AUTOTUNING OF PID CONTROLLER BY MEANS OF HUMAN MACHINE INTERFACE DEVICE

More and more control systems are based on industry microprocessors like PLC controllers (Programmable Logic Controller). The most commonly used control algorithm is PID (Proportional-Integral-Derivative) algorithm. Autotuning procedure is not available in every PLC. These controllers are typically used in cooperation with HMI (Human Machine Interface) devices. In the study two procedures of autotuning of the PID controller were implemented in the HMI device: step method and relay method. Six tuning rules for step methods and one for relay method were chosen. The autotuning procedures on simulated controlled object and PLC controller without build-in autotuning were tested. The object of control was first order system plus time delay