Hi!
I am a very beginner in Octave. I need your help in the following task: I need to obtain and plot the step response of a system whose state-space matrices are known and it can be represented by xdot=A*x+B*u y=C*x+D*u For this purpose, I have written this code: /%State-space system parameters w=314.159; ki=1.5; kp=5000; A=[0 1 0 0 0 0; 0 0 1 0 0 0; 0 -4*w^2 0 0 0 0;0 0 0 0 1 0;0 0 0 0 0 1;0 0 0 0 -4*w^2 0]; B=[0 0 0 0 0 0; 0 0 0 0 0 0;0 0 -1 0 1 0;0 0 0 0 0 0;0 0 0 0 0 0;0 0 0 -1 0 1]; C=[2*(w^2)*ki 0 ki 0 ki*w 0;0 ki*w 0 2*(w^2)*ki 0 ki]; D=[1 0 -kp 0 kp 0;0 1 0 -kp 0 kp]; %Perform system simulation stname = {'xd1', 'xd2', 'xd3','xq1','xq2','xq3'}; sys = ss (A, B,C,D,'stname', stname) t=linspace(0,3,1000) [y,t,x]=step(sys) plot(t,y) / However, an error message is obtained at the console for the command plot(t,y) saying that the dimensions of one of the plot arrays are not correct. Any suggestion? Thanks -- Sent from: http://octave.1599824.n4.nabble.com/Octave-General-f1599825.html _______________________________________________ Help-octave mailing list [hidden email] https://lists.gnu.org/mailman/listinfo/help-octave |
On Tue, Jan 9, 2018 at 6:20 AM, Beginner1 <[hidden email]> wrote:
Hi! did you try step(sys) _______________________________________________ Help-octave mailing list [hidden email] https://lists.gnu.org/mailman/listinfo/help-octave |
Hi! Thank you for your answer. I have just tried your proposal but an error again appears: error: invalid use of script D:\Users\108907\step.m in index expression error: called from state at line 20 column 1 And I need also to plot the response and to add initial conditions for x and y vectors Any suggestion? De: Doug Stewart [mailto:[hidden email]]
On Tue, Jan 9, 2018 at 6:20 AM, Beginner1 <[hidden email]> wrote: Hi! did you try step(sys) DAS _______________________________________________ Help-octave mailing list [hidden email] https://lists.gnu.org/mailman/listinfo/help-octave |
On Tue, Jan 9, 2018 at 9:30 AM, Haro Larrode, Marta Emilia <[hidden email]> wrote:
I tried your code with step(sys) and it works for me. What OS are you using? What version of octave are you using? what version of control do you have? Doug
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OS: Windows 7 professional copyright 2009 Service Pack 1 Octave version:
4.2.1 Control version: control 3.0.0 Kind regards De: Doug Stewart [mailto:[hidden email]]
On Tue, Jan 9, 2018 at 9:30 AM, Haro Larrode, Marta Emilia <[hidden email]> wrote: Hi! Thank you for your answer. I have just tried your proposal but an error again appears: error: invalid use of script D:\Users\108907\step.m in index expression error: called from state at line 20 column 1 And I need also to plot the response and to add initial conditions for x and y vectors I tried your code with step(sys) and it works for me. What OS are you using? What version of octave are you using? what version of control do you have? Doug
-- DAS _______________________________________________ Help-octave mailing list [hidden email] https://lists.gnu.org/mailman/listinfo/help-octave |
On Tue, Jan 9, 2018 at 9:50 AM, Haro Larrode, Marta Emilia <[hidden email]> wrote:
does this work for you? num=10 den=poly([-2 -3+3j -3-3j]) sys=tf(num,den) step(sys)
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