Hi Guys,

I met a question when built the simulink model.

I wanna change the munerator coefficients parameter of Transfer Fcn dynamiclly,but pop up an error,i don't know how to deal with it .

the modle is below:

pop up the error:

The attachment is the model.

**Original Attachment has been moved to: Model_1.slx.zip**

Hi Eden Li,

This has nothing to do with the modelling - it is pure math, especially control system theory :-) What are you trying to do is not accurate - you can't swap the coefficient from Laplace domain to Z-domain

First of all the H(s) is a continuous function and before calculating the Z-transform of H(s) you need to sample . What you want is to convert the H(s) -> H(z) by calculating the Z-transform of h(t) sampled of different intervals T and is know as inverse Laplace transform of H(s)

My recommendation is to read these Mathworks articles about continuous2discrete and discrete2continuous transformations.

After that you should get similar waveforms.

Hope this helps!

Best regards,

Daniel