Intergral time absolute error minimization for PI controller on coupled-tank liquid level control system based in stochastic search echniques

Abstract

This paper introduces the application of a stochastic search technique, known as Simulated Annealing to the problem of tuning the proportional–integral controller for a linearized coupled tank liquid level control. After describing the basic principles of the Simulated Annealing, the proposed method concentrates on finding the optimal solution of PI controller by optimizing the performance index, the Integral Time Absolute Error, ITAE. The efficiency of Simulated Annealing algorithm for tuning the controller is compared with an evolutionary method, Genetic Algorithm. The comparison is based on the time response performance. The results shows the effectiveness and the capability of the SA to tune the proportional–integral (PI) controller for the coupled tank liquid level control. The proposed method does not depend on the system order and has the ability to tune the controller even there is unknown process parameters. In addition, the technique avoids the requirement for mathematical modeling of the system and the overall results have shown that SA yields better performance as compared to GA, hence, it is recommended for an alternative for optimizing the PI controller.