Contact Decomposition Controller

Contents

• About
• Docker Container Installation
• Run Examples
• Troubleshooting
• Contributing
• License
• Contact

About

The crisp_contact_decomposition repository extends the CRISP ROS2 controllers to a task-space hybrid control formulation that decomposes SE(3) into independant pose-controlled and wrench-controlled subspaces, allowing for simultaneous position and force control in real time. This controller is compatible with ROS2, and is experimentally verified on hardware via the Franka Research 3 manipulator arm.

All work supported by the Hybrid Intelligent Experimental Robotics Lab at North Carolina State University. Visit the HIER Lab website.

Features

• An exposed selection_vector interface and correspondingly modified crisp_py publisher for control over task-force decomposition
• Slight performance enhancements to the original cartesian_controller

Run Examples

Franka arm operational space control

This demonstration is a direct application of the CRISP OSC controller and a good starting point for verifying everything works correctly.

After installing the docker container:

1. Ensure FCI is enabled We recommend running the communication_test before running the example for the first time.

   communication_test <robot-ip>

2. Start the controllers In a seperate terminal, start the CRISP cartesian controller and franka gripper node

   cd /ros2_ws/ && source install/setup.bash
   export ROBOT_IP=<your robot ip address>
   ros2 launch contact_decomp_demos franka.launch.py robot_ip:=$ROBOT_IP & ros2 launch franka_gripper gripper.launch.py robot_ip:=$ROBOT_IP

   In the future, these will likely be launched from the same file. The gripper launch configuration will depend on the specific gripper connected to the arm.

3. Run the operational space control demo In the original terminal (with .venv activated), run the demo.

   cd /ros2_ws/src/contact_decomp_demos/examples/
   python3 01_figure_eight_osc.py

Troubleshooting

libfranka issues

If you encounter libfranka issues, it is recommended to set up this package in isolation to verify it works independantly of this project. Please refer to the libfranka installation instructions

A real-time kernel is essential to ensure proper communication and to prevent timeout issues. For guidance on setting up a real-time kernel, please refer to the Franka installation documentation.

Contributing

Contributions are welcome! Please fork this repository and create a pull request with your changes.

License

All packages of crisp_contact_decomposition are licensed under the Apache 2.0 license.

Contact

For questions or support, please open an issue on the GitHub Issues page.

Or, contact me at dmalexa5@ncsu.edu.