Securing commercial vehicles

Autonomous emergency braking (AEB) systems are good news all round. For those new to the technology, it uses either one or a combination of a camera, a radar or a lidar (laser light sensor) to monitor the road ahead for obstacles that could lead to a collision – typically the rear-end shunt kind. When they detect what looks like an accident, most AEB systems (but not all of them) prompt an audiovisual warning in the cabin; if the driver still doesn’t react, the system takes over and automatically hits the brakes.

Now assessed as part of Euro NCAP’s crash test, vehicles fitted with AEB are 27% less likely to be involved in an accident, according to safety body Thatcham, and have a 38% greater chance of avoiding a “real-world rear-end crash” according to a Euro NCAP and Australasian NCAP study.

Popularity has followed the proof. In March last year, the Society of Motor Manufacturers and Traders (SMMT) reported that 58.1% of all new cars registered in 2015 were available with some form of autonomous technology, including AEB which was sold either as standard or optional fitment on almost two in every five cars.

However, the bigger the vehicle, the bigger the deal AEB becomes. Put simply, it can do more good if it stops a van, a bus or a truck containing cargo or people.

The technology is less prevalent in light vans than it is cars or other forms of commercial vehicle, but it is making inroads. Volkswagen Commercial Vehicles became the first LCV manufacturer to fit the technology as standard across its range in June this year. AEB, at least in VW’s case, requires no adaptation between cars and vans, so the LCVs use the same, radar-based system as the passenger cars.

The manufacturer said AEB had been “proven to cut third party injury insurance claims by 45%”, which, in the case of cars and vans where it is not yet a legal requirement, can lead to lower insurance premiums for individuals and fleets operating vehicles fitted with the technology as standard.

As for lorries, AEB has been mandatory for vehicles sold in Europe since November 2015 (it’s also the case for coaches and buses). There are some exceptions such as vehicles with steel suspension and four-axle HGVs where the operation of the vehicle could theoretically affect the performance of the sensors, but for your average road going truck, AEB has been standard fare for almost two years.

Again, it isn’t wildly different from car or van equivalents, but lorries typically employ an extra step, as Phil Moon, marketing manager at DAF Trucks explains, “It uses the same technology [as cars and vans] and it goes through a three-stage process. First of all, it gives an audible warning to the driver, then it will go through what’s called a haptic warning, which gives a physical indication that there’s an issue. In our case, the vehicle jabs the brakes; it is designed specifically to wake up a perhaps drowsy or inattentive driver. If, at that point, the driver still hasn’t taken any sort of evasive action, it will then go into an emergency braking situation.”

The technology gets a bit smarter for buses and coaches. “Even in a coach with 50 or more seats and the same number of seat belts, there will always be two or three passengers on the way to the toilets or to their luggage – some of them will always stand in the aisle,” says Peter Schumacher, product engineering senior manager for chassis/systems at Daimler, “For those people, sudden braking can be more dangerous than the avoided situation.

“In a coach, knowing that there could be passengers in the aisle, we have a very low jump [early warning jab of brakes] – but we do have one. Then we have a phase of about two seconds where we increase the deceleration; we build it up to around 30% in that time. That gives everybody the chance – and it’s a natural reaction when you feel the deceleration – to hold on to something, a seat for example, or to brace yourself in some way. Once you have reached this stage, then you can apply much higher brake forces or full application of the brakes, if you want.”

In June, Daimler announced its latest generation of commercial vehicle AEB, known as Active Brake Assist 4 (ABA 4), with a pedestrian recognition system. It will be available on Mercedes and Setra coaches from spring 2018 and uses a long and short-range radar system to identify objects smaller than conventional vehicles – i.e. pedestrians and cyclists. AEB with pedestrian recognition can be found in passenger cars, but this is the first time it has been applied to anything as large as a coach at a production level.

“We are also working on an application for city buses, and there, we know almost everybody is standing, or just a few are sitting in the seats and very few are buckled up,” adds Schumacher, “But in a city bus, we will never apply full automated braking [because of the danger to standing passengers]. In the next step, we will start asking two different sensors about an object and asking for a different conclusion; so having a radar sensor and a video camera and mixing the result of both sensors, which will increase the quality and the maturity of the evaluation. Then we can react even smarter and earlier.”

AEB’s benefits run beyond crash reduction, too. Heavy commercial vehicle fleets are unlikely to see instant discounts, but those using the technology could reasonably expect their insurance premiums to drop over time because typically it has a positive effect on accident rates and claims. Couple that with reduced vehicle and driver downtime and it starts to look even more appealing.

“By bringing them in in this mandatory way [for heavy vehicles], I think perhaps people have come to recognise that there is a value to AEB systems,” says Moon, “and maybe, when new safety systems come along, like pedestrian and vulnerable road user detection, perhaps [the industry] will be a little bit more trusting, and maybe more willing to invest in those sort of technologies, because we know that they do work.”