Research On Nodes Localization And Target Tracking Technology In Wireless Sensor Networks

Wireless sensor network(WSN)integrates the micro-electromechanical technology,sensor technology,embedded technology,wireless communication technology and distributed information processing technology.It is an important development and transformation in the field of information science and also one of the research hotspots in current emerging technologies.Due to some characteristics of WSN,on the one hand,it has very broad application prospects in the fields of both military and civilian,but on the other hand,it also faces many theoretical and practical challenges.Automatic localization of sensor nodes is the foundation of many wireless sensor network applications.The design of nodes localization algorithm which can not only try the best to save the extremely limited nodes resources but also has high localization accuracy as possible is a significant technical hotspot.Target tracking is one of the numerous WSN practical applications.It has a very broad application prospects in battlefield surveillance,environmental monitoring,disaster forecast and disaster relief.But it is restricted by nodes computing power and energy,and also influenced by the complex environment in practical application.It is a hot spot in the study of wireless sensor network to realize the reliable,high precision and real-time target tracking.So in this paper,the node localization and target tracking technology in wireless sensor networks are studied systematically.The following is the specific research contents:1)Research on ranged-based localization algorithms of wireless sensor networkThe ranging technology based on received signal strength indicator(RSSI)has many advantages.So RSSI is the most widely used ranging technology in ranged-based localization algorithms of wireless sensor networ.Using particle swarm optimization(PSO)which has high precision and is easy to implement to make up for the low precision problem of RSSI ranging technology.In order to improve the positioning accuracy,the convergence conditions of PSO algorithm is analyzed firstly.And then an improved PSO algorithm is proposed to estimate the unknown node's position under the constraints of convergence conditions.At the same time,the initial search space of particle swarm optimization is optimized by combining the characteristics of wireless sensor network localization.Simulation results show that RSSI-based localization algorithm which using the improved PSO algorithm has good performance in several key indicators.2)Research on ranged-free localization algorithms of wireless sensor networkDistance Vector-Hop(DV-Hop)algorithm is the most widely used in several major range free localization algorithms.But the positioning accuracy of DV-Hop algorithm is not high due to errors caused by hop information,the average hop distance of unknown nodes and positioning methods and so on.Firstly,the corresponding improvement countermeasures are put forward,and finally the improved DV-Hop algorithm is proposed.The simulation results show that the improved DV-Hop algorithm can improve the positioning accuracy by 26%~53% compared with the original DV-Hop algorithm.And the energy consumption and computation of the localization algorithm do not increase.3)Research on target tracking algorithm based on wireless sensor networksParticle filter can effectively solve the problem of target tracking in nonlinear and non Gauss environment.A distributed wireless sensor network target tracking method based on improved particle filter algorithm is designed under the guidance of practical evaluation and four main indicators.Firstly,a distributed dynamic clustering mechanism is established.Then the detailed steps of distributed particle filter algorithm is given.And the resampling step is improved in an effective way but without increasing the algorithm complexity to overcome the problems of particles sample impoverishment and improve the tracking accuracy.The simulation results show that the distributed wireless sensor network target tracking algorithm has good tracking comprehensive performance.4)The realization of coal mine safety positioning and monitoring systemAccording to the actual needs of the current coal mine production safety,a coal mine safety positioning and monitoring system based on wireless sensor network is designed.The system architecture has two layers.The lower layer adopts 2.4GHz communication frequency.The positioning calculation of miners and collection of related environmental datum are running is this layer.The upper layer adopts 433 MHz communication frequency.It is used to transmit datum between underground and ground monitoring center.The ground control center can monitor the underground safety production through real-time monitoring datum and and can send relevant instructions to the underground.