Research On Node Coverage And Routing Algorithm With High Energy Efficiency In Wireless Sensor Networks

Wireless sensor network is a self-organizing network composed of a large number of low-power nodes,which can be widely used in military,medical,agriculture and many other fields.Due to the limited energy of sensor nodes and the limited application environment,it is difficult to supplement energy.Energy efficiency is an important research content of wireless sensor networks and one of the key factors limiting the application of sensor networks.In order to solve this problem,a lot of work has been done to improve energy efficiency and prolong the network lifetime from different angles.Combined with node scheduling and routing design,this paper will study the energy-efficient routing strategy and coverage control strategy to ensure network coverage.The specific work is divided into the following three aspects.Firstly,in order to reduce the energy consumption of wireless sensor networks and prolong the network lifetime,based on the analysis of the characteristics of wireless sensor networks,combined with node scheduling and routing design,a hybrid strategy routing protocol based on clustering is proposed.Aiming at the energy waste caused by a large number of redundant nodes in sensor networks,the improved genetic algorithm is used to find the minimum number of working nodes that meet the coverage requirements,that is,the optimal node set,and the other sensor nodes enter the sleep mode.On this basis,a new clustering algorithm is proposed to construct non-uniform clusters and maintain the load balance between clusters to prolong the lifetime of the network.In the data transmission stage,for the sensor nodes closer to the sink than any cluster head,make them directly communicate with the sink with the minimum power.When one node dies,begin a new round of node scheduling and routing.In order to reduce the switching complexity and time,a node wake-up mechanism is proposed.The simulation results show that compared with the existing routing protocols,the designed routing mechanism can effectively save the energy of a single node,balance the network energy consumption and prolong the network lifetime.Secondly,according to the characteristics of 3D sensor networks,a clustering routing protocol suitable for 3D sensor networks is proposed by further combining node scheduling and routing design.Firstly,the three-dimensional network is modeled,and the improved genetic algorithm is used to obtain the optimal node set,that is,to minimize the number of working nodes on the premise of meeting the full coverage of the monitoring target.Based on the optimal node set,the improved LEACH protocol is used to cluster the nodes in the set,the cluster head is selected considering the residual energy and location of the nodes,and the combination of single hop and multi hop is used for inter cluster communication.In the process of intra cluster communication,the next hop node is selected according to the ratio of the distance from the node to the neighbor node to the transmission energy consumption,and the space angle composed of the current node,the destination node and the neighbor node,so as to ensure that the transmission distance of the selected next hop node is the farthest and the energy consumption is the least,and the limitation of the space angle prevents the transmitting node from deviating too far from the destination node.In addition,the energy consumption caused by retransmission caused by poor channel quality in the process of information transmission is further considered.In order to ensure that there are enough communication signals between adjacent nodes to transmit data,a minimum signal-to-noise ratio threshold is established.Only when the signal-to-noise ratio received by the sensor node is greater than the threshold,the two sensor nodes are allowed to communicate.When the network continues to run and the node dies,according to the spatial relationship of the node,the neighbor node wake-up mechanism is adopted to activate the dormant neighbor node.Simulation results show that the algorithm is superior to other similar protocols in network lifetime,throughput and energy consumption.Finally,in order to solve the problem of uneven node distribution and even network connectivity caused by random deployment of sensor nodes,a coverage optimization strategy for wireless sensor networks based on flower pollination algorithm is proposed.Aiming at the shortcomings of slow convergence speed and low accuracy of flower pollination algorithm,it is improved,and the benchmark function test shows that the improved algorithm has better convergence performance.On this basis,the network coverage optimization problem is modeled as a multi-objective optimization problem based on the coverage of monitoring target points,energy consumption of the sensor node movement and the network connectivity.According to the complexity and characteristics of the problem,a node mobility algorithm based on improved flower pollination algorithm is proposed.The nodes judge the network connectivity in the process of mobility,and optimize the network coverage through the continuous iteration of the algorithm.Simulation results show that the proposed algorithm can cover and repair the blind area of network coverage while ensuring network connectivity,and the average distance of node movement is the shortest.