Surface Water Quality Monitoring And Evaluation Based On Wireless Sensor Networks

In recent years,with the development of society and the improvement of people's living standard,water quality safety has become the focus of people's attention.Therefore,the research on surface water quality monitoring and evaluation has made remarkable achievements.The traditional methods of water quality monitoring and evaluation need the aid of manpower to collect data,and even set up special stations for collecting and analyzing.These methods have certain advantages in certain period,but it is very difficult to carry out real-time and effective monitoring in large area.Traditional methods often need to devote more manpower and material resources.With the development of wireless sensor technology,the application of wireless sensor in surface water monitoring becomes a reality.The monitoring of surface water quality by wireless sensor network and its related technologies can effectively overcome the disadvantages of traditional surface water quality monitoring methods such as bad real-time,high monitoring cost and limited monitoring ability.This thesis presents a monitoring method of surface water quality based on wireless sensor network and designs a reliable monitoring system.Meantime,introducing a new solar module into the water quality monitoring system to expand the scope of application of the system.The fuzzy neural network is used to analyze the monitoring data,and the results of water quality change in the monitored waters are obtained.The main contents of this thesis are summarized as follows.First of all,the wireless sensor network and its related technologies will be briefly introduced,and focus on the actual needs of this thesis analysis.Because the ZigBee technology is mainly used in this thesis,the characteristics and application fields of ZigBee technology are analyzed emphatically.Design the water quality monitoring system hardware part of this thesis.The design of the system is included,in addition,the design process of the hardware connection circuit including the chemical oxygen demand sensor module,the dissolved oxygen acquisition module,the PH Data acquisition module and the heavy Metal acquisition module are introduced in detail.In this thesis,the solar power supply module is introduced into the data acquisition module,which improves theapplication range of the system.In this thesis,the hardware of ZigBee node is designed,including the selection of ZigBee chip,the hardware design of coordinator and router etc.Design the entire system software architecture,including the overall design of the system software and the design of each data module.For the data acquisition module,after the node collects the datum,the RF module is used to transmit data to the intermediate node,and then the data is transferred to the host computer.In addition,the communication program between nodes of ZigBee system is designed,including data transmission between nodes and serial communication programming,considering the coordination of communication between different nodes and increasing the maximum utilization of resources.Finally,the data of the monitoring and evaluation system for the surface water quality of wireless sensor networks are processed.The T-S fuzzy neural network model is used to analyze the acquired data according to the characteristics of the design system.Considering 6 important factors in the analysis of water quality in the later stage,this thesis designs a fuzzy neural network evaluation model comprising 6input neurons and one output neuron.And this model is used to analyze the water quality of a city in the Yangtze River from 2014 to 2017.The analysis results are basically consistent with the actual situation.It is indicated that the T-S fuzzy neural network designed in this thesis meets the design requirements.