Introduction to Model-Based PID Tuning in Simulink
You can use PID Tuner to for interactive tuning of PID gains in a Simulink model
containing a PID Controller, Discrete PID Controller, PID Controller (2DOF), or Discrete
PID Controller (2DOF) block. PID Tuner allows you to achieve a good balance between
performance and robustness for either one-degree-of-freedom or two-degree-of-freedom
PID controllers. When you use PID Tuner, it:- Automatically computes a linear model of the plant in your model. PID Tuner
considers the plant to be the combination of all blocks between the PID controller
output and input. Thus, the plant includes all blocks in the control loop, other than the
controller itself. See “What Plant Does PID Tuner See?” on page 7-4. - Automatically computes an initial PID design with a balance between performance and
robustness. PID Tuner bases the initial design upon the open-loop frequency response
of the linearized plant. See “PID Tuning Algorithm” on page 7-4. - Provides tools and response plots to help you interactively refine the performance of
the PID controller to meet your design requirements. See “Open PID Tuner” on page
7-6.
For plants that do not linearize or that linearize to zero, there are several alternatives for
obtaining a plant model for tuning. These alternatives include:- “Design PID Controller from Plant Frequency-Response Data” on page 7-49 — Use
the frequency-response estimation command frestimate or the Frequency Response
Based PID Tuner to obtain estimated frequency responses of the plant by simulation. - “Interactively Estimate Plant from Measured or Simulated Response Data” on page 7-
73 — If you have System Identification Toolbox, you can use PID Tuner to estimate
the parameters of a linear plant model based on time-domain response data. PID
Tuner then tunes a PID controller for the resulting estimated model. The response
data can be either measured from your real-world system, or obtained by simulating
your Simulink® model.
You can use PID Tuner to design one-degree-of-freedom or two-degree-of-freedom PID
controllers. You can often achieve both good setpoint tracking and good disturbance
rejection using a one-degree-of-freedom PID controller. However, depending upon the
dynamics in your model, using a one-degree-of-freedom PID controller can require a
tradeoff between setpoint tracking and disturbance rejection. In such cases, if you need
both good setpoint tracking and good disturbance rejection, use a two-degree-of-freedom
PID Controller.Introduction to Model-Based PID Tuning in Simulink