Quanser`s High Definition Haptic Device (HD2) User Manual
Contents
1. The HIL Interfacing and the HD Interface blocks perform the same functionality as described in the HD2_Interface mdl section The x mean and theta signals which are outputs of the HD Interface block contain world co ordinate position and orientation of the HD s end effector The first sample of this signal denotes the initial position of the end effector when the model is running This sample is latched and assigned to x cmd As already mentioned the HD2_Position_Control mdl controller diagram uses a world based postion control in order to command the device to a desired position and orientation The Proportional plus Velocity PV scheme is implemented in the World Based PV Con troller block It compares the desired Cartesian coordinate position and velocities with the 3 element vector measured position and velocity of the end effector from the HD2 I O block and computes the force needed to attain the desired position It also compares the de sired angular position and velocities with the measured angular position and velocity from the HD2 I O block and computes the torque needed to attain the desired position These forces and torques are fed to the HD2 I O block and it calculates how much voltage to feed each power amplifier in order to drive each motor such that the setpoint is reached 8 1 2 2 Operating Procedure Before running the following example please ensure the following has been performed Document Num2. CCW rotation when facing the motor output shaft and vice versa 3 2 3 HD Amplifier To Motor Connection Table Table 7 details the connections between both HD power amplifiers and the HD six motors or axes attained through both Motor and Encoder cables Amplifier ID Motor Location Q8 Encoder Motor Joint ID Facing The Robot Input Channel Used in Modeling Amp 0 Top Left EI 0 Shoulder Motor 1 Amp 1 Top Middle EI 1 Shoulder Motor 2 Amp 2 Top Right EI 2 Base Motor 3 Amp 3 Bottom Left EI 3 Shoulder Motor 4 Amp 0 Bottom Middle EI 4 Shoulder Motor 5 Amp 1 Bottom right EI 5 Base Motor 6 Table 7 Amplifier To Motor Connection Nomenclature Document Number 560 Revision 02 Page 16 HD User Manual Each encoder on the HD is directly mounted on a motor and its signal can be measured using a Q8 encoder channel as expressed in Table 7 Note Note that a rotation of the encoders i e motors in the counterclockwise direction when facing the motor output shaft results in an increasing positive number of counts and vice versa Table 7 also defines the mapping used for each amplifier motor pair The numbering used for the motors is consistent with the kinematic and dynamic modeling used in the Haptics blocks of QuaRC Targets Simulink toolbox The chosen motor numbering is illustrated in Figure 12 where M1 M2 M3 M4 M5 and M6 denote Motor 1 Motor 2 Motor 3
3. Button seeoseseseesesseresoressiesesersrestssestastnsessrsersesoresessesereresoresseeeene 12 Figure 9 Connection of the Q8 board and the Q8 To Amplifier Adapter Bos 15 Figure 10 HD2 Motor Number Asetenment 18 Figure 11 HD2 Co ordinate EE 21 Figure 12 HD2 Motor Number Asetgenment 22 Figure 13 HD2 In Home Positiones ee EE EE 23 Figure 14 HD2 and sphere virtual reality wmd 28 List of Tables Table 1 HD2 Component NOMmENClAtit ic ccnccsssctecaemstscisinsenctenesbenstsabeshanageeuiadinshanes enter tes 7 Table 2 HD2 Arm Characteristic EE 9 Table 3 HD EED Description EE Il Fable 4 HD2 Cable Set Keesen Eerst 13 Table 5 Q8 DIO Connection Nometteg dg een deeg EE deg 16 Table 6 Q8 AIO Connection Nomenclature 17 Table 7 Amplifier To Motor Connection Nomenclature 17 Table 8 HD2 Specifications at Home Position Refer to Figure 11 for the System Coordinate EN 20 Table 9 Files Supplied With the HD2 System Document Number 560 Revision 01 Page ii HD User Manual CAUTION NOTICE This product is intended for experienced engineers only The user is solely responsible for the implementation of the controller Quanser is not responsible for any material or bodily damage that ensues from the use of this equipment All software supplied is only to be considered a sample and should not be used on a regular basis The users should write their own control software Read this manual before operating the supplied system How
4. bar of the Simulink diagram Document Number 560 Revision 02 Page 26 HD User Manual 8 1 3 Virtual Reality Example Sphere 8 1 3 1 Description Executing this file requires the Matlab Virtual Reality Toolbox When QuaRC is running the virtual environment in Figure 14 loads The virtual HD handle is controlled by the HD end effector on the haptic device When the sphere is touched through the middle point and the two ends of the end effector handle a force feedback control allows the user to feel a slightly spongy sphere TX Wand and sphere VR vid Bry sl go e E e _untitled_1 Pos 0 00 1 00 0 00 Dir 0 00 1 00 0 00 Figure 14 HD and sphere virtual reality window The virtual environment is designed using the Mathworks Virtual Reality Toolbox To summarize a WRL file is created using a program called V Realm Builder The WRL file generated is then processed by the VR Sink block from the VR Toolbox This block Document Number 560 e Revision 02 Page 27 HD User Manual displays the virtual environment when the Simulink diagram is ran 1 e that is when it is run in External mode with QuaRC 8 1 3 2 Operating Procedure Before running the following example please ensure the following has been performed e The device has been properly calibrated as described in Sections 7 e Disable the E Stop by pulling on the red E Stop push button The E Stop compo nent 27 light should go off on the
5. movement along the positive z axis Rotations about each of these axes are denoted by 0x pitch Oy roll and Oz yaw respectively The forward and inverse kinematics are modeled based on this co ordinate system and the actual dimensions of the HD In order to control the HD the user needs to transform the end effector workspace coordinates into their counter parts in the joint space and vice versa The forward kinematics are used to transform joint space to workspace coordinates while the inverse kinematics are used to transform wokspace to joint space coordinates These transformations are carried out using customized forward and inverse kinematics blocks available in a library called HD2_Interface mdl which is supplied with the system Section 8 1 of this document provides information about each of the blocks present in this library Document Number 560 e Revision 02 Page 20 HD User Manual 6 Motor and Encoder Assignment Figure 12 shows the numbering assignment used for the 8 motors of the HD system Figure 12 HD Motor Number Assignment As seen in Figure 12 the top shoulder motors are numbered M1 and M2 while the bottom shoulder motors are numbered M3 and M4 The top and bottom base motors are numbered M5 and M6 respectively Please keep in mind that the above convention applies to all vector signals containing motor torques currents that are mentioned in the remainder of this document In other words whenev
6. sphere at the middle and the two ends of the handle Document Number 560 Revision 02 Page 28 HD User Manual Step 16 To stop the session hold on to the device handle and click on the Stop button in the Simulink model tool bar 8 1 4 HD2_Cube mdl This model can be used as a demo to familiarize the user with basic operation principles of the HD system The user is encouraged to read the description given above about the HD2_Position_Control mdl file before running this demo since the HD2 Cube mdl file has the same underlying structure as this file The demo defines an imaginary cube with user chosen dimensions around the starting position of the end effector When the model is run the end effector can be moved around freely as long as it stays within the cube dimensions However once you try to bypass any of the cube sides opposing forces will be exerted on the end effector not allowing you to move it outside the cube dimensions The HIL Interfacing and the HD Interface blocks perform the same functionality as described in the HD2_ Position_Control mdl section The x mean and theta signals which are outputs of the HD Interface block contain world co ordinate position and orientation of the HD s end effector The first sample of this signal denotes the initial position of the end effector when the model is running This sample is latched and assigned to x_cmd In the World Based PV Controller block you
7. to contact Quanser Consulting 905 940 3575 Telephone 905 940 3576 Facsimile 119 Spy Court Markham ON Mail Canada L3R 5H6 http www quanser com Web Kc mailto info quanser com General information Disclaimer While every effort has been made to ensure the accuracy and completeness of all information in this document Quanser Inc assumes no liability to any party for any loss or damage caused by errors or omissions or by statements of any kind in this document its updates supplements or special editions Quanser Inc further assumes no liability arising out of the application or use of any product or system described herein nor any liability for incidental or consequential damages arising from the use of this document Quanser Inc disclaims all warranties regarding the information contained herein whether expressed implied or statutory including implied warranties of merchantability or fitness for a particular purpose Quanser Inc reserves the right to make changes to this document or to the products described herein without further notice Document Number 560 e Revision 02 Page 3 HD User Manual 1 General Description Overview 1 1 Hardware System Presentation A typical Quanser s High Definition Haptic Device HD is depicted in Figure 1 ST h GiS yee CD Counterbalance kl Weights for fi Gravity Compensation Counterbalance Weights for Gravity Compensation Capston M
8. Motor 4 Motor 5 and Motor 6 respectively Figure 10 HD Motor Number Assignment Document Number 560 e Revision 02 Page 17 HD User Manual 4 System Parameters The specifications on the HD model parameters are given in Table 8 Description I ef KE TEL Value Unit Linear Current Amplifiers Each Channel Motor Power Rating 90 W Motor Torque Constant 0 115 N m A Motor Peak Current 5 A Build In Power Supplies Each Power Supply Power Linear Amplifier Peak Power 140 W Linear Amplifier Maximum Continuous Current 3 A Linear Amplifier Peak Current 5 A Linear Amplifier Gain 1 2 41 A V 315 9 Power Supply Voltage Optical Encoders Each Current Sense Current Sense Calibration At 10 Device Geometry Encoder Line Count 1 000 lines rev Encoder Resolution In Quadrature 4 000 counts rev Encoder Sensitivity In Quadrature 0 0015 count Encoder Type TTL Encoder Signals A B Index Motor Arm Length 0 280 Forearm Length 0 290 m End Effector Arm Length 0 175 m Document N umber 560 e Rev fision 02 Page 18 HD User Manual Device Geometry Force Feedback Workspace At Operating Position Maximum Output Force At Operating Position Translation Along X 0 520 m Translation Along Y 200 550 mm Translation Along Z 100 275 mm Rotation About X Roll 90 Rotation About Y
9. Pitch 90 i Rotation About Y Pitch Continuous S Maximum Continuous Output Force Along X 10 84 N Maximum Continuous Output Force Along Y 10 84 N Maximum Continuous Output Force Along Z 7 67 N Maximum Continuous Output Torque About X 0 948 N m Maximum Continuous Output Torque About Y 0 948 N m Maximum Continuous Output Torque About Z 0 948 N m Peak Output Force At Operating Position Peak Output Force Along X 19 71 N Peak Output Force Along Y 19 71 N Peak Output Force Along Z 13 94 N Peak Output Torque About X 1 72 N m Peak Output Torque About Y 1 72 N m Peak Output Torque About Z 1 72 N m Table 8 HD Specifications at Home Position Refer to Figure 11 for the System Coordinate Frame Document Number 560 e Revision 02 Pa g e 1 oO HD User Manual 5 Kinematics As mentioned earlier the HD interface has six Degrees Of Freedom allowing for three translations along the x y and z axes as well as three rotations roll pitch and yaw The adopted workspace co ordinate system for the HD is shown in Figure 11 below Figure 11 HD Co ordinate System As seen in Figure 11 when directly facing the HD s front side moving the end effector to the left corresponds to a movement along the positive x axis moving the end effector towards yourself corresponds to a movement along the positive y axis and finally moving the end effector up corresponds to a
10. Specialty Plants Haptics Quanser s High Definition Haptic Device HD User Manual HD User Manual Table of Contents 1 General eeneg Ee ENEE A E H Ee e EEN A Se ore E Te EE 5 2 HD2 System Components edel Ee 7 2 i Comp nent Nomencl t te EE 7 2 2 Compon nt DesriptioN ee EE E E E 9 2 2 1 Aluminum Arm and End Effector Handle Components 3 And 241 9 ee DC Meter H 22 3 Optical HEIEREN 9 2 2 4 Counterbalances Component 7 s sssssssssssessessssssesresssesressessresressessrrrssseeesse 10 2 2 5 Analog I O Switch Component 2731 10 2 2 6 LEDs Component 24 to 28 s 2 cccs ovesdsscnsstncesudedeatcevisaacncdsdaavoeciaedventceseescletieee 10 22 TOS E DE 11 2 2 8 Q8 To Amplifier Adapter Board 12 DDO EN EE 12 2 2 10 Emergency Stop Push Button icc Secs ate eege 12 DD D Kee 13 3 Cabling ofthe HD2 EE 14 3 ls Cabling EE 14 SAID PCO Lan E 14 SO ER HD2 A E EE E 14 3 1 3 Inside PC Adapter Box Ree ET 14 3 1 4 HD2 Pedal Interface Optional serie cia stews sicctccatendarstpiesiadiisuietewles i taamcavene 15 3 2 Signal Connection NOmene Aur eege Eed 16 3 2 1 Q8 Digital Input And Output DIO Connection Table 16 3 2 2 Q8 Analog Input And Output AIO Connection Table 16 3 2 3 HD2 Amplifier To Motor Connection Table 17 4 Syste Parameters E 19 5s ANGINA LES tee o a eee E E E ri e a E a E a a ie 21 6 Motor and Encoder EIERE ed uer tee eebe eg 22 7 Calibration PEO CS CUE sae ites tear
11. They are la beled with J1 J2 and J3 Table 4 HD Cable Set Description Document Number 560 e Revision 02 Page 12 HD User Manual 3 Cabling of the HD This section describes the wiring steps required to appropriately interface the HD unit to the customized controller PC 3 1 Cabling Procedure The overall interface between the HD and the PC is divided into three sub interfaces as described below The following hardware accompanying the HD is assumed e Data Acquisition Card Quanser s Q8 HIL board e Signal Interface Board Quanser s Q8 To Amplifier Adapter Box e Enable Tool Quanser s E stop Push Button AN CAUTION ZN Perform all connections with the PC and HD units turned off 3 1 1 HD PC Interface The HD interface consists of the wiring between the SCSI connector on the back side of the device and the PC Figure 4 depicts the SCSI connector Component 18 on the back side of the HD unit 3 1 2 HD E stop As described in Section 2 2 10 the E stop button is using a 6 pin mini DIN connector which should be connected to the corresponding connector Component 20 in Figure 4 on the back side of the HD unit 3 1 3 Inside PC Adapter Box Q8 Interface Connect the three Q8 flat ribbon cables from the Q8 HIL board to the appropriate connectors on the Q8 To Amplifier Adapter Box as depicted in Figure 9 Make sure that the ribbon cables labeled with J J2 and J3 are conne
12. an be used as an analog input for the device For instance a force sensor can be attached to this connector When the switch is set to low the connector will output the six sensed currents in the device amplifiers 2 2 6 LEDs Component 24 to 28 The LEDs are used to show the status of the system Summarizes the the description of each LED It should be mentioned that the Fault LED Component 28 is used to check whether any of the amplifiers are not working for any reason Most usual case is when the simula tion is not running and the amplifiers are not enabled in simulation Please refer to Section 3 2 1 for more information on enabling the device amplifers Document Number 560 Revision 02 Page 9 HD User Manual LED ID Number Description 28 Fault It is On when the simulation is not running It is Off when the simulation is running Contact Quanser s Customer Service in case this LED is On during the Simulation 27 E stop It is On when the E stop is pressed and has deactivated the amplifiers It is Off when the E stop is depressed 26 Q8 It is On when the Q8 board is connected to the HD unit through the SCSI cable 25 Enable It is On whenever the amplifiers are enabled through the digital channels 9 and 10 in the simulation It is Off when the amplifiers are not enabled Refer to Section 3 2 1 for further information 24 Amplifier It is an optional trouble shooting LED for systems that are equ
13. arm providing it with a third degree of freedom pitch Made of lightweight materials HD equivalent weight over its entire workspace is further minimized by two adjustable brass counterbalances mounted on one of the two motors at each base This state of the art device is equipped with 6 built in high performance linear current amplifiers i e Quanser LCAM devices which along with the use of parallel mechanisms and capstan drive actuators make it possible for the device to provide the user with stiffness coefficients as high as 20 000 N m A user push pedal is provided with the device as a digital input for switching applications For instance it can be used as a clutch to temporarily deactivate the HD system in situa tions such as tele operation where the user has reached the threshold operating range and needs to disconnect the master robot from the slave robot and move the end effector to a new position to continue operation The system is controlled via a PC using Quanser s lead ing edge Q8 superior performance hardware in the loop HIL control board 1 2 System Software Presentation The HD system is supplied with Quanser s flexible QuaRC software and application examples to perform real time control using MATLAB Simulink For details regarding QuaRC Quanser s real time data acquisition and control software please refer to Refer ences 2 and 3 It is assumed that you are familiar with QuaRC and its operation before you use th
14. ber 560 Revision 02 Page 25 HD User Manual e The device has been properly calibrated as described in Sections 7 e Disable the e stop by pulling on the red e stop push button The E Stop component 27 light should go off on the device back panel e It is recommended that the calibration jig be removed using the two thumbscrews Component 10 Follow these steps to run the Tracker Example Step 1 Load Matlab and set the Current Directory to the location of the lab files provided on the HD CD these files should be copied to your hard disk Step 2 Open the HD2 Position_Control mdl Simulink diagram Step 3 If you have several Q8 boards installed double click on the HIL Initialize block and enter in the Board identifier input box the board number of the Q8 connected to the corresponding HD Ignore this step and keep the board to 0 if you only have a single Q8 board installed in your PC Step 4 In the Simulink diagram click on QuaRC Build to generate the QuaRC executable Step 5 Move the HD end effector to a desired position inside workspace where you want the controller to freeze the end effector in that place Step 6 Click on the Run button in the Simulink model tool bar to begin running the controller The device end effector handle should stay in its initial position and orientation Step 7 To stop the controller be ready to catch the device end effector and click on the Stop button in the tool
15. brackets and push it down A tight fit must be obtained as shown in Figure 13 Step 4 Open the Simulink diagram HD2_Calibrate mdl and make sure it is compiled build the model if necessary Document Number 560 e Revision 02 Page 22 HD User Manual A Caution If your PC has more than one Q8 board you may have to specify the board e g 0 or 1 before doing the calibration Step 5 With the end effector inside the calibration jig run the model for a short time half a second for instance Make sure that all the encoder readings are set to zero in the Display block Step 6 The HD is now calibrated and you can now remove the calibration jig and close the Simulink diagram Once calibrated you do not need to re initialize the encoder counters unless you turn off PC The Q8 encoder counters keep counting the encoder pulses even after a program has been stopped Caution All subsequent programs should not re load any number of counts into the A encoder counters If any subsequent program resets the number of counts the HD position you start the program at will be considered the zero position and the system will be mis calibrated unless you started at the home position Document Number 560 Revision 02 Page 23 HD User Manual 8 Supplied Files Table 9 outlines the files supplied with the HD system along with a brief description about each file Detailed description about the contents of each file is given in the
16. can specify the Dead Zone block parameters where you can set your cube dimensions by specifying the dead zone upper and lower ranges By subtracting x_cmd from x the controller knows if the user is operating in the dead zone or not If this difference falls in the dead zone range meaning that the user is still inside the cube dimensions the value zero is fed into the controller and hence Force will be zero As soon as the user tries to bypass one of the cube sides the difference between x mean and HD2_Cmd falls outside the dead zone range and Force will not be zero anymore In this case you will feel an opposing force on the HD not allowing you to move the end effector outside the cube dimensions It is the Force signal that is fed into the HD Interface block where the torque to be applied to the motors is calculated using the HD Jacobian This torque is converted to a current and assigned to the HD2_Current signal before being written to the Q8 Document Number 560 Revision 02 Page 29 HD User Manual 9 References 1 Q4 Q8 User Manual 2 QuaRC HTML Help Files 3 QuaRC Installation Manual 4 HD Dynamic Equations Maple Worksheet Document Number 560 e Revision 02 Page 30 HD User Manual Appendix A HD Software Subsystems Description 9 1 HD2_Interface mdl This file contains customized blocks that are used in other Simulink models supplied with the system These blocks are used
17. cted to their related connectors J J2 and J3 on the Adapter Box respectively Both Q8 board and the Adapter Box are connected Document Number 560 Revision 02 Page 13 HD User Manual to the PCI slots inside PC For more information ragarding the installation of Q8 board please refer to Reference 1 I O Ribbon Cables J1 J2 and J3 Figure 9 Connection of the Q8 board and the Q8 To Amplifier Adapter Box 3 1 4 HD Pedal Interface Optional In case a push pedal is provided with the device the two digital connectors recognized with the ID 16 and ID 17 can be used to interface the pedals with the HD unit Document Number 560 e Revision 02 Page 14 HD User Manual 3 2 Signal Connection Nomenclature This Section details the connections actually attained with the cabling described above 3 2 1 Q8 Digital Input And Output DIO Connection Table Table 5 details the Digital Input and Output DIO connections between the Q8 and HD attained through the Q8 To Amplifier Adapter board OS DIO Signal Func Channel tion DIO 0 to 7 User Defined Signals DI 8 The fault LED Component 28 state Input Fault No Fault DO 9 HD Amplifier General Enable Signal Output Disable Enable DO 10 HD Amplifier General Enable Signal Output Enable Disable DI 11 E stop State Input Pressed Not Pressed Table 5 Q8 DIO Connection Nomenclature Table 5 summarizes among
18. device back panel e It is recommended that the calibration jig be removed using the two thumbscrews Component 10 Follow these steps to run the VR Example Step 8 Load Matlab and set the Current Directory to the location of the lab files provided on the HD CD these files should be copied to your hard disk Step 9 Open the HD2_Sphere mdl Simulink diagram Step 10 If you have several Q8 boards installed double click on the HIL Initialize block and enter in the Board identifier input box the board number of the Q8 connected to the corresponding HD2_Sphere mdl Ignore this step and keep the board to 0 if you only have a single Q8 board installed in your PC Step 11 In the Simulink diagram click on QuaRC Build to generate the QuaRC executable Step 12 Move the device end effector to the center position where it is approximately in the middle of the workspace The sphere is defined such that it always starts a few centimeters away on the right hand side of the end effector at the time the simulation starts running Step 13 Click on the Run button in the Simulink model tool bar to begin running the controller The VR Sink window shown in Figure 14 should load Step 14 Move the device end effector around and observe how the virtual HD handle in the VR Sink window moves accordingly Step 15 Now move the HD end effector to touch the sphere You should feel some resistance when the handle comes into contact with the red
19. e HD The complete kinematic and dynamic modeling of the system as well as the system parame ters are provided to streamline the implementation of the control scheme of your choice The open architecture design of the system allows users to develop any control algorithm they desire With the QuaRC HIL API users can develop their own controllers on the platform and environment of their choice e g C C Java NET MATLAB For more information see the QuaRC External Interfaces section in Reference 2 Document Number 560 Revision 02 Page 5 HD User Manual 2 HD System Components 2 1 Component Nomenclature As a quick nomenclature Table 1 below provides a list of all the principal elements composing the HD system Every element is located and identified through identification ID number Table 1 on the HD represented in Figures Description Description 1 Base Plate 2 Frame 3 Aluminum Motor Arm 4 Aluminum Forearm 5 DC Motors 6 End effector Encoder Cable 7 Counterbalance Weights 8 U Universal Joint 9 Calibration Jig 10 Calibration Jig Screws 11 End Effector Handle 12 Encoders 13 End effector Encoder 14 Capstan Drive Gimbal 15 Capstan Cable 16 Digital I O Connector1 Channels 0 3 17 Deal I O Connector2 Channels 18 SCSI Cable Connector 4 7 19 Analog I O Connector 20 E stop Connector 21 Power Key 22 Power Connector 23 Ana
20. e joint torques in in Newton Meters to motor torques in Newton Meters Table 12 Joint Torque to Motor Torque Block 9 1 4 Jacobian Block Block Screen Shot Block Input s Block Output s Block Function 6 element vector containing Ampli gt fiers desired current in Amperes Amps_to_Volts 6 element vector containing Ampli fiers desired voltage in Volts It is a current to volt age converting gain Table 13 Current to Voltage Converting Block Document Number 560 Revision 02 Page 32 HD User Manual 9 1 5 Two Link Planar Arm Forward Kinematics and Jacobian Block Block Output s Block Screen Shot Block Input s Block Function SBAR Linkage Kinematics Input 1 3 element joint angles for each of the top and bottom two link planar arms Input 2 3 element linear forces in the global frame Output 1 3 element po sition vector in the global frame for each of the top and bottom two link planar arms Output 2 The filtered velocity of the Output Ouput 3 3 element joint level torques cal culated based on the In put2 Output 4 a 3by3 Jaco bian matrix calculated based on Input This block contains the forward kinemat ics and Jacobian ma trix matrix for a two link planar arm robot Two of these blocks are used to find the top and bot tom linear position of the device end ef fector in the global frame It al
21. echanism to Achieve Higher Torques Auxiliary Analog and Digital Input Quick Connect Through SCSI Cable Figure 1 HD Front View HD is one of the latest highly engineered robotic manipulators designed and manufactured in Quanser As a haptic device it enables the human user to interact with virtual or remote environments using programmable force feedback Compared to other commercially available haptic devices in the market HD has a relative ly large workspace and very low intervening dynamics It is also highly backdrivable with negligible inertia and friction Using seven high resolution optical encoders the motion of the operator can be tracked in 6 degrees of freedom i e three translational motions in Cartesian space and three rotational motions i e roll pitch and yaw The device can apply Document Number 560 e Revision 02 Page A HD User Manual force feedback to the user in 5 degrees of freedom HD model consists of double two link planar arm configurations connected in parallel to a rod using two universal joints U joints to form the end effector of the device Each two link planar arm solely is actuated by two capstan drive DC motors using a parallel mecha nism which lets the motors be mounted at the base of the arm As a result the displayed in ertia to the operator is highly reduced while the rigidity of the structure is maintained A third DC motor is mounted at the waist of each two link planar
22. er a vector is mentioned that contains motor torques currents the order of elements in this vector is the same as the order of the motor numbering assignment mentioned above The same convention applies to vectors containing encoder counts For example the first element in each such vector would correspond to the number of counts on M1 s encoder and so on Document Number 560 Revision 02 Page 21 HD User Manual 7 Calibration Procedure The HD calibration procedure consists of positioning the device in its home position and of presetting each actuated joint position reading to its corresponding pre computed angular value according to the HD kinematic model The HD home position is depicted in Figure 13 Figure 13 HD In Home Position In order to calibrate the robot measurements you need to use the calibration jig shown as component 9 in Figure 2 The calibration procedure is as follows Step 1 In order to successfully run the calibration procedure first ensure that the HD is wired as previously described in Section 3 Wiring Procedure and that the system is powered on Step 2 Attach the calibration jig supplied with the device with the two thumbscrews depicted as components 10 in Figure 2 in front of the HD The calibration jig constitutes the datum defining the calibration or home position Step 3 Position the HD as shown in Figure 13 and push the end effector handle inside the calibration jig holding
23. in implementing the control algorithms of the HD Each block is presented with its input s output s and a description about the block s functionality 9 1 1 Angle Calculator Block Block Screen Shot Block Function Angle Calculator Block Input s 2 vectors of 3 ele ing the positions of the top and bottom of the end effector handle ment each contain Block Output s Three angles in ra dians This block takes the the two top and bot tom end effector po sitions the angle that the two end effectors make with w r t the global axes are the outputs of this block Table 10 Angle Calculator Block 9 1 2 N m to Amps Block Block Screen Shot Torque N m j to Amps A Block Input s 6 element vector containing motor torques in Newton Meters Block Output s 6 element vector containing motor currents in Amperes Block Function Converts the torques to be applied to the motors from Newton Meters to a current in Amperes Table 11 N m to Amps Block Document Number 560 Revision 02 Page 31 HD User Manual 9 1 3 Joint Torque to Motor Torque Block Block Output s Block Function Block Screen Shot Block Input s 6 element vector E containing joint torques in Newton Meters Joint Torque to motor torque 6 element vector containing motor currents in Newton Meters It is a gear ratio gain It Converts th
24. ipped Power with more than six amplifiers Table 3 HD2 LED Description 2 2 7 Q8 HIL Board The Q8 Hardware In The Loop data acquisition board depicted in Figure 6 is installed in the customized PC supplied with the HD The power amplifier inside HD is designed to be fully compatible with the Q8 board For details regarding the Q8 board please refer to 1 Figure 6 Q8 HIL Board Document Number 560 e Revision 02 Page 10 HD User Manual 2 2 8 Q8 To Amplifier Adapter Board This adapter board is used to redirect the signals on the three flat ribbon cables of the Q8 board to the SCSI cable being connected to HD unit Figure 6 depicts the Q8 To Amplifier board outside the PC shows the adapter board connected to both the Q8 and the SCSI cable Figure 7 Q8 To Amplifier Adapter Box Out of PC view 2 2 9 Customized PC This is a PC on which the Q8 HIL board MATLAB Simulink and QuaRC are installed Measured signals are read in via the Q8 Board and manipulated using MATLAB Simulink and QuaRC Calculated control commands are applied to HD motors via the Q8 The Q8 board and the Q8 To Amplifier adapter box are placed inside the PC where the SCSI cable is the connection between the PC and the HD unit 2 2 10 Emergency Stop Push Button An emergency stop push button e stop is supplied with the system as pictured in Figure 8 The e stop cable has a 6 pin mini DIN connector that should be p
25. log I O Switch 24 LEDS Amplifier Power 25 LED4 Amplifier Enable 26 LED3 Q8 Board 27 LED2 E Stop 28 LED1 Fault Table 1 HD Component Nomenclature Document Number 560 Revision 02 Page 6 HD User Manual Figure 3 HD Back Top View Figure 4 HD Back Bottom View Document Number 560 e Revision 02 Page 7 HD User Manual 2 2 Component Description This Section provides a description of the individual elements comprising the full HD system 2 2 1 Aluminum Arm and End Effector Handle Components 3 And 4 The system consists of seven arms configured into two parallel planar arms They are made out of Aluminum tubes of uniform cross section For each planar arm two aluminum rods are used to form the motor arm and one aluminum rod makes the forearm Another alu minum tube is used for the end effector handle Description Value Unit Motor Arm Length 0 280 m Forearm Length 0 290 m End Effector Handle Length 0 175 m Device Total Mass 22 kg Table 2 HD2 Arm Characteristics 2 2 2 DC Motor The HD unit incorporates 6 custom made Faulhaber Coreless DC Motor 3863V006 as represented in Figures 6 and 7 by component 9 This model is a high efficiency low induc tance motor resulting in a much faster response than a conventional DC motor CAUTION High Frequency signals applied to a motor will eventually damage the gearbox and or the motor brushe
26. lugged into the corresponding connector Component 20 on the back of the Endonasal device All six motor linear amplifiers are disabled when the e stop is not connected or when the e stop is connected with the red button pushed down In this case the red LED on the back of the device Component 27 will be on The amplifiers shall be active i e enable if and only if the remote safety push button a k a e stop is connected and depressed In this case the red LED Component 27 will be off Figure 8 E Stop Push Button Document Number 560 Revision 02 Page 11 HD User Manual 2 2 11 Supplied Cables Each HD is supplied with the three cables described in Table 4 Two sets of the cables are used in the wiring of the HD system Please note that other cables such as HD and PC power cables are also required for proper operation of the system The Interfacing section of this document will describe the necessary steps to appropriately wire the HD system and its PC components Description Motor Cable The SCSI cable connects HD Unit to the Q8 To Ampli fier adapter box on the PC This cable carries the digital sensor signals encoder reading signals and power ampli fier enable and current signals Three I O flat ribbon cables connect the Q8 HIL board to the Q8 To Amplifier Adapter Box This flat ribbon cable carries the digital sensor signals encoder reading signals and power amplifier enable and fault signals
27. n i e x mean in meters and the 3 element angle vector i e theta in radians Document Number 560 Revision 02 Page 24 HD User Manual The vector theta shows the angle of the end effector around the coordinate frame axes as described in Figure 11 Another ouput of the block named x gives the position of the top first three elements and bottom next three elements of the end effector These two points correspond to the end effectors of each two link planar arms that are connected through the end effector handle The ouput Handle_Angle gives the end effector encoder reading in radians The output named Pedal contains two digital The first input to the block named force is a 6 element vector The first three elements correspond to forces along x y and z directions for the top planar arm end effector and the next three elements correspond to forces along x y and z directions for the bottom planar arm end effector The second input of the block named torque is a three element vector and is used to apply torques around the three axes of the device coordinate frame as described in Figure 11 8 1 2 Position Control Example Fixed Point 8 1 2 1 Description The Tracker Example is a world based position control The setpoint or desired device position is given in Cartesian coordinates and the controller calculates how much force is needed in each motor for the HD to attain this position
28. s The most likely source for high frequency noise is derivative feedback If the derivative gain is too high a noisy voltage will be fed into the motor To protect your motor you should always band limit your signal especially derivative feed back to a value of 50Hz 2 2 3 Optical Encoders Digital position measurement of all six actuated joints and the rotation of the device end ef fector is obtained by using seven high resolution quadrature optical encoders Six of the op tical encoders are directly mounted on the rear of each one of the six motors The motor en coder has a resolution of 1000 lines per revolution In quadrature mode this gives 4000 counts per full rotation of the encoder shaft Document Number 560 Revision 02 Page 8 HD User Manual The internal wiring diagram of the encoder is depicted in Figure 5 ELP CON ENCODER ELP SCKT RDIN S 180 ELP ENC USD Ee 1000 Figure 5 HD Encoders Internal Wiring 2 2 4 Counterbalances Component 7 Two brass counterweights are mounted behind both waist joints to minimize the arms effec tive mass You can manually adjust their positions forward or backward on the screw so that the HD end effector handle is perfectly balanced at the desired operating point of its workspace 2 2 5 Analog I O Switch Component 23 This switch is used for toggling the status of the analog connector with ID 19 depicted in Figure 4 When the switch is set to high the connector c
29. s ee 23 ER EE 25 Sals File EE 25 8 1 1 HD2 Interface Ee eegener E E O a E s 25 8 1 2 Position Control Example Fixed Bot ic teveacssssessitessatecdetesdadlanavenreisncdstcanstees 26 8 1 3 Virtual Reality Example Sphere a iccccsdsudvesaassesnessiaghoncsansescecihouies cdndueiccaeoermenansee 28 E CR e EE 30 EE 31 Appendix A HD2 Software Subsystems Descrpton 32 Document Number 560 Revision 01 Page i HD User Manual OL HD2 lt Interfacemd k cerios ue eet eege 32 O11 Angle Calewlator Block ci schsetssczessataseodsinioaacssasens heats tassel eenieder ini noake 32 9 1 2 Nemt Amps BlO Cis veeeggeb Abt er sinnini RENAS 32 9 1 3 Joint Torque to Motor Torque leg egceiee eege gege tens ioscan 33 9 1 4 Jacobian BOC cares sere i nee hast Au ties aide dele Salta mae fd Cs E 33 9 1 5 Two Link Planar Arm Forward Kinematics and Jacobian Block 34 9 1 6 Angle Calculator BOG is ycxcaies vc caecel taht is cine va oiesaa ca taxiah cel cuee tts cons Sealed oh odie teex 35 List of Figures Eeer TEE 4 Big ise CAR ER Front EE 8 Figure 3 HD2 Back Top RT 8 Figure 4 D2 Back Bottoni WiGW ede dee ie ee ees Godel bole er anne 8 Figure 5 HD2 Encoders Internal Wiring siscccsscagssessceescicounatandocnaoseyenad vavsncebintiavar eege 10 Pigsure 6 Q8 HIL Boards csccetesvossa vans siaveserssvatnnaiiowassaveunasunevsdercevoans tad ssawentsveusdawevenlviasdibeouss 11 Figure 7 Q8 To Amplifier Adapter Box Out of PC view 12 Figure 8 E Stop Push
30. section entitled File Descriptions that follows Please note that this table does not include all the files supplied with the HD It only includes the files that the user needs in order to interact with the system File Name Description NEIE A Simulink library containing customized blocks that are used in implementing the control algorithms of the system The model used to reset all the encoder counts to zero for E device calibration HD2_ Position Control md The model used to control the HD end effector position A demo model that allows the user to move the HD end ef HD2_Cube mdl fector around in an imaginary cube with pre defined co ordi nates A demo model that allows the user to move the HD end ef fector around and touch the surface of a sphere at three dif ferent points the middle and the two ends of the end effec tor handle HD2_Sphere mdl Table 9 Files Supplied With the HD System 8 1 File Description This section provides detailed descriptions about each of the files outlined in Table 9 The file named HD2_Interface mdl is intentionally explained first since later sections of this document will repeatedly refer to blocks contained in this file 8 1 1 HD Interface Block 8 1 1 1 Description This This I O block contains subsystems in which reads from and writes to the Q8 HIL board take place It provides the user with the device end effector 3 element vector positio
31. so calcu lates the joint torques for each of the top and bottom of the two link pla nar arms of the HD Table 14 Two Link Planar Arm Forward Kinematics and Jacobian Block Document Number 560 Revision 02 Page 33 HD User Manual 9 1 6 Angle Calculator Block Block Screen Shot Block Input s Block Block Function Torque 2 Force Input A 3 element global position of the bottom two link planar arm end effector Input A 3 element global position of the top two link planar arm end effector Input3 The 3 element angles vector that is calculated in the an gle calculator block Input4 The 3 element torque vector defined in the global frame Output s of the linear force for the top two link planar arm in the global frame of the linear force for the bottom two link planar arm in the global frame Outputl A 3 element vector Output2 A 3 element vector It calculates the linear forces in Newtons based on the input torques in Newton Me ters The output forces are added to the linear forces that are de fined in the global frame and used inside the Two Link Planar Arm Forward Kine matics and Jaco bian Block Table 15 Angle Calculator Block Document Number 560 Revision 02 Page 34
32. st others the enable features of the linear current amplifiers The E Stop state is available to be read on the Q8 from DIO 11 The HD amplifiers can be enabled by setting the digital channel 9 to zero and digital channel 10 to one Lastly more switches can be implemented and defined by the user on the digital lines from channels 0 to 7 3 2 2 Q8 Analog Input And Output AlO Connection Table Table 6 details the Analog Input and Output AIO connections between the Q8 and the amplifiers attained through the Q8 To Amplifier Adapter box Document Number 560 Revision 02 Page 15 HD User Manual Amplifier ID Q8 AO Channel Q8 AI Channel Amplifier Command Current Measurement Amp 0 AO 0 Al 0 Amp 1 AO 1 Al 1 Amp 2 AO 2 Al 2 Amp 3 AO 3 Al 3 Amp 4 AO 4 Al 4 Amp 5 AO 5 Al 5 Table 6 Q8 AIO Connection Nomenclature The command to each motor current is applied from six of the Q8 Analog Outputs AO s As expressed in Table 6 the six motor current commands are set by the AO from channels 0 to 5 Each amplifier gain is internally set to 1 2 41 A V The current in each motor can be individually monitored using six of the Q8 Analog Inputs AI s The six motor currents are available to be read on the AI from channels 0 to 5 The gain of the current sensor is 0 5 V A Note Note that a positive voltage or current applied to one of the six DC motor inputs results in a Counterclockwise
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