| In recent years,with the development of science and technology,navigation and positioning technology have advanced by leaps and bounds.People’s demand for navigation and positioning is also increasing.Single outdoor positioning technology and indoor positioning technology can no longer meet the needs in specific application scenarios.For example,in the fields of industrial production,navigation services,artificial intelligence and so on,there have been the transformation and shuttle between indoor and outdoor scenes.The purpose of indoor-outdoor seamless positioning technology is to ensure stable and accurate positioning services in the above scenarios.As the demand for seamless indoor-outdoor positioning is becoming more and more obvious,the research on seamless positioning in indoor-outdoor scenarios has gradually become a research hotspot in the field of positioning.Therefore,this paper studies the positioning in indoor-outdoor scenes.The research contents are as follows:(1)This paper analyzes the research status of outdoor and indoor positioning technology as well as the development of indoor-outdoor positioning,then studies the technology and principle of satellite positioning and the common technology and algorithm of indoor positioning,and focuses on the feasibility analysis of the application of 5G technology in indoor positioning.(2)This paper deeply studies the switching problem in the process of indooroutdoor positioning and analyzes the difficulties and core problems in indoor-outdoor positioning,then studies a Beidou+5G joint positioning algorithm combined with requirements of indoor-outdoor positioning.In the transition area between indoor and outdoor,the joint positioning solution based on Beidou pseudo-range measurement and5 G TDOA observations is realized.The test shows that the joint positioning system can ensure great positioning accuracy in the indoor and outdoor overlapping areas,in which the static accuracy can reach 3 meters and the dynamic accuracy can reach 4 meters.It provides a better solution to the problem of difficult positioning in the indoor-outdoor overlapping area.(3)The paper analyzes the three positioning modes in the transition area of indoor-outdoor positioning,and study the switching model of Beidou+5G indoor-outdoor positioning system.A positioning switching algorithm based on multi-parameter decision is proposed and the threshold selection of each parameter is analyzed.The influence of ping-pong effect is reduced by switching the settings of counts and threshold.The simulation results show that the multi-parameter switching algorithm has great positioning performance and can achieve the switching of indoor-outdoor positioning.(4)In order to solve the problem of sudden positioning changes caused by the multi-parameter decision positioning switching algorithm,this paper studies the theory of pattern recognition and neural network,then proposes an indoor-outdoor pattern recognition method based on neural network,which can identify the selection probability of each positioning mode in the positioning process.Four key parameters that can reflect signal quality and positioning performance in the process of external positioning are used as the input of the indoor-outdoor positioning pattern recognition neural network,and the acceptance probability of each positioning mode is output.After simulation verification,the accuracy of indoor-outdoor positioning pattern recognition neural network can reach 98.5%.Then the paper analyzes the optimization strategy by using the indoor-outdoor positioning mode neural network to the results of the multi-parameter positioning switching algorithm.The results show that the optimization of the neural network can further improve the positioning accuracy and smooth the localization track of the switching area.It provides a better solution to the problem in indoor-outdoor positioning scenarios.(5)The paper builds a test platform to test and verify the Beidou+5G indooroutdoor positioning method by semi-physical simulation,including the two situations of outdoor to indoor and indoor to outdoor.The final system positioning trajectory basically matches the reference trajectory,and the positioning accuracy can reach about3 meters.The experimental results show that the Beidou+5G indoor-outdoor positioning method proposed in this paper can ensure better positioning accuracy in the transition area between indoor and outdoor and meet the positioning requirements in most indoor-outdoor scenarios,which has broad application prospects. |
