Optimum Design of PID Controllers using Only a Germ of Intelligence

The social foraging behaviour theories of many species provide us with consistent hints to algorithmic approaches for the design of powerful intelligent optimization technology, with direct applications in a high variety of social sciences and engineering fields. In this paper a novel design method for determining the optimal proportional-integral-derivative (PID) controller parameters based on the foraging behaviour of E. coli bacteria is proposed. Bacterial foraging (BF) scheme is selected since it represents an earlier proposal for distributed optimization and control based on natural foraging capacities. The PID controller designed using this method is called the BF-PID controller. In order to assist estimating the performance of the proposed BF-PID controller, a new time-domain performance criterion function was also introduced. To show the validity of the proposed method, two typical control systems were tested. Comparisons with the genetic algorithm (GA) are presented and discussed