Sensors have been at home in automobiles since the invention of the gas gauge and the speedometer, but nearly a century after their introduction, sensors are now looking out for vehicles almost as much as they look in on them.
Domestic and foreign automakers have introduced a bevy of sensor-based driving aids and collision-avoidance systems as sensor technology becomes cheaper and spreads across a broader range of products.
"Sensors are starting to play more of a key role in safety systems," said Nady Boules, director of General Motors Co.'s electrical and control integration laboratory.
"When we're talking about driver assistance systems, blind-zone detection, parking assist, frontal collision warning, lane departure warning, these are systems that will warn the driver if there is something endangering the vehicle."
Automakers have a number of sensor-based systems already on showroom floors or heading there, including:
• Adaptive cruise control, which uses radar to automatically slow down a cruising vehicle when it detects a slower vehicle getting too close;
• Blind-spot monitoring, which uses radar or laser-based systems to issue either a visual or audible warning when other vehicles are located within a driver's blind spots;
• Rear-looking, cross-path monitoring, which uses sensor data to determine and issues a warning if objects are either in the path of a vehicle in reverse, or approaching from the sides, such as when a driver is backing out of a parking space;
• Collision-avoidance systems, which use sensors to monitor the distance between a vehicle and objects and vehicles ahead, intervening by either automatically engaging brake systems or, at the least, alerting the driver, and
• Tool-tracking systems, introduced by Ford Motor Co. as part of its Ford Work Solutions system in its trucks, which uses small tags applied to individual tools to allow the truck to "inventory" what's on board and alert the driver when a tool has been left at a work site.
Chrysler Group LLC spokesman Nick Cappa said the broader use of sensor technology has largely been made possible because the underlying technology required has become smaller and cheaper.
"[These] systems would not have been realized if it were not for the commercialization of very small short range radar sensors," he said, adding that radar systems used by Chrysler are about "the size of a deck of playing cards, allowing us to squeeze the sensors into a very small space behind the rear tires under the rear bumper."
So where is all of this sensor data heading? According to GM's Mr. Boules, out of the car, and into a network that could one day lead to a truly autonomous automobile.
"We are working on another kind of sensor, completely different, based on wireless communication between vehicles. That would be the ultimate, really, because there's nothing cheaper than radio wave systems," Mr. Boules said. "We've proven that that's adequate to provide information for safety. It would only work if every car broadcasts it, and that would be the problem in implementing it."
Along those lines, Audi last week revealed that it is testing a system in Ingolstadt, Germany it calls its "travolution project." The project is a sensor-driven dialogue between automobiles and traffic signals that allows drivers to reduce the amount of time spent at a standstill or accelerating, reducing fuel consumption.
Audi has incorporated wireless devices into traffic lights that transmit data to vehicles that display it in graphic form, telling the driver, for example, how fast to go so that the next traffic light changes to green before the car reaches it.
The system also allows the test vehicles to transmit a warning - and in some cases even interrupt power from the engine - when approaching a traffic light that is going to turn yellow or red.