Research Of Automatic Monitoring System Of Sewage Treatment Based On RS485 Fieldbus

In recent years, the quantity of wastewater process plant increases sharply in our country, at the same time, the wastewater process cost becomes more and more, but the economic benefit is less, so it needs to strengthen the process control of city wastewater process urgently, apply the advanced automatic control technique into the wastewater process, in order to improve the automatic level of wastewater process.This paper takes the monitoring system of a wastewater process plant in a county as the background, through the study and analysis of wastewater process course, as well as the common automatic control technology of modern city wastewater process plant, it develops the automatic monitoring system of wastewater process based on RS485 bus, which composed of computer, intelligent module and transducer. Firstly, this paper introduces the topic background and the development of automatic monitoring system in wastewater process; then, it introduces the city wastewater process method, water quality index and the flow of wastewater process in this county abovementioned in detail; finally it analyzes and chooses the control technology of modern wastewater process, determines the transmission medium of data communication and bus communication standard, at the same time, according to the automatic monitoring system requirement of wastewater process, it designs a set of automatic monitoring system plan, which adapts to the wastewater process of the county abovementioned. This paper also explains the program design reason of PCAuto6.1 configuration software, as well as the method achieving the communication with the locale hardware.Due to the features of wastewater process like non linearity, lag and change along with time, this paper discusses the application of fuzzy control in the parameter of wastewater process, and takes the DO parameter of middle ditch in orbal oxidation ditch as the example, designs a fuzzy controller with double inputs and single output aiming at the regulating speed of rotating disk aerator, which carries out emulate experiment for fuzzy control system usingthe Simulink tool in Matlab.At present, the installation and commissioning of hardware and software of this system has been finished, the test run is good, and the water quality is in accordance with the national second-class standard. In addition, this monitoring system improves the efficiency, reduces the cost and labor intensity, and it also improves the management level of wastewater process plant.