Research On The Hybrid Positioning Strategy For Vehicle Using Enhanced Maps

The integration of Global Navigation Satellite System(GNSS)and Inertial Navigation System(INS)can effectively overcome the limitations of a single sensor,and it has been widely used.However,it is difficult to meet the positioning accuracy in the complex urban traffic environment.To deal with this problem,a vehicle positioning system based on enhanced maps is presented in this dissertation.Moreover,hybrid positioning strategy and multi-weight map matching algorithm are studied.The main research work and fruits are summarized as follows:(1)The multi-sensor collection platform has been constructed according to the demands for vehicle positioning.The platform can acquire multi-sensor data,followed by saving and processing.(2)Enhanced maps with a variety of geographic information have been designed and produced.Among them,raw data with sub-meter accuracy of the digital maps are collected through a high-precision integrated navigation system.The plan curve of roads and lanes are fitted by cubic spline.The road direction data are obtained by the cubic spline and stored in the enhanced maps.(3)The preliminary positioning results of vehicle have been obtained by a vehicle positioning model,which was established based on inertial navigation and satellite pseudo-ranges,and then optimized by enhanced maps,using a mothed of multi-weight map matching which is proposed in this paper.The multi-weight map matching algorithm integrated the information of distance,direction and topological relation,and can detect the lane-change of vehicle by vehicle sensors.(4)The presented positioning strategy has been tested extensively on real-road data.Those experiments include the results of the two positioning stages,followed by analysing and summarising.