Tuning of the PID control gains by GA

PID controller has been extensively used in the industrial world. But in this controller it is difficult to tune the PID gains. We apply the genetic algorithm (GA) to tune the PID gains. The GA is an optimization algorithm using the biotic genetics. First, the GA encodes a solution's candidate of the problem to a string. There are few ways of encoding: one of the most popular ways is a binary encoding (bit string), because it is simpler to operate and prove the GA than the other encoding methods. In this study, we propose an alternative method which is based on a real number string to use the PID controller. The method described is compared with a usual bit string method by simulations.