Strange noises and barely noticable jerky movement when using test_controller.py

[MyGodItsFull0fStars]

Hello!

I recently connected my workstation to a real Panda robot and tested moving the robot.

Here some details about my setup:

• ROS melodic
• Python 2.7.17
• ros-melodic-libfranka version: 0.8.0-1bionic.20201017.031455
• ros-melodic-franka-ros version: 0.7.1-1bionic.20210304.174422

The movement works as expected using the libfranka executables such as communication_test.

But when I use the franka_ros_interface/franka_ros_controllers/scripts/test_controller.py file the robot starts to make some weird noises similar to old HDD drives reading input and has barely noticeable jerky movement. This behavior is also present when using the joint_positions_keyboard.py file.

Beforehand I started the interface.launch file using the command: roslaunch franka_interface interface.launch load_demo_planning_scene:=false start_moveit:=false

If you need further information please let me know.

Kind Regards, Christian

[justagist]

Hi, Yes, this happens for me as well, and it is because (as far as I can tell) the trajectory is not smooth enough. I found these effects can be reduced by smoothening the trajectory further, or providing trajectory points that are more dense (subsequent points close to each other), or even changing the control rate. I would suggest using the impedance controller instead if you want to command positions (comment out line 50 and uncomment line 49), or use torque or velocity controllers.

[MyGodItsFull0fStars]

Hi, I will try your suggestions and will inform you if and what fixes the issue with the Panda robot.

Thanks for the quick reply!