[QUESTION] Application of model-based controllers

[Mlahoud]

I am interested into applying model-based (MPC, computed torque, passivity based) controllers into the flexiv_rdk. However, from the Flexiv RDK Manual I can only find that the non linear dynamics are compensated. Is this something that is feasible using the RDK?

Thank you in advance for your help!

[pzhu-flexiv]

@Mlahoud Hi, it should be feasible if you use the RT_JOINT_TORQUE control mode.

[Mlahoud]

Hi @pzhu-flexiv Thank you very much for your reply. Just to make sure I understand correctly, when using the RT_JOINT_TORQUE mode, are the internal gravity, friction, and other dynamic compensations still active? Or is it possible to send raw torque commands without these compensations applied? If the compensations are active, is there any way to disable them or access the compensation values through the RDK? I really appreciate your time and guidance as I try to better understand the low-level control possibilities with the Flexiv robot.

[pzhu-flexiv]

Hi @Mlahoud, You can only disable gravity compensation when using RT_JOINT_TORQUE mode, the other nonlinear dynamics compensation are still active, including frictional, centrifugal and Coriolis torques. You can get centrifugal and Coriolis torques through rdk::Model API, but the frictional torques are not available to the users because its compensated directly in the high-frequency embedded system instead of in the software.

[Mlahoud]

Hi @pzhu-flexiv Thanks a lot for your help, I can close this issue. Have a great day!