Background for questions below: I am using Python to communicate and control the motors. I am sending the SM commands (e.g., MP, PT, ADT, etc.) to the serial port with Python. My application is to have humans interact (push/pull) on levers connected to the motors. The motors will be used to apply dynamic forces based on the human response.
A few questions I have regarding the programming of the motors:
1. Can you suggest a way to set a velocity limit while in torque mode (MT)? As mentioned, I am working in Python, so I can do anything in terms of program logic and flow on that side. Right now I am thinking to monitor the velocity of the motor and either reduce torque if velocity exceeds a threshold. I'm assuming my limitation might be with motor response time for a command coming from PC. That is, the time it takes for Python to send T=0 and the motor torque to go to 0. I plan to test this using position mode at first.
2. I need to do closed-loop torque control. From my understanding of SM commands, I will need to set up a custom PID controller in Python that commands controller output (T) to the motor as it is . I noticed that the SM Guide says that the motor current variable (UIA) "should not be assumed it is directly related to torque." What would you recommend using to get the torque proportional current for the motor? Is it possible?
3. How much of a concern is back driving the motor? I saw this mentioned briefly in the Dev Guide, and was wondering how concerned I should be about the consequences. It will not happen a lot in my applied, but it could happen a few times if I am not very careful.