Abstract: In the conventional methods it is difficult to select the right PID parameters in the initial stage, and these parameters need to be fine tune when the system is running. The main objective of this paper is to test the performance of the developed bacterial foraging leaning by particle swarm optimization algorithm PID controller tuning. Attempt has been made to realize globally minimal error squared error integral criteria in the step response of a process that is cascaded with PID controller by tuning the Kp proportional gain, Ki integral gain and Kd differential gain values. Generally, the selection of the controller coefficients is implemented by approximate methods, which in turn will not guarantee globally optimal solution for control applications. The values of Kp, Kd and Ki resulting through the BF, PSO and (BF-PSO) methods after ensuring the presence of all the poles of the transfer function confined to the left half of the S plane. The performance of the developed algorithm is experienced with transfer functions of systems of different orders. The cost function here is the square of integral error. The closed loop PID controller cascaded with the process is tuned for values Kp, Ki and Kd.

Keywords: Bacterial Foraging, Close Loop Controller, PID, PSO, Optimization.