I'm supposed to plot (x1 vs x2) for a system. (Dynamics and Controls)
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
I have a system in state space model x'=Ax where A = [0 1; -14 -4]. The system quation is x(t) = e^At*x(0) where given x(0) is [-0.2; 0.2] Now I'm supposed to solve for x(t) which gives a matrix [x1(t);x2(t)] and plot the graph of the elements x1(t) vs x2(t) which is also known as Phase portrait. I believe its a simple code but I'm going wrong somewhere. Can you help me where and what's wrong? Any help is appreciated. Thank you!
A=[0 1;-14 -4];
t=linspace(0,10,300);
x=zeros(2,300);
matA = zeros(2,2,300);
x0 = [-0.2;0.2];
for k=1:300, matA(:,k) = expm(A*t(k)); x(:,k) = matA(:,k)*x0;end;
plot(x(:,1),x(:,2))
0 commentaires
Réponse acceptée
Star Strider
le 13 Nov 2014
You’re almost there. You did everything correctly, but you need a ‘C’ output matrix (part of the ‘ABCD’ matrices in a state space system). I added one I considered appropriate to your problem, and since this creates ‘x’ as a (2x300) array, I changed the plot references to reflect that:
A=[0 1;-14 -4];
t=linspace(0,10,300);
x=zeros(2,300);
matA = zeros(2,2,300);
x0 = [-0.2;0.2];
C = [1 0; 0 1];
for k=1:300,
matA(:,:,k) = expm(A*t(k));
x(:,k) = C*matA(:,:,k)*x0;
end
figure(1)
plot(x(1,:),x(2,:))
grid
The plot looks as a phase space plot should!
4 commentaires
Star Strider
le 13 Nov 2014
My pleasure!
Have fun in your controls course, and take as many others as you can!
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Get Started with Control System Toolbox dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!