How to program a robot manipulator with ROS2?

28 Haz 20:43

My first foray into manipulator programming with ROS2 involved trying out MoveIt2, especially for rapid prototyping on a dynamic arm. While MoveIt2 worked seamlessly with PR2 or UR series robots in ROS2, my use case was a 6DOF industrial arm, and I couldn’t escape wrestling with config files. The main headache was manually entering each joint limit into MoveIt2’s configuration files—one wrong number and the simulation would have the arm contorting into bizarre geometries. Then, when it came to dynamic planning, MoveIt2’s reliance on OMPL trapped me into offline planning instead of real-time feedback in ROS2. That pushed me toward ROS2 Control, particularly having to write controller plugins with the ros2_control package. On the real-time control side, the biggest challenge was ensuring ROS2 actually behaves deterministically at every node. The approach that worked best for me was working with ROS2 Real-Time Systems (PREEMPT_RT or ACRN) and using ros2_control’s hardware_interface layer to set up PID feedback through the JointTrajectoryController rather than communicating directly with motor drivers. But it’s worth remembering that ROS2’s default scheduler (SCHED_OTHER) falls short for systems that truly need low latency. Here, as I did, you often have to isolate certain nodes (using taskset) or use custom threads in C++. The toughest part was synchronizing servo motors with ROS2’s loop rate—on top of that, if you’re using fast protocols like CAN-FD or EtherCAT, you’ve got to minimize timer delays between them. In the end, I reduced my dependency on move_group, but I’m still fine-tuning everything to make ROS2 truly non-blocking.