DC Motor Control Report By Mohawk College

Non-Technical Report Summary

1. Setpoint Control

The PID controller results showed that it has a 56% overshoot value, versus edeX which had an overshoot value of 0%. In addition, the PID control system had a settling time of ≈ 1.6 seconds after going through an oscillation phase, whereas edeX was 146% faster.

edeX therefore had a smoother response.

2. Torque Disturbance

A torque disturbance was applied after the motor had reached a steady-state (constant) speed. When the torque was applied, edeX controlled motors dropped 11% less below the setpoint than PID controlled motors. edeX was able to recover the motor speed  ≈ 0.3 sec faster than the PID. When the applied torque was removed, edeX increased the motor speeds by ≈ 42% over the setpoint and then reached a steady state in ≈ 0.7 sec, whereas the PID motors increased speed by 56% over the setpoint and took ≈ 1.5 sec to reach a steady state. This means edeX recovers 114% faster, or in less than half the time compared to the PID.

Using edeX the motors had a faster recovery time both when the torque was applied and removed, and edeX had a lower overshoot than the PID. This means that motors are more stable using edeX.

Technical Report Summary

1. Setpoint Control

The PID controller results showed that the rise time for the motor speed signal is ≈ 0.125 sec with a 56% overshoot value. In addition, the PID control system had a settling time of ≈ 1.6 seconds after going through an oscillation phase.

edeX- FLC results showed that the rise time for the motor speed signal is ≈ 0.6 sec, a settling time of ≈ 0.65 sec, a 0% overshoot. Given, the selected performance criteria, PID had a faster (37% faster) risetime when compared to the FLC system; however, the FLC outperformed the PID controller from the overshoot perspective since there was zero overshoot; and from a settling time perspective the FLC system was 146% faster than the PID controller system.

It can be seen that, although the PID controller presented a faster rise time, it also presented oscillations and a longer settling time than the smoother response of the FLC controller.

2. Torque Disturbance

Using the PID controller, the torque disturbance was applied after the motor had reached a steady-state (constant) speed. When the torque was applied, the PID output increased to compensate for the speed loss in the motor, which initially caused the motor speed to drop by 39% of the step set-point. The PID controller was able to recover the motor speed in ≈ 1.1 sec and then continue with slight oscillations, likely due to the small torque variations. When the applied torque was removed, the motor speed increases by 56% of the set-point, followed by oscillations and reaching steady state after ≈ 1.5 sec.

Using edeX-FLC, the torque disturbance was also applied after the motor had reached a steady-state (constant) speed. The edeX-FLC output increased to compensate for the lost motor speed, which dropped by 27% below the set-point. The edeX-FLC controller recovered the motor speed in ≈ 0.82 sec after the torque was applied. When the applied torque was removed, the motor speed increased by ≈ 42% of the setpoint and then reached a steady state in ≈ 0.7 sec after the torque was removed, without any oscillations.

It can be seen that edeX-FLC presented a faster recovery time when the torque was applied and removed, as well as having a lower overshoot than the PID controller.