Matlab R13 vs Labview v 7.1

[Adham Atallah]

Hello guys

I have some problems solved previously with MATLAB need to be solved
with labview using the new Control Design Toolbox.

A really simple problem appeared while using the Transfer function to
State space model conversion VI because the results appear totally
different from those in matlab.

The main problem is when u use SS to TF VI and feed it back to TF to
SS VI u don't get the same result.

I examined the SS to TF VI and i think the problem is cause with a
stability matrix T where it is multiplied to the matrices A,B,C and D
which are correctly computed in the first step of the VI.

If any body have any information on this topic. Please respond.

Thank you

[BrandonS]

There is no set procedure for how these transformations should occur. Each systems response should be the same despite the different transformations used in converting from a transfer-function to a state-space model.

It appears that Matlab will return the state space system in controller companion form. You can use the "CD Canonical State-Space Realization VI" to convert from the form returned from the "CD Convert to State-Space Model VI" to the controller companion form you are observing in Matlab. You just have to specify �Controller Companion� as the form type.

I will attach my VI and M file for comparison.