Research On The Coverage Control In Wireless Sensor Networks

WSN (Wireless sensor network) mainly aims at completing target monitoring and information acquisition; it is one of the necessary conditions to complete the task that the monitored area should be totally covered by wireless sensor network. Coverage control, as one of the core issues of WSN research, does not only guarantee the regular operation of WSN, but also greatly influences many important parameters like, energy-consumption, life time and service quality, etc. Therefore, it is of great importance to study the coverage problems of WSN.WSN and its characteristics, basic theory and research status are researched. On the basis of the research, it emphasizes on the coverage control algorithm of WSN and makes analysis on its theory; with regard to the coverage problems existing in much coverage area overlaps in high density and random distribution area and uneven coverage of hybrid sensor network with few mobile nodes, it summits related coverage control algorithm respectively. The major work is shown as follow:(1) With regard to the problems of much coverage area overlaps in high density and random distribution area of fixed sensors network, many redundant nodes and uneven energy distribution, the minimum covering node sets are selected and the balance problems of coverage areas is considered; on that basis, the multi-objects optimization algorithms with coverage rate, working nodes number and network energy balance as the optimal targets is adopted; with regard to the local optimization problems existing in solving multi problems with multi genetic algorithm, a kind of adaptive adjustment crossover and mutation probability method is introduced to improve the multi-objective optimization algorithm. At the same time, multi genetic algorithm is used to solve the above multi-objective problem, and the optimal coverage network is gained. The simulation results show that this kind of coverage control strategy can obtain a relatively high coverage rate; and at the same time, it can reduce the energy consumption and guarantee energy balance efficiently so as to maintain the stability of network operation and expand the life cycle of network.(2) With regard to the coverage holes caused by the uneven coverage of hybrid sensor network with few mobile nodes; for the Voronoi algorithm cannot detect the coverage holes exactly under the shadowing effect of perception model, with the combination of Voronoi diagram and perimeter coverage algorithm, it submits coverage hole detecting algorithm-VPCA based on Voronoi diagram and Perimeter Coverage Algorithm. At the same time, when repairing the coverage holes, the moving route of mobile nodes runs in broken line or even reciprocation, on the basis of minimum cost matching algorithm, the concept of virtual mobility is introduced, and the repair algorithm of coverage holes with target of maximizing the residual energy of all mobile nodes is submitted based on virtual mobility of nodes. The simulation results show that this kind of algorithm cannot only improve the coverage rate of network but also save the energy for the mobile nodes, which extends the life time of network efficiently.