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ros-industrial / ros_canopen

CANopen driver framework for ROS (http://wiki.ros.org/ros_canopen)
GNU Lesser General Public License v3.0
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Mode Switch timeout is too short for some drives #457

Open aatb-ch opened 2 years ago

aatb-ch commented 2 years ago

I have successfully setup canopen_motor_node on a Festo CMMP-AS drive, took me a while to get all parameters corrects by following various Q&As and issues, but the last nagging thing turned out to be a vendor-specific behavior:

When switching to Profile Position mode, no problem, it instantly switches mode, but I need Interpolated Position with a Joint Trajectory Controller, and it seemingly has been starting or crashing randomly. I read through all the Festo docs and once all params are set correctly and mode switch 7 is asked the drive returns mode -1 while it goes through a synchronization phase, after which it will return mode 7.

It just so happens that this phase takes between 3 to 6 seconds, randomly varying at each mode switch. The timeout for mode switching is hardcoded at 5s, I recompiled from source by setting it to 20s and the drive will switch to mode 7 every single time.

https://github.com/ros-industrial/ros_canopen/blob/e10f4905c6b773f8f31f99b900665a69a6a7678a/canopen_402/src/motor.cpp#L333

Maybe would be good to have this as a YAML parameter for the motor layer? I would happily try to get a PR going but my C++ skills are not the sharpest.. I could give it a try though.

aatb-ch commented 2 years ago

I have read further the sources to check something else, and fell on this line:

https://github.com/ros-industrial/ros_canopen/blob/e10f4905c6b773f8f31f99b900665a69a6a7678a/canopen_402/include/canopen_402/motor.h#L299

This is specific to state switching, I should be able to use this template to add a second timeout parameter for mode switching.