AUTOMATIC TUNING OF PID CONTROLLER USING 2ND-ORDER PLUS TIME DELAY MODEL

A new identification method using the second order plus time delay mod el for the automatic tuning of the PID controller and a simple and exp licit tuning method are proposed, We present a relay feedback test com bined with a P controller to identify the process using the second ord er plus time delay model, Thus, the difficulty to determine the initia l proportional gain is overcome. Since the proposed identification met hod uses the second order plus time delay model to identify the prodes s, it can incorporate more various processes such as underdamped and h igh order processes than the identification method using the first ord er plus time delay model, In addition, a simple and explicit tuning re lation for the second order plus time delay model is proposed in this paper. This tuning relation shows almost the same performance as the o ptimal tuning parameters, The proposed method needs no numerical techn ique and shows good performances in both simulation and experimental s tudy.