DETECTING PERIODIC PART OF A SIGNAL

HEY.I HAVE A COMPLEX SIGNAL. I WANT TO DETECT IF THIS SIGNAL HAS PERIODIC PART.OF COURSE IT MIGHT HAS MORE THAN 1. I JUST NEED THE FIRST PERIODIC PART.THE OTHERS ARE NOT NECESSARY. BUT HOW CAN I DO THAT? PLEASE HELP.

I don't think I can implement it. I attached a image. You can see my model and my scope output. I want to determine the output signal period(when it is periodic). It's a pid autotune implement.

[Image Analyst]

Duplicate of http://www.mathworks.com/matlabcentral/answers/165831-how-can-i-determine-transfer-function-osilation-period

Answer 1

[mehmet celik]

this is more spesific about my problem. I added a graph and output. I deleted the other one. Thank for your answer but its not applicable for this structure. Pls help :(

Answer 2

[mehmet celik]

is there anybody here to answer this basic question?

Answer 3

[mehmet celik]

pls helpp :(