A Hybrid of ε-Constraint and Particle Swarm Optimization for Designing of PID Controllers

In this paper, an optimum approach to design PID controllers has been proposed. PID control schema based on classical control theory has been widely used in industrial control processes. Since most of the control systems have nonlinear properties, it is difficult to determine optimal parameters for a given PID controllers. This study utilizes the particle swarm optimization algorithm as solution method to search for PID parameters that capable of minimizing the integral absolute control error. At the same time, the transient response is guaranteed by minimizing the maximum overshoot, settling time, rising time of step response. Moreover, we also utilize ε-constraint method to improve the performance of the controllers. Finally, experimental results demonstrate that better control performance and robustness can be achieved in comparison with known methods.