Subaru's new EyeSight driver-assist system can help prevent a rear-end collision and/or other incidents via engaging one or more of seven technologies: precollision braking, precollision brake assist, precollision throttle management, lane-departure warning, lane-sway warning, adaptive cruise control, and lead-vehicle start alert.
“EyeSight is a supplement, not a substitute for the driver,” David Sullivan, Subaru of America’s Cross Car Line Planning Manager, said during a media briefing in September at the Willow Run Airport in Ypsilanti, MI.
Two charge-coupled device cameras and a processing unit—mounted inside the car at the top edge of the windshield’s center point—are EyeSight’s key components.
EyeSight scans horizontally with a forward range of about 260 ft (80 m) as well as laterally every 0.1 s. From the vehicle’s center line, the black and white cameras have a 25-degree angle of view and a 13-degree upward viewing angle. The system needs a 20 mph (32 km/h) speed differential—essentially 2.5 s—to recognize an object.
“By comparing the left camera image with the right camera image, EyeSight determines the distance to the vehicle or obstacle in front. The cameras need contrast in the vertical surfaces to see in the daytime or nighttime. But in order for an obstacle to be detected at night, it must be within the headlight pattern,” Sullivan told AEI.
As a general rule, if an obstacle is detected while traveling less than 20 mph, precollision braking can stop the vehicle. At speeds above 20 mph, precollision braking slows the vehicle.
“There is only one situation in which EyeSight will override what the driver is doing. If the vehicle is heading straight toward an obstacle and the system senses that there will be a collision—even if the driver is already braking—the system will apply brake assist to ensure that the obstacle is not hit or that the collision is mitigated as much as possible,” Sullivan said about the system programmed to recognize vehicles, motorcycles, bicyclists, pedestrians, and other objects.
The driver can disengage precollision braking for off-road operation, but the system defaults to an active feature each time the car is started. The system also shuts down temporarily to reset whenever three consecutive instances of precollision braking occur if uninterrupted by a vehicle restart.
Precollision throttle management occurs if the driver depresses the acceleration pedal before the vehicle in front has moved. The technology is designed to prevent a rear-end collision during a right-hand turn if the vehicle ahead does not follow through after an initial move forward.
Adaptive cruise control, operational up to 90 mph (145 km/h), enables the driver to use a steering wheel switch instead of foot pedals to keep a safe distance from the vehicle ahead during an expressway cruise. The distance between vehicles varies, depending on the setting and speed.
Lane-departure warning provides a visual and audio alert if the vehicle strays outside the lane at speeds higher than 32 mph (52 km/h). The system can be turned off, and turn-signal usage negates the warning.
Co-developed with Hitachi, the cameras need a clear view of the surroundings.
“Heavy rain or snow temporarily disables EyeSight, but if that occurs the driver will get a visual and audible alert. The cameras also are unable to see around curves, so attempting to use adaptive cruise control on winding roads could result in false warnings and braking,” Sullivan said.
Limited contrast or repetitive pattern images may not be seen by EyeSight.
The first-generation of EyeSight launched in Japan on 2007 MY Subaru vehicles. Second-generation EyeSight debuted in Japan with the 2011 MY, followed by Australia in the 2012 MY and then the U.S. and Canada in the 2013 MY.
It is likely that all Subaru vehicles will have EyeSight available after the third-generation system is developed, according to company representatives.