“…Considering the limitations of the Ziegler-Nichols method and some empirical techniques in raising the performance of PID controller, recently artificial intelligence techniques such as fuzzy logic [18,21], fuzzy neural network [2,10], and some stochastic search and optimization algorithms such as simulated annealing [20], genetic algorithm [11,19], particle swarm optimization approach [4], immune algorithm [14], and ant colony optimization [6] have been applied to improve the performances of PID controllers. In these studies, it has been shown that these approaches provide good solutions in tuning the parameters of PID controllers.…”