PID Controller (Proportional-Integral-Derivative Controller)

A PID controller is a device used to automatically maintain a system at a desired state or level. It works by continuously measuring the current condition, comparing it to the target, and calculating the difference (error). The controller then applies a correction based on three parts: the proportional term (responds to current error), the integral term (accounts for past errors), and the derivative term (predicts future error). Together, these help smoothly and accurately keep the system stable and at its set point, like maintaining a steady temperature or speed.