Version 8.2 (R2008b) Control System Toolbox™ Software Release Notes

Version 8.2 (R2008b) Control System Toolbox Software

This table summarizes what's new in Version 8.2 (R2008b):

New features and changes introduced in this version are

• New Design Tools for Linear-Quadratic-Gaussian (LQG) Servo Controllers with Integral Action

• New Upsampling Method for Rate Conversion in Discrete-Time Models

• New Scaling Tools to Enhance the Accuracy of Computations with State-Space Models

• New Command to Reorder the States of State-Space Models

• Enhanced Support for Customizing Response Plots

New Design Tools for Linear-Quadratic-Gaussian (LQG) Servo Controllers with Integral Action

You can now design a Linear-Quadratic-Gaussian (LQG) servo controller for set-point tracking using the new lqi and lqgtrack commands. This compensator ensures that the system output tracks the reference command and rejects process disturbances and measurement noise.

For more information on forming LQG servo controllers, see Linear-Quadratic-Gaussian (LQG) Design, the lqi reference page, and the lqgtrack reference page.

Current Flag Moved from lqgreg to kalman

The 'current' flag was moved from the lqgreg function to the kalman function.

Compatibility Consideration.   The following code:

kest = kalman(sys,Qn,Rn) 
c = lqgreg(kest,k) 

now returns the current regulator instead of the delayed regulator .

To update your code to return the same results as in previous releases, use the following code with the added string 'delayed' in the kalman command:

kest = kalman(sys,Qn,Rn,'delayed') 
c = lqgreg(kest,k) 

For information on using these functions with the current flag in the kalman function, see the kalman and lqgreg reference pages.

New Upsampling Method for Rate Conversion in Discrete-Time Models

You can now upsample a discrete-time system to an integer multiple of the original sampling rate without any distortion in the time or frequency domain using the upsample command.

For more information on upsampling, see the upsample reference page and Resampling of Discrete-Time Models in the Control System Toolbox™ User's Guide.

New Scaling Tools to Enhance the Accuracy of Computations with State-Space Models

You can now scale state-space models to maximize accuracy over the frequency band of interest using the prescale command and associated GUI. Use this functionality when you cannot achieve good accuracy at all frequencies and some tradeoff is necessary. A warning alerts you when accuracy may be poor and using prescaling is recommended.

For more information on setting the frequency band for scaling state-space realizations, see Scaling State-Space Models and the prescale reference page.

New Command to Reorder the States of State-Space Models

You can now reorder the states of state-space models according to a specified permutation using the xperm command.

For more information on reordering states, see the xperm reference page.

Enhanced Support for Customizing Response Plots

You can now make the following changes to your Control System Toolbox response plots using the figure plotting tools:

• System name

• Line color

• Line style

• Line width

• Marker type

For more information on customizing the appearance of response plots using plot tools, see Customizing Response Plots Using Plot Tools in the Control System Toolbox User's Guide.

Control System Toolbox Release Notes

Version 8.1 (R2008a) Control System Toolbox Software