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Research paper : Integrated development of automotive navigation and route guidance system (H. Ito )−164−Synthesiology - English edition Vol.4 No.3 (2012) of the car as electronic data. The current location and destination on the roadmap were sought using the displayed bearing of the car, direction of the road, and landmarks. The second product was NAVICOM that used dead reckoning, where the current position was estimated from the distance traveled and the bearing data of the electronic compass, to display the direction to the destination and the remaining distance from the start point (current position) to the destination point. It was installed in Toyota Celica XX in 1981. Nissan launched a similar product at the same time. Honda’s Electro Gyrocator employed the method of using the gas rate gyroscope to calculate the changes in azimuth rather than the bearing. The fact that similar products were launched at the same time indicates that the engineers’ dreams were shared with society, and they tried to realize their dreams using the emerging electronic technology. The Electro Gyrocator set the map display by employing the CRTNote 1) display screen. In 1985, Toyota Soarer was equipped with the Electro Multivision that used a color CRT to display diagnosis, fuel consumption monitor, highway map, drive information (suspension condition), manual for on-board equipment, TV (worked only when the car was not in motion), and others. These were part of the information display function installed in later navigation devices. To provide the manual and map information, the cassette tape that was used generally for music was used as the memory medium. 2.2 Development phase after market introduction: Use of [supporting technology]In 1987, the Electro Multivision, which was a product close to the current navigation device and deployed the CRT display and dead reckoning, was installed in Toyota Crown. The navigation was added as one of the functions of the on-board information device that started from Toyota Soarer. This car used CDNote 2) as the memory medium containing map information, and digital map display was possible. The digital map data was initially prepared by the individual automobile companies, but unification movement occurred[2] since the development and maintenance costs of the maps were great. The memory evolved from cassette tape to CD and DVDNote 3), and then to SDNote 4) memory card and HDDNote 5). This led to the increased speed and capacity of data storage, and enabled multiple functioning. As the memories for audio and computer developed, these technologies were used where appropriate to automobiles.In 1991, the display shifted from CRT to TFT-LCDNote 6) with significant achievement in thinning, lightweight, and low voltage. Installability in cars increased dramatically. Also, the positioning precision was increased due to the use of GPSNote 7) that was considered to be a specialized military technology. In dead reckoning, the current location is obtained by calculating the travel distance information and azimuthal/angular velocity information from the sensors, and if the sensor information contains errors, accumulated positional errors will result. In GPS, the vehicle position is obtained continuously as long as the reception is alive, and temporary errors can be corrected. Also, the position can be corrected by map matching where the swept path of the car and the map data are compared[2], and this improves the positional precision, and enables various functions such as route guidance, swept path display, and point registration based on the route-finding software technology. Hence, a practical navigation became possible with the introduction of 32-bit microcomputer. This was a step toward door-to-door navigation that is the goal of car navigation.2.3 Turning point2.3.1 Turning point of route guidance: Use of telecommunication1) Development of VICS and othersIn 1996, VICSNote 8) was created by the collaboration of the National Police Agency, former Ministry of Posts and Telecommunications, and former Ministry of Construction. VICS is a system where the navigation device receives the traffic information (such as traffic jam, expected time of arrival, accidents/stalled cars/construction areas, speed and lane limitations, position of parking lots, and vacancies of parking lots) that are transmitted by optical beacon, radio beacon, and FM multiplex broadcasting, to obtain information for selecting the shortest route, as well as for displaying information. Currently, it is estimated that this is installed in about half of the car navigation devices. This means that the car no longer runs alone, but is linked with the infrastructure, can exchange information, and select/determine the best route.Also, the ITSNote 9) on-board device that integrates the DSRCNote 10) and the navigation device is being introduced. This provides the navigation, VICS, and ETCNote 11) in a single on-board device, whereas they used to be provided individually.2) Issue: Central navigationRather than the individual cars doing the route finding, it may be more efficient and precise if the data for current position and destination are uploaded, and the infrastructure such as the traffic control center would offer routing and guidance while considering traffic jam control. This is a future issue.3) Additional external informationMany applications of the navigation display are expected. One is the collision avoidance system. The display for cars that approach from the blind side in an intersection and warning for traffic jams ahead of a blind curve using the road-to-vehicle communication are being tested.

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