Vol.3 No.4 2011

47/72

Research paper : How car navigation systems have been put into practical use (H. Ikeda et al.)−288−Synthesiology - English edition Vol.3 No.4 (2011) Furthermore, despite its limited number of pages, the paper mentions the establishment of the Japan Digital Road Map Association, collaboration with other corporations, and cooperation with government agencies as important elements of research and development management. This makes the paper a representative one on Synthesiology.2 General perspective on combining individual elemental technologiesComment (Akira Kageyama)The paper refers to: (A) location detection, (B) route calculation and (C) route guidance as key elemental technologies and, beginning with map-matching, introduces. the reader to candidate technologies usable for the completion of (A), several technologies suited to the completion of (B) and a few technologies needed to complete (C). I think the paper can include an illustration or a list of elemental technologies used to complete NAVS as a practical technology, in order to help readers unfamiliar with the subject field understand the topic. Such an illustration or list would facilitate reader understanding of the need of a lot of technologies in producing NAVS.Comment (Motoyuki Akamatsu, Human Technology Research Institute, AIST)If a figure is provided showing how course changes were made when selecting technologies regarding each individual major technological element, such as map-matching, location identification, digital map and route calculation, depending on new factors of the time (GPS, CPU and storage devices), readers would immediately understand that the development scenario underwent dynamic changes to keep up with technology trends.Answer (Hirosaka Ikeda)We inserted Fig. 7 in “5. Summary” to show relationships among elemental technologies.3 Importance of software technology development for unified control of diverse hardware technologiesComment (Akira Kageyama)The paper states that not only sensor technology, but also software technology is important. I think it is better to place more emphasis on the importance of OS and other software research and development. Software appears to play a critical role in combining sensor technology and digital maps, location correction and processing of data received from radio-wave or optical beacons.Answer (Hirosaka Ikeda)A NAVS is an onboard device in which software technology plays an important part, as you point out. Its software size is far larger than those of other onboard devices. The paragraph on vibration gyros in subchapter 3.1 of the paper now has an additional description about software improvement needed for the use of vibration gyros, since they are poorer than optical fiber gyros in performance of the hardware itself, specifically in drift amount. Regarding beacon data reception, the paper describes the need for complex internal processes due to intensive loads, such as switching to an interruption screen after receiving beacon data.4 Technological development processQuestion (Akira Kageyama)The paper states that a huge increase in software development cost necessitated the withdrawal of Sumitomo Electric Industries, Ltd. from NAVS business. Sumitomo Electric’s withdrawal is very regrettable, since the company led the industry in the early days of NAVS. Nonetheless, could you please, from an engineering or industrializing perspective, summarize key technological or management points that enabled NAVS and ETC to later develop into high growth industries?Answer (Hirosaka Ikeda)(1) Key points that led to high industrial growth1) One key technological point is that the NAVS is, as with television, a commodity that is used repeatedly. Once a customer tries it, he or she cannot go without it. Take the example of television in the early days; people argued, from an educational point of view, that they had no need for television in their homes, as it would lead to home environment degradation. Today, multiple television sets are found in every home.The NAVS was in a similar situation in its early days. Most staff at automakers’ electronics divisions said that automobiles did not need navigation systems. One said: “What are you doing, Mr. Ikeda, at this busy time? You should stop fiddling with NAVS development.” He later took the post of NAVS development manager and said: “Mr. Ikeda, I was wrong.” At that time, market surveys showed that few people wanted a NAVS in their cars. On the other hand, interestingly, one automaker executive did not trust so-called marketing approaches. He said: “Mr. Ikeda, it’s meaningless to ask customers whether they want a product that is not yet on the market. They have no idea.” Professional taxi and company drivers said that they needed no NAVS, that looking at a map would be sufficient. The NAVS has now become a necessity for them. In this sense, the NAVS is a driving assistance system. Derivative words from NAVS are now used in other fields, proving the wide acceptance of NAVS.2) Few automotive parts cost more than ¥10,000, and even fewer exceed ¥100,000. However, the NAVS has proven that expensive onboard equipment can be viable. Moreover, the NAVS involves extensive supporting industries. For instance, there is a market even for onboard LCD alone.3) NAVS software was the largest embedded automotive software. Since its quality and reliability requirements were far higher than those in other industries, including the PC industry, NAVS software improved noticeably. As with hardware, software quality requirements are high in the automotive industry. Users would immediately notice defects. General IT companies would not be able to take part in genuine brand NAVS production. Company distinction was created in that business sector, according to quality. The sector was characterized in that zero bug tolerance was a fundamental requirement. But this was a trap that Sumitomo Electric fell into when conducting its development management.(2) Software breakthroughWhen you build software, you need to think about both functional differentiation through pursuit of your originality, as well as ease of expandability provided by commonality. In my view, Sumitomo Electric was preeminent above all others in NAVS performance. However, in the years following 1995, it became necessary to add major features such as compatibility with VICS and support for the Internet. We should have been aiming for commonality at that time. Nonetheless, Sumitomo Electric took the course of developing its proprietary OS in order to achieve functional differentiation and fast operation. As a result, the company had no choice but to provide major additional features by itself. We revised the paper to include this information.5 Information on Etak’s NAVSQuestion (Motoyuki Akamatsu)Etak, the company that released the world’s first map-matching technology, launched a NAVS in 1985, while the paper states that Mr. Yumoto became interested in map-matching technology in 1983. Did he learn about the technology because there were some papers on map-matching published before Etak commercialized it?Answer (Hirosaka Ikeda)When Yumoto, then working for Sumitomo Electric, visited

※このページを正しく表示するにはFlashPlayer9以上が必要です