how to get the parameters of step response?
조회 수: 6 (최근 30일)
이전 댓글 표시
hi everybody.. how can get 'num' and 'den' when i have the step response? i'm using matlab 2010. please help me.thank you.
댓글 수: 0
답변 (2개)
Ryan G
2012년 11월 27일
You can use the system identification GUI to analyze data and estimate a transfer function from that data. In this case you are using step response data so the input would be the step and the output would be the response.
댓글 수: 2
Ryan G
2012년 11월 27일
If you have a transfer function, say sys, you can obtain the num and den like this:
sys = tf(1,[1 1]); %demo transfer function
num = sys.num;
den = sys.den;
Rajiv Singh
2012년 11월 27일
To elaborate on what Ryan wrote, suppose y is the vector of step response data and Ts is the sampling time.
N = length(y);
u = [zeros(10,1); ones(N,1)];
y2 = [zeros(10,1); y];
stepdata = iddata(y,u,Ts);
model = tfest(stepdata, numpoles, numzeros); % available >=R2012a
where numpoles and numzeros are the desired number of poles and zeros for the transfer function.
[num,den] = tfdata(model); % or, simply do model.num and model.den
The zero-padding of the data was done to ensure that the step transition (0 to 1) is evident in the data.
Rajiv
댓글 수: 2
Rajiv Singh
2012년 11월 27일
[num,den] = tfdata(model), or, simply do model.num and model.den where model is the transfer function
참고 항목
카테고리
Help Center 및 File Exchange에서 Uncertainty Analysis에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!