The Application Of Curve Matching In Navigation Based On Dead-Reckoning

With the development of transportation, a concept of intelligent transportation systems is put forward to resolve the confliction between requirement of increasing road-network resource and their constructing speed. The potential of road-network resource is excavated by intelligent management. Navigation is one of the most important parts of intelligent transportation systems. In the management of city transportation, navigation of satellite cannot meet the practical requirement because of shielding and interfering of satellite signal. Therefore, map matching and dead-reckoning (DR) is used to assistant navigation. This combination is defined as GPS/DR integrated navigation system, in which the map matching is used for correcting the orientation and distance errors of DR. The matching method will improve the navigational precision based on DR, when GPS and/or GLONASS signals are lost.Matching technology is kernel point of map matching. It is integrated with computer, pattern recognition, and artificial intelligence. Matching technology is widely used in photogrammetry, navigation, artificial intelligence, computer vision, machine manufacture, physic, remote sense, GIS, drawing, archaeology, environmental protection and so on. Therefore, many scholars are attracted by matching technology. Nowadays, this technology is also one of research hotspots in surveying and mapping fields.This article pays attention to make use of curve matching to correct the distance error of dead-reckoning. Matching algorithm improved by Woleson is dependent on redrawing characteristic point and corresponding relation. The accuracy of redrawing characteristic point and finding corresponding relation determines the accuracy of matching, even success of matching or not. In fact, there are some errors in redrawing characteristic point. Therefore, this is inevitable to increasedifficulty to find the corresponding relation between characteristic points. In some case, the improper corresponding relation is found by Woleson's algorithm. Based on the study of Woleson, a way of point traversal is put forward in this article. The method can decrease the number of finding the characteristic points. It is firstly suppose that each node may correspondingly match curve's original point. Secondly, the curve to match is divide into some sections. The absolute errors between two matching curves are compare in every section. Then, the resemblance of two curves is judged by their absolute errors. Based on Woleson's matching algorithm, matching process is mended. The new algorithm is more suitable for practical application in matching between vehicle navigation track based on DR and electronic map than old one. At last,some practical navigation data in Hong Kong are processed by algorithm improved and Woleson's. It is proved by the results of experiments that new algorithm not only decreases the number of characteristic point, but also predigests curve matching algorithm. The new algorithm makes full use of curve characteristic information in matching process. On the other side, the new algorithm is not sensitive to max errors between two matching curves. When curve characteristics are not obvious (as line), the matching result is not ideal.