The market for a location equipment using the Global Positioning System (GPS) is growing and there will be a demand in the future for more low price, high accuracy equipment, as part of the vehicle navigation equipment, to be used with Intelligent Transport Systems (ITS) as a location service. At the present time, the conventional GPS receiver is inexpensive but it is inedequate for monitoring the variation and continuity of the vehicle's position. The differential GPS (DGPS) receiver is efffective as a means of improving the accuracy of the vehicle's position but it can only be used over a geographical area where DGPS correction data is received. These GPS receivers cannot be used by a user who wants a highly accurate position continuously. So, a conventional GPS receiver is used with other sensors in consumer vehicle navigation equipment in Japan. This paper describes the method of locating the vehicle's position continuously, with smaller variations than those from a conventional GPS receiver, by fusing a conventional GPS receiver with low cost sensors. (A*)
Abstract