s-function cannot be linearized ?

Hi.

I have builded my dynamics on level 2 s-function.

the simulink model that include level 2 s-function cannot be linearized for PID tuner things ?

because, PID tunner not working with level 2 s-function block.

I am not sure everything now. could you give some clue to me ?

please, let me know.

Answer 1

[Siddharth Jawahar]

Hi Minjae Woo,

S-function blocks do not have analytical jacobians which are essential for linearization. That's the reason PID tuner is not able to linearize your model. As a alternate, you can use the frequnecy response estimation technique in PID tuner to get a frequency response of your system out that the PID tuner can use for tuning your gains. Please see below for documentation on:

1) Frequency response estimation with PID tuner with an example:

https://www.mathworks.com/help/slcontrol/ug/design-pid-controller-from-plant-frequency-response-data.html?s_tid=srchtitle

https://www.mathworks.com/help/slcontrol/ug/designing-pid-controller-in-simulink-with-estimated-frequency-response.html?s_tid=srchtitle

2)Understand how linearization is carried out in Simulink in Simulink Control Design:

https://www.mathworks.com/help/slcontrol/ug/exact-linearization-algorithm.html?s_tid=srchtitle

HTH,

Sid