Tuning of PIID controller

when I am trying to tune PID controller, I am getting an error message below, The Simulink model abc could not be linearized because the blocks listed below have individual linearizations with A, B, C, or D matrices which are not finite. Either linearize at another operating point or remove the blocks. These blocks are:

abc/Subsystem

[M]

Is A/B definite ?

[Yaser Arafat]

no these are uncertain e.g. Name: 'a' NominalValue: 5 Mode: 'PlusMinus' Range: [4 6] PlusMinus: [-1 1] Percentage: [-20 20] AutoSimplify: 'basic'

Answer 1

[Arkadiy Turevskiy]

Hi there,

The way you are trying to model uncertainty in Simulink is not supported. If you define uncertain parameters in Robust Control Toolbox using ureal, you cannot parameterize Simulink blocks with them, as you are trying to do. before you even try tuning a PID controller, try running a simulation, and you will get an error message.

If you are trying to tune a controller that would perform robustly in the presence of uncertainty, please follow the approach explained in this example .