Simulink Control Design™ - MathWorks

Choosing Exact Linearization Versus Frequency Response

Estimation

In most cases, to obtain a linear approximation of a Simulink model, you should use exact

linearization instead of frequency response estimation.

Exact linearization:

• Is faster because it does not require simulation of the Simulink model.


• Returns a parametric state-space model.

Frequency response estimation returns frequency response data. To create a transfer

function or a state-space model from the resulting frequency response data, you must

fit a model to the data using System Identification Toolbox™ software.

Use frequency response estimation:

• To validate exact linearization accuracy. For more information, see “Validate
  Linearization In Frequency Domain” on page 2-145.


• When your Simulink model contains discontinuities or non-periodic event-based
  dynamics.


• To study the impact of amplitude size on frequency response. For more information,
  see “Describing Function Analysis of Nonlinear Simulink Models” on page 5-101.

Linearization Using Simulink Control Design Versus Simulink

How is Simulink linmod different from Simulink Control Design functionality for

linearizing nonlinear models?

Although both Simulink Control Design and Simulink linmod perform block-by-block

linearization, Simulink Control Design functionality is enhanced by a more flexible user

interface and Control System Toolbox™ numerical algorithms.

Simulink Control Design

Linearization

Simulink Linearization

Graphical-user interface Yes. See “Linearize Simulink

Model at Model Operating Point”

on page 2-74.

No

2 Linearization