GM Develops New Collision Warning System

General Motors is planning to equip the 2012 GMC Terrain with the industry’s first, “affordable” crash avoidance system. The system is based on a single camera placed in front of the rear-view mirror to help drivers avoid front-end and un-signaled lane departure crashes.

It’s by no means the first collision avoidance system on the road, but the new technology significantly lowers the price compared to existing designs that may use multiple cameras, radar sensors or both, putting the system within the price range of mainstream, rather than luxury, buyers.

“Digital image sensors are used in just about everything from cameras to mobile phones to computers and this is making them a more-affordable alternative for use in vehicles,” said Raymond Kiefer, General Motors Technical Fellow for crash avoidance systems.  “By combining a digital camera with state-of-the-art image processing algorithms, we’re able to estimate when a crash may be imminent,” he said.

This dual-benefit crash avoidance system will cost $295, which is significantly less expensive than the systems now available in luxury cars, GM’s experts said. The maker developed the system with extensive help from suppliers, including Magna, TRW and Mobileye.

(GM announces new center-front airbag system designed to reduce deaths and injuries in side-impact crashes. Click Herefor the complete story.)

The crash avoidance system uses a high-resolution digital camera mounted on the windshield ahead of the rearview mirror that looks for shapes of vehicles and lane markings. Special software examines each frame captured by the camera – about 14 frames per second – searching for shapes characteristic of vehicles.

Detected vehicles are then checked over successive frames for changes in size to calculate the time-to-collision. The system also uses speed, directional change, and sensors showing how the accelerator and brake pedal have been applied to determine whether and when to alert the driver.

The system uses audible warnings and a high-mounted visual display to warn the driver if he or she is following another vehicle too closely, if a collision is imminent, or when departing a lane without signaling first.

The warning display contains green “vehicle ahead” and “lanes detected” icons, as well as flashing red “forward collision alert” and amber “lane departure warning” icons that are accompanied by warning chimes. The new system operates at speeds above 25 mph and warns a driver if they are following too closely or in imminent danger of a front-end crash. When a collision is predicted to be imminent, vehicle brakes are pre-charged to help drivers quickly reach maximum braking.

The system combines four separate exposures to create each high-resolution image for analysis under varying light. Night time target recognition is also enhanced by looking for pairs of lights moving together that indicate taillights.

The system does have a drawback.  It operates as long as the camera eye is unobstructed, such as by snow or mud or a heavily iced-over windshield.

In addition to searching for other vehicles, the image processor also looks for lane markings to provide lane departure alerts. Available at speeds above 35 mph, the lane departure warning icon shines green when lane markings are detected to indicate the system is active. If the vehicle drifts out of the lane without a turn signal, the lamp switches to flashing amber and is augmented by warning beeps.

Rear-end crashes account for approximately 28% of the nearly 6 million police-reported incidents that occur annually. The National Highway Traffic Safety Administration maintains that the majority of rear-end collisions involve driver inattention, and the Insurance Institute for Highway Safety says forward collision warning systems have the potential to help prevent such crashes.

“GM is committed to providing protection before, during and after a crash, but the best scenario is to avoid a collision in the first place, and this technology is designed to assist drivers for that purpose,” said Gay Kent, GM executive director of Vehicle Safety and Crashworthiness.