By Avijit Ghosh
The Need for Blind-Spot Monitoring Systems
Each year, more than 826,000 vehicles in North America are involved in lane-change blind-spot accidents, according to the National Highway Traffic Safety Administration. Although the fatality rate is only 1 percent, low compared to other types of accidents, the extent of property damage and injury is high. This has therefore remained a cause of concern for years. Although several preventive measures have already been taken, they could not drastically reduce the number of these accidents. By 2007, automakers are expected to introduce vehicles equipped with high-tech radar systems that can see beyond the driver's peripheral vision - the dangerous blind spots.
Blind spots are areas in adjacent lanes of traffic that are blocked by various structures in the automobile. The physical constraints in eye movement and head and body rotation make certain areas invisible to the driver. The blind spots in cars depend on their construction. The direct blind spots are:
- Area covered by the A-pillar, between the front door and windshield
- Area covered by the B-pillar, behind the front door
- Area covered by the C-pillar, ahead of the rear windshield
Apart from these, there are certain indirect blind spots like the region between the driver's peripheral vision on the sides and the area that is covered by the rear view mirror. The unseen areas are immense for drivers of medium and heavy trucks as compared to drivers of passenger vehicles. Areas directly to the right of the cab extending past the trailer, directly behind the trailer, to the immediate left of the cab and directly in front of the cab are blind spots for truck drivers.
Drivers of cars should try to stay out of these areas.
Highway congestion is the main cause of blind spot-related accidents. According to the U.S Department of Transportation, highway congestion will outpace new road construction by 13 percent every year. This means more cars on the same lane-miles of road, thereby increasing the probability of blind spot-related accidents. Hence automakers are now searching for a suitable technological solution. Radar systems are likely to be the most effective alternative.
Blind-Spot Detection Using High-Tech Radar System
Valeo Raytheon Systems Inc., one of the world's top-ten automotive suppliers, has come up with a system for preventing blind spot-related lane-change accidents. Valeo Raytheon's lane-change assistance system consists of two radar sensors joined to a control module and two LED warning indicators mounted in the side rear-view mirrors. The sensors continuously monitor the presence, direction and velocity of vehicles in the lanes adjacent to the vehicle, thus creating a digital picture of the vehicle's surrounding. The central control module processes the digital information. When any vehicle moves into the blind spot, the control module alerts the driver by lighting the warning indicator in the appropriate side mirror. As the system is currently designed, if a turn signal is kept engaged, the central controller can turn on an audio alarm inside the cockpit to give an additional warning. Therefore, this system can help reduce the number of lane-change accidents and accidents when merging to join a stream of traffic. According to Valeo Raytheon, this system, expected in 2007, would be priced around $450 to $500 for vehicle buyers.
Other Possible Technological Solutions
Other technologies, both high-tech and low-tech, also are being explored.
Multi-radius mirrors having a 40-degree field of view have been a popular option for consumers in Europe and Japan for more than 20 years. But in the US, this cannot be the solution, since government regulations permit only flat mirrors, having a 15-degree field of view. Regulations permitting multi-radius mirrors could be a low-tech solution to the blind-spot problem.
A different blind-spot detection device has been developed by Advanced Technology Products of Toronto, Ontario. The system uses a patented passive infrared sensor technology, which the company claims can sense thermal energy radiating from the tires of a moving vehicle. This temperature difference is used to trigger a flashing red light to warn the driver of the hazard.
Netherlands-based Mobileye NV has displayed a computer chip named EyeQ, which processes images from a small mirror-mounted camera. Apart from detecting nearby objects, it can determine shapes as well. If the driver starts moving into another lane, occupied by a vehicle, both visual and audio alerts are generated. The whole system consist of the EyeQ processing unit and one or two complementary metal-oxide semiconductor (CMOS) video cameras, compact enough to fit into a side rear-view mirror. The chip possesses the equivalent computing power of two powerful Pentium computers and is completely programmable to accommodate a wide range of visual processing applications. This system will be available as an aftermarket item for fleet customers beginning this June and for the consumer market shortly thereafter. Pricing has not yet been set.
Michigan-based Magna Donnelly Corp. has developed panoramic vision displays involving three cameras, which can give an image of both sides and of the back of the vehicle, covering a 70-degree field of view with almost no blind spots. The three cameras replace the exterior and interior rear-view mirrors. This is likely to be introduced in concept vehicles in 2005, whereas the impact of radar-based system can only be known in 2007.
In mid 2004, Volvo cars with cameras fitted in outside rear-view mirrors to detect obstacles in blind spots will be introduced.
Future of Radar-Based Technology
Most automakers see radar-based systems as the future, since the need for extended coverage favors this technology. These systems will have sensors covering a wide radius from the side to the back of the vehicle, and will be capable of differentiating between mobile and stationary objects.
Can radar-based technology make an impact? Whether consumers will embrace this blind-spot detection device as a legitimate safety feature worth the price remains to be seen. This is a serious thought, because blind-spot detectors hardly are technologically unique in an environment of lane-departure warning systems, night-vision cameras, and airplane-like "black boxes" that keep running logs of driving activity. But the concept could take off if the price is right. Since vehicle buyers are strongly aware of the danger of accidents due to blind spots, blind-spot monitoring systems could become a major selling point, much like side-impact airbags and electronic stability control systems.