Research And Application Of Map Matching Technique Based On Mobile Terminal Navigation System

Under the background of growing demand of location-based service (LBS), the paper conducts a study on the map matching based on combination of mobile communication technology and vehicle navigation technology. A practical solution is proposed to ensure both matching accuracy and real-time matching under different road conditions. This research topic is significant for overcoming the limitations of improving positioning accuracy through hardware in mobile terminal based navigation system and is significant for making full use of digital maps to achieve integration of information from both GPS and digital maps.The paper studies the theory of map-matching technique, develops a p-parameter map-matching model based on the analysis of existing map-matching algorithm, and presents the formula of similarity factors and the parameters of the formula. The existing projection matching algorithm is improved from seven aspects to make more reliable and applicable based on the study of its limitations. An integrated hierarchical matching method based on classification management of the road network is firstly proposed considering the different characteristics of urban roads. This method is conducive to use different matching algorithm according to both different road condition and navigation demand, and can better coordinate contradictions between the accuracy and real time of matching. Data organization and management is studied according to conditions of software and hardware of intelligent mobile terminal and a new method suitable for integrated map-matching algorithm is applied to ensure real-time matching and ideal results of map matching. A complete solution of map matching is proposed based on the researches stated above. In order to maintain integrity and reliability of map matching, conditional test based on criteria of distance or direction is conducted to detect automatically and recover from a mismatch. Fuzzy comprehensive judgment method is applied to evaluate map-matching credibility, and map-matching result is used to validate positioning data based on the credibility. Vehicle position accuracy is evaluated after map matching, and data integration from both sensor and map matching is used to derive optimal position estimation so that the tight coupling of map matching and GPS is achieved. A component LBS system including six function modules is developed, based on this platform a prototype system of map matching is developed. Finally experiments are carried out to test correctness and feasibility of the complete map-matching solution.