Control System Toolbox™ 8.1

Latest Features

Version 8.1

Released: 01 Mar 2008
 

Version 8.1, part of Release 2008a, includes minor enhancements. See the Release Notes for details.

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Version 8.0.1

Released: 01 Sep 2007
 

Version 8.0.1, part of Release 2007b, includes bug fixes. See the Release Notes for details.

Version 8.0

Released: 01 Mar 2007
 

Version 8.0, part of Release 2007a, includes the following enhancements:

• New LTI infrastructure for efficient modeling and simulation of arbitrary linear systems with delays
• Ability to close any number of feedback loops with delays
• Exact analysis and simulation of control systems with long delays
• New Tustin and Prewarp options for d2d function
• New automated tuning methods in SISO Design Tool, including automated PID tuning and H-infinity loop shaping (requires Robust Control Toolbox)

See the Release Notes for details.

Version 7.1

Released: 01 Sep 2006
 

Version 7.1, part of Release 2006b, includes the following enhancements:

• SISO Design Tool supports two new feedback structures:
  • Internal model control structure
  • Multiloop cascade configuration

See the Release Notes for details.

Version 7.0

Released: 01 Mar 2006
 

Version 7.0, part of Release 2006a, includes the following enhancements:

• Full support for descriptor state-space models with singular E matrix (PID, improper models, and linearized DAEs)
• New commands for calculating time-domain performance metrics such as rise time, settling time, and overshoot
• Full support for LSIM and INITIAL simulations in the LTI Viewer
• Simplified, name-based scheme for connecting models with CONNECT, FEEDBACK, SERIES, PARALLEL, and LFT
• True state-space representation of MIMO transfer functions with I/O delays
• New LTI methods and operators (LTI/EXP, FRD/FCAT, FRD/FSELECT, FRD/FNORM, and SS/GETDELAYMODEL)
• Numerous improvements to the performance and robustness of the numerical engine
• Support for multiloop compensator design in the SISO Design Tool
• Automated tuning of compensators in the SISO Design Tool using PID, IMC, and LQG design methods
• SISO Design Tool support for optimization-based compensator design subject to time- and frequency-domain requirements (with the Simulink Response Optimization Toolbox; required, available separately)
• Support for compensator design in Simulink via the SISO Design Tool (with the Simulink Control Design; required, available separately)

See the Release Notes for details.

Version 6.2.1

Released: 01 Sep 2005
 

Version 6.2.1, part of Release 14 with Service Pack 3, includes minor enhancements. See the Release Notes for details.

Version 6.2

Released: 07 Mar 2005
 

New Command-Line Interface for Customizing Response Plot Options

The new command-line interface lets you generate plots with pre-specified response plot units, labels, limits, and other plot options, and modify the options after the plot is generated.

New and Upgraded SISO Design Tool Constraints

The SISO Design Tool now includes:

• New gain/phase exclusion regions for Nichols plots
• Improved linear constraints for root-locus and Bode plots
• All design constraints displayed as shaded regions

New Bode and Nichols Plot Options

When editing Bode and Nichols plots, you can now:

• Manually set the lower limit of the magnitude
• Adjust the phase offsets by multiples of 360 degrees to facilitate comparing multiple responses

New Commands for Model Approximation and Order Reduction

• The new function hsvd computes and plots the Hankel singular values
• The new function balred computes low-order approximations using a numerically-stable, balancing-free algorithm and offers the capability to perform multiple approximations with a single command

For additional details, see the Release Notes.

Version 6.1

Released: 22 Sep 2004
 

Known Problems and Corrections

Version 6.1 corrects the following software problems:

• The toolbox plots executed improperly after being compiled by the MATLAB Compiler.
• The toolbox calculated the wrong closed-loop system gain for SISOTool prefilter configurations that included an improper compensator. The product now calculates the closed-loop system gain correctly.

Version 6

Released: 02 Jun 2004
 

Upgraded numerical engine now uses the LAPACK and SLICOT libraries for faster and more accurate computations

These upgrades improve the efficiency and accuracy of the following calculations:

• Computing the transfer function or zero/pole/gain representation of state-space models
• Computing system zeros
• Solving Lyapunov and Riccati equations
• Performing model order reduction with balreal and modred functions

New and Upgraded Functions

• The new function stabsep separates the stable and unstable modes of a system.
• The new function modsep performs model decompositions in n-arbitrary regions.
• The upgraded function balreal now handles unstable and marginally stable models.

Known Problems and Corrections

Version 6.0 corrects the following software problems:

• The LTI Viewer improperly set the frequency range when converting frequency units.
• The function allmargin failed to detect phase crossings for some discrete models with poles near z=1.
• The function sigma produced empty plots for MIMO systems with decoupling between I/O pairs.
• The function rlocus produced incorrect plots for improper systems.