# help with code system response state space

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## help with code system response state space

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## Re: help with code system response state space

 On Tue, Jan 9, 2018 at 6:20 AM, Beginner1 wrote: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 did you try step(sys) DAS _______________________________________________ Help-octave mailing list [hidden email] https://lists.gnu.org/mailman/listinfo/help-octave
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## RE: help with code system response state space

 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]] Enviado el: martes, 09 de enero de 2018 15:23 Para: Haro Larrode, Marta Emilia CC: Help GNU Octave Asunto: Re: help with code system response state space       On Tue, Jan 9, 2018 at 6:20 AM, Beginner1 <[hidden email]> wrote: 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   did you try    step(sys)   DAS   _______________________________________________ Help-octave mailing list [hidden email] https://lists.gnu.org/mailman/listinfo/help-octave
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## Re: help with code system response state space

 On Tue, Jan 9, 2018 at 9:30 AM, Haro Larrode, Marta Emilia 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   Any suggestion?     De: Doug Stewart [mailto:[hidden email]] Enviado el: martes, 09 de enero de 2018 15:23 Para: Haro Larrode, Marta Emilia CC: Help GNU Octave Asunto: Re: help with code system response state space       On Tue, Jan 9, 2018 at 6:20 AM, Beginner1 <[hidden email]> wrote: 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   did you try    step(sys)   DAS   -- DAS _______________________________________________ Help-octave mailing list [hidden email] https://lists.gnu.org/mailman/listinfo/help-octave