ROS2 Interface for the CCA Planner

This repository provides robot-agnostic ROS2 packages that interface the Closed-Chain Affordance(CCA) planner with robotic systems. The CCA planner offers an intuitive approach to planning joint trajectories for robot manipulation tasks that can be thought of as linear, rotational, or screw motions. Defining a task is as simple as specifying an axis, location, and pitch (if applicable). Additionally, it provides the capability to control the end-effector's orientation along the task path.

Core Dependencies

• affordance_util and cc_affordance_planner packages from the Closed-Chain Affordance repository

Optional Dependencies

• moveit: For self-collision checking
• moveit_visual_tools: For visualization of joint movement
• behaviortree_cpp: To utilize the CCA Behavior Tree action node

Build Instructions

1. Clone the packages into your ROS2 workspace's src folder:

   cd ~/<ros_workspace_name>/src
   git clone [email protected]:UTNuclearRoboticsPublic/closed_chain_affordance_ros.git

2. Build and source the workspace:

   cd ~/<ros_workspace_name>
   colcon build --cmake-args -DCMAKE_BUILD_TYPE=Release
   source install/setup.bash

Readily-Supported Robots

An additional cca_<robot> package containing robot-specific information is required to launch the planner for a particular robot. Packages are currently available for the following robots, with links provided below. Creating a package for a new robot is straightforward and largely automated, as discussed in the Implementing the Framework on a New Robot section.

• Boston Dynamics Spot robot
• Kinova Gen3 7DoF arm

Rviz CCA Planning Plugin

A user-friendly Rviz plugin is also available and enables visual trajectory planning and execution by simply dragging interactive markers and specifying task types and goals. Launch instructions are provided in the Interactive Rviz Plugin Planning section.

Implementing the Framework on a New Robot

Creating the cca_<robot> Package

1. Use the package creator script:

   cd ~/<ros_workspace_name>/src/closed_chain_affordance_ros
   ./cca_robot_package_creator.sh

2. Configure the generated package:

   • Complete cca_<robot>_description.yaml and cca_<robot>_ros_setup.yaml in the config folder
   • For programmatic trajectory planning and execution, implement task (affordance) details in cca_<robot>_node.cpp

3. Build the new package:

   cd ~/<ros_workspace_name>
   colcon build --packages-select cca_<robot>
   source install/setup.bash

Running the Planner

Prerequisites

• For trajectory execution, ensure a follow_joint_trajectory action server is running on the robot

Programmatic Trajectory Planning

1. Launch trajectory visualization server:

   ros2 launch cca_<robot> cca_<robot>_viz.launch.py

2. Run the planner for defined tasks:

   ros2 launch cca_<robot> cca_<robot>.launch.py

Interactive Rviz Plugin Planning

1. Start the CCA ROS action server:

   ros2 launch cca_<robot> cca_<robot>_action_server.launch.py

2. Launch Rviz with the interactive planning plugin:

   ros2 launch cca_<robot> cca_<robot>_viz.launch.py

Author

Janak Panthi (aka Crasun Jans)