Patent ID: 6937908

Claim:
A method for tuning a PID controller, wherein the PID controller is comprised in a closed PID control loop system, the PID control loop receiving an input, the PID controller being coupled to an object system being controlled, wherein the object system outputs process variables which is supplied for comparison to the input, wherein a result of said comparison is supplied to the PID controller, the method comprising the steps of: inducing equivalent relationships between PID gains of the PID controller and parameters of time delay control (TDC); selecting a natural frequency vector and a damping ratio vector so as to acquire a desired error dynamics of the closed PID control loop system; selecting a sampling time of the closed PID control loop system; determining the parameters of TDC on the basis of the natural frequency vector, the damping ratio vector and a closed loop stability condition for TDC; and selecting PID gains of the PID controller on the basis of the equivalent relationships.