PID control help

[gpetilli]

Originally Posted by notmattlythgoe

Would this be better or more efficient than having your motor1, and a motor2 that just uses a positional PID controller and the setpoint is always the position of motor1?

Yes. If motor2 is only a slave to motor1, then motor2 will not move until a sufficient error in position has occurred (due to a change in command to motor1).

What Ether suggested is basically to send the same command to both motors simultaneously, and use the Integrated error between the positions to fine tune motor2. The Integrated error has high DC gain but slow "step response".

The settled response for both systems should be similar, but the match while changing position should be much better with Ether's system.