Technology Sidebar: Subaru EyeSight System

At the 2012 New York Auto Show, Subaru introduced its EyeSight driver assistance system, which integrates adaptive cruise control, pre-collision braking, and vehicle lane departure warning. The system uses a pair of CCD (charge-coupled device) cameras mounted at the top of the windshield inside the car, adjacent to the rearview mirror.  According to Subaru press information, the EyeSight system processes stereo images to identify the vehicles traveling in front, as well as obstacles, traffic lanes and other items. The video information is relayed to the EyeSight computer, which is also networked with the car’s braking system and electronic throttle control. Below speeds of approximately 19mph, EyeSight is capable of detecting pedestrians in the vehicle’s path and can activate in order to mitigate or even avoid the collision. Under certain circumstances, Eyesight is able to bring the car to a complete stop, thus avoiding a collision.

The 2014 Subaru Forester 2.5i Touring is the first EyeSight-equipped Subaru that Autosavant has tested.  After a week of driving Forester with EyeSight, I came away impressed with its performance. The system does a good job of adaptive cruise control and obstacle/lane departure warning. I had a great user experience in an unexpected traffic jam, where the system had the cruise control set at 65 MPH, and as we approached a slowdown it slowed down to a crawl for a few minutes still under cruise control, and eventually stopped the Forester altogether when traffic came to a halt. When the system brakes to a complete stop, driver intervention is required, as the cruise control does turn off. The cruise control is actuated by steering wheel-mounted switches for programming speed and following distance, and there is an option to operate the cruise in “non-adaptive” mode.

The white-on-blue monochromatic digital display in the center of the instrument cluster shows adaptive cruise control set speed, following distance, and vehicle detection status (i.e, whether the system has sensed a vehicle ahead from which it is maintaining a following distance). Additionally, the color LCD display on the dash has a cruise-control screen displaying a pictogram of the distance to the vehicle ahead (when one is detected), comparison of actual speed to set speed, and a pictogram of the Forester whose brake lamps illuminate when the brakes are automatically applied by the system.

Obstacle detection causes a red warning indicator on the dash to illuminate and warning beeps to sound. I was able to intentionally trigger the obstacle detection by not slowing for stopped vehicles I was approaching; I never was brave enough to wait for the Subaru to start braking by itself. When driving “off-road” on a narrow forest road, the obstacle-detection function occasionally saw overhanging branches as obstacles; a switch in the ceiling console near the camera housing allows the obstacle detection to be switched off in such conditions.

The system also will alert you if the car ahead of you has driven away and you haven’t yet responded, which could be useful for inattentive drivers in stop-and-go conditions. I tested it exactly one time and it worked as advertised, beeping and displaying “Car ahead has moved” on the LCD display. I’m sure the cars behind me were ready to start honking their horns at me.

The Lane Departure warning works well on roads whose markings are distinct, though I did find that pavement irregularities combined with faded lane striping could fool the system into thinking that the vehicle had departed the lane when it actually had not. Showery weather conditions also caused false “lane departure” warnings, typically with wet roads and sunny conditions (from passing showers). As sunlight reflected off of the wet ground, the cameras were somehow confused as to whether we were still in the lane or not; I had this occur three or four times during my week with the Forester. Because the system is only a lane departure monitor (without any active vehicle intervention) the erroneous alert was only an annoyance rather than a problem.

In addition to the erroneous lane departure warnings, the EyeSight system’s camera-based technology does have its limits.  In a heavy spring shower on the freeway at 70 MPH, significant amounts of mist generated by vehicles ahead prevented the camera system from detecting vehicles we were following until we were quite close; this was especially true when following light colored cars whose color was obscured by the mist- that prompted me to stop using the adaptive cruise control until the rain shower had passed. Shortly thereafter, the EyeSight system turned off due to poor camera visibility. When that happened, there was a notification displayed on the LCD screen that EyeSight was disabled, and icons in the instrument cluster illuminated to indicate that Lane Departure and Obstacle Detection were disabled. After about 15 seconds the system resumed functionality without any intervention on my part.

Due to the fact that most Subaru vehicles are economical mainstream vehicles rather than high-end luxury cars, they don’t tend to have integrated infotainment displays as are found on more expensive vehicles. That said, the informational displays for the EyeSight aren’t as “fancily” integrated into the instrument panel as in more expensive vehicles with similar systems (which makes sense). Obstacle detection and lane departure warning indicators are small red and amber (respectively) icons which illuminate in the instrument cluster, with corresponding beeping tones (single beep for lane departure, multiple chirps for obstacle detection). The beeping is not replicated through the audio system, meaning that listening to music loudly or even driving with the windows or sunroof open can drown out the sounds of the beeping. The small icons down in the instrument panel don’t necessarily catch the eye either, meaning that the notification can go unnoticed. Of course, the auto-braking function would get your attention really quickly.

The hardware used in the camera-based EyeSight system is somewhat less-expensive than radar hardware used in other adaptive cruise control systems, and Subaru claims that its location inside the vehicle cabin reduces the possibility of damage in fender-bender collisions, whereas radar-type systems have hardware located damage-susceptible locations at the front of the car.

As a part of a $2400 option package on the Forester, the EyeSight system adds an element of active safety to a popular family vehicle which is already an IIHS Top Safety Pick+. I was impressed with both the functionality and the affordability of the EyeSight system which Subaru has integrated nicely into the Forester, Outback, and Legacy models.

Author: Kevin Miller

As Autosavant’s resident Swedophile, Kevin has an acute affinity for Saabs, with a mild case of Volvo-itis as well. Aside from covering most Saab-related news for Autosavant, Kevin also reviews cars and covers industry news. His “Great Drive” series, with maps and directions included, is a reader favorite.

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2 Comments

  1. Very interesting, and merely part of the first wave of these technologies we’ll see on cars.

    BTW, I see in your profile that you cover Saab news, but Saab has been gone for a long time now, so what’s your replacement fixation?

  2. I’m glad you found the write-up of the EyeSight system interesting, Nathan.

    Outside of the world of Autosavant, I’m still plenty fixated on Saabs, I’m currently tracking down the perfect classic 900 Turbo hatchback project car. I’m quite interested in new vehicular technology: safety stuff like EyeSight and other passive safety, as well as potential improvements to the traffic infrastructure for both user safety (users being vehicle occupants, cyclists, pedestrians, etc) and for traffic flow.

    Thanks for reading, hope you’ll enjoy some of my future postings too!

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