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We were the first in the world to start mass-producing the fiber optic gyroscope for an automobile navigation system. The fiber optic gyroscope was installed in an automobile in order to improve position detection accuracy. However, mass-producing the fiber optic gyroscope for an automobile navigation system was not possible before because it was difficult to achieve the high performance required under many operating conditions, especially in wide temperature ranges between -20 °C∼70°C. In order to overcome these problems, we have developed a new signal processing for a fiber optic gyroscope having the compensation functions of cancelling the fluctuation of the optical signal. The navigation system using this gyroscope has been installed in the Nissan Motor Company's 1991 CEDRIC, GLORIA, and CIMA models.

The recently developed navigation systems discussed in this paper include location detection using map-matching, map display, and improved man-machine interface functions, and are contained in a stand-alone system installed in passenger cars. The newest system uses a fiber optic gyroscope as a rotation rate sensor, and improved map-matching method to get high accuracy. As to driving guide information, the system can display road information from road side radio beacons, and can play CD-ROM discs based on CDCRAFT which is proposed in Japan as a common standard of CD format and application program for navigation systems.

This paper describes the man-machine interface and control software of a Navigation System for private automobiles. The system shows the accurate position of the vehicle on a CRT map display and can also provide useful information such as the locations of hotels, golf clubs, etc. The man-machine interface of this system consists of a menu display and touch-sensitive switches on the screen. Due to safety considerations, some of the displays and operations are prohibited while the vehicle is in motion. A multi-tasking software system controls these functions. Most of the programs were written in “C”, but assembly language was used for some basic input/output control programs. The total program size is about 384 Kbytes. This navigation system was installed in Mitsubishi's Diamante models in 1990.