Inverse laplace - symbolic tool box

Hi,

I'm trying to perform inverse laplace on the transfer function but could not be able to get an answer.

I have let it run for more than 12 hours and still no results.

Can you please help here. Please find the attached file.

There was a mistake in earlier attached file.

Answer 1

[Dimitris Kalogiros]

I had a look at your file.

The definition of the laplace transform A contains a syntax error. It has an extra "=" without meaning. So, first of all you must correct it.

A second issue is that, for such a complicated function of "s", it is extremelly difficult an inverse laplace transorm to be found. I suggest to give values at your parameters before the calling of the ilaplace() function.

[Jochen Baier]

Hi,

Thanks for the answer!

Yes, just saw the syntax, it occured while copying the transfer function. But when I ran the calculation it was ok.

I simplified the transfer function and assigned values to the variables. Still the result is not good. Part of the calculation is still in s-domain.

Also, I do not understand the result.

[Dimitris Kalogiros]

So, is this your transfer function ?

[Dimitris Kalogiros]

By the way, I suggest to upload the file which contains some values for the parameters.

[Jochen Baier]

Yes, BTW 's' is not the subscript

[Jochen Baier]

Please find the attached. You will find more details

[Walter Roberson]

Zc=(Rpc/((s*C*Rpc)+1))+(s*Lc)+Rsc);

has bad )

Perhaps you meant

Zc=(Rpc/((s*C*Rpc)+1)+(s*Lc)+Rsc);

If so then the iplace(tf) is calculated quickly. It does, however, involve the sum of 5 roots of a quintic, and that is something that has no closed form solution in "algebraic numbers"

[Jochen Baier]

Thanks for the explanation. I'll reduce the order and see.