How to give input from sensor to pid in matlab (mfile)

I am trying to implement the system in matlab(mfile)which I have uploaded at:

http://tinypic.com/view.php?pic=2w33slt&s=6.

My system has two portions Image processing(sensor) & control systems. The piece of code is:

clear,close

%your model and its input output

mot=tf(1,[1  1]),

model=ss(mot);

[F,h,c,d]=ssdata(model);

%your pid controller

r=pid(5,1/0.05,10)

sys.inputname='u'

sys.outputname='y'

Ci.inputname='e';

Ci.outputname='u';

som1 = sumblk('e = r - y');

%global model with all conneection

modelg=connect(som1,r,model,'r','y')

%simulation

step(modelg)

Above code is the model representing the PID then statespace and then its output as feedback but I have to give input from my sensor(image processing part e.g 3) and compare it with my reference value. I need to know where that input value will be adjusted in this code. Any guidance would be highly appreciated.

Answer 1

[Arkadiy Turevskiy]

Your code does not make sense at the moment. Specific issues:

1. You define input and output names for variables sys and Ci, as if they are meant to represent a plant and the controller, but your plant is stored in variable mot, and your controller is in variable r
2. You use function connect in the wrong way - please see documentation on the input arguments and their right order

The correct code would be:

clear,close
%your model and its input output
mot=tf(1,[1  1]);
mot.inputname='u';
mot.outputname='y';
%your pid controller
r=pid(5,1/0.05,10);
r.inputname='e';
r.outputname='u';
% summation junction
som1 = sumblk('e = r - y');
%global model with all conneection
modelg=connect(mot,r,som1,'r','y');
%simulation
step(modelg);

% another way to do the same
step(feedback(r*mot,1));

Arkadiy

[Beenish Mazhar]

It was a certain typing mistake. My code is: clear,close

%your model and its input output

mot=tf(1,[1 1]),

Ci=pid(5,1/0.05,10)

[ne,de]=tfdata(mot,'v');

[A,B,C,D]=tf2ss(ne,de);

inputs = {'u'};

output = {'y'};

sys = ss(A,B,C,D,'inputname',inputs,'outputname',output);

sys.inputname='u';

sys.outputname='y';

Ci.inputname='e';

Ci.outputname='u';

%adding a reference r with som2=r-y

som1 = sumblk('e','r','y','+-');

%global model with all connection

modelg=connect(sys,Ci,som1,'r','y')

I have to add the value taken from sensor as mentioned above. How to adjust that in the above code.