Understanding Smart Sensors - Nomads.usp

188 Understanding Smart SensorsAntennaReceiverMainswitchDoor lockcontrol relayKey unlockwarning switchDoor lockmonitorDoor courtesyswitchKeyTransmitterswitch (push)Figure 8.8 Remote door lock control system.8.3.6 Intelligent Transportation SystemThe ITS, formerly known as intelligent vehicle highway system (IVHS) in theUnited States and by other names (and nicknames, including “smart cars” and“smart highways”) around the world, requires several sensing technologies,many of which are RF based, to implement full functionality. ITS has definedseveral areas that are being addressed to varying degrees, from research to productionsystems. These areas attempt to solve a number of system-related problemsas well as provide new functions and services to drivers. The applicationareas include advanced traffic management system (ATMS), advanced travelerinformation system (ATIS), advanced public transportation system (APTS),advanced vehicle control system (AVCS), advanced rural transportation system(ARTS), and commercial vehicle operation (CVO).The various systems require a number of sensors, including GPS sensing,closed-circuit TV monitoring, IR detectors, dead reckoning, automatic vehiclelocation, and identification [20]. Dead reckoning can be accomplishedby differential wheel-speed sensing and a fluxgate magnetic compass or a