TransCore makes a variety of other advanced electronic systems for the intelligent highway. One example is the automatic toll violation and red-light violation cameras that photograph the license plates of vehicles that get away. Other TransCore products include Advanced Traveler Information System kiosks, which give road and weather data to drivers at airports, as well as Advanced Traffic Management Systems, which include traffic-light controls and highway-sign radio systems.
Typical short-range RFID products are those made by Microchip Technology. The MCRF355/360 products operate in the FCC's no-license industrial, scientific, and medical (ISM) band at 13.56 MHz. The passive windshield tag/transponder is available in various sizes (Fig. 3). The larger the tag, the greater the read distance. A 2- by 2-in. tag will give a range of over one meter with maximum transmitter power and a large read antenna.
A tag contains a 154-bit reprogrammable memory. The 154 bits of data stored there includes the following fields: a 9-bit header, an 8-bit customer number, 104 bits (13 bytes) of user data, a 16-bit checksum, and 17 zero bits between the various fields and data bytes. This information is transmitted back to the reader at a 70-kbit/s rate using a Manchester-encoded signal that amplitude-modulates the 13.56-MHz carrier.
Such low-cost RFID systems target an enormous range of applications, from airline-baggage identification, to automatic ski-lift ticket validation, to work-in-progress (WIP) management in automobile manufacturing, to the previously mentioned automotive uses (Fig. 4). The RFID products may replace bar coding in some applications.
As we move toward more intelligent vehicles and highways, you will begin to see some truly amazing products. Drive-by-wire (or X-by-wire as it's called in the automotive field), fully automatic guided vehicles, and remote diagnostic systems are only a few examples.
X-by-wire is similar to fly-by-wire systems, which have been available on aircraft for many years. X-by-wire systems effectively replace the mechanical links existing between the driver's controls and the mechanism that actually performs the function. The most common functions being designed are X-by-wire for steering, brakes, and throttle control.
In conventional steering systems, there's a direct link between the steering wheel and the steering components in the front end by way of gears and hydraulic assists. X-by-wire would eliminate that. In such a system, a transducer, like a potentiometer attached to the steering wheel, will send steering-position input signals electrically to a servo system in which electric motors on the steering components provide the power to turn the wheels.
The same scenario applies with brakes. A brake switch or variable transducer activated by the driver's foot will send an electrical signal to the brake system. The mechanical link between the gas pedal and the fuel-injection system will similarly be replaced by a remote control device using a servo actuator.
These types of systems are no longer just experimental. Test systems have been developed using stepper motors, high-power MOSFET switches, and multiple embedded controllers. Such systems also set the stage for fully automatic remote control of the vehicle by wireless signals or guidance sensors embedded in the road. Autopilots have been available for years on boats and planes, so why not on cars?
Additionally, remote diagnostics are being developed. Sensors in the vehicle keep track of vehicle usage, miles traveled and at what speeds, engine-speed extremes, oil-change intervals, tire pressure, condition of shocks, and a variety of other engine and chassis conditions. These conditions are stored and then automatically transmitted to a diagnostic computer at a dealership garage. This analyzes the data and recommends the type of service or repair necessary and maintains a database of the vehicle's service.
As with most large undertakings, the biggest issue is cost in building intelligent highways and cars. Adding telematics and other high-tech goodies only makes it worse. Of course, buyers will always pay more for added value, especially for safety and convenience items. But there's a limit. Most of the costly hardware becomes more affordable once high volume has been attained. So an evolutionary approach to introducing intelligent components is still the best way to go.
Another issue is complexity. As the vehicle subsystems grow more sophisticated, dealing with them requires greater driver knowledge and skill. A key design goal is to make the intelligent systems as transparent to the driver as possible. Excessive complexity puts drivers off. We don't need a dashboard that looks like it came out of a new 777 aircraft. Just operating a multidisk CD player in a car is a challenge to many. The more buttons, dials, knobs, levers, switches, and displays, the greater the driver confusion.
Are we facing a future that must include driver training and check rides in our new cars? As usual, the working term here is "keep it simple." Make any intelligent systems fully automatic or very easy to apply. Furthermore, make them as nondistracting as possible.
Last but not the least of these issues is customer acceptance. Will drivers actually want all of the stuff engineers are capable of designing and building? Many of the intelligent systems take away driver duties and responsibility, and a lot of drivers don't want that. For example, many drivers still like shifting gears by themselves. Plus, remote-control X-by-wire may never happen. Do you want it in your car? Perhaps we will evolve into it. But without question, most of us will support any device or service that provides safety and convenience while also improving the traffic situation. (For more information, see "Useful Web Sites," at left)