Research of Feed Forward Control of a Sewage Treatment Process Fuzzy Control System

Sewage treatment process is a nonlinear system with a large time-delay. The system is vulnerable to interference. Control of sewage treatment process is a challenging problem. This paper proposes an effective method that combines an optimized fuzzy controller and a feed-forward controller to control a sewage treatment process. Firstly, an optimized fuzzy controller based on adjusting of a parameter α is designed. The optimized controller can generate different rules by changing the parameter α. The value of α is determined by solving the objective function optimization problem. Secondly, a new feed-forward controller based on back propagation (bp) neural network is designed that doesn't need mathematical models of control channel and interference channel. Simulation results show that the bp network based feed forward controller could compensate interference in the fuzzy control system. It is valuable especially when mathematical models of control and interfere channels is unknown. Simulation results also show that the proposed method is more effective than single fuzzy control method. It achieves a higher performance in the elimination of interference and reducing stable error.