The aquaplaning warning system

Wet weather always brings added risk to our roads, but one company is developing a system that will make driving in the rain that bit safer, as Chris Randall reveals here.

If you spend any time driving on dual carriageways or motorways, chances are you’ll have encountered bad weather and with it the risk of aquaplaning. Hitting a patch of standing water, there’s that momentary feeling of lightness at the steering wheel, perhaps accompanied by a slight pull to one side. It can be pretty scary when it happens at speed.

Aquaplaning occurs when a layer of water builds up between the tyre and the road surface, meaning proper contact between the two is lost, and it can be generated by just a few millimetres of water. Add excessive speed and tyres with low tread depth into the equation and loss of control can result, which explains why many motoring organisations and tyre manufacturers advocate replacing tyres when there is 3mm of tread remaining, rather than the legal limit of 1.6mm.

It’s a sensible policy, but further assistance could be on the way because April 2018 saw tyre giant Continental announce it was working on an Aquaplaning Warning System to alert drivers to the risk of accidents. As Frank Jourdan, head of Continental’s chassis and safety division, explains: “Even with the best tyres, sudden aquaplaning is always a frightening moment and can mean the danger of an accident. We are developing a high-performance technology based on sensor information and software that detects a potential risk of aquaplaning and warns the driver in time.”

Although Continental’s Europe-based engineers are currently working on the hardware and software, they admit it is still early days for the technology and that we aren’t likely to see a functional system until the next generation of vehicles. But it’s a promising start and anything that makes driving safer is something we very much welcome.

How the system works

It turns out that there are two primary elements to the technology. The first involves the use of carefully-positioned cameras that can detect excessive water displacement. The images are generated by the wide-angle, surround-view cameras that some vehicles already utilise as part of a 360° view system, with those mounted in the side mirrors recognising a specific splash and spray pattern from the tyre. Complex computer algorithms process the images and, when they detect a pattern that exceeds pre-determined criteria, control electronics that recognise this as the beginnings of aquaplaning and alert the driver accordingly.

However, there’s a second layer of information being fed to the computer that comes from sensors within the tyres themselves. Dubbed the electronic Tyre Information System (ETIS) by Continental engineers, the sensors monitor not only tyre pressure and temperature, but also the centrifugal acceleration of the rolling tyre. When water builds up in front of the tyre, leading to aquaplaning, it causes an oscillation in the sensor signal that’s not present on a normal dry or wet road, with the computers recognising this change in the signal. The sensors also collect information on the rolling characteristics of the tyres over time, and comparing this with stored data can determine the amount of tread remaining.

Combining all of this information with the images from the on-board cameras, the warning system can not only alert the driver to the risk of aquaplaning, but also recommend a safe speed for any given wet road. It’s easy to see such a system could be of huge benefit in today’s driving, but as Continental themselves point out, the Aquaplaning Warning System could also play a key role as the future of the car develops.

One of the technologies being explored by car-makers is vehicle-to-vehicle communications (V2V), where all manner of information can be shared between cars in a bid to improve traffic flow and reduce accidents. Being able to warn following motorists of an aquaplaning risk up ahead has obvious benefits. And it’s hardly a stretch to see how such communications could be shared with wider traffic control systems, allowing the authorities to alter speed limits and post warning signs appropriately.

Then there’s the seemingly endless rush to develop autonomous vehicles. A divisive subject it may be, but there’s no doubt that a greater level of autonomy will be a part of future motoring. Without a driver to react to changing road situations, having a system that can detect something like aquaplaning is likely to prove crucial when it comes to the safe operation of such vehicles.

Testing of the Aquaplaning Warning System began in 2017 and early evaluation looks promising, so Continental is aiming for further development in 2019.