How to write a system to PID

Question

Kevin Tran 2020-5-17

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/526171-how-to-write-a-system-to-pid

回答： Nikhil Sonavane 2020-5-20

Hi guys,

I'm currently in a course in control engineering and still pretty new on the whole subject. I got this system: y''+25y'+25y=u

The problem is I want to make a PID where I can change the parameters Kp, TI and TD. I know how to write the system into matlab with ode45:

[T2,Y2]=ode45(@diffeq2,[0 10],[0;0]);
plot(T2,Y2)
function dy = diffeq2(t,y)
    
if t < 0
 u = 0;
else
 u = 1;
end
dy = zeros(2,1);
dy(1) = y(2);
dy(2) = u - 10*y(2) - 25*y(1);
end

but I have no idea how to change the script so I can change the parameters Kp, TI and TD for example to Kp=1 TI=0.1 and TD=0.2 to get a better step response like my professor did. He didn't show how to do it just that with those parameters you will get a better step response and then he showed the graph but no script on how to do it. I have searched everywhere and watched several videos for hours without understanding anything. So my last resort is asking the matlab community for help.

Thanks in advance if you can help me!