tappan-at-git / ros_control_boilerplate

Provides a simple simulation interface and template for setting up a hardware interface for ros_control

ros_control Boilerplate

Provides a simple simulation interface and template for setting up a hardware interface for ros_control. The idea is you take this as a starting point for creating your hardware interfaces, and it is needed because ros_control documentation is sparse. This boilerplate demonstrates:

• Creating a hardware_interface for multiple joints for use with ros_control
• Position Trajectory Controller
• Control of 2 joints of the simple robot "RRBot" pictured below
• Loading configurations with roslaunch and yaml files
• Generating a random trajectory and sending it over an actionlib interface
• Partial support of joint mode switching (but this feature has not been release with ros_control)
• Visualization in Rviz

Developed by Dave Coleman at the University of Colorado Boulder

Video Demo

See YouTube for a very modest video demo.

Install

This package depends on gazebo_ros_demos for its rrbot_description package, so be sure to git clone that along with this package and build in your catkin workspace.

Run Demo

This package is setup to run the "RRBot" two joint revolute-revolute robot demo. To run its ros_control hardware interface, run:

roslaunch ros_control_boilerplate rrbot_hardware.launch

To visualize its published /tf coordinate transforms in Rviz run:

roslaunch ros_control_boilerplate rrbot_visualize.launch

To send a random, dummy trajectory to execute, run:

roslaunch ros_control_boilerplate rrbot_test_trajectory.launch

Customize

To test this as a simulation interface for your robot:

• Rename all files in /launch to use your robot name
• Find-replace all strings in /launch from "rrbot" to your robot name
• Customize /config/rrbot_controllers.yaml to have joints corresponding to your robot's URDF

To test this as a hardware interface for your robot, you'll also want to rename the files in /src and find-replace the string "generic" to your robot's name. Then add the necessary code to communicate with your robot via USB/serial/ethernet/etc. Feel free to PR this package with better step by step instructions for this.

Setting an Initial Position, Using with MoveIt!

If you need your robot to startup at a particular position in simulation, or you would like to use this funcitonality to simulate your robot with MoveIt!, see the downstream package (it depends on this package) moveit_sim_controller

Other Helper Tools - Recording to CSV

Write to file

rosrun ros_control_boilerplate controller_state_to_csv SAVE_TO_FILE_PATH CONTROLLER_STATE_TOPIC TIME_TO_RECORD

Read from file

rosrun ros_control_boilerplate csv_to_controller READ_FROM_FILE_PATH CONTROLLER_STATE_TOPIC TIME_TO_RECORD

Limitations

• Does not implement joint limits, estops, transmissions, or other fancy new features of ros_contorl
• Does not have any hard realtime code, this depends largely on your platform, kernel, OS, etc
• Only position control is fully implemented, though some code is in place for velocity and effort control

Contribute

Please add features, make corrections, and address the limitations above, thanks!