Design PID Controller from Plant Frequency-Response
Data
Most Simulink Control Design PID tuning tools design PID gains based on a linearized
plant model. When your plant model does not linearize or linearizes to zero, one option is
to design a PID controller based on simulated frequency-response data. Simulink Control
Design gives you several ways to do so.Use Frequency Response Based PID Tuner
Use Frequency Response Based PID Tuner to design a PID controller using estimated
plant frequency responses near the target open-loop bandwidth. Advantages of this
approach include:- Frequency Response Based PID Tuner works even if disturbances are present in
the plant model. - You can configure the estimation and tuning in one dialog box, making tuning less
complex than using frestimate or Linear Analysis Tool to estimate the frequency
response.
For more information about using Frequency Response Based PID Tuner, see
“Frequency-Response Based Tuning” on page 7-51.Use frestimate or Linear Analysis Tool
Use the frestimate command or the frequency-response estimation workflow in Linear
Analysis Tool to estimate the plant frequency response over a range of frequencies that
you specify. This approach results in a frequency-response data (frd) model object that
you then import into PID Tuner. Advantages of this approach include:- You do not have to specify a control bandwidth ahead of time. PID Tuner chooses an
initial control bandwidth, which you can adjust to achieve the desired balance between
performance and robustness. - You can use the interactive tuning and analysis tools of PID Tuner to examine the
estimated linear response of the tuned system in the frequency domain. Also, you can
use the frd model of the plant for other analysis tasks. - Depending on the particulars of your model, this approach can be faster, because
Frequency Response Based PID Tuner simulates your model twice.
Design PID Controller from Plant Frequency-Response Data