Study Of Localization Algorithms Forwireless Sensor Networks Based On DV-Hop

Wireless sensor network has been widely applied in many fields such as environmental monitoring?smart home?medical care etc,node localization has great influence on the application of wireless sensor network applications.There are two main kinds of node location algorithms: range free localization and range based localization algorithm.The latter has the advantages of simple implementation and low power consumption,so it is more suitable for node localization.DV-Hop algorithm,as one of the algorithm,still has the problem of low positioning accuracy,so it necessary to be further studied.The specific research content can be summarized as follows:(1)DV-Hop location algorithm based on jump number correction and average jump distance weighting is researched.Firstly,The signal intensity value received by the node is converted to the distance between nodes through the Shadowing model,the jump value is corrected by the ratio of the distance value to the communication radius;Secondly,the reciprocal of the jump value between the unknown node and the beacon node is used as the weight of the average per hop distance,and the weights are normalized;Finally,the maximum likelihood method is used to obtain the coordinates of the unknown nodes.(2)DV-Hop location algorithm based on bat optimization is researched.Firstly,the jumped several correction and the average distance weighting method is used to improve the algorithm;Secondly,aiming the existing problem of coordinate calculation of maximum likelihood method,the positioning problem of nodes is transformed into solving minimum value problem of a nonlinear system of equations;Finally,the improved bat algorithm instead of the maximum likelihood algorithm is used to calculate the coordinates of the unknown node.There are three main improvements to bat algorithm: The area of bat initialization is reduced;the? value is adjusted according to the current fitness function value of bat;The differential evolution algorithm is used to local search to obtain a new solution.(3)A wireless sensor network positioning system is set up.It is made of unknown nodes?beacon nodes?coordination node and host computer.The CC2530 chip is applied to the wireless communication chip of node,and the function development of the beacon node?the unknown node and the coordinator node is completed through the IAR development software.The host computer developed by C# language is used to receive and process the data sent by coordinator,achieve the storage and query of hop count and distance information between unknown nodes and beacon nodes,and display the information of node coordinates.The function test of the positioning system has been tested,and it has been verified by experiments that the unknown nodes have obtained better positioning results in the system.