Development Of Networking Control System Of Urban Sewage Treatment

The water resource in our country is not rich,and on the other hand,water resource is seriously polluted due to the sewage brought by economic and social development,city expansion.With the water environment problem get worse day by day,our country has increase sewage treatment efforts,after years of development,the sewage treatment industry has developed rapidly.But sewage treatment is a complex biochemical process,it has the characteristics such as highly nonlinear,strong coupling,uncertainty.and on the other hand external flowing component fluctuation influence is very big,conventional control is very difficult.To make the result achieve effluent discharge standards,and to reduce the operation cost of sewage treatment plants,the application of advanced control technology is a potential method.In view of the above situation and based on the requirements of the sewage treatment process,taking CASS(Cyclic Activated Sludge System)treatment process as the research object,this paper puts forward a design scheme based on the homemade controller and the configuration software of sewage treatment control system.Firstly,this thesis introduces the development status of domestic sewage treatment automatic control system and discusses the principle and process of CASS process for treatment of wastewater.According to the requirement of sewage treatment,we design of the network controller sewage treatment.Secondly,we mainly introduces the hardware system of wastewater treatment meeting the requirements of process,The hardware includes a dedicated controller for sewage treatment plant in town,we take STM32F407 as the core processor of the control system.In the input and output interface.we protect the core processor by using Opto-couplers isolation and ULN2003 The whole system has the capability to drive more controlled element.By adopting DP83848,MAX3232,SN65VHD230 chip connecting with the controller,the system has rich and stable communication interface(Ethernet interface,UART interface,CAN interface *2).These interfaces effectively makes the coordination of internal system and the reliable and stable of communication between processor with the remote and on-site monitoring display equipment.Thirdly,we mainly introduces the software system based on Configuration software,including the lower computer software knowledge introduction and the functions of every modules.Finally,in the part of sewage treatment,optimization control we select dissolved oxygen as the control input,and the conversion to total nitrogen as the control output.Based on this,predictive control strategy of intelligent control of treatment is studied.And according to the dynamic matrix control algorithm shortcomings,we improve the control strategy.The introduction of PID makes the dynamic matrix control algorithm in terms of robustness a very good improvement,and makes the control system more efficient in optimizing control.At the same time,it brings a better real-time performance to the whole system,At last,the system is simulated by MATLAB,and we observe the effect of output.