Gripper Example - RethinkRobotics/sdk-docs GitHub Wiki

Gripper Control

Summary

Use gripper control as an example of controlling Baxter's grippers.

Overview

Uses the keyboard or joystick to control Baxters grippers. Position, velocity, holding, and moving force can be controlled and sensed. Both logitech and xbox game controllers are supported.

Usage

Start gripper control from an RSDK terminal session using:

$ rosrun baxter_examples gripper_keyboard.py

IMPORTANT: You will have to calibrate both grippers before using any of the other commands using C/c commands:

Once calibrated, future calibrate commands will not do anything unless you send a 'reset' first.

Key Bindings

Get a list of commands by entering '?'

Key Left Key Right
? Help Esc Quit
c left: calibrate C right: calibrate
q left: close Q right: close
w left: open W right: open
u left: decrease position U right: decrease position
i left: increase position I right: increase position
v left: decrease velocity V right: decrease velocity
b left: increase velocity B right: increase velocity
h left: decrease holding force H right: decrease holding force
j left: increase holding force J right: increase holding force
f left: decrease moving force F right: decrease moving force
g left: increase moving force G right: increase moving force
z left: decrease dead band Z right: decrease dead band
x left: increase dead band X right: increase dead band
[ left: set 100% velocity { right: set 100% velocity
] left: set 30% velocity } right: set 30% velocity
r left: reset R right: reset
s left: stop S right: stop

You can monitor the changes you are making using the following rostopics which you can monitor from a different shell:

rostopic echo /robot/end_effector/left_gripper/command

rostopic echo /robot/end_effector/right_gripper/command

Joystick Control

To use the example gripper program using a joystick game controller to control the grippers:

First ensure that joy drivers are installed.

$ rospack find joy

If not run:

$ sudo apt-get install ros-groovy-joystick-drivers

To run the example:

$ roslaunch baxter_examples gripper_joystick.launch joystick:=<joystick_type>

Where <joystick_type> is 'xbox', 'logitech', or 'ps3'.
(If using a ps3, make sure you run the node from the ROS ps3joy package in a separate sudo terminal. See instructions here: ps3joy )

Note: This method uses an included ROS launch file to start both the gripper example and joy_node using the roslaunch tool. You can exit the gripper example by hitting any keyboard key, however you will have to ctrl-c to also cleanup the joy_node.

Joystick Button Mappings

NOTE: Don't forget to calibrate each gripper first.

Press any keyboard key to quit. (And no, the 'joystick left <-> robot right' mappings are not typos; they assume the user is in front of the robot when using the joystick.)

Buttons Action Buttons Action
Function 1 or 2 (e.g. Select/Select) Help <Any Keyboard key> Quit
Top Button right: calibrate Right Button left: calibrate
Left Button right: reset Bottom Button left: reset
Left Trigger [PRESS] right: close Right Trigger [PRESS] left: close
Left Trigger [RELEASE] right: open Right Trigger [RELEASE] left: open
Left Bumper right: stop Right Bumper left: stop
Stick Axes Action
Left Stick Horizontal right: increase/decrease position
Right Stick Horizontal left: increase/decrease position
Left Stick Vertical right: increase/decrease holding force
Right Stick Vertical left: increase/decrease holding force
Directional Pad (D-Pad) Action
dPadUp right: increase velocity
dPadRight left: increase velocity
dPadLeft right: decrease velocity
dPadDown left: decrease velocity

Troubleshooting

For common issues specific to using gripper_control with Baxter, check out the Troubleshooting page.

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