Simulink Control Design™ - MathWorks

PID Tuning for Setpoint Tracking vs. Disturbance

Rejection

This example uses systune to explore trade-offs between setpoint tracking and

disturbance rejection when tuning PID controllers.

PID Tuning Trade-Offs

When tuning 1-DOF PID controllers, it is often impossible to achieve good tracking and

fast disturbance rejection at the same time. Assuming the control bandwidth is fixed,

faster disturbance rejection requires more gain inside the bandwidth, which can only be

achieved by increasing the slope near the crossover frequency. Because a larger slope

means a smaller phase margin, this typically comes at the expense of more overshoot in

the response to setpoint changes.

Figure 1: Trade-off in 1-DOF PID Tuning.

This example uses systune to explore this trade-off and find the right compromise for

your application. See also pidtool for a more direct way to make such trade-off (see

"Design Focus" under Controller Options).

PID Tuning for Setpoint Tracking vs. Disturbance Rejection