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Model Reduction

Model order reduction, low-order approximation, pole-zero cancellation

Working with lower-order models can simplify analysis and control design. Simpler models are also easier to understand and manipulate than high-order models. High-order models obtained by linearizing complex Simulink® models, interconnecting model elements, or other sources can contain states that do not contribute much to the dynamics of particular interest to your application. Use the Model Reducer app or functions such as balred and minreal to reduce model order while preserving model characteristics that are important for your application.

For more information about ways to reduce model order, see Model Reduction Basics.

Apps

Model Reducer Reduce complexity of linear time-invariant (LTI) models

Functions

balred Model order reduction
balredOptions Create option set for model order reduction
balreal Gramian-based input/output balancing of state-space realizations
minreal Minimal realization or pole-zero cancelation
sminreal Structural pole/zero cancellations
modred Eliminate states from state-space models
freqsep Slow-fast decomposition
freqsepOptions Options for slow-fast decomposition
hsvd Hankel singular values of dynamic system
hsvplot Plot Hankel singular values and return plot handle
hsvdOptions Create option set for computing Hankel singular values and input/output balancing

Topics

Model Reduction Basics

Model-order reduction can simplify analysis and control design by providing simpler models that are easier to understand and manipulate.

Reduce Model Order Using the Model Reducer App

This example shows how to reduce model order while preserving important dynamics using the Model Reducer app.

Balanced Truncation Model Reduction

Compute lower-order approximations of higher-order models using the balanced truncation reduction method in the Model Reducer app or at the command line.

Pole-Zero Simplification

Pole-zero simplification reduces the order of your model exactly by canceling pole-zero pairs or eliminating states that have no effect on the overall model response.

Mode-Selection Model Reduction

Model selection eliminates poles that fall outside a specific frequency range of interest.

Visualize Reduced-Order Models in the Model Reducer App

The plotting tools in the Model Reducer app let you examine and compare time-domain and frequency-domain responses of the original model and the reduced models you create in the app.

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