Too many output arguments. Requested 3 output(s), but only 1 output(s) available.

function cost_value=cost_func(k,plotfig)
ke=k(1,1);
kce=k(1,2);
ku=k(1,3);
X=k(1,4);
z_a=abs(k(1,5));
v_a=abs(k(1,6));
% negative big
NB=-X;
% negative medium
NM=-X/2;
% positive medium
PM=X/2;
% positive big
PB=X;
Z=0;
% Compute function value
opt = simset('solver','ode23tb','SrcWorkspace','Current');
[tout,xout,yout] = sim('ACO_TS.slx',[0 0.5],opt);
% compute the fitness value
z1=sqrt(mean(rmse)); % rms error
z2=(mean(iae)); % integral absolute error
z3=(mean(itae)); % integral time multiplied absolute error
z4=(mean(ise));
cost_value=z1+z2+z3+z4+mean(thd1);

Error using cost_func

Too many output arguments. Requested 3 output(s), but only 1 output(s) available.

Error in ACO (line 58)

cost(A)=cost_func(tour_selected_param,0); - Show complete stack trace

[Sam Chak]

Hi @Sahithi Kandhukuri

The block diagram looks like a Fuzzy PD plus fixed Integral controller. Are you trying find the gain values of ke, kce and ku using Ant Colony Optimizer (or any other optimization algorithm) that minimizes the overkill cost function of combined vectored square error (incorrectly labelled as rmse), ISE, IAE, and ITAE?

Is the system (plant) linear or nonlinear?

[Sahithi Kandhukuri]

Yes I m trying to implement ant colony optimization technique for fuzzy logic that Is to be used in shunt active filter for UPQC.

[Sam Chak]

Have you resolved the issue? Can you find the optimal gain values?

[Sahithi Kandhukuri]

No the issue is not yet resolved. I am unable to find optimal gain values.

[Sam Chak]

Hi @Sahithi Kandhukuri

Can you count the number of output(s) available in your Simulink model? Perhaps you requested these three outputs (in individual vectored data form) from the Simulink model in the cost_func() function, but it's possible that you consolidated all the data into a single simulation output object named 'out', as pointed out by @Walter Roberson.

If you are unfamiliar with the object-oriented programming (the dot notation stuff), then better configure the Simulink model to log the requested data as tout, xout, yout, rmse (incorrect!), ise, iae, and itae.

Answer 1

[madhan ravi]

You expect three outputs to be returned from sim() whereas only one output can be returned from sim() command

https://in.mathworks.com/help/simulink/slref/sim.html#bvfe92n-3

[madhan ravi]

So just change your code to

 Simout = sim('ACO_TS.slx',[0 0.5],opt);
 % compute the fitness value
 z1=sqrt(mean(out.rmse)); % rms error
 z2=(mean(out.iae)); % integral absolute error
 z3=(mean(out.itae)); % integral time multiplied absolute error
 z4=(mean(out.ise));

[Sahithi Kandhukuri]

Unable to resolve the name 'out.rmse'.

Error in cost_func (line 23)

z1=sqrt(mean(out.rmse)); % rms error

Error in ACO (line 58)

cost(A)=cost_func(tour_selected_param,0);

getting this error

[Sam Chak]

@Sahithi Kandhukuri, it appears that you have decided to retain the Simulink.SimulationOutput object (Simout), which is perfectly fine.

Just out of curiosity, what is the exact purpose of calculating the mean values of cumulative ISE, cumulative IAE, and cumulative ITAE?

Additionally, what impact does minimizing the summation of these mean values (z1, z2, z3, z4) have on the fuzzy controller's gain?

[madhan ravi]

In the screenshot you share ACO.m doesn’t seem to invoke cost_func() but the error shows it’s being invoked at line 58. If you want the problem to be debugged , please provide the necessary files to replicate your error.

As per out.rmse is concerned make sure the the To Workspace block parameter Save format is Array.

[Sahithi Kandhukuri]

These are the related links and program I used

[madhan ravi]

change this

Simout = sim('ACO_TS.slx',[0 0.5],opt);

to

out = sim('ACO_TS.slx',[0 0.5],opt);

Here's a simple example i created for you to understand:

a = 1;
b = 1;
V = func_cost(x, b)
function x = func_cost(a, b)
out = sim('Trial.slx');
x = a + b + out.tt;
end

x =

     1


b =

     1


Simout = 

  Simulink.SimulationOutput:

                   tout: [51x1 double] 
                     tt: [51x1 double] 

     SimulationMetadata: [1x1 Simulink.SimulationMetadata] 
           ErrorMessage: [0x0 char] 


ans =

    2.0000
    2.1987
    2.3894
    2.5646
    2.7174
    2.8415
    2.9320
    2.9854
    2.9996
    2.9738
    2.9093
    2.8085
    2.6755
    2.5155
    2.3350
    2.1411
    1.9416
    1.7445
    1.5575
    1.3881
    1.2432
    1.1284
    1.0484
    1.0063
    1.0038
    1.0411
    1.1165
    1.2272
    1.3687
    1.5354
    1.7206
    1.9169
    2.1165
    2.3115
    2.4941
    2.6570
    2.7937
    2.8987
    2.9679
    2.9985
    2.9894
    2.9407
    2.8546
    2.7344
    2.5849
    2.4121
    2.2229
    2.0248
    1.8257
    1.6335
    1.4560

[Sahithi Kandhukuri]

[madhan ravi]

Ofcourse, you didn’t define that variable thd1. Attach your code as .m file.

[Sahithi Kandhukuri]

[madhan ravi]

and now all the errors are gone

[Sahithi Kandhukuri]

yeah thank you for your support but the expected output should be as shown below.

[madhan ravi]

Sorry my goal was to clear all the errors as stated in your original question. Regarding the correctness of your question , it"s better you post a new question.

[Sahithi Kandhukuri]

Ok @madhan ravi thank you so much for your support

Answer 2

[Walter Roberson]

I suspect that your model has been configured to return a single output;

https://www.mathworks.com/help/simulink/gui/singlesimulationoutput.html