PID controller
Summary
PID controller is a classic feedback control mechanism used in industry to regulate a process variable by combining proportional, integral, and derivative actions. The article covers fundamental operation, different forms (standard and parallel), tuning methods (manual, Ziegler–Nichols, Cohen–Coon, Åström–Hägglund, SIMC), and practical considerations such as windup and derivative filtering, along with historical origins from early control theory.