Study On Localization And Indoor Mapping Of Wireless Sensor Network

Since the 1990 s,the development of micro-electro-mechanical system technology,wireless communication and digital electronics has prompted scholars at home and abroad to devote a great deal of energy to the study of wireless sensor network applications.In these applications,the location information of sensor nodes and the indoor environment information of nodes are essential.Scholars at home and abroad have put forward many solutions to the problems of localization and indoor mapping,and great results have been achieved.However,most of the existing algorithms are suitable for two-dimensional environment,and the centralized way of calculation increases the difficulty of hardware implementation.This paper mainly considers the problem of distributed localization and indoor mapping based on relative position information in three-dimensional environment,and deeply studies the related algorithms with high robustness and low error rate.In the first part of this paper,we mainly study the distributed localization algorithm based on relative position information in three-dimensional environment,and propose the sufficient conditions to ensure the effectiveness the algorithm.The algorithm uses Laplacian matrix to skillfully transform the position information between local coordinate system and global coordinate system,and gives the process of calculating the weight of directed edge.At the same time,the convergence of the distributed algorithm is proved in detail.Then,the algorithm is simulated by using MATLAB.The simulation starts from whether there is noise or not,and verifies the robustness of the distributed algorithm by introducing noise interference.The simulation results show that the proposed algorithm can achieve high positioning accuracy,and verify that the noise interference has no effect on the effectiveness of the algorithm.In the second part of the paper,the focus is on the cooperative localization and indoor mapping with multi-sensor nodes,and the algorithms of indoor mapping in two-dimensional space and three-dimensional space are proposed.By introducing the concept of virtual nodes,the two algorithms transform the indoor reflection wall into virtual nodes.Through the detailed process of virtual node transformation,we can transform the problem of cooperative localization and indoor mapping into a simple localization problem with virtual nodes.At the same time,this paper puts forward the sufficient conditions to solve the problem of coorperative localization and indoor mapping and gives the corresponding proof.Finally,the effectiveness of the algorithm is verified by numerical simulations,and it is shown that the selection of directed edge's weight will directly affect the iteration speed of the algorithm.