Simulink Control Design™ - MathWorks

Single Loop Feedback/Prefilter Compensator Design

This example shows how to tune multiple compensators (feedback and prefilter) to

control a single loop using Control System Designer.

Open the Model

Open the engine speed control model and take a few moments to explore it.

open_system('scdspeedctrl')

Design Overview

This example introduces the process of designing a single-loop control system with both

feedback and prefilter compensators. The goal of the design is to:

• Track the reference signal from a Simulink step block scdspeedctrl/Speed
  Reference. The design requirement is to have a settling time of under 5 seconds and
  zero steady-state error to the step reference input.


• Reject an unmeasured output disturbance specified in the subsystem scdspeedctrl/
  External Disturbance. The design requirement is to reduce the peak deviation to
  190 RPM and to have zero steady-state error for a step disturbance input.

In this example, the stabilization of the feedback loop and the rejection of the output

disturbance are achieved by designing the PID compensator scdspeedctrl/PID

Controller. The prefilter scdspeedctrl/Reference Filter is used to tune the

response of the feedback system to changes in the reference tracking.

9 Classical Control Design