Advanced Control Theory Cast In Waterworks Coagulation Drug Control

With the rapid development of urban construction in our country, the requirement to the quality of urban water supply is increasing. Automatic control of water treatment process is the key of protection of water quality. The most difficult focuses on the auto control of coagulant process. However, either forward and feedback control or classical feedback control is currently used in coagulation dosing in many water treatment factories in our country. But the results of both controls are not very good. There are some questions of chemicals wastage and sediment output water qualities varieties. Therefore, the paper is mainly to research the automatic control in coagulant dosing based on advanced intelligent control theory .The main research achievements are as follows:(1) Aiming at Streaming Current Detector's low accuracy of measuring coagulation process, an improved detection method using multi-sensor data fusion technology is developed in this paper. The method adopts two main factors that affecting coagulation reaction (influent turbidity and flow) to correct the value of Streaming Current. So it can detect coagulation process accurately, which lays the foundation for optimizing control in dosing process.(2) In order to improve control performance, the paper brings forward a piece of new fuzzy controller used in water treatment drug control. Firstly, controller can automatically chooses rules set basing on different state of effluent turbidity in the process of coagulation dosing. Secondly, according to the streaming current's deviation and its rate of change, each rules set can give concrete control rule which is suitable to be used in different state of the environment.(3) In order to improve adaptability of controller, this paper introduces a control model of the fuzzy neural network. Combining fuzzy controller's fuzzy reasoning ability with the neural network's learning ability, it can adaptively handle all kinds of complex situations in auto control of dosing process. It provides new approaches for the auto control of coagulant dosing in the water factory.