Simulink Control Design™ - MathWorks

Linearization Troubleshooting Overview

If you do not get expected results when you linearize your Simulink model, you can

diagnose and fix potential linearization issues using Simulink Control Design

troubleshooting tools. The definition of an expected linearization result depends on your

specific application.

Troubleshooting Workflow

To determine whether a linearization is successful and find potential linearization issues,

first check the equations and response plots of the linearized model.

Result to Check Signs of Successful

Linearization

Signs of Unsuccessful

Linearization

More Information

Linear analysis

plots

Time-domain and frequency-

domain response plot

characteristics, such as rise

time and bandwidth

respectively, capture the

expected dynamics of your

system.

Response plot

characteristics do not

capture the dynamics of

your system. For example:

• Bode plot gain is too
  large or too small.


• Pole-zero plot contains
  unexpected poles or
  zeros.

“Analyze Results

Using Linear

Analysis Tool

Response Plots” on

page 2-151.

Linear model

equations

• State-space matrices have
  expected number of
  states, inputs, and
  outputs. The linearized
  model can have fewer
  states than your Simulink
  model because, often, the
  path between linearization
  input and output points
  does not reach all the
  model states.


• Poles and zeros are in
  correct locations.
  
  
  • Zero linearization (D =
    0 )
  
  
  • Infinite linearization (D
    = Inf)
  
  
  
  

“View Linearized

Model Equations

Using Linear

Analysis Tool” on

page 2-149

4 Troubleshooting Linearization Results