Control System Toolbox Release Notes

Chapter 1
Control System Toolbox 5.2 Release Notes

New Features

This section summarizes the new features and enhancements introduced in the Control System Toolbox 5.2.

If you are upgrading from a release earlier than Release 12.1, then you should see New Features in the Control System Toolbox 5.1 Release Notes.

Response Plots

New features for response plots include

• Normalization of time plots for easy trend comparison
• Driving input signal shown in linear simulation (lsim) plots
• Standard zooming for all response plots
• A Full View right-click menu
• Ability to toggle magnitude and phase visibility in Bode plots
• In Bode plots, a modified phase correction algorithm that produces consistent phase at w=Inf and is robust to perturbations of the pole/zero structure at the origin
• Showing only positive frequencies in Nyquist plots
• A new function, iopzmap, that plots the transfer poles and zeros for each I/O pair in a MIMO system

LTI Viewer

The LTI Viewer no longer restricts importing models with unequal numbers of inputs and/or an unequal numbers of outputs. You can import any combination of LTI models into the viewer.

The zoom property in the LTI Viewer right-click menu has been removed. You can access this functionality from the new toolbar.

The import and export dialog boxes are now easier to use.

The LTI Viewer now seamlessly imports SISO models from the System Identification Toolbox. The noise model is automatically discarded and the IDMODEL is converted to ZPK format.

SISO Design Tool

The following are new features in the SISO Design Tool.

Additional Feedback Structures

The SISO Design Tool has support for two new feedback structures:

• Feedforward configuration
• Cascade configuration with filter F in the minor loop

All the usual functionality (e.g., graphical tuning of F and G) is available in the new feedback structures.

Analysis Menu

The SISO Design Tool contains a new Analysis menu that raises Loop Responses under Tools to the top level. New plots available from this menu are

• Input disturbance rejection
• Output disturbance rejection

Real-Time Updating of Linked LTI Viewers

LTI Viewers that are linked to the SISO Design Tool update response plots in real-time during mouse-driven compensator tuning. This is the default behavior. To deactivate this feature, clear the Real-Time Update check box in the linked LTI Viewer. In this case, plots update only when you release your mouse.

Import of System Identification Toolbox Models

The SISO Design Tool now seamlessly imports SISO models from the System Identification Toolbox. The noise model is automatically discarded and the IDMODEL is converted to ZPK format.

Reworked Store and Retrieve Windows

A new window, the Design Archive, combines both store and retrieve functions within a single, more intuitive GUI.

Nichols Plots

You can now trace the frequency by placing your mouse cursor over the Nichols contour.

Enhancements to the c2d Function

The c2d function has a new impulse-invariant discretization method that guarantees matching continuous and discrete responses for pulse inputs.

Control System Toolbox Release Notes

Major Bug Fixes