Re: OCTAVE MIMO system step response

[Torsten Lilge]

On Fri, 2021-05-14 at 11:41 +0530, swagata Mukherjee wrote:
> Dear All,
> I have a MIMO system with 11 state variables, 2 input variables.
> 
> How can I plot step responses of each state variable against each
> input variable?
> 
> System definition as follows:
> A =
> 
>  Columns 1 through 10:
> 
>   -0.0361   0.0004   0.0141  -3.4872  -2.5472  -2.4402   1.7499      
>  0        0        0
>    0.0125  -0.0050   0.0771   1.2086   0.8828   0.8457  -0.6065      
>  0        0        0
>    0.0228   0.0044  -0.0963   2.2000   1.6070   1.5395  -1.1040      
>  0        0        0
>    3.5893   2.6491   2.6491  -0.0361   0.0901   1.7743   2.3880      
>  0        0        0
>   -3.5045  -2.5865  -2.5865   0.0352  -0.1233  -1.7324  -2.3315      
>  0        0        0
>   -0.0000  -0.0002  -0.0002  -0.0008  -0.0004        0        0      
>  0        0        0
>         0        0        0        0        0   1.0000        0      
>  0        0        0
>    0.1303   0.1338   0.1333   0.0869   0.0928   0.2303  -0.0278  -
> 0.2653        0        0
>         0        0        0        0        0        0        0      
>  0  -0.0037   0.0003
>         0        0        0        0        0        0        0  -
> 2.1221        0  -0.0531
>         0        0        0        0        0        0        0      
>  0        0   0.0053
> 
>  Column 11:
> 
>    0.0005
>   -0.0055
>    0.0049
>         0
>         0
>         0
>         0
>   -0.0000
>    0.0001
>         0
>   -0.0014
> 
> B =
> 
>  Columns 1 through 10:
> 
>   -1.7094   0.5924   1.0784        0        0        0        0      
>  0        0        0
>    0.5924  -6.6907   5.8880        0        0        0        0      
>  0        0        0
>    1.0784   5.8880  -7.3491        0        0        0        0      
>  0        0        0
>         0        0        0  -1.7092   1.6688        0        0      
>  0        0        0
>         0        0        0   1.6688  -2.2846        0        0      
>  0        0        0
>         0        0        0        0        0   0.0006        0      
>  0        0        0
>         0        0        0        0        0        0  -1.0000      
>  0        0        0
>    0.0593  -0.0205  -0.0374  -0.0863   0.0843        0        0  -
> 1.0000        0        0
>         0        0        0        0        0        0        0      
>  0  -1.0000        0
>         0        0        0        0        0        0        0      
>  0        0  -1.0000
>         0        0        0        0        0        0        0      
>  0        0        0
> 
>  Column 11:
> 
>         0
>         0
>         0
>         0
>         0
>         0
>         0
>         0
>         0
>         0
>   -1.0000
> Regards,
> Swagata
> 

Hi Swagata,

you can just use the step() function but you have to define your system
properly. You say that your system has 2 inputs, but then, why has your
B matrix 11 instead of only 2  columns?

step() gives you the responses from each u_i to each y_j, thus, When you
want to have the step repsonses from u_i to x_j you have to define C as
the identity matrix, i.e., C = eye(n,n) (here: n = 11). 

Best
Torsten