Driver assistance systems, just in case

Modern assistance systems make driving more relaxing, regardless of the situation. As popularity grows for anti-lock braking systems (ABS), electronic stability control (ESC), cruise control, parking assistance and light sensors, these features are becoming almost standard, if not mandatory, in new vehicles. This is no less true for advanced cruise control or ACC, which combines both cruise control and headway distance control, and which, according to experts, is set to conquer the market in the next few years.

Pivotal to the development of ACC, and with it the increase in driver safety and comfort, was a team of inventors comprising Stéphane Kemkemian, a radar expert in the 1990s with French aerospace company Thales Systèmes Aéroportés, and his colleagues Pascal Cornic, Jean-Paul Artis and Philippe Lacomme. At the start of the 1990s, this team collaborated on the development of one of the first simple radar sensors with an accompanying central control unit and a range of 150 m and, through the solutions they selected, laid down the conditions that have helped lower the cost of this technology and make it more widespread in the mid-size car segment and, above all, in trucks.

Some experts reckon with 5.2 million ACC units manufactured annually by 2015, while others predict a market volume in excess of EUR 20 billion (USD 30 billion) for 2016. "The highest cost component of ACC has always been the radar sensor", says ABI Research principal analyst David Alexander, "and now the cost advantages of silicon technology are going to take effect." He believes that this development will have a positive impact on market volumes.

"With their talent for innovation, Europe's inventors benefit society as a whole", observed Benoît Battistelli, President of the European Patent Office (EPO), in a tribute to the team's commitment. In further recognition of the team's achievements, the members have been nominated for the European Inventor Award 2011, to be presented in Budapest on 19 May.

Simple is best

Keen to minimise manufacturing costs, the team decided to keep the hardware as simple as possible without compromising their vision of a radar sensor that would continuously monitor speed difference and distance relative to the car in front, coupled with a control unit to regulate engine and brake function for optimum convergence. Their first attempts however were anything but successful: vehicle vibration or rain interfered with the sensitive electronics and obstructed interaction between the individual components. Faced with these difficulties, the team decided to return to the drawing board and concentrate on developing new signal processing methods. This time, results were good, and any initial teething problems encountered have long been overcome.

While modern ACC systems still work best on trunk roads and motorways, they are getting better and better at coping with changing traffic conditions. Thus, traditional ACC systems now also offer stop-and-go features for reliable vehicle response in traffic jams or slow-moving queues, taking the pressure off drivers and allowing them to concentrate more on the traffic situation.

Economic benefits

With traffic fatalities in Europe at around 35 000 a year, the European Commission was prompted last summer (2010) to launch an initiative to improve road safety. Siim Kallas, Vice-President of the European Commission and Transport Commissioner, explained that "the number of fatalities and injuries on our roads is still unacceptable ... and we want to cut road deaths in half by 2020."

ACC and successor systems can contribute to this objective. For some time now, for instance, motor vehicles have been using systems that, while imperceptible to the driver, activate the brakes in preparation for a possible emergency braking manoeuvre, thereby shortening the stopping distance in a crisis and providing optimum protection for the vehicle's occupants.

Following a study of 600 truck accidents involving personal injury and serious material damage, Germany's Allianz Zentrum für Technik (Allianz Centre for Technology) concluded in 2005 that two-thirds of serious rear-impact truck collisions on motorways could be avoided by using ACC. It also found that, irrespective of the road type, a total of 7% of all truck accidents could be avoided with ACC. And if a crash were nevertheless to occur, the consequences would be significantly diminished as a result of the lower collision speed.

In a further study, a commercial vehicle manufacturer equipped 500 trucks with ACC, lane departure warning systems and electronic stability control, thereby halving the number of accidents compared with the control group of 500 trucks with no assistance systems. Total damages fell by as much as 90%. Extrapolating from these results, the German Federal Highway Research Institute arrived at a figure of 17.5% fewer serious accidents resulting in personal injury across all vehicle types, that is both trucks and cars.

In December 2010, the Dutch national road safety research institute (Stichting Wetenschappelijk Onderzoek Verkeersveiligheid) published a summary of current research and experience with ACC in the Netherlands. According to this review, a field trial found a 3% reduction in fuel consumption due to greater speed constancy, leading to a decrease in exhaust emissions. In addition, thanks to optimised headway distances, not only was tailgating avoided, but road capacity was increased. (With a 40% ACC equipment rate and a one-second headway time, researchers estimated throughput gains at 13%.)

Versatility

Emergency Brake Assist, which up to now has mainly been used in trucks, is another of ACC's promising successors. Based on the provisions of the Vienna Convention on Road Traffic, which currently bans fully autonomous assistance systems, this tool can be manually overridden by the driver at any time. In practice, it works like this: the assistance system emits an optical and acoustic warning if the approach speed to the car in front is too high. If the driver doesn't react, a partial braking manoeuvre is triggered. If the driver still fails to react, full braking is automatically performed, bringing the car to a standstill. Systems of this kind are due to become mandatory in the EU from 2013 onwards.

But innovation doesn't stop there and developers around the world have come up with more or less concrete ideas for tankers, motorcycles, and even take-off and landing zones at commercial airports.

The pioneering work of Stéphane Kemkemian, Pascal Cornic, Jean-Paul Artis and Philippe Lacomme was responsible for blazing a trail into a new field. Since 1992, when the team filed its first patent application in this area, 28 more patents have been granted with at least one team member involved in each invention's development. Nowadays, the number of patent applications on "ACC with radar technology" is in the region of 200 a year from Japan alone. The USA and Germany, Japan's closest competitors, are trailing far behind with some 40 to 50 applications a year each. With about 30 applications a year, China and the Republic of Korea have made up considerable ground in the last ten years.

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