Research On Dam Safety Monitoring System Based On Wireless Sensor Networks

Currently, the wired acquisition is mainly used in the dam monitoring system, and it has the characteristics of accurate signals, good anti-interference, and series product. Otherwise, the wired sensor monitoring network has some shortcoming:large wiring, high maintenance costs, and inability of wiring in some specified structures. In this paper, wireless sensor network is used to the dam safety monitoring based on its advantage of the miniaturization, integration, little installation time and low maintenance costs, and key technologies of sensors as well as nodes deployment and data fusion in wireless sensor networks for dam safety are studied. The main contents of the paper include:(1) In order to guarantee the long transmission distance of dam signals and low power consumption, Wireless Sensor Network for Dam Safety (DS-WSN) is presented making full use of the advantages of clustering and multi-hop. The clustering and multi-hop network structure are used in the system, which ensures high reliability and low power consumption. Besides, the JN5139ZigBee modules are applied, which guarantee that the sensor nodes have the characteristics of small size, long transmission distance and low power consumption. Furthermore, the system can connect to the Internet and the GPRS network through the sink node, which facilitates the remote transmission of the wireless signals. DS-WSN has higher reliability and lower power consumption than the typical wireless sensor network architecture.(2) According to the dam monitoring characterizes, the key sections are determined, and the deployment of sensors and sensor nodes is studied based on the graph theory. In order to ensure that fewer nodes can measure effectively, the finite element analysis method is adopted to determine the key sections. To ensure high cover efficiency, coverage strategies of the sensors on the dam key sections based on the full coverage theory of the three circles are researched, and based on the minimum coverage circle theory, the coverage holes are repaired by take advantage of the empty boundary conditions, which ensures full coverage of the key sections. In order to guarantee the effective transmission, on the basis of consideration of the influencing factors such as signal attenuation and shielding, according to the monitoring corridor topology diagram, a backbone network with connected set is raised based on the maximum communication distance. Besides, the redundancy deployment of the backbone network is considered to improve the sensor nodes connectivity in the dam environment. (3) On the basis of DS-WSN, to get proper monitoring data, the data fusion is researched according to data processing capacity of the dam sensors. The data fusion is divided into homogenous fusion and asynchronous fusion. Homogeneous fusion occurs mainly in the cluster member nodes and the cluster head, and a threshold determination mechanism and the adaptive weighted fusion algorithm are applied to reduce the amount of data transmission. While asynchronous fusion mainly occurs in computer management center or PC linked on the sink node, and an evolutionary neural network based on principal components analysis is used to forecast the dam safety. The comparison between the prediction model and the traditional neural networks indicates that the model predicts accurate, and is time-saving.(4) A dam safety monitoring and management system is developed to analyze and manage all kinds of the monitoring data. The monitoring experiment of DS-WSN shows that DS-WSN can network normally, the data transmission is reliable, the collected data are precise, the lives of the WSN nodes are long, which can meet the requirement of the dam safety monitoring.