Research On Simplification And Selection Method Of Urban High Precision Road Network

In recent years,with the demand of new industries such as intelligent transportation and unmanned system for high precision location data,the concept of high precision road navigation map has been proposed,which has been widely concerned by academia and industry.High precision is becoming an important trend in the production of road data.However,the traditional precision road data still has a very rich application.It is necessary to study the production of traditional precision road data by map generalization of high precision road data.Based on the analysis of the research status of the road network generalization at home and abroad,the paper takes the urban high precision road network as the object,through the simplification and selection of it,it can produce the traditional precision road data well.The main research works of this paper are as follows:(1)This paper studies the maintenance method of spatial relationship in the process of urban high precision road network simplification from centimeter level to meter level.In view of the difference between the accuracy of traditional road network data and high precision road network data,the paper analyzes the change of spatial directional relationship in the process of simplification,and describes the change rules with a cone model.Then different maintenance methods of spatial directional relationship are used respectively at the end points and shape points,which effectively maintains the similarity of spatial directional relationship before and after the reduction of the accuracy of road network data.(2)The mesh construction method and stroke connect method of urban high precision road network are realized.In order to meet the needs of special structure detection and road network selection,meshs are constructed and strokes are connected for urban high precision road network.In process of constructing mesh,first identify suspended road and bridge road,and then build mesh through polygon search.Based on the analysis of existing stroke connection rules and strategies,geometric rules and every best fit stategy are used to connect stroke.(3)The detection method and processing method of special structure in urban high precision road network are designed.In order to meet the needs of the seletion of urban high precision road network,three special structures are detected and processed: roundabout,parallel lane and auxiliary lane.For the roundabout,through analyzing the compactess of the polygon where the roundabout is located,and then collapses the roundabout.For the parallel lane,a detection method combining parallel lane polygon and parallel coefficient is proposed,and then collapse the parallel lane through polygon centerline generation method based on Delaunay triangulation.For the auxiliary lane,detect it through parallel lane and generalized Y-type vertex,and then delete the auxiliary lane.(4)This paper studies the selection method of urban high precision road network considering the graphic expression.Based on the analysis of traditional mesh amalgamation method which do not consider the clarity of graphic expression,the conflict degree of graphic expression of road is measured through the analysis of road buffer in mesh,and priority should be given to deleting the road with high conflict degree in the process of mesh amalgamation.For the suspended road after mesh amalgamation,the method of stroke selection is adopted,and the bottom-up search strategy is adopted in the selection process.