Research On Coverage Control Algorithms In Wireless Sensor Networks

Wireless Sensor Networks is composed of a large number of low-cost and low-power nodes. They perceive, process and communicate the information of the object by self-organization. In the network, the problem of node’ layout is the first concern. This problem is evolved into the question of the space location of all nodes in the network then. That is how to dispose the noses to ensure the best monitoring degree of the objects. That is the origin of coverage problem which is one of the key problems in Wireless Sensor Networks. It main concern is how to meet the different quality requirements by the network under the circumstances of energy content of battery, capability of perception, computing performance and capacity of communication of nodes. Besides, it should configure the network resources reasonably and maximize the lifetime of network. This is the foundation of all other work, which should be solved firstly in Wireless Sensor Networks. Therefore, the research of coverage control is particularly important.This paper makes a investigation of the hot spot problems in coverage control and propose several improvement ideas towards some problems on the basis of systematic analysis of the coverage problem in Wireless Sensor Networks. The study includes the following aspects mainly. It summarizes the interrelated knowledge and research achievements by domestic and foreign scholars in the field of Wireless Sensor Networks. Besides, it researches the smoothing method of the covering path in the self-organization of nodes. A strategy has been proposed to solve the target coverage in Visual Sensor Networks. In addition, this work presents a mixed algorithm to deal with the separate situation of research on area coverage or target coverage in Visual Sensor Networks. The main innovations of the thesis are as follows:(1). Proposing a novel smoothing algorithm of node paths of area coverage in Wireless Sensor Networks. This algorithm is based on the omnidirectional sensing model of sensor node. It aims to solve the problem of unsmoothed node path which cased by topology events in the process of self-organization. The algorithm studied of the force of nodes deeply in the process of moving and introduced the shunting model in biology. It solved the problem of hard turning of node paths effectively and has achieved a very good coverage effect.(2). Designing of a high efficiency and energy saving target coverage algorithm in Visual Sensor Networks. The algorithm is based on the directional sensing model of sensor node. The algorithm is based on the perceptual model of sensor node. It has proposed a solution to solve the problem of coverage redundant and imbalance of residual energy of nodes in the process of target coverage. The algorithm first sought out the coverage relationship between the nodes and the targets firstly. Then it mined the frequent association of target set and selected the nodes with more residual energy to work in the corresponding node set. The dynamic rotation of election went on. So it can balance and save the energy consumption of nodes effectively, and the survival time of the network has been prolonged.(3). Proposing a multiple algorithm of area coverage and target coverage in Visual Sensor Networks. The algorithm is based on the directional sensing model too. The purpose is to solve the problem of the separate situation of research on area coverage or target coverage and neglecting the requirements of coverage quality of the hot targets in Wireless Sensor Networks. The algorithm made a stress analysis of the nodes and the "center of mass of the sensing area". It used the virtual potential field to make the sensor nodes shifting positions and changing directions automatically in the monitoring area. With the completion of multiple prior coverage of hot targets which needing higher quality requirements, the algorithm can maximize the coverage rate throughout the monitoring area.