Controlled Controllogix-based Sewage Treatment System

With rapid economic development and urbanization process accelerating, the volume of urban sewage emissions become larger and larger. In order to keep the sustainable economic development, urban sewage treatment has become indispensable to the development and construction of facilities.In this paper, an automatic control system is designed based on one wastewater treatment plant in Qingdao, which adopt the improved sewage treatment process ICEAS(Intermittent Cycle Extended Aeration System). The control system platform used ControlLogix which is fully functional, configuration flexibility, friendly interface, suitable for expansion, and mature technology, cost-effective. In this automatic control system, the program of upper computer is realized with RSView32 based on Windows 2000, and lower computer PLC is designed by trapezoid graphic software RSLogix5000.In view of the characteristic of complexity, the control system is large time-delay and nonlinear. During the process of DO controlling, simuliation model is constructed by matlab fuzzy toolbox. The Fuzzy PID controller is used to automatically adjust PID parameters by the fuzzy algorithm, and the result of simuliation shows the robust of the control system is well. It lays a foundation to guarantee the stability of the effluent water and sewage treatment costs of the economy.