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The P, I and D Terms

A PID controller combines three effects that each solve a problem: the P term gives a fast response proportional to the error, the I term integrates the error over time and removes steady-state error, and the D term reacts to how fast the error is changing and damps overshoot. Good control is about balancing the three against each other.

C(s)=Kp+Kis+KdsC(s)=K_p+\dfrac{K_i}{s}+K_dsideal PID controller

Symbols

KpK_pproportional gain
KiK_iintegral gain
KdK_dderivative gain

Example

Kp=3K_p=3, Ti=0.5T_i=0.5 s:

Ki=Kp/Ti=3/0.5=6K_i=K_p/T_i=3/0.5=6.

More KpK_p gives a faster response but more overshoot – add an I term instead to remove steady-state error.
Practise pID control for free →

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Part of Control Engineering: PID control.