Filter coefficient (N) in PID block?
显示 更早的评论
Good evening folks!
While tuning my quadrotor model in Matlab I found that the Matlab PID function had a Filter coefficient (N) term in the PID equation. However I have not encountered such a term in my typical PID programs. How would one implement this term into the PID equation and what would be some simple C code to add this term into the derivative? I tried generating C code from my model but got a lot of header and C program files with nothing close to simple.
My current PID code line in C is:
U2 = KP * phi_error + KI * phi_errorsum + KD * (PHI_RATE_desired-PHI_RATE);
Many Thanks, Robert
采纳的回答
Arkadiy Turevskiy
2013-3-12
The code would look like that.
FilterCoefficient = (Kd * u - Filter_DSTATE) * N;
y = (Kp * u + Integrator_DSTATE) + FilterCoefficient;
Integrator_DSTATE += Ki * u * 0.01;
Filter_DSTATE += 0.01 * FilterCoefficient;
HTH.
Arkadiy
4 个评论
Arkadiy Turevskiy
2013-3-13
0.01 is the sampling time I specified in the block before generating code. You can set the sampling time to whatever you want and the code will of course be updated accordingly.
Marzieh Hosseini
2021-5-6
Hi,
Is it the same code if I want to implement PID in Matlab code, while I am controlling a device directly with Matlab and I got real time information in my Matlab?
Andre Elliot
2023-5-15
Hi what are u, N, y and the meaning of DSTATE? nice day.
更多回答（4 个）
Shashank Prasanna
2013-2-17
2 个投票
Hi Robert, this link should give you a better idea of what N means:
If you have Simulink Control Design toolbox, then you can use the built in pidtune functionality to tune the PID.
1 个评论
Brian Candiloro
2023-1-13
Can this filter term be realized in a physical opamp differentiator circuit or only in code?
Robert
2013-2-21
0 个投票
1 个评论
Seng Tak Goh
2019-3-11
Hi Robert,
In essence, the filtered derivative is doing a first order filtering on the change of the inputs, scaled by D gain.
The 1/s integrates the previous output scaled by N term, then adding the input change scaled by D * N to produce the output.
If you multiply the D term of the continuous form by s, you will see it better how the filtering comes into play.
In discrete form:
y[n] = D*N*(u[n]-u[n-1]) + (1-N*Ts)*y[n-1];
类别
在 帮助中心 和 File Exchange 中查找有关 PID Controller Tuning 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
