how to write PID function in .m file

but my model is a space state model, and it has many tf. and i dont know how to connect space state form and PID controller. so could you please tell me how to use PID in m file which is not in tranfer function. thank you Arkadiy

Arkadiy Turevskiy 2012-5-17

well, how many inputs and outputs does you system have? If is a single-input-single output system, then everything shown in the demo is still applicable.If you more comfortable dealing with transfer functions, convert your state space system to a transfer function using tf:

ss_sys=ss(a,b,c,d);

tf_sys=tf(ss_sys);

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Answer 2

Krishnendu Mukherjee 2012-5-14

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38281-how-to-write-pid-function-in-m-file#answer_47734

a way is there : suppose ur tf is (1/a+s) which is to be fed to a pid controler. then the overall tf will be: (Kp+Ki/S+Kd.S).(i/S+a)/(1+(Kp+Ki/S+Kd.S).(i/S+a)). now if you want to give step input then : num=[............] den=[............] tf=num/den ster(tf) so you have to transfer the PID and the tf to a overall transfer function.

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sujan 2012-5-17

thank you,

but my model is a space state model and its has 9 state parameters. and i dont know how to use PID in my system. and it is a MIMO system. 4 inputs and 9 outputs. so could you please help me to write a PID function for space state form not in tf. thank you

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Answer 3

Daniel 2014-10-24

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38281-how-to-write-pid-function-in-m-file#answer_156449

Please where's the demo? I'm also trying to write a matlab function for pid using the user-defined function block

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Suyog 2023-5-11

How to write pid function in m file

Sam Chak 2023-5-11

Hi @sujan

You can use the pid() function directly.
You can describe that in transfer function.
You can model it using the descriptor state-space.
Finally, you can put the pid equation in the way that is similar to the ordinary differential equation (ODE).

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