VOLVO’S NEW AUTOMATIC BRAKING TECHNOLOGY – RESPONDING TO BOTH VEHICLES AND PEDESTRIANS
The next generation of preventive safety technology from Volvo is a groundbreaking function that can detect a pedestrian who has walked out in front of the car, as well as automatically braking to avoid the person at speeds below 15 mph if the driver does not react in time.
Concurrent with the launch of the all-new Volvo S60 in 2010, Volvo Cars will be unveiling the next generation of preventive safety technology – Collision Warning with Full Auto Brake and Pedestrian Safety. The new safety functions represent the next stage in Volvo Cars’ continuous development of technology to detect dangerous situations and help the driver avoid accidents.
“The previous stages were developed to help the driver avoid collisions with other vehicles. Now we are taking a giant step forward with a function that also boosts safety for unprotected road-users. What is more, we are advancing from fifty percent to full automatic braking power. To our knowledge, none of our competitors have made such progress in this area,” explains Thomas Broberg, safety expert at Volvo Cars.
Accidents with pedestrians common in urban traffic
In the EU, the proportion of pedestrians figuring in overall traffic fatalities varies between 10 and 25 percent depending on the country. In the EU countries’ capital cities, 1,560 people died in road accidents in 2007. Of these, 43 percent were pedestrians.
The speed of a car is of considerable significance to the outcome of an accident. The risk of a pedestrian being killed in an accident at 31 miles per hour is 85 percent higher compared to if the speed is 15 miles per hour.
Avoids collisions at speeds below 15 mph
“Our aim is that this new technology should help the driver avoid collisions with pedestrians at speeds below 15 mph. If the car is travelling faster, the aim is to reduce the impact speed as much as possible. In most cases, we can reduce the collision force by about 75 percent. Considering the large number of pedestrian fatalities that occur, if we manage to reduce the fatality risk with 20 percent this new function will make a big difference. In specific situations the fatality reduction can be up to 85 percent”, says Thomas Broberg.
This technology is also highly beneficial in the event of rear-end impacts with other vehicles. Statistics reveal that half of all drivers who hit another vehicle from behind do not brake at all prior to the collision.
However, the main aim is still for the initial warning to be sufficient for the driver to brake or manoeuvre away from the hazard. If the driver does not respond to the warning, only then does the system step in with full braking force moments before a collision is imminent. In such cases, Collision Warning with Full Auto Brake can help entirely avoid a collision if the relative speed difference between the two vehicles is less than 15 mph.
Safer detection with state-of-the-art technology
Collision Warning with Full Auto Brake and Pedestrian Safety consists of a new dual-mode radar unit integrated into the car’s grille, a camera behind the inside rear-view mirror and a central control unit. The radar and camera continuously monitor the road in front of the car. The radar’s task is to detect objects and measure the distance to them. The camera’s function is to determine what type of objects they are.
As with Volvo’s current City Safety technology, the system is programmed to respond to cars in front that are at a standstill or moving in the same direction. Thanks to the state-of-the-art radar, which has a far wider field of vision than before, pedestrians about to step into the roadway can be detected early. What is more, the camera has better resolution than in the previous generation, allowing the system to monitor pedestrians’ movement patterns.
“We’ve been working on this technology for ten years now. We have had test cars out on the roads for several years and we’ve driven in many different countries. Factors like traffic behaviour, road conditions and climate must be taken into account in the design of the final system. We can also use the information from these real-life traffic tests to conduct advanced computer simulations,” says Thomas Broberg.
New technology permits full braking power
In an emergency situation, the driver first gets an audible warning together with a flashing light in the windscreen’s head-up display. In order to prompt an immediate, intuitive reaction, the visual warning is designed to look like a brake light coming on. If the driver does not respond to the warning and the system assesses that a collision is imminent, the car’s brakes are applied with full braking power.
“Active brake deployment requires that the object is confirmed by both the radar and the camera. Thanks to state-of-the-art sensor technology, it is now possible to engage full braking power. We are probably among the very first in the world to offer full-braking protection for pedestrians,” explains Thomas Broberg.
He adds: “The system is built along the same principles as the human eye and, just like our own eyes, vision is impaired in the dark and in poor weather.”
Upgraded Adaptive Cruise Control
Volvo’s Adaptive Cruise Control (ACC) has now been upgraded with a function that, in combination with automatic transmission, even operates at very low speeds. The radar-based adaptive cruise control system maintains the set gap to the car in front all the way down to standstill. This means that this comfort-enhancing system becomes usable even in slow-moving queues with repeated starting and stopping. The previous version was not active at speeds below 18 miles per hour.
City Safety – prevents low-speed collisions
City Safety was introduced as standard in the new Volvo XC60 in 2008. The technology was developed in-house by Volvo Cars and can reduce or even entirely avoid impacts at speeds below 18 mph. In both heavy city traffic and when driving in slow-moving queues, rear-end collisions are a very common accident scenario. About 75 percent of all collisions occur at speeds below 18 miles an hour, and studies show that in 50 percent of these cases, the driver has totally failed to brake prior to the collision.
With City Safety, the car brakes automatically if the driver fails to respond in time when the vehicle in front slows down or stops. If the relative difference between the speeds of the two vehicles is less than 9 miles an hour, the collision is avoided entirely. If the speed difference is between 9 and 19 miles an hour, the speed of impact is lowered to reduce the severity of the collision and the subsequent consequences.