Multi-source Fusion Indoor And Outdoor Seamless Positioning Technology Research

With the advent of the information age,services based on location information play an increasingly important role in various application scenarios,and navigation and positioning technologies are constantly evolving.In outdoor scenarios,the Global Navigation Satellite System(GNSS)can already provide real-time,reliable and stable global positioning and navigation services.However,in many similar indoor scenarios such as underground garages,traffic tunnels,and urban canyons,satellite signals are lost.This also gave birth to many indoor positioning wireless technologies,such as ultra-wideband and WIFI technology.How to use the existing positioning technology for accurate positioning is becoming more and more critical,and multi-source fusion positioning technology has been proposed accordingly.It uses information fusion methods to process satellite navigation and positioning,wireless sensor positioning and other auxiliary positioning technologies,and finally obtain reliable,accurate and stable positioning services.This subject mainly designed the combined positioning scheme of Ultra Wide Band(UWB),Inertial Navigation System(INS),GNSS and barometer,and studied the fusion positioning algorithm in different indoor and outdoor scenarios.The main research work of this paper is as follows:First,in a static positioning scenario,in order to reduce the impact of obstacles and non-line-ofsight interference on UWB positioning performance,make full use of non-line-of-sight information,fuzzy reasoning is introduced,and a new UWB fingerprint matching positioning algorithm is proposed.The algorithm uses the distance information between the base station and each location tag to establish a fingerprint database,and proposes a location optimization threshold T,which is processed by improving the weighted fuzzy rules to obtain the corresponding location results.Tests show that the positioning error of this algorithm is maintained at about 10 cm,and compared with a weighted KNN algorithm of fuzzy inference,the positioning accuracy of the algorithm is improved by 17.8%,which improves the accuracy and stability of the overall positioning.Secondly,in the dynamic positioning scenario,an indoor positioning method using barometer to assist UWB is proposed.On the basis of UWB two-dimensional plane positioning,the air pressure data of the floor is collected through the differential air pressure height measurement module to construct the floor air pressure model to assist the UWB positioning in the indoor height direction.At the same time,a PDR-assisted UWB indoor non-line-of-sight positioning method is proposed.Based on the calculation of UWB and PDR position information,the non-line-of-sight correction coefficient? is introduced,and UWB and PDR positioning are dynamically weighted according to certain rules.PDR positioning is used to correct the positioning error of UWB in non-line-of-sight.Finally,the generalized continuation filter is used to process the pedestrian information and the calculated positioning result,which reduces the number of base stations and improves the positioning performance.Finally,in order to achieve seamless indoor and outdoor positioning as a whole,good positioning accuracy can still be achieved when the GNSS signal is out of lock,in outdoor situations,GNSS combined inertial navigation is first used for positioning calculation,and a heading angle correction algorithm based on a filtering method is proposed.After entering the room,the PDR assisted UWB multi-source fusion indoor positioning method proposed in this paper is used,and the barometer is combined to correct the positioning height direction.At the same time,a new fusion positioning filtering algorithm is proposed to fuse data from different positioning sources to achieve multi-source fusion positioning.Test results show that this method can achieve centimeter-level positioning in outdoor situations,and it can still maintain continuous and accurate positioning during the transition phase between indoor and outdoor.In indoor GNSS satellite signal loss scenarios,it can still achieve decimeter-level positioning.