Control System Toolbox Function Reference

sisotool

Initialize the SISO Design Tool

Syntax

sisotool
sisotool(plant)
sisotool(plant,comp)
sisotool(views)
sisotool(views,plant,comp)
sisotool(views,plant,comp,options)

Description

When invoked without input arguments, sisotool opens a SISO Design GUI for interactive compensator design. This GUI allows you to design a single-input/single-output (SISO) compensator using root locus and Bode diagram techniques.

By default, the SISO Design Tool:

• Opens root locus and Bode diagrams.
• Places the compensator, C, in the forward path in series with the plant, P.
• Assumes the prefilter, F, and the sensor, H, are unity gains. If you want to include F and H in the design model, open the Import Model window and select the models you want to use for each. Once you specify F, P, and H, they are fixed in the feedback structure.

This picture shows the SISO Design Tool.

sisotool(plant) opens the SISO Design Tool with plant imported. If your plant is any SISO LTI object (created with ss, tf, or zpk) that exists in the MATLAB workspace, sisotool(plant) initializes a SISO Design Tool with the plant model P set to plant and initializes the plant model P to plant (any SISO LTI object).

sisotool(plant,comp) initializes both the plant model P to plant and the compenensator C to comp. Both plant and comp must be SISO LTI models.

sisotool(views) or sisotool(views,plant,comp) specifies the initial configuration of the SISO Design Tool. The argument views can be any of the following strings (or combination thereof):

• 'rlocus' -- Root Locus plot
• 'bode' -- Bode diagrams of the open-loop response

For example

        sisotool('bode')

opens a SISO Design Tool with only the Bode Diagrams on.

sisotool(plant,comp,options) allows you to override the default compensator location and feedback sign by using an extra input argument options with the following fields:

• options.Location = 'forward' -- Compensator in the forward loop
• options.Location = 'feedback' -- Compensator in the feedback loop
• options.Sign = -1 -- Negative feedback
• options.Sign = 1 -- Positive feedback

You can design compensators for one of the following two feedback loop configurations.

Figure 0-1: The SISO Design Tool Supports Two Feedback Structures.

For more details on the SISO Design Tool, see Designing Compensators in Getting Started with the Control System Toolbox.

See Also
bode        Select gain from the root locus plot

ltiview     Open an LTI Viewer

rlocus      Plot root locus

sigma

size