Fractional Order PID Controller with an Improved Differential Evolution Algorithm

Abstract

Differential Evolution algorithm has recently emerged as a simple yet very powerful technique for real parameter optimization. This article describes an application of DE for the design of fractional order proportional Integral Derivative controller. FOPID controller parameter are composed of the proportional constant, integral constant, derivative constant, derivative order and integer order, and its design is more complex than that of conventional integer order PID controller. Here the controller synthesis is based on minimising the integral square error of given plant by which a single objective optimization problem achieved. This article proposes a tuning method of fractional order PID controller for a given plant by nature inspired algorithms which is Differential Evolutionary for better dynamic and static performance. The mutation of DE algorithm is modified by which the optimal response is obtained and also compared with Genetic Algorithm and PSO algorithm. The comparison is done on the basis of step response with characteristics like maximum overshoot (M p%), rise time(t r) and steady state error. Simulated results are represented on matlab 2012(a).