We need to do discrete simulation before using Simscape.

[cnpcshangbo]

Discrete simulation needs to be done before using Simscape.

[cnpcshangbo]

This is the continuous one.

[cnpcshangbo]

Now, lets add some samplers(sample time=0.3sec) and see.

[cnpcshangbo]

From this, we know that the continuous controller doesn't work for the sample-based system. Therefore, we should do something to convert the transfer function to z transfer function.

[cnpcshangbo]

Later, I found even if I convert the transfer function to z transfer function, the control performance doesn't get better. The way to get it better is to get the sampling period smaller.

purple: Ts=0.3
blue: Ts=0.1

[cnpcshangbo]

FOPD Ts=0.1

[cnpcshangbo]

Conclusion: FOPD discretization is verified. The thing to get performance better is to use smaller Ts. We do not need to manually use c2d. The system can treat continuous tf and z tf the same.

[cnpcshangbo]

The system still has a bad behavior.

I am going to verify the z domain stability.