Before you can use the PID Tuner, you must:
Create a Simulink® model containing a PID Controller or PID Controller (2DOF) block. Your model can have one or more PID blocks, but you can only tune one PID block at a time.
If you are tuning a multi-loop control system with coupling between the loops, consider using other Simulink Control Design™ tools instead of the PID Tuner. See Design and Analysis of Control Systems and Cascaded Multi-Loop/Multi-Compensator Feedback Design for more information.
The PID Controller blocks support vector signals. However, using the PID Tuner requires scalar signals at the block inputs. That is, the PID block must represent a single PID controller.
Your plant (all blocks in the control loop other than the controller) can be linear or nonlinear. The plant can also be of any order, and have any time delays.
Configure the PID block settings, such as controller type, controller form, time domain, sample time. See the PID Controller or PID Controller (2DOF) block reference pages for more information about configuring these settings.
To open the PID Tuner and view the initial compensator design:
Open the Simulink model by typing the model name at the MATLAB® command prompt.
Double-click the PID Controller block to open the block dialog box.
In the block dialog box, click Tune to launch the PID Tuner.
When you open the PID Tuner, the following actions occur:
The PID Tuner automatically linearizes the plant at the operating point specified by the model initial conditions, as described in What Plant Does the PID Tuner See?. If you want to design a controller for a different operating point, see Tune at a Different Operating Point.
Note: If the plant model in the PID loop linearizes to zero, the PID Tuner provides the Obtain plant model dialog box. This dialog box allows you to obtain a new plant model by either:
The PID Tuner computes an initial compensator design for the linearized plant model using the algorithm described in PID Tuning Algorithm.
The PID Tuner displays the closed-loop step reference tracking response for the initial compensator design in the PID Tuner dialog box. For comparison, the display also includes the closed-loop response for the gains specified in the PID Controller block, if that closed loop is stable, as shown in the following figure.
Tip After the tuner opens, you can close the PID Controller block dialog box.