Building custom Franka controller for visual servoing

Question

My goal is to control the Franka Panda system in cartesian velocity coordinates using vision data that is being published within my ROS network.

I'm currently writing a custom controller as recommended in Franka ROS: https://frankaemika.github.io/docs/franka_ros.html#writing-your-own-controller

The cartesian velocity controller works well, but I have no method of subscribing to the input data since Franka ROS controllers are real-time.

What is the recommended method of achieving this? I saw somewhere that ROS controllers can host services, but this seems suboptimal. Do I have to implement a hardware interface? And if so, how I can write that to wrap a ROS subscriber?

Thanks

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Originally posted by hmccarty on ROS Answers with karma: 16 on 2022-06-25

Post score: 0

Answer 1

I ended up using the realtime_tools package to solve this. You can use a RealtimeBuffer to pass data from your non-RT thread (like a subscriber callback) to a RT thread (like your controller update function). An example is detailed in the ackermann steering controller.

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Originally posted by hmccarty with karma: 16 on 2022-06-26

This answer was ACCEPTED on the original site

Post score: 0