give arbitrary, unknown and in-real-time input value to transfer function

Hi,

I am writing a control system program and I have a function to get an input value from external hardware. This value need to be operated by my transfer function in real time and then I can get a output value. Here is the problem, I dont know the input value beforehand. There is a function close, lsim . But the input argument u of the function lsim request an exact matrix which is confirmed and known beforehand. All I can do is collecting the input values, but I dont know the next. So, how can i do to accomplish? Is there any matlab function I can use to solve this problem? Help me please! I have been annoyed for many days!

Millions of thanks.

April 11, 2016

I have a stupid and rude idea taday. To collect the input value in an array. Then it is operated by function lsim. I will get the final value of the output array as my output value, and give it to my external hardware.But I think this is not efficient.

I have a stupid idea again. When I collect the input value to the array, I delete the earliest value from the array and keep this array short. And then use lsim to get the final value as output value.

But I think there is a simple and smart way to accomplish it. I need your help.

Or is there someone who can amend lsimplot.m or lsim.m for my problem? Thanks so much.

I found something, Simulink® Real-Time™. It seems that simulink can probably solve my problem. But I dont want to use simulink now if possible.

Answer 1

[Walter Roberson]

u should be the data values read in at real time.

Are you trying to create a symbolic transfer function?

[wilson hoo]

You mean get the inverse Laplace transform of the symbolic transfer function by matlab? The function ilaplace is only used in MuPAD. I have thought about it but not tried yet.

[Walter Roberson]

ilaplace is available through the MATLAB interface to MuPAD.