Toyota Debuts Collision Avoidance Systems in Lexus

Toyota Motor Corp. is adding new radar- and sensor-based safety sensors to its vehicles that could sense and prevent rear-end collisions. The new technology will debut in the LS460 Lexus that will be released in Japan this month.

As part of Toyota's integrated safety management concept, the company is integrating stability control, anti-lock braking and sensing systems to determine the optimal support to give a driver to prevent an accident.

The pre-crash safety system uses millimeter-wave radar to detect vehicles and obstacles on the road ahead and help reduce the severity of collisions, along with newly developed stereo camera to detect pedestrians and support evasion maneuvers by the driver.  Rear millimeter-wave radar has also been added that detects a vehicle approaching from behind. A near-infrared projector located in the headlights supports nighttime detection.

The system retracts the seatbelts and warns the driver when it determines a high possibility of a collision. If the driver does not brake, the pre-crash brakes are applied to reduce collision speed. When the driver takes emergency evasive maneuvers, VGRS (variable gear ratio steering) and AVS (adaptive variable suspension) control the steering gear ratio and suspension to support the driver's measures. 

If the rear radar detects a vehicle approaching to quickly, it flashes the hazard lights to warn the other driver. Sensors in the seats adjust the headrests to reduce whiplash in case of impact.

The cruise control on the car can also maintain a fixed distance from vehicles ahead in traffic based on the other car's speed.

A Lexus spokesperson said that the U.S.-spec LS 460 will offer an intelligent parking assist system that aids with parallel parking. Toyota was unable to say at this time if or when the pre-collision systems would be available on U.S. models.

The Toyota system is yet another example of new technology aimed at reducing the frequency and severity of collisions. Earlier this year, Mercedes announced its new PRE-SAFE brake system, a self-braking feature that helps drivers avoid collisions by partially engaging the brakes when the vehicle approaches another car. It is available as an option on the Mercedes S-Class and CL-Class Coupe this fall. The company's Brake Assist PLUS system provides visual and audible warnings if the car is about to run into another vehicle, and automatically calculates the brake force needed to prevent a crash. These systems are based on near-range radar sensors. In trials, Mercedes found that automatic braking reduced crash severity by approximately 40 percent.

According to the Insurance Institute for Highway Safety, improvements to both vehicle structural designs and safety technology have largely been responsible for the continuing decline in motor vehicle death rates per registered vehicle.

"Death rates per vehicle and per mile have been going down for decades, and they still are," says institute president Adrian Lund. "In recent years it's the vehicles, not better drivers or improved roadways. [Our] study reveals not only the importance of the vehicle design changes and the kinds of vehicles motorists are choosing to drive but, on the downside, the loss of momentum for effective traffic safety policies on belt use, alcohol-impaired driving, and speeding."

Another IIHS study, announced in June, found that electronic stability control (ESC) systems, also based on sensor technology, reduced the risk of fatal multiple vehicle crashes by 32 percent.

These new technology advancements also help explain why, although the number of crashes has been declining, the cost of repairing vehicles (and the percentage of total loss vehicles) has been steadily rising during the same period, according to insurance industry studies.

Exactly how drivers will respond to vehicles that take control of their operation during accidents has yet to be determined. The Volpe National Transportation Systems Center of the U.S. Department of Transportation's Research and Innovative Technology Administration, in conjunction with the National Highway Traffic Safety Administration, evaluated a system designed by General Motors and Delphi Electronics for light vehicle applications.

According to the study, an automotive collision avoidance system, integrated with forward collision warning and adaptive cruise control systems, could prevent between 6  and 15 percent of all rear-end crashes.

However, false alerts issued by these systems tended to undermine their credibility with drivers, and overall driver acceptance was mixed.