What is autonomous emergency braking?
AEB is the most important car-safety development of the decade. But do you know what it does, asks David Linklater.
Autonomous Emergency Braking (AEB) is undeniably the ‘‘it’’ car technology of the modern age. Experts have compared its safety significance to the seatbelt, the Australasian New Car Assessment Programme (ANCAP) won’t give a car a five-star safety rating without the tech and mainstream car advertisements boast about its inclusion in the latest models.
A recent study by ANCAP concluded that the fitment of AEB to new cars has increased tenfold since 2015. European authorities are pretty keen to make it mandatory in the near future.
It’s not all good, however: the complexity and cost of AEB is also being blamed for the impending demise of no-excess cover for windscreens in the New Zealand insurance industry. Price of progress?
Anyway, the point is: AEB is a thing. A big thing. So here’s the question: do you know what it is?
It seems many of us don’t. A survey in March this year commissioned by British road safety organisation Brake revealed that 58 per cent of drivers didn’t know what AEB was. Even once explained,
12 per cent remained unsure about whether their car had it or not.
It’s all in the name: ‘‘autonomous’’ braking will stop or slow the car, to avoid or mitigate an impact even if the driver does nothing. Unlike, say, airbags, which are a ‘‘passive’’ safety feature because they only work when an accident happens, AEB is ‘‘active’’ because the idea is that it does everything it can to prevent a crash happening.
AEB has only been available for around a decade. As ever, the car industry aims to confuse customers with different names for different systems, but whether its Volvo’s City Safety or Ford’s Active City Stop or Mazda’s Smart City Brake Support, they are all AEB systems that work to the same basic principles.
AEB systems use windscreenmounted cameras and other sensors, including radar, and lidar (think of it as radar but with a laser), to detect potential accident hazards. If a dangerous situation is detected and the driver does not act, the AEB system can apply the brakes autonomously to avoid a crash – or at least minimise its severity.
The first AEB systems were designed for urban use, as global research shows that most collisions occur at low speed (less than 40kmh). These mainly worked via relatively short-range sensors. Volvo’s first City safety system fitted to the 2008 XC60 SUV, for example, was designed to work at up to 30kmh and when the speed differential was less than 15kmh. But British safety specialist Thatcham found that the AEB-equipped XC60 still had 23 per cent fewer crashes than similar-size SUVs.
The latest systems combine radar and lidar with windscreen-mounted cameras to ‘‘look’’ at the road ahead in three dimensions and identify not just vehicles at higher speeds, but also other shapes such as pedestrians.
The visual giveaway to this latest AEB technology is generally the complex-looking set of cameras and sensors mounted at the top of the windscreen. This is also what’s causing consternation among the Kiwi insurance industry as the cost of replacing the glass and associated hardware rises.
But there are other insurance benefits to AEB: Thatcham in the UK recently compared the latest Volkswagen Golf 7 with the non-AEB generation-6 model: it found that injury crashes had been reduced by 45 per cent.
You won’t feel AEB working unless you have a really close call, because it only intervenes at the last possible moment. It’s intended to be a last resort, not a driving tool.
And don’t confuse AEB with another common new-car technology, Forward Collision Alert.
While FCW detects when you are approaching another vehicle or object too quickly and can even assist with braking pressure, it doesn’t actually apply stopping power unless the driver does too.