Research On Coverage Control Algorithm Based On Dynamic Optimization In Wireless Sensor Networks

With the rapid development of science and technology,information collection technology is highly intelligent.With its large-scale,low-cost,and self-organizing features,wireless sensor networks are widely used in various fields,such as defense military,precision agriculture,Internet of Things,and space exploration.Coverage control technology is one of the research focus in wireless sensor networks and an important support for other technologies in the field of wireless sensing.The difficulty of research in coverage control technology is how to improve network coverage and ensure network connectivity.Therefore,the research focus of this thesis is to reduce network coverage holes by dynamically optimizing node location,and when node failure causes network connectivity damage,deployment Relay nodes to restore network connectivity.The main innovations are as follows:Traditional coverage optimization algorithms cause the network to fall into local optimality due to too few constraints,node overlap coverage,and a large number of coverage holes in the network.In view of the above problems,this thesis introduces geometric graph theory to the traditional virtual force algorithm,and proposes an improved virtual force relocation overlay control algorithm.Firstly,according to the coverage of Voronoi polygon,the virtual force of Voronoi polygon centroid and the virtual force of uncovered grid points in Voronoi polygon are proposed,and the virtual force is used to drive the node to dynamically repair the network coverage dead zone and improve the network coverage.Secondly,the Delaunay triangle is used to detect the partially covered holes in the network,and the virtual force at the center of the empty circle is used to optimize the topology structure and further improve the quality of the network.In the process of node movement,this thesis adopts variable moving step size instead of fixed step size,thereby reducing the energy consumption of the network.Simulation results show that the algorithm proposed in this thesis can improve the coverage of the network in different scenarios,reduce node energy consumption and optimize the uniformity of the network nodes.When the nodes in the network fail on a large scale,the network is divided into multiple sub-networks,and the connectivity of the network needs to be restored.To solve this problem,this thesis uses Steiner tree theory to propose a fault-tolerantrecovery algorithm based on Steiner points.Firstly,select the candidate node from the boundary nodes of each sub-network as the gateway of the partition,and then restore the network connectivity through the quadrilateral Steiner tree.When the quadrilateral Steiner point is inside the obstacle,the triangle Steiner tree needs to be reconstructed to avoid the obstacle.Finally,in order to improve the fault tolerance of the network,this thesis builds a circular skeleton based on the position of Steiner points,and at the same time uses the suboptimal candidate nodes of the partition to construct a 2-vertex connected topology graph.The simulation results show that this method can effectively achieve the obstacle avoidance reconnection of the partitioned network when using a small number of relay nodes,and at the same time improve the average node degree and fault tolerance of the network.