Onboard Navigation System Operating via GPS

Motor vehicles play an indispensable role in the modern society as a means of individual transportation. For higher safety and efficiency in the automotive transportation, integrated automotive information systems are now under vigorous research and development in major countries of the world.

In the United Sates, a lot of governmental and nongovernmental private projects are under way under the coordination by the IVHS (Intelligent Vehicle Highway System) which is an advisory organ to the DOT. Meanwhile in Europe, major programs are actively promoted including the program PROMETHEUS (Programme for a European Traffic with Highest Efficiency and Unprecedented Safety) which is a part of the nongovernmental project EUREKA (European Research Coordination Agency), and the government-led project DRIVE (Dedicated Road Infrastructure for Vehicle Safety in Europe). In the mean time in Japan, studies are being made on the construction of social infrastructure for the traffic information supply under the leadership of the National Police Agency, the Ministry of construction, the Ministry of Posts and Telecommunications, and other governmental organizations. The studies are now expected to advance further to the reality since a number of road traffic information media including RACS (Road Automobile Communication System), and AMATICS (Advanced Mobile Traffic Information and Communication System) have been integrated into the VICS (Vehicle Information and Communication System). The VICS is projected to provide the following information services:

1. 1)
   Traffic congestion,
2. 2)
   Traffic regulations as road constructions and accidents,
3. 3)
   Parking area locations and availability, and the route to the places,
4. 4)
   Intersection guide, etc.

The services are to help drivers stay away from traffic congestions and easily find parking space, thus easing their mental stress for safer drive. Moreover, the resultant raise in the driving efficiency is expected to save fuel consumption and reduce exhaust emissions.

The key to the effective use of the information is the establishment of the basic technology of knowing the vehicles' own current positions, in addition to the establishment of information supply technologies.

In April, 1991, we launched a passenger car “Eunos Cosmo” into the Japanese domestic market, which is equipped with the CCS (Car Communication System) that totally controls the external and internal vehicle information. The central part of the system is the onboard navigation system (GPSS (Global Positioning System with Satellite)) with world's first automotive application of the GPS (Global Positioning System).

The GPSS is a complex navigation system based on the combination of dead reckoning and satellite navigation methods drawing advantages on both sides by the artificial intelligence technique, and is the establishment of the technology for obtaining the current position automatically and accurately. This paper presents the outline of the GPSS and major new technologies used in it.