Making Reversing Easier and Safer
For any driver, reversing is always a chore not only because it means driving in a direction that is ‘unnatural’ but also that you have often have to turn your body around to look back, as well as consult the rearview mirrors. Most drivers will do this to ensure that they don’t hit another car or something hard, while the more responsible ones will do so out of genuine concern for a person, especially a small child, being accidentally knocked down.
The manufacturers have tried to minimise the dangers of this manoeuvre, first by putting a rearview mirror in every car. However, as designs evolved and vehicles grew in size and stood taller, the problem grew: rear windows became smaller while rear ends got higher, obscuring the view at the back. Thus, a small child who happened to squat down (and they do, much as adults warn them never to do so behind a vehicle) is out of sight and can be rolled over.
In Japan, some models have had rearview cameras installed, an idea adapted from buses and trucks but this is an expensive solution. Back in 1982, Toyota was probably the first company in the world to introduce a reversing sensor using sonar. This was installed in the bumper of the Corona that year; today, the reversing sensor has become a low-cost item which can be found in numerous models from the Satria to the BMW 745Li.
The technology has been improving as sensors have become more sophisticated and at Delphi Automotive Systems – a major global supplier to the automobile industry – it has reached a very advanced stage of evolution in the Forewarn Back-up Aid. Part of the Forewarn Collision Warning family of products, the Back-up Aid assists the driver in detecting children, pets, vehicles, and other objects in the vehicle’s rear blind spot. With a rear detection zone that is three times deeper than ultrasonic-only parking assists, Forewarn Back-up Aid is said to be useful for both backing and parking manoeuvres.
“The blind spot is a very real concern, especially in larger vehicles,” says Mary Schafer, business line executive for Delphi’s Chassis and Safety Product Line. “Drivers of luxury cars, minivans, and SUVs have larger blind spots to contend with.”
Measuring as high as 0.9 metre (3 feet) and two vehicle lengths, the blind spot can “hide” a wide variety of obstacles. Hitting a child is the most frightening example of back-over accidents. Other incidents are annoying, with substantial costs for damage to golf clubs, bicycles, and other objects, not to mention vehicle bumpers.
“Delphi’s Forewarn Back-up Aid helps drivers ‘see’ what’s behind them,” Schafer adds. “That capability is great for everyone, and it’s invaluable when you’re around small children.”
Other rear detection devices, which typically use ultrasonic sensors, are most useful in low-speed operation, which limits them to mainly parking manoeuvres. Delphi’s Forewarn Back-up Aid is the first radar-based obstacle detection-system on the market coupling ultrasonic sensors with a single-beam radar sensor in the rear bumper.
This combination is claimed to give the longest rear-sensing detection range available-up to 5 metres (16.4 feet). That larger detection area effectively extends the device’s useful speed range – from parking speeds (generally less than 3 km/h) to normal backing speeds (about 11 km/h).
“Before developing the Back-up Aid, Delphi studied the issue,” says Dan Pitcock, marketing and portfolio manager for the Chassis and Safety Business Line. “We wanted to enhance parking-assist technology, so we examined typical backing speeds, reaction times, and braking distances. And we found that at typical reverse speeds (up to 11 km/h), drivers needed to be warned about 5 metres before an obstacle to respond to alerts and brake in time to avoid hitting it. The Back-up Aid was therefore designed around that need.”
With the larger detection area, the Back-up Aid can help give drivers more time to avoid impacts. In a vehicle equipped with Back-up Aid, audio (and on some models, visual) alerts notify the driver of objects in the rear vehicle path. These alerts – beeps – vary in intensity and rate to indicate how closely and how quickly the driver is approaching an object.
In reviewing the Ford Expedition (a model larger than the Explorer SUV) equipped with Delphi’s Back-up Aid, USA Today reported that the back-up alarm looked and performed better than other systems. “The warning beeps no longer start so early that you disregard them, and the speed of the beeps is better matched to how close you really are to whatever’s behind you.”
With the longer detection range, drivers have more time to alter course and stop. It helps drivers feel more in control and also helps improve overall driver performance. It can also help save drivers significant amounts of money in repair costs. According to the US Insurance Institute for Highway Safety (IIHS), which has tested rear bumper impact using both flat barriers and poles, costs can be very high – averaging between US$674 (RM2,560) for flat barrier impact and US$1387 (RM5,230) for damage from collisions with poles.
Radar technology not only improves the functionality of the Back-up Aid but also contributes to vehicle design enhancements, a benefit appreciated by vehicle designers and consumers alike. Typical parking assist systems use four ultrasonic sensors to achieve the sensing coverage area. These sensors are mounted behind the rear bumper and require holes, or buttons, to create a “line of vision.”
The radar sensor on the Back-up Aid can transmit through most bumpers, so it can usually be hidden behind the bumper fascia. While the radar-based sensor offers longer range detection, the two ultrasonic sensors on today’s model “fill in” the corner areas, helping to complete the rear detection zone. The current generation of the device requires just two buttons for the ultrasonic sensors, but Delphi engineers are working towards an all-radar Back-up Aid, which will be completely hidden, complementing sleek vehicle styling.
Concealing the sensors enhances vehicle styling and also helps prevent damage to the sensor in low-speed impacts, such as collisions with shopping carts. And radar-based sensing offers consistently reliable performance: it isn’t affected by loud noises (eg power drills or jet aircraft), adverse weather, or road dirt, which can hinder detection or cause false alarms.
The Forewarn Back-Up Aid is available in some models sold in the US market and is expected to become more common as time goes on and more companies select it. Its appearance in Malaysian models will be dependent on either selection by local assemblers or as a standard item in imported models. At this time, Delphi has not mentioned its availability as an after-market product.
