How to constrain genetic algorithm input u?
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My real system (buck converter) can only take an input of 0 to 1 (duty ratio) and I need to constrain the system so the controller action does not go past this. How can I do this?
The code for the project is below, it is steve bruntons genetic algorithm coding. https://youtu.be/S5C_z1nVaSg?t=470
I assume the u variable is the duty ratio but I am not sure.
---------------------------------------------------- First live script with Ga cmd in it-------------------------------------
clear all, close all, clc
dt = 0.000001; % this is 10^-6
PopSize = 30 % was 500
MaxGenerations = 10; %was 1000
s = tf('s');
G = (1439928003.68621)/(s*s+5333.33333333333*s+95995200.2457475) % got this by doing feedback cmd
options = optimoptions(@ga,'PopulationSize',PopSize,'MaxGenerations',MaxGenerations,'OutputFcn',@myfun);
[x,fval] = ga(@(K)pidtest(G,dt,K),3,-eye(3),zeros(3,1),[],[],[],[],[],options);
function J = pidtest(G,dt,parms)
-----------------------------------------------in adjacent live script------------------------------------------------
s = tf('s');
K = parms(1)+ parms(2)/s + parms(3)*s/(1+0.000001*s)% this is 10^-6
Loop = series(K,G);
ClosedLoop = feedback(Loop,1);
t = 0:dt:0.05; % this indicates length of time to show
[y,t] = step(ClosedLoop,t);
CTRLtf = K/(1+K*G);
u = lsim(K,1-y,t); % not sure if this is what I should change
Q = [1]; % Q weighting (couldn't get it so it looked at inductor current also) effecfts response of system?
R = 0.005; % R weighting effects controller action
J = dt*sum(Q*(1-y(:)).^2 + R*u(:).^2) % LQR is my cost function
step(5*ClosedLoop,t)
h = findobj(gcf,'type','line');
set(h,'linewidth',2);
drawnow
---------------------------------------------------------------------------------------------------------------------------------
Thanks in advance, if anymore information is desired please ask away.
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