPC555 property editor 32 Once you have loaded the correct configuration click Commit and return to the Guide tab within TTP Build to continue error checking 33 In order to see detailed information about any errors or warnings open the various trees and click the links to be directed to the problem configuration page Once you have resolved all application errors click the Next button in the Guide to continue to the Making a schedule page 34 Again this page is similar to the TTP Plan Making a schedule page Click the Schedule button and then click Next to continue to the Generate FT COM code page 99 35 The Generate FT COM code page will create all of the files needed to build the FT COM layer of the TTP Node This will create a MEDL and source code for the Node in question You will still need to run a make file to compile the source code prior to loading into the Node Click the FT COM button to generate the code and then click Next to continue to the Congratulations page You have completed one of the Nodes in the development cluster Repeat Steps 3 32 for each other Node in the development cluster Once you have completed each node you will then need to compile your code After the executable has been bui
40. vehicles and light trucks employ ABS as part of a host of critical systems that modern drivers depend on every day Central to each of these systems are the embedded computers and communications infrastructure that allow each to perform at blinding speed and accuracy far faster and accurate that a human is capable Four wheel independent anti lock braking and traction control systems allow drivers to navigate terrain that previously would be impossible to traverse Given that all of these systems are absolutely critical in the safe functioning of the vehicle and that each must be able to perform under non optimal conditions the design and protocol used in these systems must be able to function under duress and must handle failures without compromising safety Additionally like any safety critical system components used must be cost effective and easily testable prior to deployment One protocol that meets these needs is the time triggered protocol Developed at the University of Vienna TTP has undergone over 10 years of research and development This protocol differs from the more common event driven protocol in that all messages sent across the bus do so based on a schedule Therefore performance of the system is deterministic and the worst case message transmission rate is equal the average message transmission rate for a given system Since the time triggered protocol requires the entire system and schedule of communication be created at design tim
41. within a TDMA cluster that are no longer able to communicate When a single node is unable to communicate with the cluster it should recognize that it has entered an error state and restart in an attempt to reintegrate into the cluster When more than one node partition off into groups without a clique avoidance algorithm the nodes in each group are able to communicate with a subset of nodes and thus are unaware of the much larger error involved The TTP protocol defines a clique avoidance algorithm that monitors the creation of subgroups and always forces the subgroup with a majority of nodes to win causing the other smaller groups to reset and reintegrate In this experimental scenario a clique error is generated when two nodes are knocked out and the entire cluster resets To avoid the clique error an attempt is made to 37 disrupt each node on alternating rounds The resulting average wheel speed is shown in Figure 4 24 This wheel speed is identical to the undisturbed state as the pedal sensor output is available from at least one node during each round FVM Pedal Sensor Disturbance Wheel Speed vs Round 350 300 250 200 150 100 50 Wheel Speed m s 0 T T O 100 200 300 400 500 600 700 800 900 Round Figure 4 24 FVM Alternating Pedal Sensor Disturbance 38 7 Conclusion Anti lock braking systems are one of the cornerstones in modern automobile safety Millions of passenger
42. 00 gt lt scenario gt rs C Ck C 0k c Ck Ck Ck 0C CC Ck Ck ck Ck Ck CK C Ck Ck Ck Ck Ck Ck ck CK cC Ck CK ck Ck ck ck kk ck ck Ck ck Ck ck Ck ck ck ck ck kk Sk Sk Sk Sk Sk Sk ko ko kx kv kx Xo Runs the disturbance scenario gt scenario name do gt 132 lt destroy to consecutive rounds to trigger ack failure gt lt run_scenario name disturb gt lt repeat_scenario name no_disturb loop 4 gt lt scenario gt Runs the disturbance scenario gt scenario name disturb gt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF scenario Runs the disturbance scenario gt scenario name no disturb lt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON delay unsigned intvalue value 50 gt lt delay gt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF gt scenario lt disturbance gt H6 QVM Pedal Sens
43. 18c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 800800038 60225c52f ed98c1dd400000000 a3a0aaaba0a9a2aabef2e6f4beala3a3aa933aa7d2d5a6aa aba7aaa9a0d5d5d730333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 2020202020202020982 0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a081 1101100000000808080a500991c9F 0c111011c00080008080c0a500993c87000800000000ffff ff Ha Fffffeb000011001 100000000808080a50099f2640411 001100000000808080a5009938c808110011000000008282 80a500987bae0c11001 1c00000008080c0a50099f5960011 001100000000828280a50098 7c704110011000000008282 80a500983ad6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f medl reboot lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt lt run_scenario name do gt lt scenario gt Succ Ck CK Ck Ck CK CK Ck Ck C Ck KC C CC Ck CK C Ck CK Ck Ck CK CC Ck Ck Ck Ck Ck Ck Ck CK CI CK CK CI Ck CK CC KC Ck Ck Sk Kk S Kk x AAA ko ko ko ko gt Runs the disturbance scenario gt scenario name do gt lt destroy to consecutive rounds to trigger ack failure gt lt repeat_scenario name disturb loop 2500 gt lt scenario gt
44. 20982 0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000808080a50099 2640411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f lt medl gt lt reboot gt lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt lt repeat_scenario name do loop 2500 gt lt scenario gt lt l XC Ck KC Ck CK CC CC CK CI CK CC CC CK CC CC CK CI C CK C CC KK KK KK A KK Ck KK KA KA Sk ke kx Kk AAA Runs the disturbance scenario gt scenario name do lt destroy to consecutive rounds to trigger ack failure gt lt run_scenario name disturb gt run scenario name no_disturb gt scenario 138 Runs the disturbance scenario gt scenario name disturb lt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt Starts the disturbance gt run definition name const
45. 3200104000 334c00b7018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 800400038 60225c52f ed98c1dd400000000 a3a0aaaba0a9a2aabef2e6f4beala3a3aa933aa7d2d5a6aa aba7aaa9a0d5d5d730333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 2020202020202020982 0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000808080a50099 2640411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f Fh medl reboot 1 Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 blackout detection roundslot 0 gt Yr 153 lt repeat_scenario name do loop 2500 gt lt scenario gt eem KKKK C Ck Ck CK CI CC CCS CK Ck Ck CK CK CC CC Ck Ck CK CC CC CK CK C C CI CI C CCS C C C CK CI CI CI CI CC C Ck Ck C S A A A A AAA A A kx X M M Runs the disturbance scenario gt scenario name do gt lt destroy to consecutive rounds to trigger ack failure run scenario name disturb
46. 500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 740 gt duration signal low lt source gt lt definition gt Sc CK C Ck CK CC CC CK C CC CI CIC CC CK CC CK CK CI CI CIC CK CK CC CK CI CI CC A CK CK CK CIC CCS C Ck Ck CK Ck C Ck Ck Ck Sk Sk Sk kx AAA x x gt Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66f 6a3900080018c000403200104000 9238500c6018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 4a7100038427c95alccad98c1dd400000000 90939998939a91998dc1d5c78492909099a303a94e1e69894 597939a95e1e59230333938343a31392d6175672d323030 150 392020202020202020202020202020206a7367697474696e 20202020202020209adc0004000000000002fffffff f0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000 ffff ffffffffeb000011001100000000828280a850098f 7c70411 001100000000808080a5009938c808110011000000008282
47. 6018c00040320 0104000 000000c80000006001800554002c000400030004 000000000005001400024000000300000004000301be09ab 00000000003 4a7100038427c95al1ccad98c1dd400000000 90939998939a91998dc1d5c78492909099a03a94e1e69894 597939a95e1e59230333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 20202020202020209adc0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000 ffff ffffffffeb000011001100000000828280850098f 7c70411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a5009834d6508110011000000008282808500987bae0c11 0011c05080538282c0a50098eb6f lt medl gt lt reboot gt lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt lt repeat_scenario name do loop 2500 gt lt scenario gt Sb KKEKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK KKK gt Runs the disturbance scenario gt scenario name do gt destroy to consecutive rounds to trigger ack failure gt 146 lt run_scenario lt run_scenario lt run_scenario lt run_scenario lt run_scenario lt run_scenario lt run_scenario lt run_scenario lt
48. 6a7367697474696e 2020202020202020982 0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000808080a50099 2640411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f medl reboot lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt lt repeat_scenario name do loop 2500 gt lt scenario gt Sl KKEKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK KKK gt Runs the disturbance scenario gt scenario name do gt destroy to consecutive rounds to trigger ack failure gt 134 lt run_scenario name disturb gt lt repeat_scenario name no_disturb loop 3 gt lt scenario gt Runs the disturbance scenario gt scenario name disturb lt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON Starts the disturbance gt run definit
49. 7697474696e slot where the protocol performs default roundslot 0 gt troy to consecutive rounds to trigger ack failure 20202020202020209adc0004000000000002 ffffffff0Db78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000828280a50098f7c70411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099F5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f medl reboot Specifies the tim the clique avoidance algorithm optional blackout detection roundslot 0 repeat scenario name do loop 2500 gt scenario UE Ck Ck KC Ck CK Ck Ck CK CC C CK C Ck CK CIC CK CI CK CC CC CC Ck CK C Ck CIC CC Ck Ck Ck Ck Ck Sk Ck Sk Ck Sk Sk Kk Sk ke kx Kk Sk kx ko ko kx Runs the disturbance scenario gt scenario name do gt des gt lt run_scenario name di lt run_scenario name di lt run_scenario name di run scenario name di run scenario name no disturb sturb sturb sturb sturb 142 lt scenario gt Runs the disturbance scenario gt scenario name disturb lt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5
50. 8080a500991c9f 0c111011c00080008080c0a500993c87000800000000 ffff ffffffffeb000011001100000000828280850098f 7c70411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f lt medl gt lt reboot gt lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 lt blackout_detection roundslot 0 gt lt repeat_scenario name do loop 2500 gt lt scenario gt 148 SES AS Runs the disturbance scenario gt scenario name do gt lt destroy to consecutive rounds to trigger ack failure run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb run scenario name disturb gt run scenario name disturb run scenario name disturb gt run scenario name disturb gt run scenario name disturb gt run scenario name disturb gt run scenario name disturb gt run scenario name disturb gt run scenario name disturb run scenario name disturb gt run scenario name disturb gt run scenario name disturb run scenario name disturb run scenario name disturb run sc
51. 8202NF B E MATLAB ii Node3 ddb 5 Matlab Install SS node3_appl s19 H E Program Files Ei Node3_MPC555_AS8202NF_B 73 system sav ti Node ddb 3 TTP S node4 appl s19 H E TTTech E Node4 MPCSS5 AS8202NF B a WINDOWS E README TXT Figure B6 FT COM files Si 11 11 31 21 601 5I 21 601 5I 21 601 5I 21 60 I 5I 11 10 The s19 files are the executables that will be uploaded into the cluster using TTP Load This is covered in the TTP Load quickstart appendix 52 Appendix C TTTech TTP Plan Quick Start Guide 1 Start TTP Plan Start Button gt All Programs gt TTTech gt TTP Plan 5 5 7 gt TTP Plan 2 TTP Plan will start in Guide Mode If it is not in Guide Mode click the Guide Tab at the top of the page see Fig C1 TTTech TIP Plan File Edit Check Schedule Reports Windows Scripts Help Guide Y Pilot f Errors f Report Topology Figure C1 Guide Tab TTP Plan Guide mode is a guided tour through the definition of a TTP cluster It leads you through all the steps necessary to create a cluster design At each point in the design you can click Next to continue to the next step Back to return the previous step and Edit to change values for the current step Take a moment to save your new cluster definition This folder will then be the target for all auto generated files within TTP Plan 3 Click Next and go to the Cluster Step 4 Click Edit This will bring
52. 96e 2020202020202020982 0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9 125 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000808080a50099f 2640411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099F5960011 001100000000828280a50098 7c704110011000000008282 80a500983ad6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f medl reboot lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt run scenario name do scenario RE CA CC CK CK Ck Ck CK C C CC Ck Ck CK C CC CC CK C C CK CI CIC CC C CC CK CK CI CI CCS C CK CK CI CI CI CI CC Ck Ck Ck CK S S A E x Kk Sk Sk ko Sk kx Ax X X Runs the disturbance scenario gt scenario name do gt lt destroy to consecutive rounds to trigger ack failure gt lt repeat_scenario name disturb loop 2500 gt lt scenario gt Runs the disturbance scenario gt scenario name disturb gt Specifies the slot where the disturbance starts wait for roundslot roundslot 4 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt Starts the disturbance gt
53. A Study of Time Triggered Systems John Gittings Advisor Dr J Zalewski FGCU Ft Myers FL 33965 December 11 2009 Table of Contents 1 Introduction to time triggered systems adurren iain conc Einne EROE EENE nnnm nns 4 2 Problem Description Anti lock Breaking System sssssssssseeeeenenes 8 23 Sol tior Models z 5 Ace eot it dabas ee ad eg ada detur epe Pop pas 14 3 1 Quarter Vehicle Model sssssssssssssseseeenee nennen entente intrent enne 14 3 2 Four Wheel Vehicle Model oooooooccccoonoccccnonocccononoccnonanancnnnano cnn n nano cnn n cano nennen nnne nns 17 4 ExpetliTients 5 52 dde ditiis tay ATE S N or ed PH edet ne Partida dee va dere ie et 19 Lo PE 21 4 1 1 Experiment A Undisturbed State sssssssssseeeeeee 21 4 1 2 Experiment B Disturbing Individual Nodes enne 23 4 1 3 Experiment C Interval Disturbance of Pedal Sensor sssss 27 4 1 4 Experiment D Disruption of Bus Channel sse 33 4 2 4 VM teet ld altas 34 4 2 1 Experiment E Undisturbed Model sseeeeee ee 35 4 2 2 Experiment F Individual node disturbance ess 35 4 2 3 Experiment G Pedal Sensor Disturbance ssssssssssseee 37 A GONCIUSION EET 39 MSIE 42 Appendix A Overview of development for the TTTech Demonstration Cluster
54. C AAA AAA AAA AAA x o gt Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66f d0050066018c000403200104000 0823006 018c00040320 0104000 000000c8000000600180052c002c000400030004 00000000000500140002d000000300000004000301af0965 00000000003 549e0003d14382369ff0d98c1dd400000000 156 4e7edece7 5edf9b5alb3f9e6e4e4edd43ae09592e0e1 91e290eee0e1929230333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 2020202020202020c2470004000000000002fffffff f0b78 0011101100000000808080a1009570230411101100000000 808080a00094171 0811101100000000808080a0009451da 0c111011c00080008080c09 00934bde000800000000ffff ffff ffffebo000011001108000805848480a10092e35b0411 0011080a080 848480a000915e8508110011081408198484 80a000917a280c110011c00000008080c09f009382cf0011 001100000000828280a10094171204110011000000008282 80a000931a42408110011081e0823848480a000917d2c0c11 0011c05080538282c09 00929c36 medl reboot lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt run scenario name do scenario lt CC CK CK CK Ck KKK KKK KKK KKK KKK K
55. C CK CK CI CI CC C Ck CK CK CK CIC CK Ck Ck Ck C Ck Ck Ck AAA x A A X ox Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66f 6a900080018c000403200104000f9a8b600c6018c00040320 0104000 000000c80000006001800554002c000400030004 000000000005001400024000000300000004000301be09ab 00000000003 4a7100038427c95alccad98c1dd400000000 90939998939a91998dc1d5c78492909099a03a94e1e69894 597939a95e1e59230333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 20202020202020209adc0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000828280850098f 7c70411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6bP0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f Fh medl reboot 1 Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt blackout detection roundslot 0 repeat scenario name do loop 2500 gt lt scenario gt xI Ck Ck CK Ck Ck
56. CK CC CK CI CI CIC CC CK CK CK CI CIC CC Ck CK CK CI CI CCS CK Ck Ck Ck Ck Ck Sk Ck Sk Sk Sk A Ax AAA x x gt Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 6a900080018c000403200104000f9a8b00c6018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 4a7100038427c95a1ccad98c1dd400000000 a8abala0aba2a9alb5f9edffb5aaa8a8al983aacd9dea0ac dbaddba2a deacaf30333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 20202020202020209a8c0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000828280a50098 7c70411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f Fh lt medl gt lt reboot gt lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt lt repeat_scenario name do loop 25
57. Cluster Mode uses Message Select filter not and or cluster_mode message Link test_modes gt msg3 deleted Figure C18 Cluster mode message linker dialog 73 33 First select the cluster mode you want to define by selecting it within the red highlighted area Next select a message you want transmitted during that cluster mode in the blue highlighted area Click New and this link will be added to the cluster_mode and message lists above Finally select each cluster mode message link in the list and click Edit You will be present with the following dialogue in Fig C19 Link test_mode lt msqg1 Required attributes Optional attributes max round TTA Cluster max_tdma_rounds 0 min round 4 0 redundancy_degree 1 sampling factor fi 0 sampling_phase o 0 J Cancel E eee d period Maximum transmission period of message in microseconds Figure C19 Cluster mode message link property editor 34 This is where we define the frequency of message transmission The only required field 74 d_period is the maximum number of microseconds that can elapse between transmission of the message more information on page 15 optional values are defined on page 81 Enter a value and click Commit Do this for each cluster mode message link Finally click Close on the link editor dialogue box and then click Next in the Guide You will continue to the Mode cha
58. In fact in at least one instance the ability of the TTTech system to detect more complicated system level errors prevented the experiment from inadvertently creating a clique situation where two or more groups of node began working independently from one another While this made it difficult to test the ABS models functioning under stress for that particular scenario it did serve as a learning point about the many error detection subsystems built into the TTP controllers There is still much to be done with both the TTTech development hardware and the investigation of safety critical systems like the ABS models discussed in this paper For one the models used here are largely only useful from a teaching perspective as they fall well short of what would be necessary if they were to be deployed in a real world environment While they were quickly created and molded to fit within the four node design of the development cluster they failed to mirror the data produced by real world ABS systems In the future creating a more robust model that achieved maximum braking force quickly and then oscillated about a tires slip point would be the logical next step There were hurdles to this however and the amount of time afforded this project prohibited developing a more realistic model Furthermore the ability to simulate the road surface tire interaction more realistically is a notoriously difficult and demanding 40 task which is often handled by tire
59. KK KK KKK KKK KKK CK CK CI KKK KKK CK CI KKK KKK KKK KKK KKK KKK ko ko kx Ax X X Runs the disturbance scenario gt scenario name do gt lt destroy to consecutive rounds to trigger ack failure gt lt repeat_scenario name disturb loop 2500 gt lt scenario gt Runs the disturbance scenario gt scenario name disturb gt Specifies the slot where the disturbance starts wait for slot slot 1 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt lt scenario gt lt disturbance gt H18 FVM Node 3 Disturbance XML disturbance start_scenario set_to_run xmins xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation Distu_XML_Schema xsd gt ES esc 157 disturbs node 3 of fvm 730 us low voltage signal wheel 3 and 4 5 us offset sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt Sends a constant differential high signal on both channels for 100 microseconds gt duration unsigned intvalue value 730 duration signal low lt source gt lt
60. Plan TTP Build TTP Load and TTP View To begin this appendix goes over the structure for how the TTTech system is normally deployed and the philosophy behind development for TTP systems in the automotive and aerospace industries Next it briefly overviews the TTP scheduling system and the premise behind time triggered systems Finally it outlines the steps needed to go from a basic application idea to design and implementation on the TTTech development cluster It must be noted however that at no time is this document or any of the other quick start manuals a replacement for the TTTech documentation This appendix is designed to assist in getting a user up to speed with development and not meant as a comprehensive guide to the embedded systems or protocols of the TTTech hardware A1 The Time Triggered Protocol The TTP time triggered protocol is used to ensure predictable and reliable communication over real time safety critical systems It differs from the more common event driven systems where every item on the bus can communicate at once in that each system on the bus is allowed to communicate only at predetermined time intervals The communications for systems on a time triggered bus are defined at design time and will not change from that point on Since many different producers and subcontractors are used in the creation of the final product it allows for more certainty that when the parts are finally all put together they will f
61. TTTech Object Editor for test Node1 TTA Node App_Task TTA Node App_Task lask2 task1 bcet 10 us time budget Figure D7 Task editor list 10 Select a task on the list and then click Edit You will then open the edit task dialogue shown in Fig D8 84 TI Tech Object Editor for test Node1 TTA Node App_Task DEOR TTA Node App Task task1 i Required attributes time source oatme 4 xj Optional attributes il beet 10 us or m 18 execute in system mode b ay e ladstaskchan oo ywje may run with init values b ayj uses float ay e lime budget Amount of CPU time allocated for the execution of this task microseconds If a task exceeds this limit a deadline Figure D8 Task property editor 11 The two required fields are time budget and time source see page 10 time budget is implementation specific but the value should not be larger than the time alloted to the node during a single TDMA round In fact it will need to be quite a bit smaller to incorporate the time taken to pull the data from the bus move it to memory and then reverse the process during transmission time source depends on the application requirements If your task needs to be run regardless of whether the global clock is available then run on local time Optional values are described on page 21 12 Once you ve added the required values click Commit Then add the required values for any other tas
62. The make files needed for the project are located in the root build directory There are 4 make files used during compilation and linking see Fig B4 49 8 C3 root A node o Om Enode2 C3 node1 nodes 3 node2 Sjnode4 C3 node3 FS copy_node_to_ddb bat O node4 C make bat E release FS make_all bat C3 cdb e prj setup bat C3 node1 C3 node2 C3 node3 O node4 Figure B4 Make files 7 If you maintain the directory structure as outlined and save your cdb and node database files as listed the only file you need to edit is prj setup bat Once you have named and saved your cluster database file you must set the CLUSTER NAME variable to the name of your cluster This is used during the final copy of your executable The location to edit is highlighted in red in Fig B5 50 P prj setup bat Notepad File Edit Format View Help techo off rem Me RR W rem Project related setting rem HHH HHH HHH if Xl goto setit if Xl set goto setit if l clear goto clearit goto error rem Me HH setit rem HHHHHH HHH if XBSP MPC5553 goto find mysetup if XBsP TTPCX goto find mysetup if XBsP TTTECHX goto find mysetup if XDIABDATA PATHX goto find mysetup Set HWMODEL pn312 set CTYPE C2NF WWW Must add Clustername value for the copy portion of make to work et CLUSTER NAME rem set the toolset Figure B5 Project setup batch file 8 Once you have generated your FT COM code
63. The second section contained in the middle scenario node defines the MEDL which allows the TTTech disturbance node to synchronize with the cluster and send signals during specific rounds in the cluster cycle This section also defines the number of times the disturbance should loop before completing In this example the scenario do which contains one sub scenario disturb a will be run 2500 times Finally the last series of scenario nodes define the round slot at which the disturbance signal should be sent and if a timing offset is needed before sending the signal In this example the scenario disturb a is triggered on round slot 0 and round slot 1 of the TDMA cluster cycle and has a timing offset of 5 microseconds the disturbance node will wait 5 microseconds before sending the low voltage signal The scenarios in use for the following experiments have been developed by the author in order to test features inherent to the TTP protocol For the purposes of this paper the disturbances are of two forms removal of a node and intermittent interruption of messages from a node during the TDMA round Every scenario s XML file is included in section H of the appendix Please note that modifications to the existing TTTech QVM braking model are 20 introduced by the author to facilitate data acquisition during scenario execution The TTTech braking model is not cyclical and thus disturbing the entire model from the starting point is prohibitive
64. a000915e8508110011081408198484 80a000917a280c110011c00000008080c09f009382cf0011 001100000000828280a10094171204110011000000008282 80a00093142408110011081e0823848480a000917d2c0c11 0011c05080538282c09f00929c36 medl reboot blackout detection roundslot 0 gt repeat scenario name do loop 2500 gt scenario scenario name do gt run scenario name disturb_a gt lt scenario gt lt scenario name disturb_a gt wait for roundslot roundslot 0 offset 5 trigger name TRIGGER 1 switch 0N run definition name const signal 19 trigger name TRIGGER_1 switch OFF wait for roundslot roundslot 1 offset 5 trigger name TRIGGER 1 switch 0N run definition name const signal trigger name TRIGGER 1 switch OFF scenario scenario name no disturb a wait for roundslot roundslot 0 offset 5 trigger name TRIGGER 1 switch 0N delay unsigned intvalue value 50 gt lt delay gt trigger name TRIGGER 1 switch OFF scenario disturbance Figure 4 1 XML contents of disturbance node configuration The XML file is broken up into three sections At the top is the definition node which specifies the length and type of signal used for the disturbance In this example a low voltage signal will be sent on both channels and will last 700 microseconds
65. a3a0aaaba0a9a2aabef2e6f4beala3a3aa933aa7d2d5a6aa aba7aaa9a0d5d5d730333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 2020202020202020982 0004000000000002ffffffff0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9 0c111011c00080008080c0a500993c87000800000000ffff ffffffffeb000011001100000000808080a50099 2640411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f lt medl gt lt reboot gt lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt lt run_scenario name do gt lt scenario gt lt KEKE KKK KKK KKK KK KK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KK KKK KK KK Sk Sk Sk ko AAA Runs the disturbance scenario gt 127 lt scenario name do gt lt destroy to consecutive rounds to trigger ack failure gt lt repeat_scenario name disturb loop 2500 gt lt scenario gt Runs the disturbance scenario gt scenario name disturb gt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 5 offset 5 Output trigger f
66. am at the wheel level but does not adequately model the safety needs of such a critical system This model presents multiple single points of failure The system will fail if the speed sensor fails to transmit or if the bus transmitting the signal from the sensor fails In order to avoid these failures it would be necessary to add additional speed sensors to the wheel as well as redundant connections to ensure that adequate data returned to the abs controller It is also possible to have a failure at the ABS controller Given the nature of the failure and the implementation of the embedded operating system and control logic the controller may be able to recover through a system restart or the system may become inoperable if only a single controller is used Thus the ABS controller would also require a redundant copy However in the commercial automotive market this amount of redundancy would prove difficult to bring to market It may drive the price high enough to prove noncompetitive while also adding in additional points of maintenance for the consumer In practice the desired redundancy is achieved in the operation of four independent speed sensors one located at each wheel Loss of information from a single wheel does not necessarily cause failure of the entire ABS system Fig 2 2 HYDRAULIC UNIT including master cylinder aril stars ke Ranin uid reservoir valvos p amp actuators Bae Figure 2 2 Complete
67. application model is adding a TTP Matlink main dialogue object to the model Fig C6 Simulink Library Browser File Edit View Help D oa Enter search term v 29 Libraries Library TTP Matlink Search Results none Simulink Control System Toolbox VO for MPC555 VO for PowerNode Neural Network Toolbox Real Time WWorkshop Simulink Control Design Simulink Extras Cy TTP Matlink fault fcn call d 49 Matlink Main Dialog es Msg Rec Matlink Main Dialog Msg Send subsystem task E gt Read oe gi Figure G6 TTP Simulink objects 10 Select TTP Matlink under the Libraries heading red highlight and then click and drag an instance of the Matlink Main Dialog blue highlight into the model window as shown in Fig C6 117 11 Your model should now look like this Fig C7 El untitled File Edit View Simulation Format Tools Help Dee Slt BElSoT Rs gt m 10 0 Normal y Model Browser ley x Matlink Main Dialog Figure G7 First object in TTP model 12 Now double click on the orange TTP Matlink box to bring up the properties dialog Fig C8 118 TIP Matlink 2 6 51 lt untitled gt Configuration Cluster Mapping Build Calibration Extras Round duration us 1 0000 Update periods Transmission speed kbit s 5000 Byte order on TTP bus big 15 endian
68. ates the FT COM layers for each node and finally the target application for that node TTP Plan is the first tool used in this process With it the architect of the system can outline when each node should communicate on the bus the size of those messages how long each cycle should be and many other parameters that define the interaction between all the nodes Essentially TTP Plan creates a schedule and the subsystems in the object model Once completed the architect will generate a cluster database and final schedule for all the nodes The cluster database is then passed onto each subcontractor for use in configuring the nodes with TTP Build A developer will specify each of the messages used on that node during a given application mode Each message will be associated with a task and the parameters for that task will be defined Once completed TTP Build will generate the FT COM layer that handles all the bus communication Finally the developer will move on to their development environment of choice to create the main application code Here the developer will use the TTP OS API to 46 interface with the bus for sending and receiving data Compilers and linkers will need to be micro controller specific in order to generate final binary executable For the development cluster make files will be provided with instructions as to their use The second and less frequently used method for development is rapid prototyping using MATLAB Simulink and
69. below the rate of wheel speed reduction and the curve of the graph trended toward the graphs depicting absence of the pedal sensor message Figures 4 9 4 11 and 4 13 4 18 inclusive show the time needed to come to rest gradually increasing from 700 rounds to over 1800 rounds Furthermore as the time needed to stop increases the rate of change slows as well and the graphs become increasingly linear As mentioned above two graphs do not follow this pattern Disturbances of 1 4 Figure 4 10 and 1 2 Figure 4 12 display an unexpected outcome Namely the simulation comes to rest sooner despite a decrease in the number of braking messages sent across the bus As has been pointed out previously in this paper the model in use here does not accurately reflect real world conditions and responses As such it is the author s opinion that these aberrant results would be eliminated as the model was modified to more closely match a real world environment 27 However for the sake of completeness these results were included to show that testing was performed at regular intervals beginning at 20 1 5 disturbance all the way to 97 40 41 disturbance Despite the notable weakness of the model it is encouraging to see that the model was capable of handling the intermittent disturbance without failing outright At 75 total disturbance the model was only reduced in effectiveness by 1696 stopping within 800 rounds where the undisturbed model comes to
70. bsystem_runs_Task page 7 On the TTA Node Subsystem_runs_Task page you will be linking subsystems and tasks Tasks are the functional units in the TTP model in other words the application that you create to use the data transmitted over the TTP bus Each task is executed by exactly one subsystem but each subsystem may execute as many tasks as necessary Click the Edit button to open the following dialogue show in Fig D5 81 TlTech Link Editor for test Node1 TTA Node Subsystem_runs_Task DE Figure D5 Subsystem task linker 82 8 The red highlighted field will contain the subsystems you defined in TTP Plan The blue field will initially be empty You will add tasks here by typing their name into the field Once you ve entered a subsystem and task click New to create the link When done your links will look something like those shown in Fig D6 TTTech Link Editor for test Node1 TTA Node Subsystem_runs_Task DER Select filter t and r subsystem task sub2 2 Y 5 hasi amp v Select filter t r Select filter i New link sub2 task2 created al Figure D6 Examples of subsystem task links 83 9 Click Close when you ve created all your links Click Next in the Guide to continue to the TTA Node App_Task page You will edit parameters for the tasks you just created in the previous step Click Edit to bring up a list of the tasks running on this Node see Fig D7
71. cd Files of type TTP Cluster Database cdb Cancel Figure F2 Open file dialog 5 Select your cluster file and then click Open If you already have a view database you will then need to answer yes to create a new database or no to update see Fig F3 The project C gittings demo_pn312 5 5 43 release cdb demo_app vdb is Found from which you can update your project settings You can continue creating your new project but the settings of your old project will be lost IF you want to update this existing project please select Update project from File menu Do you want ko continue with creation of your new project Mo 108 Figure F3 Create new project modal dialog 109 6 Once you ve opened the view database you should see Fig F4 7 TIPview Untitled File Edit View Controls Window Scripts Help d Da Sele 4 33A simi Tech B x Status rea Subsystems 3 Messages l Counter1 89 Counter1_sub_status lz Counterz A Counter1 55535 l Counter2 B 3 SwitchState 9 SwitchState B s Current Round Trace Start Step fi Round in CC Trace End Figure F4 Variables loaded for monitoring 7 In the red highlighted area your applications variables are listed In order to begin monitoring your variables you must click and hold a variable from the red area and drag it to the green area You will then see a
72. d 2 What s New Current Directory O x Workspace Command Window x e r1 3 O New to MATLAB Watch this Yideo see Demos or read Getting Started All Files Type This is a Classroom License for instructional use only Research and commercial use is prohibited RADA TTP Mat link 2 6 51 IO Toolbox 3 2 1 TTP Plan 5 5 7 TTP Build 5 5 40 TTP Load 6 5 11 Copyright C 2001 2008 TTTech Computertechnik AG All right Schoenbrunnerstrasse 7 A 1040 Vienna Austria support lt lu AAA Command History WARNING Real Time Workshop is not installed Getting started enter brake and double click the Matlink M p amp 8 5 09 12 i s 8 5 09 1 23 PM Gone gt gt Figure G1 MATLAB main window 3 For an initial basic tutorial of the windows and general functionality of MATLAB please see the following videos Getting Started 112 C AMATLAB R2008a toolbox matlab demos html GettingStartedwithMATLAB html Working with the desktop http www mathworks com support 2008a matlab 7 6 demos WorkinglnTheDevelopmentEnviron ment html Writing a program http www mathworks com support 2008a matlab 7 6 demos WritingAMATLABProgram html 4 The focus of this appendix is to create models in MATLAB using the TTP Simulink objects for developing applications 5 Select File gt New gt Model see Fig C2 Open Ctrl O Figure Close Command Window Variable Model Im
73. definition gt SES CK C Ck CK C CC CC CK CC CC CIC CC CK CC CK CK CI CI CIC CK C CK CK CI CIC CC CC CK CK CK AAA Ck Ck Ck Ck C AAA AAA AAA AAA xo gt Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66f d0050066018c000403200104000 0823006 018c00040320 0104000 000000c8000000600180052c002c000400030004 00000000000500140002d000000300000004000301af0965 00000000003 549e0003d14382369f f0d98c1dd400000000 4e7edece7 5edf9b5alb3f9e6e4e4edd43ae09592e0e1 91e290eee0e1929230333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 2020202020202020c2470004000000000002ffffffff0b78 0011101100000000808080a1009570230411101100000000 808080a00094171 0811101100000000808080a0009451da 0c111011c00080008080c09 00934bde000800000000 ffff ffffffffeb000011001108000805848480a810092e6355p0411 0011080a080 848480a000915e8508110011081408198484 80a000917a280c110011c00000008080c09f f009382cf0011 001100000000828280a10094171204110011000000008282 80a00093142408110011081e0823848480a000917d2c0c11 0011c05080538282c09 00929c36 medl reboot 1 Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt blackout detection roundslot 0
74. e it allows for easy integration of component nodes This determinism also makes testing and certification a much easier and cost effective process The time triggered protocol also incorporates many features that layer system safety without any need for additional application code Communication across the bus is sent on two channels Subsystems can be redundantly deployed on multiple nodes in the system and the messages they produce are integrated by the TTP controller and presented to the application without any application code becoming involved 39 Many tools exist to rapidly prototype and develop for TTTech systems As shown in this paper models develop quickly with tools such as MATLAB and can be field tested quickly with hardware like the TTTech development cluster Even more valuable failure and problems in the system can be created and tested in a systematic way with the addition of the TTTech Disturbance Node This is a potent combination of hardware and software that allows system architects to develop test and finalize complicated new applications that rely on time triggered technology The experiments discussed in this paper sought to demonstrate the various safeguards inherent in the time triggered protocol while also demonstrating the operation of a simple ABS model under various levels of stress In all instances the TTTech development cluster performed as expected with the various safety systems performing as per the protocol
75. e and resources to make this a reality 41 6 References H Kopetz The time triggered architecture In Proceedings of the 1 st international symposium on object oriented realtime distributed computing April 1988 pp 22 29 IEEE Press 2 D A Gwaltney and J M Briscoe Comparison of Communication Architectures for Spacecraft Modular Avionics Systems Marshall Space Flight Center Alabama 2006 3 M Pont Patterns for Time Triggered Embedded Systems Building Reliable Applications with the 8051 Family of Microcontrollers 2001 Addison Wesley Professional 4 TTP Seminar TTP mechanisms the protocol in detail June 2009 5 TTTech Company Overview http www tttech com company overview company profile 2009 6 Q amp A s Antilock brakes cars trucks motorcycles Insurance Institute for Highway Safety http www iihs org research qanda antilock html 2009 7 25th Bosch ABS Anniversary http www bosch com assets en company innovation theme03 htm 2003 8 D Burton et al Evaluation of Anti lock Braking System Effectiveness April 2004 Royal Automobile Club of Victoria Ltd 9 Courtesy Goodyear Tacoma Washington http goodyeartacoma com services brakes 2009 42 Appendix A Overview of development for the TTTech Demonstration Cluster The goal for this document is to give the reader a broad overview of the process and interaction between the software components used in the TTTech Development cluster TTP
76. ed since each subsystem has access to every frame Click the Edit button to open the dialogue box show in Fig C11 63 TI Tech Link Editor for test TTA Subsystem_sends_Message Select filter not and or Ti Select filter l or Copy Rename Reload Close E e Link out1 lt counter1_out deleted El gj Figure C11 Subsystem and message link editor 64 21 In the red highlighted box select a subsystem and in the blue highlighted box enter in the name of a message that subsystem sends Click New to create the link This will add them to the subsystem and message lists at the top of the dialogue Please note that each message is sent by exactly one subsystem but each subsystem may send as many messages as necessary For more information please see page 11 in the manual When you have created your links you should have something similar to the following example In this example sub1 sends two messages msg1 and msg2 while sub2 only sends one message msg3 See Fig C12 TlTech Link Editor for test TA Subsystem_sends_Message Select filter _ ee l susytem message ss EN xr 4M me ay Select filter Select filter a New link sub2 msq3 created Figure C12 Example subsystem message links 65 22 Click close when finished and then click Next in the Guide to continue on to the TTA Msg_Type_P page This screen will l
77. elect the TTP Download ddb button to begin the download process as shown in Fig E7 the term download here refers to downloading the new MEDL into the monitoring node You are in fact pushing the new node firmware to each node in turn via the monitoring node TT Tech TIP Load for cluster demo_app ddb lt unsaved gt File Edit Check TTP Reports Windows Scripts zx je rss 192 168 47 11 E 105 Figure E7 TTP download button 10 You will see a series of progress bars If there were no errors find the compiled s19 files you will see the development cluster enter into download mode Each node will stop the current running task and you will see LED output to signify download mode 106 Appendix F TTTech TTP View Quick Start Guide 1 Start TTP View Start Button gt All Programs gt TTTech gt TTP View 6 5 6 gt TTP View 2 TTP View will start up and you will begin with this window see Fig F1 iges 22 TIPview File Edit View Controls Window Scripts Help delo Beira Rai sm Ready NUM Current Round Time Trac Figure F1 TTP View main window 107 3 If this is your first use of TTP View with your cluster the click the red highlighted button create a view database from cluster database 4 This will open a file dialogue box where you should locate your cluster database see Fig F2 Look in C3 cdo ct Ed E demo app ddb is demo app cdb File name f
78. emoved from the wheel only when wheel lock occurs Fig 3 3 If wheel speed remains above zero proportional brake force is applied If wheel lock occurs the switch condition sends a zero value instead of the calculated brake force uint32 0 null speed comp brake force Figure 3 3 MATLAB model of ABS control logic Once a brake force is applied to the wheel the resulting deceleration is determined based on the model shown in Figure 3 4 Please note that the presence of the previous round s wheel speed is used only for the purpose of restarting the simulation after wheel speed has reached zero It is not used in the calculation of the current rounds speed Product wheel speed 100 Lookup Data Type Conversion Table 2 D Discrete Time T Integrator Vehicle mass Transfer Fen Compare To Zero prev wheel speed Figure 3 4 MATLAB model for quarter vehicle deceleration During simulation the ABS controller brings the wheel to a halt in 2 3952 seconds Fig 3 5 from the initial wheel speed value of 300 The brake force applied to the wheel during the simulation is shown in Figure 3 6 Figure 3 5 Wheel Speed m s vs Time sec in MATLAB Simulation brake_force Figure 3 6 Brake Force N vs Time sec in MATLAB Simulation 3 2 Four Wheel Vehicle Model The four wheel vehicle model FWM requires a different approach given the constraints of working with only the four nodes of the devel
79. enario name disturb run scenario name no disturb lt scenario gt Runs the disturbance scenario gt scenario name disturb lt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF lt scenario gt Runs the disturbance scenario gt scenario name no disturb Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt delay unsigned intvalue value 50 delay 149 lt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt scenario disturbance H14 QVM Pedal Sensor Disturbance 40 41 XML disturbance start scenario set to run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation Distu XML Schema xsd lt disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset removes pedal signal 10 out of 11 rounds cluster cycle sent on both channels repeated 2
80. es each of the wheels runs to near zero and holds until the disturbance ends In order to 35 correct this flaw in the model the averages wheel speed sensor would need to detect when an input value is missing and rather than substitute a number to replace the missing value should recalculate the average with only the inputs involved Wheel Speed m s Wheel Speed m s FVM Node 1 Disturbance Wheel Speed vs Round T 0 1000 2000 3000 4000 5000 Round Figure 4 21 FVM Disturbance of Node 1 FVM Node 2 Disturbance Wheel Speed vs Round ao a o 99 e eo n 91 o m e eo E 91 o A e o a o o T T T T 0 1000 2000 3000 4000 5000 Round Figure 4 22 FVM Disturbance of Node 2 36 FVM Node 3 Disturbance Wheel Speed vs Round 99 a o m C a o o o m e eo 150 100 Wheel Speed m s a o 0 T T T T 0 1000 2000 3000 4000 5000 Round Figure 4 23 FVM Disturbance of Node 3 4 2 3 Experiment G Pedal Sensor Disturbance Finally the attempt is made to mirror the pedal sensor disruption performed on the QVM However given that the pedal sensor is redundantly transmitted on both nodes 1 and 2 disrupting both in the same TDMA round generates a clique error within the TTP protocol and forces the development cluster to reset A clique error is the presence of two or more subgroups
81. es to zero as a function of the wheel speed model s simulation of friction on the tire QVM Node 4 Wheel Speed vs Round ao a o m C a o o o n e eo A o o Wheel Speed m s 8 91 o o T T T 500 1000 1500 2000 2500 3000 Round o Figure 4 8 Disturbance of pedal sensor in QVM in the Development Cluster 26 4 1 3 Experiment C Interval Disturbance of Pedal Sensor The following scenarios disrupt the pedal sensor message during transmission at varying intervals Disturbances are sent across the bus in gradually increasing bursts and the resulting wheel speed is monitored to determine the ability of the model to apply braking force under non ideal conditions For each of the scenarios the amount of disturbance is expressed in a ratio of the following format number of disturbances total number of rounds in this cycle Please note that the number of rounds in a cycle referenced above does not refer to a TDMA cluster or round but rather the number of rounds that are disturbed plus the number of rounds that are left undisturbed Thus a ratio listed as 1 4 would signify one disturbance of the pedal sensor message for every four transmissions of the message Initially one disturbance is sent across the bus every 5 rounds as shown in Figure 4 9 and this produces little change in the graph from the control state shown in section 4 1 1 With the exception of the two scenarios discussed
82. et you define what types of data will be carried in each message you created in the previous page You won t be linking your message to a type however during this step You will only be defining what types of data your messages will carry See page 12 for more information 23 Click the Edit button to open the following dialogue box You are presented with a number of default types as well as the opportunity to add your own see Fig C13 TI Tech Object Editor for test TTA Msg Type P Select filter TTA Msa Type P svi Reload Close float4 type_length 4 typedef E y 66 Figure C13 Message types 67 24 If you do not wish to use one of the predefined types enter a new name for your type in the red highlighted text field and click new Then highlight the type in the above list and you can edit the parameters of your type as shown in Fig C14 TI Tech Object Editor for test TIA Msg Type P _TTAMsg_Type_P typet Required attributes o 0 Q type_cat yje Optional attributes agreement Pa e description AA se pelengh e typedef el e imh e limit lov Dad major ticks 0 minor_ticks _ 0 offset do 0 scale_high Se 0 scale low AN slope EE More Help Apply Cancel length Significant length of a single message of this type i e the space that one message of this type Figure C14 Property editor for message type
83. for cars and light trucks 7 The Bosch corporation implemented the first commercially produced 4 wheel multi channel ABS system in the Mercedes S Class in 1978 6 Other manufacturers employed anti lock brakes as well The 1969 Ford Thunderbird had a rear wheel anti lock breaking system and the 1971 Chrysler Imperial had four wheel anti lock brakes 7 Today virtually all cars and light trucks have ABS as standard or optional equipment with many companies providing ABS solutions for automakers Anti lock Breaking Systems ABS are designed to maximize breaking force during periods of sustained breaking by dramatically decreasing or eliminating wheel slip Wheel slip and wheel lock reduce the braking ability of a vehicle as the dynamic coefficient of friction between tires and the road surface is much lower than the static coefficient of friction Thus the stopping power of tires in wheel lock is greatly diminished As the tire contact patch with the road is the only means of transmitting driver control for the vehicle once the wheels have locked the driver is no longer able to avoid hazards in the road to prevent a collision While the implementation of ABS has changed over the years to incorporate advances in embedded systems the fundamental principles of implementation have remained the same To demonstrate the mechanics involved in the ABS a simple quarter vehicle model consisting of a single wheel and break setup can be used Fig 2 1
84. for each node you will need to write your application code for each task in your cluster This is done in the main c file within each of the node folders A main stub file has been supplied for you within each folder It contains instructions to create the minimum code needed to compile The instructions and comments will show you where to add code for each task in your cluster For TTP OS API help please see the TTP OS manual in Start gt TTTech gt TTP OS mpc555_AS8202NF 4 11 24 gt User Manual For specific instructions on the MPC 555 chipset please see the manual in 51 Start gt TTTech gt lO Toolbox MPC555 3 2 1 gt User Manual 9 Once you ve completed the code in each of your main c files you are ready to compile the executables Click Start gt Run In the dialog box type in cmd This will open a command line prompt Navigate to your root installation and then go to the root build folder Type make all bat If no errors were reported during compilation and linking you should be ready to load your application into the development cluster All of your application files will be in the lt application gt ddb folder See Fig B6 Folders X Name B cdb A B manifest comm amp C2NF mon ddb 3 node1 is cluster ddb a node2 si Mode1 ddb C3 nodes node1_appl si9 node4 E Node1_MPC555_AS8202NF_B H E hp il Node2 ddb HE i386 Sl node2_appl s19 C Intel Applications Mode2 MPCS555 ASS
85. g C12 122 demoapp_powernode DER Fie Edit View Simulation Format Tools Help Doh amp Ea E ao Tf 22 4 Normal TTP Matlink Main Dialog Counter1 Send Counter1 sub Display3 Counter2A Send Counter2 A sub Display1 Counter2B Send Counter2_B_sub Display2 Counter1 Rec3 uint 16 Figure G12 Run simulation example 21 The run simulation button is highlighted in red The length of time for the simulation to run is highlighted in blue the value is in seconds Finally if you have display boxes their values will now be shown in the associated text fields 22 If you are happy with your model and wish to generate all the needed TTP MEDL and runtime files double click the TTP Matlink object orange rectangle and then select the Build tab as shown in Fig C13 123 TIP Matlink 2 6 51 lt demoapp_powernode gt Configuration Cluster Mapping Build Calibration Extras Tools Import TTP Plan Import from TTP Plan TTP Build Import from TTP Build Code Generation Make Nodes Build 411 TTP Load Rebuild All TTP View Build settings _TTTech Ready Figure G13 Automated TTP Build dialog window 23 Within this dialog box you can select output for any step in the process or output everything and automatically push the new code into the nodes You can also import from TTP Plan or Build if you have started your cluster design in those applications 124 Appendix H Experime
86. g a specifc mode Nodes are allowed to run in different functional modes To edit a mode click the Edit button see Fig D13 TITech Object Editor for test Node1 TTA Node App_Mode DER Figure D13 Application mode list editor 92 23 You enter in a new mode name in the red highlighted box see Fig D13 Then click New to add it to the list Once in the list select the mode and click the Edit button above the highlighted field Required attributes mam rentas 8 Optional attributes description _ al 0 drift_mode hb ay extensive schedule search hes 4y ft receiver safety margin ho A e ft sender safety margin Ho 0 ft time source eerence time av e reset message status b ay e neg correction limit max 3 TTA Cluster clock sync mac pos correction limit max 3 TTA Cluster clock_sync mac neg synch limit max 2 TTA Cluster clock sync mac pos synch limit max 2 TTA Cluster clock sync mac TN E z maximum interrupt latency Specifies the maximum interrupt latency for the schedule interrupts microseconds Only relevant for operating Figure D14 Application mode property editor 24 There is only one required field maximum interrupt latency see Fig D14 TTP Build provides a reasonable default value If you need to alter this value or need more information on the optional values see section 3 6 of t
87. gt lt scenario name set_to_run gt lt Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 d0050066018c000403200104000 0823006 018c00040320 0104000 000000c8000000600180052c002c000400030004 00000000000500140002d000000300000004000301af0965 00000000003 549e0003d14382369ff0d98c1dd400000000 4e7edece7 5edf9b5alb3f9e6e4e4edd43ae09592e0e1 91e290eee0e1929230333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 2020202020202020c2470004000000000002ffffff f0b78 0011101100000000808080a1009570230411101100000000 808080a00094171f0811101100000000808080a0009451da 0c111011c00080008080c09 00934bde000800000000 ffff ffffffffeb000011001108000805848480a10092e355p0411 0011080a080 848480a000915e8508110011081408198484 80a000917a280c110011c00000008080c09 009382c 0011 001100000000828280a10094171204110011000000008282 80a00093142408110011081e0823848480a000917d2c0c11 0011c05080538282c09 00929c36 Ha lt med1 gt lt reboot gt lt Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt lt run_scenario name do gt lt scenario gt lt Ck Ck kk Ck Ck Ck Ck CK Ck Ck Ck CC C CK C C CK CI Ck CK CC CK C CK CIC CC Ck CK KK C KA CI Ck C Ck Ck Sk AAA AAA AAA AA Runs the disturbance scenario
88. h model in action performs differently from a traditional ABS braking model in use commercially In a traditional ABS braking scenario a driver would apply maximum braking force and the ABS controller would permit the force to continue so long as the wheel 21 continues to slow at a controlled rate If the wheel begins to decelerate too quickly braking force is decreased preventing the wheel from locking The resulting graph of brake force differs significantly from that of wheel speed as braking force quickly achieves a maximum value the maximum force applicable at the edge of tire slip and oscillates around this point The TTTech model however defines the brake force and wheel speed to be directly proportional as shown in Figures 4 2 and 4 3 This model while not analogous to existing ABS systems affords an easy to use system when applied to the TTTech demonstration cluster Thus it is used in this study for illustrative purposes of the TTP protocol and demonstration cluster QVM Control Brake Force vs Round 16000 14000 12000 10000 8000 6000 4000 2000 0 O 100 200 300 400 500 600 700 800 Round Brake Force N Figure 4 2 QVM control Brake Force vs TDMA Round 22 QVM Control Wheel Speed vs Round ww al o 99 e o m m o oc o o A e eo Wheel Speed m s a a o o O 100 200 300 400 500 600 700 800 Round Fig 4 3 QVM contr
89. he TTP Build documentation Click Commit when finished 93 and then Close the Object Editor box Finally click Next in the Guide to continue to the TTA Node Task_in_App_Mode page 25 The TTA Node Task_in_App_Mode page allows you to define what tasks run in a specific application mode see Fig D15 Click Edit to begin TTTech Link Editor for test Node1 TTA Node Task_in_App_Mode DEAR Select filter t ind task app mode Select filter New cony seme Figure D15 Task application mode link editor 26 Select a task in the red highlighted field and an application mode you just defined in the previous step in the blue highlighted field Click New to create the link and add them to the list Do this for every task you wish to run in a given application mode Click Close when you ve added all your links and then click Next in the Guide to continue to the TTA Node App Mode maps to Cluster Mode page 94 95 27 The TTA Node App Mode maps to Cluster Mode page lets you create a link between the application mode you ve recently created and the cluster mode you created in TTP Plan see Fig D16 TI Tech Link Editor for test Node1 T TA Node App Mode maps to Cluster Mode DEAR est_app_mode 3 yey test mode sv Select filter t i Select filter t i New copy tenane Es EFl E zi Figure D16 Application mode cluster mode link editor 28 If the application hasn t al
90. he effects on the calculation of average vehicle speed Finally an attempt is made to remove the pedal sensor from the system to examine the effect on the model s average vehicle speed 34 4 2 1 Experiment E Undisturbed Model The experimental approach to the FVM mirrors that of the QVM First the undisturbed model is examined The baseline of the model is run and average wheel speed for the entire vehicle is shown in Figure 4 11 As can be seen in Figure 4 20 the average wheel speed curve is similar to the QVM model s undisturbed output in section 4 1 1 FVM Control Wheel Speed vs Round 99 a o m C a o o o No e o 150 100 Wheel Speed m s a o 0 T T T T T T T T O 100 200 300 400 500 600 700 800 900 Round Figure 4 20 FVM control Average Wheel Speed vs TDMA Round 4 2 2 Experiment F Individual node disturbance As in the QVM the disturbance node disrupts each of the nodes and the average wheel speed for the vehicle is shown in Figure 4 21 4 22 and 4 23 In each graph the point of disturbance occurs late in the process but completely disrupts further calculation of wheel speed for the duration of the disturbance This results from an error in the FVM model that prevents the average speed from reaching zero with out all four inputs being present As each QVM requires a zero output from the average wheel speed sensor to reset themselves back to their starting valu
91. ick the Edit button just above the red highlight This will open the edit dialogue for that message as shown in Fig D12 TT Tech Object Editor for test Node1 TTA Node IO_Message TTA Node lO Message test IO Required attributes ip A phase 0 window size Optional attributes description Ej gt d_period Design period microseconds Figure D12 Message property editor 20 There are three required fields page 13 for required fields page 59 for optional fields d_period from the manual defines the time between two consecutive I O messages This has to be an integer fraction of the cluster cycle time end excerpt This means that you must define how often the task should receive this message and that this must be received at least once per cluster cycle more is allowed 90 phase defines where in the cluster and I O message should start window_size time allotment to allow for variation when the message could be received a phase of 250 microseconds with a window_size of 500 would allow for a message to be received anywhere from 0 to 500 microseconds 21 When you have added all the required values click Commit Make sure to edit values for all additional IO messages Then click Close to leave the I O message editor window Click Next in the Guide to continue to the TTA Node App_Mode page 91 22 The TTA Node App_Mode page will let you define what tasks are run durin
92. ies dialog 13 The only required value is a unique serial number that you assign to the node page 8 Later in the build process you will match this serial number to a specific node in the development cluster Click the Commit button when you ve entered a serial number 59 14 Repeat this process of creating new nodes and entering in serial numbers until you have the 4 development cluster nodes defined see Fig C8 TlTech Object Editor for test TTA Host Select filter Hi TTA Host Figure C8 Host list with all four nodes 15 Click close to return to the Guide and then click Next to continue 16 The TTA Host runs Subsystem in Cluster Mode screen will allow us to define what job will be run on what host For example in the demo application Nodes 1 and 2 both run counter programs to increment different counter values while Nodes 3 and 4 are defined to read those values and update their LED s 60 17 Click the Edit button to begin assigning subsystems jobs to hosts nodes You will open the following dialogue shown in Fig C9 TI Tech Link Editor for test TA Host_runs_Subsystem_in_Cluster_Mode SEE L Select filter m and d host subsystem O oO cuser mode mode ERN m axis a Copy Rename Reload Close Figure C9 Host subsystem and cluster mode link dialog 61 18 We ve defined hosts in the previous page but we haven t defi
93. impact on the system 1 A bridge node will act as a gateway between two independent time triggered networks The computationally heavy application is split among multiple new nodes and an entirely new system is created The data created in this new time triggered network are presented to the original network through the bridge as if it were a single node on the original system In this way the TTA allows for expansion based on system needs without requiring complete redesigns of the system This becomes key in the commercial sector as cost and adaptability are critical components of a systems viability Many other safeguards exists within the current implementation of the TTA to handle more complex and varied real world failure states Individual nodes contain babbling idiot safeguards on the communications controller such that nodes that fail and send gibberish across the network can be silenced and restarted without colliding and disrupting communication 2 Clique detection or the detection of sub groups falling out of sync with the global schedule and remaining out of sync relies on the TTA implementation of node membership During each round 6 of communication nodes record whether or not they were able to read the data from the current transmitting node If they are able that node is recorded as good if not then that node is marked as bad Each round when the transmitting node shares its membership listing as part of the overall
94. ion name const signal gt lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF gt lt scenario gt Runs the disturbance scenario gt scenario name no_disturb gt lt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON delay unsigned intvalue value 50 delay Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt scenario lt disturbance gt H7 QVM Pedal Sensor Disturbance 1 3 disturbance start scenario set to run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset every other cluster cycle sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A 135 lt source channel BOTH gt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 750 lt duration gt lt signal_low gt lt source gt lt definition gt elim CK Ck Ck CK C CC CC CK CC CI CI CI CC CK CC CK CK CI CIC C
95. isturbance 40 41 XML H15 QVM Pedal Sensor Disturbance Channel A XML H16 FVM Node 1 Disturbance XML H17 FVM Node 2 Disturbance XML H18 FVM Node 3 Disturbance XML seessss H19 FVM Pedal Sensor Disturbance XML Appendix Special Development Platform Considerations 1 Introduction to time triggered systems Real time computing systems require not only logical correctness of calculations but that these calculations be available before a requirements defined deadline If the deadline is exceeded the data is useless Many real time systems are also safety critical and failure to meet deadlines can result is catastrophic outcomes For example an anti lock breaking systems may fail to measure the correct wheel speed in time resulting in excessive application of the brakes which could lead to wheel lockup At present there are two primary protocols for relaying data within real time safety critical systems The more commonly used the event driven system delivers data across the communication medium bus as they are being created While under ideal conditions this method of data transmission updates systems on the bus as conditions change However during periods of peak activity messages compete for space on the bus This can lead to delay or even loss of data Contrast this with a time triggered system which transmits data at regular intervals bounded at a maxi
96. k CI KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK AAA AAA Ax X X Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run lt Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 6a900080018c000403200104000 938500c6018c00040320 0104000 000000c80000006001800554002c000400030004 000000000005001400024000000300000004000301be09ab 00000000003 4a7100038427c95a1ccad98c1dd400000000 90939998939a91998dc1d5c78492909099a03a94e1e69894 e597939a395e1e59230333938343a313924d61756724323030 392020202020202020202020202020206a7367697474696e 20202020202020209adc0004000000000002fffffff f0b78 0011101100000000808080a5009990 60411101100000000 808080a500995a5a0811101100000000808080a500991c9f 0c111011c00080008080c0a500993c87000800000000 ffff ffffffffeb000011001100000000828280850098f 7c70411 001100000000808080a5009938c808110011000000008282 80a500987bae0c110011c00000008080c0a50099 5960011 001100000000828280a50098 7c704110011000000008282 80a500983d6b0811001100000000828280a500987bae0c11 0011c05080538282c0a50098eb6f H medl reboot 1 Specifies the time slot where the protocol performs the clique avoidance algorithm optional default roundslot 0 gt blackout detection roundslot 0 repeat scenario name do loop 2500 gt lt scenario gt lt les XC Ck
97. ks Finally close the Object List Editor with the Close button and click the Next button in the Guide You will continue to the TTA Node Task uses Message page 85 13 The TTA Node Task uses Message page lets you link messages to task Each message is sent by one and only one task but each task can send multiple messages To create the links click the Edit button in the Guide shown in Fig D9 TI Tech Link Editor for test Node1 TTA Node Task uses Message lask2 msg3 msg copy name receives yes sends no Figure D9 Example of task message links 14 In the red highlighted field shown in Fig D9 select one of your previously defined tasks In the blue highlighted field type the name of one of your messages that will be sent by the task please keep in mind that you should stay consistent with your naming convention used in TTP Plan Click the New button to create the link Do this for all your tasks and messages Links will be show above in the task message lists 86 15 For each link you will need to add a few required values Highlight a link and then click the Edit button just above the red highlight The will open a new dialogue box as shown in Fig D10 TI Tech Link Editor for test Node1 TTA Node Task_uses_Message Link task1 lt gt msgt Required attributes gi m TAN receives sv e ends SAAKI Optional attributes msg copy name e J y Cancel Figure D10
98. lace here specifies the lenght of the TDMA round in microseconds This value multiplied by the number of rounds in a cluster will give you the overall time period of a cluster transmission speed is the data transmission rate over the network The value is in kbit sec so a value of 1000 is roughly 1Mbit sec The value you place here must be allowed by the TTP controllers in use For the development cluster a value of 2000 is recommended 7 For all additional parameters TTP Plan will insert average default values If you wish to change these values please consult the TTP Plan manual page 56 Click commit when you ve entered in the required values The dialogue will close A new window will open that will allow you to add more cluster definitions or alter an existing one see Fig C4 Click close to continue 55 TI Tech Object Editor for test TTA Cluster Jl Select filter F 2 j TTA Cluster m ay test byte_order big_32_endian tr_period 1200 transmission_speed 2000 Figure C4 Cluster list 8 Click the Next button in the guide to continue to the next page 9 The TTA Host screen is where you will configure your TTP controller nodes 4 are provided in the development cluster Click the Edit button to begin 10 The dialogue box that opens allows you to edit existing node configurations and add new ones When starting a brand new cluster the dialogue box appears in Fig C5 56 TI Tech
99. lt you will then use TTP Load to upload the MEDL and executable to each of the nodes in turn 100 Appendix E TTTech TTP Load Quick Start Guide 1 Start TTP Load Start Button gt All Programs gt TT Tech gt TTP Load 6 5 11 gt TTP Load TTTech TIP Load File Edit Check TTP Reports Windows Scripts Help SE IP Addr 192 168 47 11 W S mm f Load YF t ola Please load a Download Data Base DDB by selecting Load cluster from the File menu Loaded plugin MPC5554_458202NF_1_1_3 Loaded plugin MPC555_458202NF_1 34 Loaded plugin MPC5567 AS8202NF 1 0 5 Figure E1 TTP Load main window 2 First we need to load the cluster definition file Select File gt Load Cluster see Fig E2 TT Tech TIP Load GS Edit Check TTP Reports 101 Figure E2 Load cluster menu item 102 3 Next navigate the location of your cluster database file ddb and then click Open see Fig E3 IBERIA TlPload filename Look in E test ddb m ex Fa My Recent Documents Q Desktop Te ocuments z c e zi My Computer e My Network Places is C2NF mon ddb is Node1 ddb s Node2 ddb is Node3 ddb is Node4 d Type DDB File Date Modified 7 29 2009 2 33 PM Size 621 bytes File name Files of type cluster ddb 2 Download database files Idb ddb Y Figure E3 Load cluster dialog Cancel
100. ly Cancel L commit _ D al zi init value Initialization value of message Figure C16 Property editor for a message 29 As shown in Fig C16 the only required field is init value Set this according to the needs of your application Click Commit to close this window Finally set the init values for each of your messages and close the messages list required field page 12 optional fields page 74 71 30 Click Next on the Guide page to continue to the TTA Message_uses_Msg_Type page On this page you will set the type for each of your messages Click Edit to open the dialogue box see Fig C17 TI Tech Link Editor for test 1TA Message uses Msg Type Select filter not and or message msg_type O anc 0 or copy Rename Reload close a d Link msgl type1 deleted Figure C17 Message message type link dialog 31 In the red highlighted field select a message In the blue highlighted field select the appropriate type one of the defaults or a type you previously created Click the New button to create the link between message and type Do this for each of your cluster s messages Click 72 Close 32 Click Next in the Guide to continue to the TTA Cluster Mode uses Message page In this step we will be defining how often a given message needs to be transmitted within a given cluster mode Click Edit see Fig C18 TI Tech Link Editor for test TTA
101. ly difficult By converting the model into a cyclical format where the system resets itself after the wheel speed reaches zero it becomes possible to introduce a disturbance at a random point in time but have the disturbance present when the system resets back to its initial state allowing data collection from a known start state 4 1 QVM The first round of tests on the QVM measure the systems response to loss of nodes during operation The disturbance node removes a node from the model by transmitting a constant low voltage signal on both channels of the bus during the target node s round This disrupts the signal from the node removing it from the TDMA group and removing the node s subsystems from the model The disturbance node must be supplied with the cluster s MEDL which is sent in the XML in order to synchronize with the development cluster In the QVM nodes 1 2 and 3 of the demonstration cluster share the brake force calculation subsystem Node 3 is also responsible for determining wheel speed based on the brake force applied Finally Node 4 simulates the pedal sensor 4 1 1 Experiment A Undisturbed State Initial measurements of the control state of the system are shown in Figure 4 2 and 4 3 Brake force and wheel speed follow an inverse logarithmic curve and the values for both come to rest in 767 rounds at 800 microseconds per round 613 6 milliseconds These measurements are for the undisturbed model Note that the TTTec
102. manufacturers Procuring one of these models was again outside the scope of this project Further work can also be done with the models and their error handling ability The author would like to see more work done on both the QVM and FVM to better handle the disruption of inputs such as the pedal sensor or a single wheels input rather than fail entirely as the models did under testing In addition application code could be written to handle the various high level system events and errors that can occur such as clique errors and babbling idiots that would allow the models to recover from these events Writing this type of application code would require more time spent with the API of the embedded controllers of the demonstration cluster as this type of code is not generated from the MATLAB rapid development tools Ultimately educating about the time triggered protocol ABS systems and the TTTech development cluster has been the goal of this paper While not producing any new scientific insights it is the author s opinion that during the process of this project a great deal of new personal knowledge regarding these systems has been obtained Much more remains to be accomplished and there is certainly room for genuine scientific inquiry regarding the time triggered protocol and the development of applications that make use of its unique benefits With time this paper could be expanded to meet these needs and it is the author s hope to have the tim
103. mum time by the deadline requirements of the system This approach guarantees complete predictability of the system as the worst case execution time mirrors the best case execution time 1 The system s behavior is predictable and deterministic The trade off for this approach is a relative level of inflexibility when attempting to add components to the system after the initial design phase Time triggered systems transmit messages based on the global schedule This global schedule separates real time into discrete units This allows units of the system throughout this report referred to as nodes to come to consensus that an event a which happens at time tick j happened for all nodes simultaneously so long as the duration of the tick is sufficiently large to account for the precision of time synchronization within the system This global schedule is then separated into rounds where each participating node is allowed to communicated once Fig 1 1 Rounds are strung together to allow for the transmission of more varied node data 4 Host brake FL brake master brake_master_2 brake FR brake_RL brake RR ABS coni Sit 0 1 2 3 4 5 E us 0 305 770 1155 1476 1860 2180 Round 1 MEME HHH HHHH E EEEE us 0 E E zzz Round 2 ESE Z B esses E Ez us 2500 mn ES NIE ES EOS Round 3 EE BER ER us 5000 Bm EE Round 4 a MM 2 ks o go 8 us 7500 EE Z3 ENSE I3 EEE no ga
104. ndent copy of this communication schedule that allows each node to know who is communicating on the bus This allows for very complex and efficient means of error checking error correction and reliability In the time triggered protocol the core unit within a schedule is the TDMA round Within a TDMA round a node is allowed to send data on the bus once and only once More importantly data sent by a node can only ever be viewed once every TDMA round by each of the other nodes In other words if the length of a TDMA round is 1000 microseconds then the fastest update rate a sensor could achieve is 1 update per 1000 microseconds Nodes do not have to communicate during every TDMA round however so depending on the needs of your application data could be sent once a 44 round or once per a multiple of rounds This leads to the notion of the cluster cycle A cluster cycle is a series of TDMA rounds that taken together will define a schedule for all data sent across the bus In the following example we have four nodes in the system Each TDMA round is 1000 microseconds Message 1 sent by nodes 1 and 2 needs to be sent every 1000 microseconds Message 2 sent by node 3 needs to be sent only one every 2000 microseconds Finally Message 3 which is sent by node 4 needs to be transmitted every 4000 microseconds The example schedule is shown in Fig A1 Nodes 1 2 3 4 Round 1 Message 1 Message 1 E Message 2
105. ned any subsystems or cluster modes yet To start you will select an existing host via the dropdown box highlighted in red Next type in the name of a new subsystem within the box highlighted blue Finally type in the name of a new cluster mode within the box highlighted green Once you ve filled out all three fields click the New button at the bottom of the dialogue box This will create a new link between one of your nodes a subsystem and a cluster mode For more infomation see page 9 in the manual An example of a possible layout is as follows in Fig C10 Select filter subsystem cluster_mode Nodes 28 ln S kest moe Select filter nx ana x Select filter mt _and or Select fitter nx ana or Copy Rename Reload Close p New link Node4 in1 test mode created Figure C10 Example host subsystem and cluster mode links 62 You can delete exisiting links by highlighting a node in the upper host list and clicking the delete button Alternatively if you would like to rename a subsystem or cluster mode you can highlight it within the appropriate list and click the rename button Click close on the dialogue when you ve created all your subsystem links 19 Click Next within the Guide to continue to the TTA Subsystem sends Message page 20 This page allows you to link subsystems and the messages that the subsystem will send You do not specify message to be reciev
106. nge permissions page 35 The mode change permissions page will let you set which nodes in the system can cold start the system and which nodes are allowed to send xframes during normal transmissions For the purposes of testing you can select the Cheat button where the Edit button is usually placed to set all nodes available for cold start Click Next 36 You are now at the Checking for errors page Click the Check button again where the Edit button has been previously placed to check for any errors in your configuration If you encounter any errors you can click on the arrow to the left of the errors to expand the error type and get a description of the problem You can then click the links provided to open the dialogue box of the specified configuration to change it as needed When you have no more errors click Next 37 You are now on the Making a schedule page To compile the plan and make a schedule click the Schedule button Once the schedule has compiled you will get a text output of the results Click Next in the Guide to move to the Edit Schedule page 38 On the Edit Schedule page click the Edit button to get a visual representation of your schedule Your completed Schedule will look something like Figure C20 75 TTTech Schedule Editor for test test mode Slot Message Subsystem Columns Node1 stet svi insg3 axi arj la sv Slot Mode1 slot Node2 slot Node3 slot Mode4 slot Number 0 1 2 3 us 0 300 600 900 Ho
107. ntal Disturbance Node XML Scenarios H1 QVM Node 1 Disturbance XML disturbance start scenario set to run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs round 4 of qvm 770 us low voltage signal brake calc node 1 5 us offset sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 770 duration signal low lt source gt lt definition gt elas CK Ck Ck CK CK CI KK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK A kx Mk A AAA gt Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 5b4d008c018c000403200104000 334c00b7018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 8004800038 60225c52f ed98c1dd400000000 a3a0aaaba0a9a2aabef2e6f4beala3a3aa933aa7d2d5a6aa aba7aaa9a0d5d5d730333938343a31392d6175672d323030 392020202020202020202020202020206a73676974746
108. ntial high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 700 gt duration signal low 159 lt source gt relay lt definition gt edo CC CK Ck CK CK CI CC CC C Ck CK CIC CC C CK CK CK CIC CC CK CK CC CI CI C CCS CC C CK CI CI CI CSS C Ck Ck C S I E A M AAA Kk A A kx X X M gt Configures all the settings needed to run the disturbance MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 d0050066018c000403200104000 0823006 018c00040320 0104000 000000c8000000600180052c002c000400030004 00000000000500140002d000000300000004000301af0965 00000000003 549e0003d14382369ff0d98c1dd400000000 4e7edece7 5edf9b5alb3f9e6e4e4edd43ae09592e0e1 91e29 0eee0e1929230333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 2020202020202020c2470004000000000002fffffff f0b78 0011101100000000808080a1009570230411101100000000 808080a00094171f081 1101100000000808080a0009451da 0c111011c00080008080c09 00934bde000800000000 ffff ff Ha Fffffeb000011001 108000805848480a10092e35b0411 0011080a080 848480a000915e8508110011081408198484 80a000917a280c11001 001100000000828280a 80a000931d240811001 0011c05080538282c09 medl reboot F00929c36 gt cifies the tim lt S
109. ol Wheel speed vs TDMA Round 4 1 2 Experiment B Disturbing Individual Nodes Next nodes 1 2 and 3 are each disturbed to test the ability of the redundant systems to maintain system integrity during an instance of a node fault as each system is redundantly calculating and transmitting applied brake force for the round Figure 4 5 shows the curve for wheel speed during the disturbance of Node 1 As expected the wheel speed curve should show no difference from the undisturbed curve in Figure 4 8 as the braking calculation subsystem redundancy protects the system in the event of a single point of failure Skipping ahead to Figure 4 7 the same pattern is apparent as again removing a single system when three are present should not affect the system as a whole The wheel speed outputs for Node 2 shown in Figure 4 6 shows an unexpected result The figure has been expanded to demonstrate the disruption of the entire braking model during the disturbance despite the existence of redundant brake calculation systems This output shows a fault in the model that requires the brake force message from Node 2 to be present in 23 order to properly calculate wheel speed This is most likely due to the author s modifications to the model introducing a timing dependance on the message as this is the last Node to calculate brake force prior to the calculation of wheel speed as shown in Figure 4 4 Figure 4 4 Timing diagram for Node 2 s brake calc
110. opment cluster Each node needs to simulate wheel speed as braking force is applied In addition each node handles an additional subsystem pedal position vehicle speed and rotational velocity ABS control and average vehicle speed In order to leverage the QVM deceleration model the FWM simulates the entire mass of the car through four independent QVM instances that are averaged to create a total vehicle speed This average is fed back into each wheels speed calculation to simulate the entire vehicle The system is shown in Figure 3 7 A disadvantage of this system is lack of variation in any wheel creating a simulation that produces too much uniformity One method to avoid this would have wheels starting speed randomized on initialization with a variation of 1 from the QVM starting value of 300 Using the model shown in Figure 3 7 the starting variation in wheel speed is averaged out quickly as the entire vehicle achieves equilibrium An alternative to this FVM model does not use the vehicle average speed as feedback to the wheels instead using the speed averager as a means to report the speed of the vehicle but allowing for the initial variation in wheel speed to remain in the system throughout braking This later model is examined during disruption in order to evaluate the validity of the simulations ped sr o ABS Controller ABS Controller ABS Controller ABS Controller Figure 3 7 Full vehicle ABS model 18 4 Experimen
111. or Disturbance 1 4 XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset every fourth cluster cycle sent on both channels repeated 2500 times gt lt definition name const_signal gt 133 Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt lt unsigned_intvalue value 780 gt lt duration gt lt signal_low gt lt source gt lt definition gt lt lss KKEKKKKK KK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK A X x x Configures all the settings needed to run the disturbance relay MEDL etc gt lt scenario name set_to_run gt lt Generated Fil gt lt medl gt 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 5b4d008c018c000403200104000 334c00b7018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 800400038 60225c52f ed98c1dd400000000 a3a0aaaba0a9a2aabef2e6f4beala3a3aa933aa7d2d5a6aa aba7aaa9a0d5d5d730333938343a31392d6175672d323030 39202020202020202020202020202020
112. or oscilloscope gt trigger name TRIGGER 1 switch ON 1 Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF scenario lt disturbance gt H3 QVM Node 3 Disturbance XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xSi noNamespaceSchemaLocation Distu_XML_Schema xsd gt lt disturbs round 6 of qvm 760 us low voltage signal brake calc node 3 5 us offset sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt lt unsigned_intvalue value 760 gt lt duration gt lt signal_low gt lt source gt lt definition gt e CK C Ck CK CC CC CK CK CC CI CI CIC CC CK CC CK CK CI CI CC CK C CK CK CI CI CIC A C Ck CK CK CIC CCS C Ck Ck CK CK C C C Ck Ck AAA kx A A A x x Configures all the settings needed to run the disturbance relay MEDL etc gt 128 lt scenario name set_to_run gt lt Generated Fil medl gt 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 5b4d008c018c000403200104000 334c00b70
113. ough the design of a specific node It leads you through all the steps necessary to create a node design At each point in the process you can click Next to continue to the next step Back to return the previous step and Edit to change values for the current step Click Next to continue 3 You will start on the Loading a cluster design page We first need to load the cluster definition created during TTP Plan Click the Load button at the bottom of the page You will be presented with a browse file dialogue to locate the cdb file of your cluster design Click the file and then click Open see Fig D2 78 TI Tech NDT cluster filename Look in test e E3 generated Dtest ddb My Recent Documents 2 Desktop My Network File name test cdb pen Places Files of type cluster database files cdb v O lo i e Figure D2 Open file dialog 4 Next you will be asked to select a node to design see Fig D3 ua T1Pb MOR Please select a host lode2 lode3 lode4 Figure D3 Node selection Select a node and then press OK At this point you should save your node If you do not do this now when you generate your FT COM layer code it will be placed in the default location the working directory of TTP Build which is ill advised Once you ve saved your node database to your own directory click Next in the Guide to continue to the TTA Host page 5
114. p the clique avoidance algorithm optional 1c00000008080c09 009382c 0011 10094171204110011000000008282 1081e0823848480a000917d2c0c11 slot where the protocol performs default roundslot lt blackout_detection roundslot 0 gt lt repeat_scenario name do loop 2500 gt Q scenario Slee CK Ck Ck KKK KKK C CK KKK KKK KKK C CK C KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KKK KK KK AAA Runs the disturbance scenario gt scenario name do gt 1 destroy to consecutive rounds to trigger ack failure gt lt run_scenario name disturb_a gt lt run_scenario name no_disturb_a gt lt scenario gt Runs the disturbance scenario gt scenario name disturb a the slot where the disturbance starts 1 Specifies wait for roundslot roundslot 0 offset 5 JS 160 Output trigger for oscilloscope gt lt trigger name TRIGGER_1 eee switch 0N Starts the disturbance gt run definition name const signal lt Resets th output trigger signal to low gt trigger name TRIGGER 1 Switch OFF wait for roundslot roundslot 1 offset 5 gt Output trigger for oscilloscope gt trigger name T LES Starts the lt run_definition RIGGER_1 switch 0N gt disturbance name const signal lt Resets the outpu
115. port Data GUI Save Workspace As Figure G2 New model menu item 6 Anew model window will appear Fig C3 113 untitled File Edit View Simulation Format Tools Help Dg EE amp 585565 m foo Noma y Figure G3 New model window 114 7 In order to add objects into the model we will need to open the object Library Click View gt Library Browser Fig C4 untitled File Edit MEA Simulation Format Tools Help v Toolbar v Status Bar Model Browser Options Block Data Tips Options Library Browser Model Explorer Ctrl H MATLAB Desktop Show Page Boundaries Port Values gt Remove Highlighting lig b Figure G4 Library browser menu item 115 8 This will open the symbols library Fig C5 Simulink Library Browser File Edit View Help OS 2 Enter search term SM Simulink i Commonly Used Blocks Continuous i Discontinuities Commonly Used Blocks j Discrete Logic and Bit Operations Lookup Tables Math Operations Model Verification Continuous Discontinuities Discrete Logic and Bit Operations Sources User Defined Functions i H Additional Math amp Discrete ben E Control System Toolbox v Lookup Tables 3 E Ez A Pl E Block Description Commonly Used Blocks Showing Simulink Figure G5 Simulink library browser 116 9 The first step in creating a TTP
116. que avoidance algorithm optional default roundslot 0 gt lt blackout_detection roundslot 0 gt lt repeat_scenario name do loop 2500 gt lt scenario gt lt l Ck Ck KC Ck CK Ck Ck CK CK CI CK CI CK CC CC CK CC CC CC CK CC CC Ck KK KK KK KK kk Ck K KA KK KK KA RAR Runs the disturbance scenario gt scenario name do lt destroy to consecutive rounds to trigger ack failure gt lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name disturb gt 144 lt run_scenario name disturb gt lt run_scenario name disturb gt lt run_scenario name no_disturb gt lt scenario gt Runs the disturbance scenario gt scenario name disturb lt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF lt scenario gt Runs the disturbance scenario gt scenario name no_disturb gt lt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON
117. ready done so create a link by selecting an app mode in the red highlighted field and a cluster mode in the blue highlighted field Click New and the link will be created After creating all your application s links Click Close to close the Link Editor window and then click Next in the Guide to continue to the Checking for errors page 29 Similar to TTP Plan this page builds the node scripts and will alert you to any configuration 96 errors Click the Check button and you will receive output similar to Fig D17 f Guide Y Pilot Errors Y Report f ClusterfPilot Help Node No errors in object internal invariants No warnings in object internal invariants No errors in local invariants No warnings in local invariants 5 errors in system invariants task2 task3 sub2 typet taski k gt test app mode e No warnings in system invariants y cw ww Figure D17 Error check output 30 Please Note Prior to generating your schedule you must make sure that your node is properly configured for the development cluster PN312 as shown in Fig D18 Go to the Node Config tab in TTP Build highlighted in red and then double click on the Node Config block highlighted in blue 97 F Node Config Node Config provides Active Component OS Target Network Interface Controller R Figure D18 Node configuration tab 31 You will need to make sure that the dialog box shown in Fig D19 contains the
118. rest within 700 rounds QVM Interval 1 5 Wheel Speed vs Round ao a o ao o o n 91 eo m o o Wheel Speed m s o a o o 91 eo e T T T T T T O 100 200 300 400 500 600 700 800 Round Figure 4 9 Disturbance Interval of 1 5 28 QVM Interval 1 4 Wheel Speed vs Round Wheel Speed m s o a o o a o o 0 100 200 300 400 500 600 700 Round Figure 4 10 Disturbance Interval of 1 4 QVM Interval 1 3 Wheel Speed vs Round 350 A o o Wheel Speed m s g a eo o T T T T T T T O 100 200 300 400 500 600 700 800 Round Figure 4 11 Disturbance Interval of 1 3 29 QVM Interval 1 2 Wheel Speed vs Round 350 300 M al o m e eo Wheel Speed m s o mn eo o a o o 0 100 200 300 400 500 600 Round Figure 4 12 Disturbance Interval of 1 2 QVM Interval 3 4 Wheel Speed vs Round 350 Wheel Speed m s sg 91 eo o T T T T T T T T O 100 200 300 400 500 600 700 800 900 Round Figure 4 13 Disturbance Interval of 3 4 30 Wheel Speed m s Wheel Speed m s QVM Interval 4 5 Wheel Speed vs Round Q a o m C a o O n e eo E 91 eo A e o a o o T 200 400 600 800 1000 1200 Round o Figure 4 14 Disturbance Interval of 4 5
119. run scenario name do gt 158 lt scenario gt em CK CK CK Ck Ck CK CI CC CC C Ck CK CK C KKK KEK KKK KK KKK KKK C CI CI C CC CK C C C CI CI CI CI CK C Ck Ck CK I S A S Kk kx Sk Kk Kk AAA X M gt Runs the disturbance scenario gt scenario name do gt lt destroy to consecutive rounds to trigger ack failure gt lt repeat_scenario name disturb loop 2500 gt lt scenario gt Runs the disturbance scenario gt scenario name disturb gt Specifies the slot where the disturbance starts gt wait for slot slot 2 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt Starts the disturbance gt run definition name const signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF scenario lt disturbance gt H19 FVM Pedal Sensor Disturbance XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs roundslot 1 and 2 of fvm 770 us low voltage signal pedal sensor 5 us offset every other cluster cycle sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differe
120. run_scenario name disturb gt name disturb gt name disturb gt name disturb gt name disturb gt name disturb gt name disturb gt name disturb gt name disturb gt lt run_scenario name no_disturb gt lt scenario gt Runs the disturbance scenario gt scenario name disturb gt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON Starts the disturbance gt run definition name const signal Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt lt scenario gt Runs the disturbance scenario gt scenario name no_disturb gt Specifies the slot where the disturbance starts gt wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON delay unsigned intvalue value 50 delay lt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt lt scenario gt lt disturbance gt H13 QVM Pedal Sensor Disturbance 20 21 XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd disturbs roundslot
121. scenario set to run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd Rr disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset every other cluster cycle sent on both channels repeated 2500 times definition name const_signal gt Disturbs a slot by sending constant signals on channel A source channel BOTH 137 lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt unsigned intvalue value 780 gt duration signal low lt source gt lt definition gt cem Ck Ck Ck CK C C CC CK C CC CIC CC CK CK CC CK CI CI CIC CC C CK CI CI CCS C Ck CK CK CK CIC Ck Ck CK CK CI S C Ck Ck Ck Sk Sk x x A M x kx x RA gt Configures all the settings needed to run the disturbance relay MEDL etc gt scenario name set to run Generated Fil gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66 5b4d008c018c000403200104000 334c00b7018c00040320 0104000 000000c80000006001800554002c000400030004 00000000000500140002d000000300000004000301be09ab 00000000003 800400038 60225c52f ed98c1dd400000000 a3a0aaaba0a9a2aabef2e6f4beala3a3aa933aa7d2d5a6aa aba7aaa9a0d5d5d730333938343a31392d6175672d323030 392020202020202020202020202020206a7367697474696e 20202020202020
122. signal lt Resets the output trigger signal to low gt trigger name TRIGGER 1 switch OFF gt lt scenario gt Runs the disturbance scenario gt scenario name no_disturb gt Specifies the slot where the disturbance starts wait for roundslot roundslot 7 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch ON gt delay unsigned intvalue value 50 gt lt delay gt Resets the output trigger signal to low trigger name TRIGGER 1 switch OFF gt scenario lt disturbance gt H9 QVM Pedal Sensor Disturbance 3 4 XML lt disturbance start_scenario set_to_run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation 2 Distu XML Schema xsd lt disturbs roundslot 7 of qvm 780 us low voltage signal pedal sensor 5 us offset removes pedal signal 3 out of 4 rounds cluster cycle sent on both channels repeated 2500 times gt lt definition name const_signal gt Disturbs a slot by sending constant signals on channel A gt lt source channel BOTH gt lt Sends a constant differential high signal on both channels for 100 microseconds gt lt duration gt 139 unsigned intvalue value 740 gt lt duration gt lt signal_low gt lt source gt lt definition gt lt CC CK CK Ck KKK KKK KKK Ck C
123. sts Node Node2 Node3 Node4 Round 1 us Round 2 m Selected Round Slot _Frame Figure C20 Demonstration schedule 39 If you would like to see a graphical representation of your schedule during any other step in process click the Edit Schedule button at the top of the application as shown in Fig C21 ITTech TIP Plan for cluster test File Edit Check Schedule Reports Windows Scripts Help DSa l Ye ojear aa aa ea Pilot Errors X Report Topology Figure C21 Edit schedule 76 40 Close the Schedule and then Click the Next button in the Guide You have finished building the Plan for your TTP application You will now need to move on to TTP Build to create the code needed to upload into the Nodes From there you will upload the code using TTP Build Make sure to save your plan and remember where you are saving the cluster definition You will need it when you design the nodes in TTP Build You can save your plan by clicking File gt Save 77 Appendix D TTTech TTP Build Quick Start Guide 1 Start TTP Build Start Button gt All Programs gt TT Tech gt TTP Build 5 5 40 gt TTP Build 2 TTP Build will start in Guide Mode see Fig D1 If itis not in Guide Mode click the Guide Tab at the top of the page TiTech TIP Build File Edit Check Schedule Reports Windows Scripts Help Figure D1 TTP Build guide mode tab TTP Build Guide mode is a guided tour thr
124. t trigger signal to low trigger name TRIGGER 1 switch OFF scenario Runs the disturbance scenario gt scenario name no disturb a 1 Specifies th slot where the disturbance starts wait for roundslot roundslot 0 offset 5 Output trigger for oscilloscope gt trigger name TRIGGER 1 switch 0N delay unsigned intvalue value 50 delay lt Resets th output trigger signal to low gt lt trigger name TRIGGER_1 lt scenario gt lt disturbance gt Switch OFF 161 Appendix I Special Development Platform Considerations This appendix outlines the current hurdles to application development for the TTTech Development cluster using MATLAB As of December 2009 all of the major software components have valid licenses that are installed and working except for one the Wind River Diab compiler version 5 1 7 FGCU does possess a valid license for version 5 7 of the Diab compiler but this has not proved easy to integrate into the existing MATLAB Real time Code Generator and TTTech tools Until a more permanent solution has been achieved there does exists a workaround to continue using the evaluation license for the Diab compiler that expired in November 2009 After logging into the development PC for the first time make sure the system clock is set to the current date and time Open MATLAB and perform a complete b
125. ts Failure state simulations are run with the use of the TTTech Disturbance Node This node connects to the bus and is activated through a serial interface with a host PC that transmits the disturbance parameters in an XML file The XML defines the method timing and length of interruption to be created An example of the XML file is shown in Figure 4 1 disturbance start scenario set to run xmlns xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation Distu_XML_Schema xsd gt lt definition name const_signal gt lt source channel BOTH gt lt duration gt lt unsigned_intvalue value 700 gt lt duration gt lt signal_low gt lt source gt lt definition gt lt scenario name set_to_run gt medl 020238000018381800283840003138710027389800470000 00000000000000000000000000000000000000000000d66f d0050066018c000403200104000 0823006 018c00040320 0104000 000000c8000000600180052c002c000400030004 00000000000500140002d000000300000004000301af0965 00000000003 549e0003d14382369ff0d98c1dd400000000 4e7edece7 5edf9b5alb3f9e6e4e4edd43ae09592e0e1 91e290eee0e1929230333938343a313924d61756724323030 392020202020202020202020202020206a7367697474696e 2020202020202020c2470004000000000002ffffffff0b78 0011101100000000808080a1009570230411101100000000 808080a00094171 0811101100000000808080a0009451da 0c111011c00080008080c09f 00934bde000800000000ffff ffffffffeb000011001108000805848480a10092e3550411 0011080a080f848480
126. uild of your project This will fail at the code generation step with a license expired error Minimize MATLAB and set the system clock to before November 17 2009 Your build should now complete without error Note that the system needs to perform that initial failed code generation under the current date and time in order to locate the license file If this step is not performed you will receive a different error in which MATLAB fails to locate the license entirely A second problem that is frequently encountered during development and testing is the lockup of TTP View Many times during active monitoring of the cluster if a disturbance is created that crosses round slot boundaries TTP View will freeze The only remedy is to close TTP View and restart that monitoring session In addition you must also reboot the monitoring node in the cluster Failure to reboot the monitoring node will cause an error in TTP View during the next attempt to record the data being transmitted on the bus even after TTP View has been restarted Finally take note that if you are unable to transmit a file to the disturbance node first reboot the node by unplugging the device Many times after repeated and prolonged communications the node will enter a failure state in which it is unable to accept new properly formatted XML Cycling the power corrects this behavior 162
127. ulation Note that within the cluster schedule this value for brake force is actually an average created from all the existing known good values of brake force calculated from the previous cluster cycle Thus node 2 should not have a heightened importance within the system Further investigation into the specific failure is warranted 24 QVM Node 1 Disturbance Brake Force vs Round 16000 14000 _ 12000 A e e e e 8000 6000 4000 2000 0 T T T T T T T O 100 200 300 400 500 600 700 800 Round Brake Force N Figure 4 5 Node 1 disturbance of brake force calculation QVM Node 2 Disturbance Brake Force vs Round 16000 14000 12000 10000 8000 6000 4000 2000 0 T T T T 0 1000 2000 3000 4000 5000 Round Brake Force N Figure 4 6 Node 2 disturbance of brake force calculation 25 QVM Node 3 Disturbance Brake Force vs Round 16000 14000 _ 12000 10000 8000 6000 4000 2000 0 T T T T T T T 0 100 200 300 400 500 600 700 800 Round Brake Force N Figure 4 7 Node 3 disturbance of brake force calculation Interruption of node 4 removes the output of the pedal sensor from the model This prevented the application of the brake and the resulting wheel speed graph is shown in Figure 4 8 Without the application of the pedal there is no brake force applied Thus the wheel speed gradually mov
128. unction as 43 specified Understanding this issue assists in piecing together all the tools used in the process of creating applications that communicate over the real time bus The method of development and deployment in the academic setting is atypical The normal pattern of development would have a systems architect who creates the higher level system designs for the project as a whole for example an automobiles break by wire system and then creates a communications schedule that each of the component parts must follow Once the schedule is created it is handed off to the components subcontractors who will then build their subsystems to specification From this we can see that all of the TTTech tools assist in the scheduling and communication of data over the bus and are less concerned with the actual applications that consume or produce that data In addition to developing software in C using the Wind River Diab compiler TT Tech does offer a method for rapid prototyping that will generate application code for designers using MATLAB Finally ESTEREL Technologies offers a model based development environment SCADE that specifically focuses on the design verification and deployment of safety critical real time Systems The core design principle in time triggered technology is the notion that communication only occurs on the network based on a predetermined schedule Systems on the bus hereafter referred to as nodes contain an indepe

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