changing Kp value in a loop for PID tuning

Hello Everyone can someone help me with this error :

The following error occurred converting from pid to double:

Conversion to double from pid is not possible.

 Kp = 1;
 for i=1:3
     C(:,:,i)= pid(Kp);
     Kp = Kp + 10;
 end

Thank you all

Answer 1

[Fangjun Jiang]

pidsys=pid(1) creats a PID controller. pidsys is an object with the class of 'pid'. You can run class(pidsys) or get(pidsys) to find out.

You seem to assign a PID controller to a numerical array C with double data type. That is the error message.