Why is Model Linearizer producing incorrect results with single data types in MATLAB R2021b?

When using Simulink Control Design with a Simulink Model in R2021b, if the data type of a constant input source for a model is set as "single", the integrator part is ignored and the results from Model Linearizer are completely incorrect. Is this a Simulink limitation or is there a setting I need to change for the discrete-time integrator?

Answer 1

[MathWorks Support Team]

This is a known issue with the Discrete Integrator block. The Discrete Integrator's Jacobian is what is used by Model Linearizer to produce the results, but this Jacobian is currently producing incorrect results for "single" data types.

This issue has been fixed in the release of MATLAB R2022b. However, the fix is not currently available for prior releases. Please use "double" precision data types as a workaround if you are constrained to use earlier releases. The links below provide some guidance on how to do so.

 

Linearize Blocks with Non-Floating-Point Data Types:

https://www.mathworks.com/help/releases/R2021b/slcontrol/ug/linearize-blocks-with-non-floating-point-signals-or-states.html

Data Type Override:

https://www.mathworks.com/help/releases/R2021b/simulink/ug/control-fixed-point-instrumentation-and-data-type-override.html