Research On Wireless Self-Organizing Sensor Network Based On Location Service

The development of wireless communication technology has made great progress in the research of wireless sensor networks.As a key technology of wireless sensor networks,positioning technology has very important research significance and application value.There is an increasing demand for location services in daily life,especially in indoor environments.GPS signals cannot penetrate buildings and the propagation of wireless signals may be affected by reflection,refraction,and multipath effects.Because of these factors,positioning in indoor scenes is far more difficult than positioning outdoors.This thesis will start with wireless sensor network positioning technology,build a self-defined protocol wireless sensor network,apply the proposed indoor positioning algorithm,and finally implement an indoor positioning system based on wireless sensor network.The main work and innovation of this thesis are as follows.Firstly,a Lo Ra-based wireless sensor network is builded by communication module with the main control chip STM8LC151 and the communication chip SX1278.The entire network uses a self-designed communication protocol and adopts a layered ad hoc network structure,which has the advantages of ad hoc networking,long communication distance,and fast data acquisition.Secondly,an improved LANDMARC positioning algorithm with distance limitation and error correction is proposed.The proposed algorithm increases the distance limitation requirements in the process of selecting the nearest neighboring reference tags by the traditional LANDMARC positioning algorithm,and improves the selection accuracy of the nearest neighboring reference tags.Then select the most similar reference label,estimate the coordinates,and calculate the error correction value.Combining the two to calculate the coordinates of the target node.Simulations show that the proposed algorithm can effectively improve the positioning accuracy.Thirdly,an indoor positioning system based on Lo Ra wireless ad hoc network was implemented.First,a wireless ad hoc network system was designed and built,and software and hardware tests were completed.Then,an improved LANDMARC positioning algorithm was applied to the system.The Lo Ra-based wireless self-organizing sensor network is a communication network,and with some of the proposed optimization algorithms,indoor positioning systems are built indoors,and experiments are compared and verified.