Research On Wireless Sensor Network Localization Algorithms Based On DV-Hop

The development of wireless sensor network technology makes it more and more close to people's life,and it is widely used in daily life,such as seawater monitoring,traffic control,geological survey,the disaster relief,but these applications rely on the sensor's self-positioning,and to make the best use of the value of these applications depend on the accurate location of sensor nodes,only the location is determined can we deal with the information.DV-Hop localization algorithm is a widely used method to determine the position in the practical environment.Under the requirement of low cost and low energy consumption,the algorithm does not depend on the special hardware,and it has more advantages than the algorithm that depends on the special hardware.However,when the sensor nodes in WSN are unevenly distributed and irregular,there are defects with low positioning accuracy.In order to make the results of positioning more accurate,and make it satisfied with the practical application requirements,this paper tracing back the inaccurate results caused by DV-Hop algorithm and proposing the improvement strategy,and the main work is as follows:1)In the research process of the DV-Hop algorithm,for understanding the algorithm and make effective analysis and improvement,the author uses Matlab's graphical interface development tool to design and develop the "experimentent platform of DV-Hop positioning algorithm",which is used to make deep exploration and analysis of the DV-Hop positioning algorithm,moreover this paper verificate the improved strategy is really effective on the platform,and visual operation greatly accelerated the efficiency of experimental operation,but also brings new inspiration and thoughts to study task.2)Aiming at the unreasonable distance in DV-Hop algorithm,this paper proposes an improved DV-Hop localization algorithm based on the degree of distance,improvements are as follows: Firstly,the improved algorithm modified average distance per hop for nodes because of the close distance between the anchor nodes is unreasonably;Secondly,for the unknown nodes in the communication radius of the anchor nodes,there is a problem that the distance from the anchor nodes is equal by caculation,and degree of distance among notes was introduced,so as to distinguish the distance between unknown nodes and anchor nodes,and make them more reasonable;Then when estimating the distance between the unknown node and the non-neighbor relation anchor node,the unknown node only obtains a correction value,which exists a certain degree of unreasonable,so it should take into account the target anchor node's own correction value to reduce the risk of error;Finally,the problems existing in the least squares equations and make the improvement by reorder the equations.The experimental results show that the proposed strategy can significantly reduce the estimated position error.3)Aiming at the improvement of the coordinates in the DV-Hop algorithm,an improved DVHop localization algorithm based on coordinate error correction is proposed.The main reference for coordinate correction is as follows: On the one hand,assuming the hop count between two nodes is 1 hop,then after positioning the distance between them shall not exceed the communication radius;on the other hand,if the hop count between two nodes is greater than 1,then after positioning the distance between them shall exceed the communication radius.An unknown node coordinate is modified according to the constraint relation of multiple anchor nodes,and the coordinate correction problem is transformed into nonlinear optimization problem.Through the experimental comparison,the improved algorithm makes the final positioning result closer to the actual value.