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Research paper : How car navigation systems have been put into practical use (H. Ikeda et al.)−286−Synthesiology - English edition Vol.3 No.4 (2011) highly capable development staff, which resulted in software development costs dragging the business down.Nonetheless, Sumitomo Electric was then developing our original NAVS operating system aiming to boost the performance of NAVS. Our aftermarket NAVS launched in 1995 was highly regarded due to its fast operation. On the other hand, specialized operating system and application software necessitated operating system upgrading for adaptation to different vehicle families of individual automakers and for implementing novel functions. To provide access to the Internet, it was necessary to develop a new original browser. These difficulties in providing new features incurred huge software development costs and man-hours. As a result, by necessity, we requested automakers to give up implementing some features.In the meantime, the NAVS released in 1997 underwent specification changes, which in part caused software development man-hours to increase from the initial estimate of some 200 man-months to 1000 man-months at the time of completion, resulting in a substantial cost increase. Moreover, the software had so many bugs, which were detected after the release, which raised maintenance costs and substantially increased the deficit. This was one major factor in our pulling out of the NAVS market.Meanwhile, “concentration on core competence” became a keyword in the business sector. Sumitomo Electric decided to withdraw from the NAVS business because it had run up huge deficits and had no prospects of improvement.5 SummaryThe NAVS has been successfully developed not simply by NAVS software development, but through synergetic effects of developing substantial infrastructure and related technologies, such as a map database, traffic information, communication modes and various hardware units. Today’s widespread use of NAVS has been achieved through cooperation among persons concerned at the then Ministry of Construction, the then Ministry of Posts and Telecommunications and the National Police Agency; Toyota, Honda, Nissan and other automakers; many NAVS suppliers including Denso, Mitsubishi Electric, Alpine and Pioneer; Panasonic, Hitachi and other infrastructure developers; and component suppliers involved in developing small vibration gyros, GPS, display units and other components.Figure 7 shows technologies and components employed in NAVS as well as related infrastructure in chronological order. Accordingly, the NAVS is complete, consisting of a number of technologies, combinations of components and software that ensures efficient use of them.Map data evolved from proprietary data possessed by individual companies to shared data. Sensors technology saw the emergence of vibration gyros. When GPS was developed, it became simple to detect the current location with high accuracy. As display devices, the price of LCDs fell. Trends in the area of functional enhancement were improved performance of CPUs, increased memory size, and advances from CD-ROM to DVD or HDD.Another factor contributing to the widespread use of NAVS was the simultaneously developed infrastructure. The Japanese Intelligent Transport System (ITS) emerged as NAVS became popular and has now become essential to automobiles. Subsequently, the development of the electronic toll collection system followed.The NAVS plays the role of an information center in a vehicle, displaying images of onboard cameras and various other pieces of information. Integration between the NAVS and driving control is advancing, as exemplified by automatic deceleration before the intersection at which the vehicle is to make a turn. Meanwhile, portable navigation devices (PNDs) are becoming popular abroad at a remarkable pace. NAVS are expected to be more ubiquitous in the future, becoming polarized into high-end OEM NAVS and affordable PNDs.AcknowledgmentsThe development of NAVS for practical use has been achieved through the efforts and contributions made by many involved parties from the industrial, governmental, and academic sectors. We hereby recognize their achievements and express our gratitude to them. We need to mention that former Sumitomo Electric executives Nobuo Yumoto Fig. 7 Correlations in development of car navigation systemDistanceCongestionRegulationsEnhanced guide to surrounding areasFor location detection (MM)For displayRout navigation usingtraffic informationRouteguidanceCurrent locationdetectionCombinationwith cell phones and PCsIntegration with other functionsFastOperationNav aloneConfigurationHDDDVD32 bitNationwide mapdivided into 3 to 5partsVICS receiverLCD16 bitCDCRTCPUMediaMap recordDisplay(BJ)Vibration gyroGPSDifference in speed of revolution of right and left wheelsMagneticfieldWheelspeedDirectionGeneral-purpose designCACS ’73RACS ’84AMTICS ’87Digital Road Map Association ’88Traffic control system ’66VICS ’91Cedric/Cima’89MM’97AccordVICS’93Aftermarket’92GBS-BJ-Route’91Optical FJITSOptical fibergyroNavPositionsensorMapHardwareSoftwareInfrastructureSumitomo’sproduct(Optical FJ)Diamante

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