PIDParameter

PIDParameter is a data construct used to configure a proportional-integral-derivative (PID) controller. It typically comprises three gain coefficients: Kp (proportional), Ki (integral), and Kd (derivative). In many software libraries, PIDParameter may also include tuning constants such as a sampling period Ts, a derivative filter coefficient N, and anti-windup limits. The PID controller uses these gains to compute the control signal u(t) = Kp e(t) + Ki ∫ e(τ) dτ + Kd de/dt, where e(t) is the error between setpoint and process variable. In discrete implementations, integrator sums over samples and the derivative term uses a finite difference with Ts.

Practically, the parameter set governs the controller’s response: gains determine speed, overshoot, and stability. Inappropriate values can cause oscillations or sluggish behavior. Gains are usually tuned with methods such as Ziegler–Nichols, Cohen–Coon, IMC, or through manual trial-and-error, aiming to satisfy criteria like settling time, overshoot, and steady-state error. Some implementations also support anti-windup strategies or output saturation to prevent integral windup.

Representations vary by language: PIDParameter may be a simple struct or class with fields Kp, Ki, Kd, Ts, N, and optional bounds or flags. It is used in control-loop modules across domains such as process control, robotics, and automation to separate controller configuration from the control logic.

See also: PID controller, control systems, tuning methods.