EtherCAT Dextrous Hand
Contents
1. If you have any questions don t hesitate to contact us at software shadowrobot com at EtherCAT Dextrous Hand User Manual 2 2 INSTALLING OUR SOFTWARE 2 Installing our Software For a typical user we really recommend installing our software directly from the apt repository see section 2 1 1 This will ensure that you keep the latest released software on your computer We assume you ve already installed ROS Fuerte as detailed on the ROS Wikit However if you plan to modify some parts of our code you can use an overlay to install some of the sources from our publicly available Launchpad repository on top of your existing installation 2 1 Installing Routes 2 1 1 From ROS apt repository recommended You can install pre built packages for Ubuntu 12 04 This is the easiest way of installing our software You ll also receive updates automatically whenever you update your system Once you ve installed ROS Fuerte you can easily install our stacks gt sudo apt get install ros fuerte shadow robot ros fuerte shadow robot ethercat ros fuerte sr visualization ros fuerte sr teleop 2 1 1 1 Install a sr_config overlay for the EtherCAT Hand If you have an EtherCAT Hand you should create an overlay for the sr_config stack this stack con tains all the different configuration files which can be modified to reflect your specific2. We re using the rqt_gui for driving the hand We implemented some plugins to help you control the hand They are all in the Shadow Robot item in the plugins menu 4 4 Checking it works 4 4 1 Reading data out of the Hand First look at the data coming out of the hand gt rostopic echo joint_ states header seq 7235 stamp secs 73 nsecs 785000000 frame_id name WRJ2 WRJ1 FFJ4 FFJ3 FFJ1 FFJ2 position 0 007345193851005405 0 0007282010249589632 velocity 0 0002164649710794793 0 0015999764385997265 effort 0 0 0 0 0 0 0 0 The data is published on the joint_states topic or gazebo joint_states for the simulated hand You will see the incoming data streaming in your console You have access to the joint names as well as the current positions in radians velocity in radians per second and effort an arbitrary value proportional to the effort applied at the motor end of the tendon for each joint as shown below stop with ctrl c You should also be able to visualise the current state of the robot using rviz To start rviz run the command below You ll need to select a base link and add a Robot Model from the add button in rviz gt rosrun rviz rviz url http www ros org wiki rqt_ gui 13url http www ros org wiki rviz wilt EtherCAT Dextrous Hand User Manual 9 4 RUNNING OUR CODE 4 4 2 Reading the
3. 0 set to 1 for left hands export LEFT HAND 0 set to 1 if you have a CAN hand url http www cyberglovesystems com 10url http bazaar launchpad net shadowrobot sr config trunk view head bashrc env_ variables bashre Tf you bought an etherCAT hand the system you ll receive from Shadow will already be configured properly for you There are no variables stating that you have an etherCAT hand in this file because the launch file for starting the simulator and the one used to run the hand are different as you can see in this manual wilt EtherCAT Dextrous Hand User Manual 6 3 NAVIGATING OUR CODE export REAL HAND 0 set to 1 if you have a CAN arm export REAL ARM 0 set to 1 if you have a muscle arm or hand export MUSCLE 0 set to 1 if you want to build the compatibility interface for the etherCAT hand makes it possible to run your programs developed for the CAN Hand on the etherCAT hand default is 1 as it just builds another node export ETHERCAT 1 port in which the etherCAT hand is plugged in more info in section 4 1 1 export ETHERCAT PORT eth1 set to 1 if you re using PWM control on the etherCAT hand motors by default export PWM_CONTROI 0 set to 1 if you want to have access to the internal firmware repository NOTE for Shadow employees only for the time being export INTERNAL FIRMWARF 0 set to 1 if you have ellipsoid fingertips ATI nano sensors export ELLIPSOID 0 set
4. command sent to the motor p the Kp for the position PID loop i the Ki for the position PID loop d the Kd for the position PID loop i_clamp the value used for clamping the I term for the position PID loop Checking the diagnostics The etherCAT Hand regularly publishes diagnostics about the state of the hardware You can view them using the robot monitor utility This way you can monitor the different state of the motors the sensors etc Murl http ros org wiki robot _ monitor wiht EtherCAT Dextrous Hand User Manual 12 5 WHERE TO GO NEXT 5 Where to go next The ROS wiki is probably the best place to start learning about ROS We strongly rec ommend going through the excellent ROS Start Guide especially the set of tutorialst You should also look at some of our tutorials for the EtherCAT Hand We d be delighted to get your contributions patches nice demos etc Don t forget our software is open source so if you want to contribute you should probably check this wiki page out url http ros org wiki 16url http ros org wiki ROS StartGuide url http ros org wiki ROS Tutorials 18url http ros org wiki shadow_robot_etherCAT Tutorials url http ros org wiki shadow_robot Contributing wiht EtherCAT Dextrous Hand User Manual 13 6 WHAT TO DO IF IT DOESN T WORK 6 What to do if it doesn t work 6 1 Check your ROS setup You can use very simple examples to
5. contact us software shadowrobot com 0url http ros org wiki roswtf lurl http answers ros org wiht EtherCAT Dextrous Hand User Manual 14 7 CHANGELOG 7 2 7 3 7 4 7 5 Vt Changelog shadow robot 19 06 2012 rev 364 Better mixed position velocity controllers 19 04 2012 rev 361 Hand with Biotacs model added 19 03 2012 rev 334 Reorganised the code in different stacks Removed some packages from the shadow_ robot stack to put them in either sr_ contrib sr_ config sr_teleop sr_ visualisation sr_ demo stacks We re keeping only the core packages in this stack for easier release maintenance sr_ config 19 03 2012 rev 1 Created the sr_ config stack to store the user specific config The values by default should work for most users simulated right hand with all the fingers Users should overlay sr_config if they want to modify the config files Useful for easy release shadow _robot_ ethercat 11 04 2012 rev 546 Using lowpass filter instead of alpha beta filter for better control 29 03 2012 rev 543 added support for three finger hands 15 03 2012 rev 539 Control inputs from the host backlash compensation on off sgl increase jiggle write eeprom 14 03 2012 rev 538 Switching from PWM demand to TORQUE demand on the fly 14 03 2012 rev 537 Added a service to nullify the demand sent to the motor easily This way the user can easily stop the control of
6. stacks in one go you can use the rosinstall files avail able here Once you ve downloaded the code using the rosinstall commands described previ ously you can build all our stacks Turl http ros org doc api rosdep2 html overview html 8url http bazaar launchpad net shadowrobot sr build tools trunk view head data shadow_ robot fuerte rosinstall Vt EtherCAT Dextrous Hand User Manual 4 2 INSTALLING OUR SOFTWARE gt rosdep install shadow_robot shadow_robot_ethercat sr_contrib sr_visualization sr_teleop gt rosmake shadow_robot shadow_robot_ethercat sr_contrib sr_visualization sr_teleop 2 2 Import our custom Environment Variables As described in section 3 1 1 we re using a file to define some useful environment vari ables To make sure the variables are imported in your setup you need to source it in your bashrc after sourcing the ros setup sh It should look like this bashre source the ros setup sh source opt ros fuerte setup sh tor the one created in your workspace if you used an overlay source workspace setup sh now source our additional environment variables source rosstack find sr_config bashre env_variables bashre Li EtherCAT Dextrous Hand User Manual 5 3 NAVIGATING OUR CODE 3 Navigating our code Our code is split into different stacks each containing a set of packages e shadow _ robot contains simulation software uti
7. to 1 if you want to publish more debug information on the etherCAT hand export DEBUG 1 3 1 2 Specifying default controllers settings and other useful settings The controller settings as well as the different mappings and polling rates for the ether CAT hand can be found in the sr_ethercat_hand_ config package You can mod ify the controller values which will be loaded by default by modifying the files in this package For example if you want to modify the mixed position velocity controllers you can opensr_edc_ mixed position velocity joint __controllers yaml in control s host We recommend using the controller tuner GUI plugin see section 4 3 for tuning and saving those parameters 3 2 Important Packages e sr_ hand Contains the code and the different launch files for the simulated Hand and the CAN hand e sr_edc_ launch Contains the main launch file for the EtherCAT Hand e sr_ example Contains some simple code examples wilt EtherCAT Dextrous Hand User Manual 7 4 RUNNING OUR CODE 4 Running our code 4 1 Starting the real hand 4 1 1 Setting up the Ethernet port The first time you connect an EtherCAT Hand you will need to check on which Ethernet port the hand is connected to Usually you will have 2 network ports in your computer one for your network the other one for the hand An easy way to see which port the hand is using is to unplug the hand network cable from your computer and then plug it
8. EtherCAT Dextrous Hand User Manual Shadow Software team softwareQshadowrobot com October 15 2012 v Shadow Robot Company CONTENTS Contents 1 Overview 2 Installing our Software 2 1 2 2 Installing Routes e g um eo ee eH he Rk ee ee a eS 2 1 1 From ROS apt repository recommended 2 1 2 From sources ae kh eae eo PRE A oO aH See ee aS Import our custom Environment Variables 3 Navigating our code 3 1 3 2 Configuration and settings 422 4 248244 beets bo eed ee REE e ES 3 1 1 Specifying system parameters 2 2 0 2200 3 1 2 Specifying default controllers settings and other useful settings Important Packages eind os ooo de beh ae hE alee es oo oe ed 4 Running our code 4 1 4 2 4 3 4 4 Starting the real hand o oo e 4 1 1 Setting up the Ethernet port soaa a 4 1 2 Starting the driver aoaaa es Starting the simulated robot soo a a Starting the GUI oaaae Checking It Works snas as mer Tai d ne Teuk D ok de Se wee Be Be eo e 4 4 1 Reading data out of the Hand o oo 4 4 2 Reading the tactile sensors o oo ek ee ee ee 4 4 3 Sending Commands tothe Hand 4 4 4 Getting information on the current state of the controllers 4 4 5 Checking the diagnostics 0220002 eee 5 Where to go next 6 What to do if it doesn t work 6 1 Check your ROS setup 0 0 000 eee ee 6 2 Use the R
9. OS community 0 0 200 002 e eee eee 6 3 Contact S o s S 4 os eee he dee eed Gd ee ees ew a 7 Changelog Vell Shadow robt se ss eee eh ee a OS eee Raw e Re Teal Te ON ss eh ee Heh ec we ek ee ee ee ee E 7 3 shadow_robot_ethercat 0 0 0 0 00 0000002 eee eee CA SACO a eh twee bade bd edd pe eee eee EE bee Se GO SC COMMID ai ae 84k ea eS A eS Eee on dook e i e EtherCAT Dextrous Hand User Manual 13 14 14 14 14 15 15 15 15 15 15 1 OVERVIEW 1 Overview This user manual will get you started with using our EtherCAT hand or simulated robots We ll guide you through installing the code in section 2 explain where to find things in section 3 and show you some basic commands and code samples in section 4 This guide ends with some pointers to essential documentation you should read section 5 and some troubleshooting tips section 6 You can find below a kinematics diagram of the Shadow Hand The joint names are indicated on the diagram As a convention and because of the way the Hand is actuated the joint 1 and 2 for the first finger middle finger ring finger and little finger are grouped in the joint 0 FFJO FFJ1 FFJ2 MFJO MFJ1 MFJ2 etc 22 00 t e at me at m 27 90 70 00 0 Ap S ae 45 0 J xX amp Ar 38 00 WRJ2 20 00 4 N 5 00 Ha
10. back in You can now type dmesg and you should see a line saying which port has just been plugged in for example in the lines below you see that eth1 is used by the hand 16661 901920 e1000e ethi NIC Link is Down 16666 460518 e1000e ethi NIC Link is Up 1000 Mbps Full Duplex Now that we know which Ethernet port is used by the hand eth1 in our example we can edit the interface in the system parameters as shown in section 3 1 1 e Make sure you ve created your overlay for the sr_config stack as described in section 2 1 1 1 e Let s open the configuration file gt roscd sr_config gt cd bashrc gt gedit env_variables bashre e Set the ETHERCAT_PORT to the correct value it is eth1 by default e Save and restart your terminal to make sure the new options have been taken into account 4 1 2 Starting the driver You can now start the driver To be able to run the driver you need to elevate the permissions to root access televate permissions gt sudo s gt roslaunch sr_edc_launch sr_edc launch 4 2 Starting the simulated robot To start the simulated robot you can simply run gt roslaunch sr_hand gazebo_ hand launch Or if you want a simulated Shadow Arm as well as our hand gt roslaunch sr_hand gazebo_arm_and_hand launch i wilt EtherCAT Dextrous Hand User Manual 8 4 RUNNING OUR CODE 4 3 Starting the GUI To start the GUI run gt rosrun rqt_ gui rqt_ gui i
11. check different things e Check you can access our stacks if this command doesn t get you to the shadow_ robot folder make sure you ve installed the code properly and sourced the generated setup sh as described in section 2 gt roscd shadow_ robot e Check you can publish and subscribe to a simple topic You ll need to start each of the following commands in a separate terminal The first command is used to start the rosmaster The second one will publish some data on the test topic while the third command subscribes to the topic and print the output on the screen If this test works you should see the incoming data streaming in your third terminal in terminal 1 start the rosmaster we start it in a separate xterm window as you need to keep it running during the whole experience gt xterm e roscore amp in terminal 2 publish data at 5Hz on test gt rostopic pub test std_msgs Float64 r 5 1 0 in terminal 3 subscribe to the test topic you should see the streaming data stop it with Ctrl c gt rostopic echo test data 1 0 data 1 0 data 1 0 e If all hope is lost run the roswtf utility 6 2 Use the ROS community A good thing to remember is that you re probably not the first one having run into this problem You should check the ROS community website answers ros org and post your question if you can t find a relevant answer 6 3 Contact us Don t hesitate to
12. lity packages This is the core stack e shadow_robot_ethercat contains the code for running our etherCAT hand e sr_ contrib contains experimental high level packages If you write an interesting package we d be happy to add it to this stack e sr_ visualization contains the GUI and visualisation tools e sr_teleop contains drivers for different tools used to teleoperate our hand cyber glove e sr_ config contains the configuration files If you have one of our Hands you should have an overlay of this configuration to make sure you don t lose your con figuration when updating your system as described in section 2 1 2 3 1 Configuration and settings We moved all the configuration to the sr_config stack The idea is to isolate the data that is specific to the user in a given stack this way you can easily create an overlay as described in section 2 to make sure your specific configuration is not overwritten by an update 3 1 1 Specifying system parameters The system parameters are specified in the file env variables bashrc To load them automatically in your environment please go to section 2 2 This File is heavily com mented and should be easy to modify to suit your installation the default options should be ok for most users env_variables bashrc set to 1 to compile sr_hand and sr_ tactiles with the gazebo interface export GAZEBO 1 set to 1 for one finger hands export ONE FINGER
13. r e Were now going to create a workspace in the workspace directory based on your currently installed ROS system we re assuming you re using ROS Fuerte and add the stacks we want to overlay to the workspace We ll then update the workspace to download the code into it gt rosws init workspace opt ros fuerte source workspace setup sh rosws set sr_config bzr lp sr config rosws update VV V e To use the newly created environment simply source the setup sh created in the previous step to have it sourced automatically when you open a new terminal simply add it to your bashrc as show on the second line gt source workspace setup sh gt echo source workspace setup sh gt gt bashre e To install the system dependencies we ll use the rosdep utility This utility needs to be initialised the first time you use it gt sudo rosdep init gt rosdep update e You now have the up to date database of system dependencies on your system You can install the dependencies for the stack you want to build gt rosdep install sr_config Finally you can build the whole stack in one go using the rosmake command gt rosmake sr_config j 2 1 2 1 Available rosinstall files This step is only recommended for people who are going to be heavily modifying our stacks or for those who are not using ubuntu and thus can t use the pre built packages If you want to install all our
14. system You shouldn t use the one installed by default as they are defined for the simu lated hand To create this overlay just follow section 2 1 2 2 1 2 From sources If you need to modify one of the packages for your own use you ll want to first install the released version from the apt repository as explained in section 2 1 1 This will ensure that you have all the code you need Once you ve identified in which stack the package you want to modify is you can create an overlay to use the source version To create an overlay we ll use the rosws utility In this example we ll overlay the sr_config stack using trunk version of the code hosted on launchpad using bz1 turl http www ros org wiki fuerte Installation Ubuntu Overlay use another version of a stack than the default installed one The path to the package in the overlay will be prepended to the ROS_ PACKAGE PATH so it will be used instead of the default installed version 3url http releases ubuntu com precise turl http ros org wiki rosws Surl http launchpad net sr config Surl http bazaar canonical com wilt EtherCAT Dextrous Hand User Manual 3 2 INSTALLING OUR SOFTWARE lp sr config e First we need to install the rosws rosinstall utilities if you haven t done so already you ve probably already installed this when following the ROS wiki instructions gt sudo apt get install python rosinstall python rosdep bz
15. tactile sensors Depending on the configuration of your hand you may have different types of tactile sensors Your sensor type is automatically detected by the driver which then publishes the correct information on the tactile topic The following command will output the data coming from the sensors on the screen gt rostopic echo tactile e The fields from the Shadow PSTs are int16 pressure an array of integers containing the current pressure value for the sensors int16 temperature an array of integers containing the current temperature for the sensors e The fields from the Biotac sensors are int16 pacO first pressure AC reading this is used to detect pressure changes behaves as a differential int16 paci second pressure AC reading int16 pdc pressure DC reading this is proportional to the pressure exerted on the finger int16 tac temperature AC reading this is used to detect temperature changes behaves as a differential int16 tdc temperature DC reading this is proportional to the temperature off the sensor int16 19 electrodes the values for the electrodes of this tactile sensor gives you information on which zone is being touched on the finger 4 4 3 Sending Commands to the Hand You can easily control the different joints of the Hand each of the joint is controlled by a controller Each of those controllers has a command and a state topic The state Lt EtherCAT Dextrous Hand User Man
16. tains a timestamp set_ point the position target process_ value the current joint position process value_ dot the current joint velocity commanded _ velocity the velocity demand generated by the position con trol loop error the different between the position target and the current position time_ step the timestep between two control cycles command the torque command sent to the motor measured _ effort the torque measurement from the motor friction _ compensation value applied from the friction compensation map not used yet position p the Kp for the position PID loop position i the Ki for the position PID loop position d the Kd for the position PID loop wilt EtherCAT Dextrous Hand User Manual 11 4 RUNNING OUR CODE position i clamp the value used for clamping the I term for the position PID loop velocity _p the Kp for the velocity PID loop velocity _i the Ki for the velocity PID loop velocity __d the Kd for the velocity PID loop velocity _i_clamp the value used for clamping the I term for the velocity PID loop e For the position controller 4 4 5 header contains a timestamp set point the position target process_ value the current joint position process value dot the current joint velocity error the different between the position target and the current position time_ step the timestep between two control cycles command the torque
17. the hand 16 12 2011 rev 532 Rewrote bootloader sr_teleop 20 02 2012 rev 329 reorganising the code Created sr_teleop stack to contain packages used to teleoperate our robots sr contrib 17 02 2012 rev 328 reorganising the code Created sr_contrib stack to contain some high level packages which may be a bit less stable than the core ones found in shadow_ robot EtherCAT Dextrous Hand User Manual 15
18. ual 10 4 RUNNING OUR CODE topic prints useful debug information regarding the controllers while the command topic is used to send new targets to the controllers To identify the topic on which you want to send the target you can use the rostopic list command Let s say we want to send a target to FFJ3 gt rostopic list grep ffj3 sh_ffj3_mixed_position_velocity_ controller command sh_ffj3_mixed_position_velocity_controller state This means that we re going to publish our target on the topic sh_ffj3_mixed_position_velocity_controller command To do this we can simply use the rostopic pub command For example to send a target of 1 rad to FFJ3 at 10Hz gt rostopic pub sh_ffj3_mixed_position_velocity_controller command std_msgs Float64 r 10 1 0 To see a code example you can have a look at the package sr_ethercat_example 4 4 4 Getting information on the current state of the controllers As you can see above each controller publishes its own state topic This topic contains lots of useful information regarding the current state of the controller If you subscribe to it you ll be able to have access to the current target position error derivative etc Different informations are published depending on the type of controller that is loaded e The mixed position velocity controller a position control loop running on top of a velocity control loop information is the following header con
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