Design of optimal PIλDδ controller for speed control of DC motor using constrained particle swarm optimization

In this paper, a novel design method for determining the parameters of an optimal Fractional Order PID (PIλDδ) controller for speed control of a Permanent Magnet DC (PMDC) motor using Constrained Particle Swarm Optimization (CPSO) is studied and presented. A PλDδ is a form of conventional PID whose orders of integration and differentiation are fractional number instead of integers. The design objective was to optimize the performance of the system subject to different constraints in frequency and time domain such as phase margin, rise time, settling time etc. CPSO algorithm yields feasible solution of five parameters of PIλDδ satisfying all the required constraints. A comparative study has been carried out on the basis of transient response and robustness of system using proposed controller with widely used ZN tuned PID controller. Moreover, the output of the system for different sets of constraints has been presented. It is shown from simulation results that the proposed method yields more improved closed loop performance.