Semi-tightly coupled integration of multi-GNSS PPP and S-VINS for precise positioning in GNSS-challenged environments  

作　　者：Xingxing Li Xuanbin Wang Jianchi Liao Xin Li Shengyu Li Hongbo Lyu 

机构地区：[1]School of Geodesy and Geomatics,Wuhan University,129 Luoyu Road,Wuhan 430079,China

出　　处：《Satellite Navigation》2021年第1期1-14,共14页卫星导航（英文）

基　　金：the National Natural Science Foundation of China(Grant No.41774030,Grant 41974027);the Hubei Province Natural Science Foundation of China(Grant No.2018CFA081);the National Youth Thousand Talents Program,the frontier project of basic application from Wuhan science and technology bureau(Grant No.2019010701011395);the Sino-German mobility programme(Grant No.M-0054).

摘　　要：Because of its high-precision,low-cost and easy-operation,Precise Point Positioning(PPP)becomes a potential and attractive positioning technique that can be applied to self-driving cars and drones.However,the reliability and availability of PPP will be significantly degraded in the extremely difficult conditions where Global Navigation Satellite System(GNSS)signals are blocked frequently.Inertial Navigation System(INS)has been integrated with GNSS to ameliorate such situations in the last decades.Recently,the Visual-Inertial Navigation Systems(VINS)with favorable complementary characteristics is demonstrated to realize a more stable and accurate local position estimation than the INS-only.Nevertheless,the system still must rely on the global positions to eliminate the accumulated errors.In this contribution,we present a semi-tight coupling framework of multi-GNSS PPP and Stereo VINS(S-VINS),which achieves the bidirectional location transfer and sharing in two separate navigation systems.In our approach,the local positions,produced by S-VINS are integrated with multi-GNSS PPP through a graph-optimization based method.Furthermore,the accurate forecast positions with S-VINS are fed back to assist PPP in GNSS-challenged environments.The statistical analysis of a GNSS outage simulation test shows that the S-VINS mode can effectively suppress the degradation of positioning accuracy compared with the INS-only mode.We also carried out a vehicle-borne experiment collecting multi-sensor data in a GNSS-challenged environment.For the complex driving environment,the PPP positioning capability is significantly improved with the aiding of S-VINS.The 3D positioning accuracy is improved by 49.0%for Global Positioning System(GPS),40.3%for GPS+GLOANSS(Global Navigation Satellite System),45.6%for GPS+BDS(BeiDou navigation satellite System),and 51.2%for GPS+GLONASS+BDS.On this basis,the solution with the semi-tight coupling scheme of multi-GNSS PPP/S-VINS achieves the improvements of 41.8-60.6%in 3D position-ing accuracy compared wit

关 键 词：Multi-GNSS PPP Visual-inertial odometry Multi-sensor fusion GNSS-challenged environment Autonomous driving 

分 类 号：P228.4[天文地球—大地测量学与测量工程]