Safety: the sights are set on leadership
Customers expect Volvo to retain its lead in the field of safety – irrespective of vehicle type. With the launch of its first-ever SUV, Volvo Car Corporation enters an entirely new segment, and the goal is perfectly clear: to lead the way in terms of safety.
As in all other Volvo models, safety in the Volvo XC90 is a holistic concern. Safety is never achieved by simply adding a number of individual stand-alone features into a car: what is important is the interaction between them – it is this interplay that shapes the result.
This holistic approach is – and always has been – one of the corner stones of Volvo’s safety philosophy.
With the entry of Volvo Cars into the SUV market, there is increased focus on several new areas. One of them is roll-over accidents, where the vehicle rolls over onto its roof one or more times.
Roll-over Protection System
Volvo’s Roll-over Protection System, ROPS, tackles the problem from two directions:
Owing to its higher centre of gravity, an SUV may have a higher risk of rolling over in certain critical situations compared with a conventional passenger car. That is why the centre of gravity in the Volvo XC90 has been kept as low as possible compared to most SUVs. In fact, it is just 89 mm higher than that of the Volvo XC70.
However, this does not mean that Volvo has compromised on one of the properties that SUV buyers value so highly: a commanding seating position. The front seats are no less than 165 millimetres higher than in the Volvo XC70.
Roll Stability Control
In order to help reduce the risk of a roll-over situation, the Volvo XC90 is equipped with an active stability-enhancing system known as Roll Stability Control or RSC. The system uses a gyro-sensor to register the car’s roll speed and roll angle. Using this information, the terminal angle is instantly calculated and thus also the roll-over risk.
If the calculated angle is so great that there is an obvious risk of rolling over, the DSTC (Dynamic Stability and Traction Control) anti-skid system is activated. DSTC responds by reducing the engine’s power and also by braking one or more wheels as necessary until the car understeers and stability is regained.
This helps reduce the risk of a roll-over accident initiated by extreme manœuvres.
RSC is the only active stability-enhancement system on the market to measure the car’s roll angle.
Special steel in a reinforced roof structure
If the Volvo XC90 experiences a roll-over the passive safety systems step in.
The goal is to reduce the risk of the occupants’ heads from coming into contact with the car’s interior roof panel or sides. Volvo has reinforced parts of the roof structure in the Volvo XC90 with extremely tough Boron steel, which is four or five times stronger than normal steel.
All the seats are equipped with seat belt pretensioners to hold the occupants securely in place. In an accident, the pretensioner pulls the seat belt firmly across the occupant’s body in order to help provide maximum protection.
In order to help prevent the head from striking the car’s sides, the Volvo XC90 is equipped with Volvo’s IC or Inflatable Curtain. IC also helps prevent the occupants from being ejected in an accident.
The Volvo XC90 has a version of IC that is specially adapted to deal with roll-over accidents.
This means that it stays fully inflated for longer so as to offer maximum protection in a roll-over scenario. What is more, the curtain is folded in its cassette in such a way that it follows the contour of the window glass as it inflates. If the occupant’s head is resting against the window at the moment of inflation, the curtain will thus slip between the glass and the occupant’s head to provide enhanced protection.
In the Volvo XC90, all three rows of seats in the 7-seat version are protected by the IC.
The problem of compatibility – when an SUV collides with a car that sits closer to the road surface – was in firm focus throughout the development of the new Volvo XC90. The typical SUV has a high ground clearance and thus often comes with high-positioned bumpers. This may create a greater risk of damage to the oncoming passenger car and more serious injuries to its passengers, since the lower car’s protective beams and crumple zones simply slip below the front of the SUV without being activated.
In order to reduce the risk of this type of injury, the front suspension subframe in the Volvo XC90 is supplemented with a lower cross-member, positioned at the height of the beam in a conventional car. This lower beam is integrated into the XC90s structure and is neatly concealed behind the spoiler.
This construction reduces risk of injuries in frontal collisions as well as in rear-end impacts and side impacts. The lower cross-member strikes the oncoming car’s protective structure, activating its crumple zone as intended so the occupants can be given the maximum level of protection.
During the development of the Volvo XC90, considerable attention was also paid to the safety of pedestrians, cyclists and other relatively unprotected road-users. The entire front of the car features clean, gentle and smooth lines, and there are no protruding parts which may cause enhanced injuries.
The engine in the Volvo XC90 is installed low in the vehicle. As a result, the bonnet has no less than 80 mm of deformation space before there is any contact with the engine below it. It thus serves as a soft impact-absorbing "bumper", reducing the risk of serious injury to a pedestrian who may be thrown onto the bonnet.
High safety level in the third row of seats
The Volvo XC90s third row of seats provides a high level of passenger safety. There is generous space behind it, so collision force in a rear-end impact can be effectively absorbed and dissipated.
The occupants of the rearmost seats sit just above the rear axle, which is the optimum position in terms of side-impact safety. These seats also feature belt tensioners, head restraints and, as already mentioned, the Inflatable Curtain or IC.
The front airbags are of the dual-stage type, with a sensor that monitors the incoming collision force and adjusts the airbag’s inflation accordingly.
Safety for the car’s youngest occupants has always been a high priority at Volvo. That is why the Volvo XC90 can be specified with the standardised attachment system for child seats, ISOFIX, in both the first and second row of seats.
WHIPS, Volvo’s award-winning Whiplash Protection System, is fitted in the two front seats of the Volvo XC90. WHIPS is activated in the event of a rear-end collision from speeds as low as 15 km/h, helping to reduce trauma on the spine and neck and thus reducing the risk of injury.