How to properly excite state-space models with time-delay using step-function?
4 views (last 30 days)
Show older comments
Hi,
I have constructed the following state-space presentation with a time-delay:
C = pid(1,0.1);
G = tf(2.5,[105 1],'InputDelay',5);
sys = feedback(ss(G),C);
step(sys);
The result is decaying to zero, however the steady state value for a unit step input should be 1 for the given system? Am I missing something here?
Best regards, Aapo Keskimölö
0 Comments
Accepted Answer
Azzi Abdelmalek
on 15 Sep 2013
Now I get it, your C PID should be in series with your model G and the feedback is the constant 1
sys=feedback(G*C,1)
step(sys)
0 Comments
More Answers (2)
Azzi Abdelmalek
on 15 Sep 2013
% I do not know how feedback function works. I can create feedback by connecting my models and signals use connect function
C = pid(1,0.1);
C.u = 'e'; % system C input
C.y = 'u'; % system C output
G = tf(2.5,[105 1],'InputDelay',5);
G.u = 'u'; % system G input
G.y = 'y'; % system G output
%-----create sum e=r-y, r is the step signal and y is your output
somme = sumblk('e = r - y');
%---------connect system+PID+input r + output y-------------------
sys = connect(G,C,somme,'r','y');
%-----------------------------------------------------------------
step(sys)
0 Comments
See Also
Categories
Find more on Dynamic System Models in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!