Decentralized pid controller design for a MIMO evaporator based on colonial competitive algorithm

Recently, Colonial Competitive Algorithm (CCA) has proven its superior capabilities, such as faster convergence and better global minimum achievement in optimization problems. In this paper, CCA is utilized to optimize the coefficients of a decentralized PID controller for a MIMO evaporator system. The optimization criterion is considered as the Integral Absolute Error (IAE) to minimize the tracking error. As the first step, the evaporator's three input-three output transfer matrix is identified using measured dataset based on the prediction error model method. In order to design decentralize controllers, input-output pairing is performed based on the relative Gain Array method. Decentralized PID controllers are then designed using Ziegler-Nichols, Genetic Algorithm, and the proposed CCA techniques. The simulation results verify the superiority of CCA to the Ziegler-Nichols and Genetic Algorithm tuning techniques for decentralized PID controllers.