Research On Indoor Positioning Technology Based On Zig Bee Wireless Sensor Networks

The rapid development of wireless sensor network,added so much color to today's era of digitalization,informatization and networking and indoor positioning as an important application of wireless sensor network,has become a hot topic that many experts and scholars are studying,gradually entering people's lives,so the location information acquisition has become a very important part in people's life demand.ZigBee technology as a wireless communication technology with advantages of low cost,low power consumption,large capacity and high reliability,has played an irreplaceable role in the wireless sensor network,so the indoor positioning technology based on ZigBee technology has important practical significance.Based on thorough study localization algorithm,ZigBee technology and ZigBee protocol stack,put forward improved localization algorithm,and setting up a platform positioning system for experimental verification.The main contents are:1)First of all,this article expounded the research status of wireless sensor network positioning technology,comparing the present stage of several common wireless location technology from the aspects of performance parameters,analyzing the advantages of the ZigBee technology in terms of positioning,this paper discusses the common positioning methods put forward by the researchers at home and abroad,studied the principle and features of several kinds of commonly used localization algorithm and coordinate calculation method,then determining the basic location algorithm used in this article.2)Secondly,this paper deeply studied related theory and the ZigBee technology and protocol stack,expounding the main features of ZigBee technology,the main functions and characteristics of three types of logical device and three types topology of ZigBee network,analyzing in detail the function and role about the PHY layer,MAC layer,NWK layer and the APS layer in protocol stack,discussing the Z-Stack the functions and characteristics,the protocol architecture and networking process of the protocol Stack.3)Once again,this article focused on the localization algorithm based on RSSI ranging,in the range phase,through the comparison of several kinds of commonly used in wireless signal transmission model,choosing the ranging model of this article,then analyzing the change of environment parameters and measuring by the current environmental parameter values,finally through comparing the simulation effect of several filtering methods,deciding to adopt Gauss filter to optimize the measured RSSI values;In phase of coordinates calculation,combined with the trilateral measurement method and the centroid localization algorithm,putting forward an improved weighted centroid localization algorithm.With the simulation results contrast of traditional positioning algorithm and distance weighted centroid localization algorithm,verifying the validity of the improved localization algorithm.4)Finally,this paper completed the overall design of indoor wireless positioning system,after comparing of several commonly used ZigBee chip,choosing CC2530 chip as the core of the locating node module,developing a simple PC display,setting up the software and hardware platform of the system.Choosing indoor environment for experiments about improved localization algorithm,this paper verified the effectiveness of the improved localization algorithm,and analyzed the error sources from five aspects.