It is known that PID controller is used in every facet of industrial automation. The application of PID controller span from small industry to high technology industry.The aim of this paper is to design a position controller of arobot armby selection of a PID parameters using genetic algorithm. The model of a robot armis considered a third ordersystem. And this paper compares two kinds of tuning methods of parameter for PID controller. One is the controller design by the genetic algorithm, second is the controller design by the Ziegler and Nichols method. It was found that the proposed PID parameters adjustment by the genetic algorithm is better than the Ziegler & Nichols’ method. The proposed method could be applied to the higher order system also.
Keywords:Robot arm, Genetic algorithm(GA), PID controller, Ziegler-Nichols (ZN)Method.