How to import a transfer function from workspace into simulink?

Hi guys, I have a problem when I want to use the "from workspace" block in simulink to bring data to simulink, actually I wanted to bring a transfer function from workspace to simulink, not data, and I see that this block just have output port in, not any input , so I can not connect this block from input to another block. How can I bring transfer function from mfile to simulink ?

Any help will be appreciated.

Thank you

Answer 1

[Sebastian Johansson]

A late answer:

Use the Lti-system block from the control system toolbox. Then just enter the name of your transfer function.

[shizhao zhang]

This is a more elegant implementation.

Answer 2

[Jesús Zambrano]

Hi Azam,

One possible solution is:

1. Create a transfer function in the workscape: for example, type in the command window

F = tf([2],[1 1 1]);

2. In your Simulink model, use a block called "Transfer Fcn" and do double-click on it.

3. In 'Numerator coefficients' write:

F.Numerator{1,1}

4. In 'Denominator coefficients' write:

F.Denominator{1,1}

With this your 'Transfer Fcn' block will have the numerator and denominator coefficients of the trasnfer function you created in the workspace. You can put step 1 in a script, execute it, and the 'Transfer Fcn' block will read the coefficients from the workspace.

Hope this solution is what you are looking for!

Best,

Jesús