Texto educativo ieee

ABSTRACT
Mutual exchange of status data between vehicles in close proximity i s the basis for safe vehicle operation. Application areas range from driver assistance/warning t o fully autonomous driving. To enable this data exchange we need an intervehicle communication (IVC) system. Vehicles involved in mutual data exchange form a kind of local area network; however, the characteristics of thisnetwork are quite different from those of conventional networks. The configuration of this kind of network changes from time to time, in terms of organization, proximity group, group position, and relative position; therefore, it is very challenging to establish. The authors have been working on this problem from the point of view of communication media and protocol. In this article thecharacteristics and requirements of IVC are discussed, and several preliminary communication protocols are proposed. The authors also present some experimental results from the implementation of a function integrating communication by infrared ray with a gap-measuring technique by the vision system.

Masayoshi Aoki, Seikei University and Haruki Fujii, /SK Association

here are many types of applicationswhich provide real-time information to/from an individual vehicle. We feel that they may be grouped into the following four categories according to the characteristics of information: general information, vehicle monitorimanagement information, personal information, and information for safe vehicle operation. The first category deals with advanced traveler information systems (ATIS)-relatedinformation, such as traffic situation, congestion, and regulation, which is broadcast from fixed stations. The second category is related to the management of vehicle groups such as taxi companies and freight transport companies; the basic function is to give commands to each vehicle. The third category deals with information exchanged between drivers; for example, “Go ahead,” “Thank you,” or “Thereis a speed trap ahead.” The fourth category deals with information used specifically to operate the vehicle, for example, vehicle status, position, speed, acceleration, and intention. For the second category, there are many widely used commercial systems available. Systems for the second category have become popular in recent years and are now in the deployment phase. The third and fourthcategories are very interesting from a technical point of view, but have not been developed systematically. These categories have become more important recently, because information exchange between drivers and also between vehicles is very important for safe driving. The fourth category is especially important for advanced vehicle control systems (AVCS) applications. We use the term intervehiclecommunication (IVC) in the broad sense, including the third and fourth categories, and in a narrower sense for the fourth category only. Some research and development activities for wider IVC can be found in Japan [l, 21 Germany 131, and the United States [ ] The 4. authors also have been working on this IVC at JSK since 1981. In this article we focus on the fourth category, and discuss its characteristicsand the requirements for the protocol. In addition we present some experimental results.

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INTERVEHICLE COMMUNICATION AND RADIO LAN
n ordinary local area network (LAN) is constructed of previously arranged and identified stations located within a range in which the stations can form direct communication links with each other. In this case, it is comparatively easy to form communicationlinks between stations autonomously, even if a master control station does not exist. In the case of IVC, constituent stations of a LAN vary from time to time, since they are mounted on moving vehicles; furthermore, we have to think about the case when a hopping transmission expands the boundary of the network over the range of each station. So for IVC, communication reliability will be different...