Study On Network Coverage Based On Particle Swarm Optimization For Wireless Sensor Networks

With the rapid development of low cost information technologies,wireless sensor networks(WSNs)have been widely adopted in our daily life,such as intelligent transportation,smart home,disaster forewarning and ecological protection.WSNs have brought us great convenience since they have the characteristics of easy deployment,high adaptability and real-time perception.Also,reliable deployment of network helps mutual cooperation between sensors.Coverage control is one of a fundamental problem in WSNs,it can reflect sensing ability of networks.Therefore,with the aim of efficient information perception and data gathering,a reliable coverage control algorithm is needed to improve quality of service in WSNs.Generally,sensor nodes are randomly and massively deployed to fully cover target area,which can result in uneven deployment of nodes and add network cost.Target point can be covered by two or more sensors in this circumstance,which give rise to coverage redundant.Once these sensors detect an event,they will then transmit data towards base station.These data contain large amounts of duplicating information,which will add unnecessary waste of energy on transmitting these redundant data.Meanwhile,this densely deployment will give rise to communication overhead,and channel contention occurs in data transmission process.Moreover,this will reduce network bandwidth and quality of service of WSNs.Researchers introduce efficient network coverage algorithms to plan positions of sensor nodes.This thesis focus on coverage control based on Particle Swarm Optimization(PSO)for WSNs,and aim to find a balance between energy consumption and coverage rate in networks.The major works are as follows:1)Classical PSO algorithm is firstly analyzed,we discuss its advantages and shortcomings.Since traditional PSO algorithm is easy to fall into premature phenomenon,we introduce a combination with PSO and mutation operator in vector-speed-update process.Then,we use our improved PSO algorithm to calculate positions of sensor nodes.Simulation results show performance of our algorithm.2)With the aim of patching coverage holes in network,we adopt mobile sensors in static WSNs,and propose a mobile assisted coverage hole-patching algorithm based on PSO.We partition the network into grids and calculate each grid's coverage rate to find coverage holes.PSO algorithm is used to calculate moving position of mobile sensors.Simulation results show that our algorithm can effectively improve network performance.3)Considering that sensor nodes can adjust their sensing radius to save energy in high-density areas,we propose a sensing radius adaptive coverage control algorithm based on PSO.We consider both energy efficiency and coverage rate for WSNs,PSO algorithm is utilized for sensing range adjustment process.