Automatic Tuning of PID Controllers for MIMO Processes

Abstract

Abstract In this paper, an automatic tuning method of PID controllers for MIMO processes is proposed. The tuning method consists of three steps. In the first, discrete sets of gain and phase of the process are identified by using of the adaptive identification method of a critical point, in the second step, the discrete sets are transformed into the parametric models, and rough decouplers are calculated. In the third step, rough decouplers are added to the process and an augmented plant is constructed. By applying the adaptive identification method of a critical point to the augmented plant, the critical point is identified for the augmented plant. PID control parameters for augmented plant are calculated by using the Ziegler-Nichols method. This method can easily be extended to any number of loops, and be applicable for automatic tuning of PID controllers with rough decouplers for MIMO processes. The efficiency of this method is shown through some simulation results.