Electronic Design

Thanks To Active Safety Systems, You Won't Buy It If You Don't Brake

I should have fastened my seatbelt. Our Cadillac, the world's first car with an auto-braking system, used GPS and wireless signals to determine its need to auto-brake and avoid hitting the car slamming to a stop in front of us!

General Motors' Dedicated Short Range Communications (DSRC) demo was one of the highlights of this year's Convergence, the semi-annual automotive electronics event held last month in Detroit. "Convergence" is taking on a broader definition as cars begin to communicate with one another and with the outside environment.

Cars now use data from GPS and other satellites as well as Internet connectivity. They're integrating infotainment and navigation systems with cell phones, PDAs, and MP3 players. Far beyond a good set of wheels, they're becoming "connected nodes" on the information superhighway.

Smarter cars also are safer cars. The U.S. auto fatality rate has been falling, with electronic stability control (ESC) systems deemed a "spectacular success" by Adrian Lund of the Insurance Institute of Highway Safety. ESC has reduced single-vehicle crashes by 40% and single-vehicle fatalities by 50%. The technology has been so effective that the systems soon will be mandated on all U.S. cars.

Still, there is room for improvement, as 15 million crashes in 2005 resulted in 1.8 million injuries and 43,443 fatalities. Joseph Kanianthra of the U.S. Department of Transportation said the institute is studying which of the new active safety systems have the best chances of reducing these counts.

The Convergence exhibit floor offered amazing active safety-technologies like collision avoidance and/or preparation, blind-spot warning and lane-change assist, steerable headlamps, lane-drift warnings, and infrared for night vision. Automotive manufacturers are still sorting out the pros and cons of competing developments, like radar, lidar, cameras, and sensors. They're also considering standards for how to warn drivers without overloading them.

"Convergence" means active safety technologies will be enhanced via integration with data from outside the car: information on weather, traffic, and even the layout of the road ahead. Delphi's vision processing uses a single camera for multiple functions: headlight control (dimming brights for oncoming vehicles), pedestrian recognition, roadsign recognition, and night vision. It also can determine driver impairment, monitoring the position of a vehicle in its lane over time.

A second Delphi development, an infrared camera inside the dashboard, watches the driver's eyes to make sure they're open and focused on the road. The system watches for "extended eye closure" and monitors drowsiness over time. "A head bob is too far down the road," said a Delphi spokesman, noting that the first adoption should be by 2008, initially in commercial vehicles where the average accident cost tops $500,000.

GM really pushed the envelope on active safety with its awesome demonstration of vehicle-to-vehicle communications. The demo was the first wireless "all directional" driver warning system and the first wireless automated collision avoidance system.

Through GPS, the system forms ad hoc networks of cars that are in the same vicinity and so need to share data. Using the DSRC 5.9-GHz radios, the vehicles communicate data such as speed, position, deceleration, and yaw with cars up to a quarter mile away. In our demo, when the lead car suddenly came to a stop, our following driver ignored all the alerts and let the auto-braking kick in. Phewww!

When a vehicle pulled into our blind spot, a steady amber icon came on in the side mirror. When our driver activated his turn signal to move into that lane, the mirror light flashed, and vibrating seats were activated. Vibration on the left or right side of the seat lets you know which side the passing car is on. All four seats had the haptic warnings, so passengers as well as the driver are aware of hazards—and enjoying the massage! Technocom showed another aspect of DSRC: roadside-to-vehicle communications, a second part of the Department of Transportation's Vehicle Integration Initiative (VII). For more on the demonstration, as well as photos and other trend and product news from the show, go to www.electronicdesign.com and see Drill Deeper 13920. And please, fasten your seatbelts!

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