error of "Too many input arguments." in my program of PSO- PI controller program

i m getting "Too many input arguments. " error while i am running the program for finding the optimum parameter values of fractional PI controller program.

[Walter Roberson]

Are you using https://www.mathworks.com/matlabcentral/fileexchange/60874-fotf-toolbox for fotf, or are you using https://www.mathworks.com/matlabcentral/fileexchange/66323-fomcon-toolbox-for-matlab for fotf, or something else?

[Anupam Ghosh]

Walter Roberson. I am using https://www.mathworks.com/matlabcentral/fileexchange/60874-fotf-toolbox for fotf.

[Walter Roberson]

That was the one I used to debug your code to point out that you used feedback inconsistently.

[Anupam Ghosh]

i didn't get your point, please elaborate suggest me a solution.

[Walter Roberson]

I used that same code for foft when I was debugging your program. By using that same code as you are using, I was able to locate the line in your code

e=1-step(feedback(plant*cont,1,t))

which tries to invoke feedback with three input arguments -- first plant*cont, then 1, then t.

However, feedback() is not defined to accept three input arguments.

About three lines earlier in the code you had

step(feedback(plant*cont,1));

which invoked feedback() with only two input arguments -- first plant*cost, then 1.

What was your intended difference in results between invoking

feedback(plant*cont,1)

or invoking

feedback(plant*cont,1,t)

? What did you expect different to happen when you passed in t as well as the other two arguments?

[Anupam Ghosh]

step(feedback(plant*cont,1),t)

I have corrected the line to the above. but now when i run my program it is giving a new error saying "In the expression "M^K", the exponent K must be a scalar integer."

please suggest a solution.

[Walter Roberson]

You create

s = tf('s')

and you have

cont=Kp+(Ki/(s)^L);

which tries to raise s to the exponent stored in L .

When you are using transfer functions, the exponent you use with ^ has to be a finite integer.

In your first call to havas to deal with the initial conditions, you used round() to ensure that all of the inputs were integers. However, when you are later looping and updating your x variables, you do not take any care to ensure that x(3) is a positive integer.

Answer 1

[Walter Roberson]

In the line

e=1-step(feedback(plant*cont,1,t))

You are invoking feedback() with three input arguments. feedback() is only expecting two input arguments.

Just a few lines earlier you had invoked

step(feedback(plant*cont,1));

which uses it with two input arguments.