Volvo has announced the new Volvo XC90 will get, as standard, a clever run-off road protection package and has revealed a series of videos that show it works.
VOLVO HAS MOVED a step closer to making good on its promise that “no-one will be killed or seriously injured in a new Volvo car by 2020 (Vision 2020)” with the introduction, on the all-new Volvo XC90, of its run-off road protection package. Volvo says this package will be standard across the Volvo XC90 range.
So, what does ‘run-off road’ mean? According to Volvo, “Run-off road is a common accident type with different causes, such as driver inattentiveness, fatigue or poor weather conditions. For example, half of all traffic fatalities in the United States are road departure crashes, while in Sweden, single-vehicle accidents involve one-third of all fatal and severe injury crashes with passenger cars.
“Run-off road crashes are also very complex situations in which occupants often move in random directions – which puts high demands on the interior restraints.”
“Our solution focuses on keeping the occupants firmly in position and introducing unique ‘energy-absorbing’ functionality in the seat,” says Prof. Lotta Jakobsson, Senior Technical Specialist Safety at Volvo Cars Safety Centre.
“This counteracts spine injuries, which are serious and relatively frequent consequences of run-off road scenarios.”
“Studying our own extensive accident data, we discovered that the occupant’s posture during the load transfer through the spine is an important factor. In several of the cases, great occupant flexion was seen as an influencing factor. Anterior wedge fractures, resulting from a combination of axial load and flexion, are the most common spine injury in run-off road events together with compression fractures,” says Lotta Jakobsson.
What’s the run-off road package include:
- Using input from the car’s advanced sensor system, the technology is able to detect a run-off road scenario. The front safety belts are electrically tightened as much as possible to retract and keep the occupants in position. The pulling capacity of the safety belt retractor is 1mm/ms – which means it can retract 100mm of safety belt in only 0.1 seconds. The belts are firmly tightened as long as the car is in motion.
- To help prevent spine injuries, energy-absorbing functionality between the seat and seat frame deforms mechanically to cushion the vertical forces that can arise when the car encounters a hard landing on terrain.
“By keeping the occupant in an upright posture while cushioning the impact, the vertical forces he or she is exposed to can be reduced by up to one-third. This helps to considerably lower the risk of the most serious and frequent spine injuries in these situations,” says Lotta Jakobsson.
To develop its run-off road safety package, Volvo developed three crash test methods, called ‘Ditch’, ‘Airborne’ and ‘Rough terrain’, for evaluating the consequences of various run-off road scenarios.
During the ‘Airborne’ method the vehicle runs off the road and becomes airborne at, say, 80km/h. The resulting impact of the vehicle landing, causes equivalent vertical forces that a fighter pilot experiences when using his ejection seat.
The ‘Ditch’ test is designed to replicate the bouncing movement when driving into an 80cm deep ditch and impacting an embankment, which causes high vertical forces, according to Volvo.
The ‘Rough road’ test simulates a bumpy ride on a rough track, producing substantial lateral rolling motions in combination with vertical and longitudinal vehicle motions.
Watch the videos of Volvo’s run-off road safety testing:
