PID torque control of DC motor

[mawad]

Dear All,
I am looking to do PID torque control on a mechanical system derived by DC motor. The system has torque sensor to measure the actual torque on the system and the motor is derived by PWM motor driver. The PWM motor driver can work in either voltage control or current control. The input to the PID control is the desired torque and I use the feedback torque to calculate the error and produce the control action to the motor driver. I am confused in this case which mode I have to use the motor driver. Is the current mode as the torque related to the current or just the normal mode which controller the PWM to provide voltage to the motor.

 

[djs]

I would use the current mode. Armature current in a shunt wound DC motor is very nearly proportional to the delivered torque.