Abstract: “This paper proposes the application of multi-objective genetic algorithm for optimizing the response of the PID controller for a three tank liquid level system. Liquid level system is a large-lag, time varying and non-linear system and finds a wide application in food processing, iron and steel, industrial chemical processing and other industries and the quality of control directly affects the quality of products and safety of equipments. Optimizing the response helps in maintaining the level set point at certain desired and be able to accept new set points dynamically. By optimizing the PID controller and comparing the results obtained by conventional methods like Ziegler-Nichols; multi-objective genetic algorithm has a vanguard advantage in satisfying the performance criterion.”

Keywords: PID Controllers, Controller Tuning, MultiObjective Genetic Algorithm , Ziegler-Nichols, Three Tank Liquid Level System.