Libralis Software Package user's guide
Contents
1. Figure 3 Warning message 30 000000 30 000000 f 30 000000 10 000001 30 000000 30 000000 30 000000 30 000000 pE T o Standard parameters values for 3DoF haptic device Figure 4 Offline Estimate Configuration Dialog 3 Libralis Tuner 3 1 3 Estimation phase The estimation starts clicking on the button The procedure is fully automatic The first step is the execution of a procedure that calculates some parameters for the estimation algorithm During the procedure the Estimate Dialog is shown see Figure 5 Click to stop the estimate procedure and go back to the software Configuration Dialog Estimation in progress 14 4 27 a Figure 5 Offline gravity estimation The Monitor Dialog see Fig 1b reports information about the device e g the position and the force exerted by the end effector and the estimate procedure e g a 3 vertex to estimate etc At the end of this phase choose the filename dat to save the estimate results Now it is possible to test the gravity estimation just performed Start Test xi Would you test last estimation Ca Figure 6 Test after estimation If the offline calibration provides accurate estimations in a reasonable time duration we suggest to save the configuration values used in an ini file with the command eventually typing a reminder comment in the apposite box 4 6 3 2 Online Gravity Compensat2. Getting started This section illustrate how to get started using Libralis with Haptik Library Add the files libralis h and libralis cpp to your existing C project In your Project properties add the following path ProgramFolder Siena Robotics and System Lab Libralis Library Include to Additional Include Directories and the following path ProgramFolder Siena Robotics and System Lab Libralis Library Lib to Additional Library Directories Include the header libralis h to C file in which you have implemented the haptic servo loop In libralis h you have to define the correct path and filename to access the gravity data file with NO file extension Link the library Libralis lib to your project Please refer to the sampleLibralis project in your Libralis Library folder 4 2 Extending Libalis to any existing API Libralis Library can easily be extended to any API used to implement the haptic servo loop and to access the haptic device To that end it is sufficient to edit header libralis h and the implementation libralis cpp accordingly These files originally comes with the inclusion of Haptik Library headers and use the data type Vector3 to represent end effector position and force feedback vectors The default libralis h file is the following include lt windows h gt include LibralisFunctions h include lt RSLib Haptik hpp gt using namespace RSLib using namespace RSLib Math define GR
3. assert copyright on the software and 2 offer you this License giving you legal permission to copy distribute and or modify it For the developers and authors protection the GPL clearly explains that there is no warranty for this free software For both users and authors sake the GPL requires that modified versions be marked as changed so that their problems will not be attributed erroneously to authors of previous versions Some devices are designed to deny users access to install or run modified versions of the software inside them although the manufacturer can do so This is fundamentally incompatible with the aim of protecting users freedom to change the software The systematic pattern of such abuse occurs in the area of products for individuals to use which is precisely where it is most unacceptable Therefore we have designed this version of the GPL to prohibit the practice for those products If such problems arise substantially in other domains we stand ready to extend this provision to those domains in future versions of the GPL as needed to protect the freedom of users Finally every program is threatened constantly by software patents States should not allow patents to restrict development and use of software on general purpose computers but in those that do we wish to avoid the special danger that patents applied to a free program could make it effectively proprietary To prevent this the GPL assures that patent
4. sliders Accuracy and Spring 4 and 4 to set the duration and the accu racy of the estimation Attention note that increasing the desired accuracy will increase also the estimation duration If the haptic device has low encoder resolution it will not be able to match high levels of accuracy This may lead the iterative estimation to get into a dead lock Moreover a low spring value means that end effector motion will be slow and smooth while high values will result in quick and impulsive motion eventually causing vibration and actuator saturation To complete the set up a comment can be inserted in o This data are not necessary for the estimate procedure The text will be eventually saved in the estimate and configuration files and shown during the online gravity compensation If some data inserted in the boxes are not correct an error message which explains the wrong typed values is shown The cube side length influences the number of the vertices to estimate in Appendix C we can see how a wrong choice for this value can reduce the dimensions of the effectively estimated grid Another problem connected with the choice of the cube side dimension exists if it is too big we could meet some trouble during the transition from a vertex to the next one In this case the haptic device end effector could be too fast and the device motors could reach the saturation 3 1 Offline Gravity Estimation 7 Choose the device
5. AVITY_COMPENSATION_FILE __TEXT path filename bool InitLibralis Vector3 Compensate Vector3 position 4 2 Extending Libalis to any existing API 11 If you desire to replace Haptik with a different API the file libralis h should be edited as shown in the following example include lt windows h gt include LibralisFunctions h include lt myHapticAPI h gt using namespace my Haptic API define GRAVITY COMPENSATION FILE TEXT path filename bool InitLibralis my_3D_vector_type Compensate my 3D vector type position Consequently also the implementation in file libralis cpp should be edited accordingly include libralis h my 3D vector type Compensate my 3D vector type position if Initialized ProbePose x position x ProbePose y position y ProbePose z position z CompensationTerm gravityCompensation ProbePose fv3Max WS fv3Min_WS amp hCompensationTable amp hEstimateTable fSide gravity else CompensationTerm x 0 0f CompensationTerm y 0 0f CompensationTerm 0 0f N I xxxxx Replace here the return type xxxxx return my 3D vector type CompensationTerm x CompensationTerm y CompensationTerm z bool InitLibralis 12 A License A License The GNU General Public License is a free copyleft license for software and other kinds of works The licenses for most software and other practical works are designed to take aw
6. File Estimate in the Main Window see Figure la to start the gravity estimation procedure Select the haptic device from those available in the Choose Dialog see Figure 2 and click the button The Configuration Dialog see Figure 4 is shown from this window all the user defined parameters can be modified as specified in the following 3 1 1 Configuration Files The panel 4 A allows to manage the configuration files load the values previously saved or edited from a user specified ini file reload the default values Apply check and apply the values inserted in the boxes if they are not valid an error message is shown check and save the values in a user specified ini file By default simple mode configuration is selected If you want use expert mode configu ration see Appendix D 21f your device is not shown in the list see the Appendix B1 3Those data are read from the config ini file to edit this file see Appendix B2 3 Libralis Tuner 3 1 2 simple mode configuration The box 4 1 a shows the name of the haptic device in use Eventually it is possible to select a different device by clicking Change Device The box 4 1 b reports the default maximum force that the haptic device is capable to exert Attention editing improperly this value can lead to actuator saturation degrading performance Select the grid bounding box and choose the side lenght of each internal cube Act on the
7. Libralis Software Package user s guide http libralis dii unisi it Contents Installation lala MBISGIGINAG I 2 ta iha Gi LAKAN Ao APA ANTOK Ah ka AGE HA ant o AB An KANAL NA 1 2 System requirements 1 3 Downloading Introduction to Libralis Software Package Libralis Tuner 3 1 Offline Gravity Estimation 3 1 1 Configuration Files 3 1 2 simple mode configuration 3 1 3 Estimationphase 3 2 Online Gravity Compensation Libralis Library 4 1 Getting started 4 2 Extending Libalis to any existing API License Configuration Files Bl Haptik config txt B2 config ini 2 4 46 a4 aa maa Grid creation D Expert mode configuration CONTENTS Www w O0DADUNUN A Aa 1 Installation 1 1 Disclaimer This software is provided as is without any express or implied warranty In no event will the authors be held liable for any damages arising from the use of this software 1 2 System requirements Microsoft Windows XP Vista 1 MB free disk space Haptik Library 1 0 Haptic Device Drivers 1 3 Downloading The Libralis Package can be downloaded from the Libralis Project website http libralis dii unisi it To start using Libralis just launch setup exe and install the application Please be sure that Haptik Library 1 0 http www haptiklibrary org and the device drivers are installed Thttp www haptiklib
8. ay your freedom to share and change the works By contrast the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program to make sure it remains free software for all its users We the Free Software Foundation use the GNU General Public License for most of our software it applies also to any other work released this way by its authors You can apply it to your programs too When we speak of free software we are referring to freedom not price Our General Public Li censes are designed to make sure that you have the freedom to distribute copies of free software and charge for them if you wish that you receive source code or can get it if you want it that you can change the software or use pieces of it in new free programs and that you know you can do these things To protect your rights we need to prevent others from denying you these rights or asking you to surrender the rights Therefore you have certain responsibilities if you distribute copies of the software or if you modify it responsibilities to respect the freedom of others For example if you distribute copies of such a program whether gratis or for a fee you must pass on to the recipients the same freedoms that you received You must make sure that they too receive or can get the source code And you must show them these terms so they know their rights Developers that use the GNU GPL protect your rights with two steps 1
9. iklibrary 14 B Configuration Files B2 config ini 2910 rows columns version 0 023 00 alpha 1000 PD stiffness kp 0 01 15 AlphaMin 0 37 01 beta 1000 PD damping kd 5 16 BetaMax 10 02 max device force N 1d 17 BetaMin 0 3 03 lambda 2 18 EpsMMax 40 04 WS X MAX mm 0001 19 EpsMMin 40 05 WS_Y MAX mm 2 20 EpsVMax 40 06 WS Z MAX mm 0001 21 EpsVMin 40 07 side mm 30 22 mass delta kg 0 20 08 initial standard mass kg 0 23 NOT USED 05 09 mass accuracy N 40 24 WS_X min mm 20 10 mass samples 40 25 WS Y min mm 08 11 velocity accuracy mm s 40 26 WSZ min mm 150 12 velocity samples 50 27 Accuracy 1 13 NOT USED 40 28 Velocity 0 1 14 AlphaMax Omega Standard orientation Figure 9 Content of the config ini file The config ini file contains all the parameter values The default values are suitable for all the 3DoF haptic devices supported by Haptik but in the config folder are present some ini files specifically designed for the most common devices We can load the parameters values from a ini file and these files can be modified by a text editor C Grid creation Figure 10 Grid creation Libralis Tuner builds a grid starting from a parallelepiped contained in the device workspace and the cube side defined by the user This cubic grid is the smallest one that contain the par allelepiped and
10. ion 9 3 2 Online Gravity Compensation This function is used for the manual testing of the gravity estimation results The testing phase or online gravity compensation can be started from the Main Dialog or it can be started once the offline estimate phase has ended and its results have been saved Online gravity compensation Compensation Enable Disable Falcon Novint Standard parameters values for Novint Falcon Figure 7 Online Gravity Compensation The test dialog is shown in Figure 7 in the box on the right some information about the loaded data are shown device model orientation and the saved comment By clicking on Enable or Disable we can enable or disable the gravity compensation during the test The button quit the testing phase During this phase the Monitor Dialog see Figure 1b reports information such as the end effector position the cube detection the eventually projected position and the gravity term computed at each position of the device workspace 10 4 Libralis Library 4 Libralis Library Libralis Library is a static library which allows developers to use online gravity compensa tion in their haptic applications The library exposes only two methods the first can be used to load gravity data from files and initialize the compensation controller while the second is used in the haptic servo loop to compute the desired compensation term at the current end effector position 4 1
11. ox 11 2 a the mass value used for parameters initializa tion can be set in 11 2 b In this way the procedure used to determine a value for the initial mass is skipped The parameters a and 3 can be set directly If during the estimation we detect an anomalous behavior of the device i e sudden shots not accurate vertices etc we can modify a and 8 remembering how they influence Kp and Kp i e the parameters of the PD control implemented to drive the haptic device The stop conditions for velocity and gravity in terms of n and e can be exactly defined in 11 4 Increasing the samples number and decreasing the confidence interval the estimate accuracy raises but at the same time also the estimate duration raises For best set up of those parameters it is needed the knowledge of the haptic encoders accuracy In set the percentage of the distance between the casual initial position and the first vertex to estimate to use for the stop condition of the automatic paramenters initialization If the distance from the initial position and the first vertex is large lower this value Instead if that distance is small increase A Configuration EXPERT MODE 30 000000 30 000000 30 000000 30 000000 30 000000 30 000000 30 000000 Standard parameters values For 3DoF haptic device Figure 11 Configuration Dialog Expert mode
12. rary org 2 3 3 Libralis Tuner Introduction to Libralis Software Package Libralis Tuner allows to perform the gravity estimation with a 3DoF impedance haptic de vice in a user defined cubic grid This software also allows the testing of the performed estimations Libralis Library is a C library that allows the developers to simply include the gravity compensation in their interactive applications Libralis Tuner Libralis Tuner File mass 0 289497 alpha 0 034750 beta 0 545200 epsG 0 514900 eps 1 118000 initial Mass 0 130902 Kp 0 144173 Kd 0 009189 Force 0 013842 1 207683 2 698812 pos 1 774341 18 951429 21 511513 des pos 0 000000 20 000000 20 000000 a Main Window b Data Monitor Figure 1 Software Main Window In Figure 1 is shown the software Main Window which appears at the program launching From the dialog on the left see Figure la the main functions can be chosen runs the offline gravity estimation starts the online gravity compensation used to test the previously estimation terminates the application The same operations can be performed by the commands on the File menu By the Help menu the About window and the Online Help can be opened In Figure Ib is shown the Monitor Dialog which reports technical information during the software execution 3 1 Offline Gravity Estimation 5 3 1 Offline Gravity Estimation Click or select the menu
13. s cannot be used to render the program non free The precise terms and conditions for copying distribution and modification follow 13 B Configuration Files B1 Haptik config txt Omega GravityCompensation FALSE Omega Brake FALSE Omega MaxForce 10 000000 Falcon GravityCompensation FALSE Falcon Brake FALSE Delta LeftHanded FALSE Delta MaxForce 10 000000 Delta MaxTorque 10 000000 Delta GravityCompensation FALSE Delta GripperMass 0 0 Delta BaseAngleDeg 0 0 Delta XOffset 0 Delta YOffset 0 Delta ZOffset 0 HaptikLibrary numberOfPlugins 6 HaptikLibrary pluginO_0 Haptik Falcon dll HaptikLibrary plugin1_0 Haptik Phantom420H dll HaptikLibrary plugin1_1 Haptik Phantom42 dll HaptikLibrary plugin1_2 Haptik Phantom40 dll HaptikLibrary plugin1_3 Haptik Phantom31 dll HaptikLibrary plugin2_0 Haptik Delta30 dll HaptikLibrary plugin2_1 Haptik Delta31 dll HaptikLibrary plugin3_0 Haptik Freedom dll HaptikLibrary plugin4 0 Haptik Remote dll HaptikLibrary plugin5 0 Haptik Spectre dll Figure 8 Content of the Haptik config txt file Please check the Haptik Config txt file see Fig 8 it is required by Haptik Library If yours device is supported from Haptik Library but is not in the list you must add it to the file by a simple text editor and you must also update the HaptikLibrary numberOfPlugins entry please refer to Haptik Library User s Guide Shttp sirslab dii unisi it hapt
14. the workspace center 0 0 0 is a vertex of this grid In the inner vertices the green ones in Fig 10 the estimation is performed instead in the extern vertices the red ones gravity and mass are calculated by a function To obtain an accurate grid we recommend to choose a value for the cube side that mini mize the gap between the parallelepiped and the inner vertices In expert mode configuration see Appendix D the grid can be loaded from a file 16 D Expert mode configuration D Expert mode configuration In the Configuration Dialog it is possible choose the expert mode configuration This method allows to set low level control parameters Attention editing low level parameters requires the knowledge of the control architecture described in detail in 1 A Formaglio S Mulatto and D Prattichizzo Iterative estimation of the end effector apparent gravity force for 3DoF impedance haptic devices In Proc EUCA European Conference on Control 2009 Budapest Hungary August 2008 2 A Formaglio M Fei S Mulatto M de Pascale and D Prattichizzo Autocalibrated gravity compensation for 3 DoF impedance haptic devices Eurohaptics 2008 Lec ture Notes in Computer Science Volume LNCS 5024 pages 43 52 Springer Verlag Madrid Spain June 2008 In the following a brief description of the advanced settings is reported Referring to the Figure 11 The grid can be loaded by a file see Fig 11 1 After check the apposite b
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