Volvo’s XC60 competes with the Audi Q5, BMW X3 and Mercedes GLK.
The designer of the car is Doug Frazer who reports to Steve Martin, director of design at Volvo Car.
Several innovations equip the car mainly in active safety, lighting and driver assistance safety systems.
Driving Vision News’ in-depth analysis of the XC60 covers three rubrics:
Front lighting, Rear lighting and Driver system assistance systems.
Front lighting was presented on the 28th of October and rear lighting on the 11th of November. We present this week the third instalment with Driver Assistance systems.
The main Driver Assistance system of note in the XC60 is the City Safety system starting in 2009. Volvo are the first car maker in the world to offer an active crash avoidance system as standard equipment.
Why such a system?
The risk of rear-end collisions is particularly great in city traffic with its constant alternation between braking and accelerating. 75% of crashes recorded by the police occur at speeds below 30 km/h. Because in half of those cases the driver had not braked at all before the collision, Volvo took the decision to launch such a system to avoid collisions at low speed.
It is in this speed range, in slow-moving or stop-and-start traffic, that the City Safety system reduces the risk of a rear-end collision.
Tear-end collisions are avoided in most cases where the speed differential to the car ahead is 15 km/h or less. At greater relative speeds, the severity of the impact is considerably reduced. At the same time, the City Safety system optimizes occupant protection by providing additional data to the airbag control unit and triggering the restraint systems as required.
What is the system?
City safety automatically applies the brakes in order to avoid or mitigate an impending collision. Software is done in house and hardware is from Continental.
How does it work?
The system uses an IR sensor developed by Continental which monitors the road ahead and detects objects, and an electronic braking system.
– Sensor: Fitted in the inside mirror area which is cleaned by the windshield wiper, the sensor uses three infrared beams to probe the road up to some 6 m in front of the vehicle. The sensor picks up vehicles which are stationary or traveling in the same direction. If the gap is less than the distance which must be regarded as critical at the current speed, the system causes the brakes to be applied automatically.
– Braking system: The MK25 E1 braking system with trailer stabilisation and roll-over protection functions will have built up pressure as a precaution if the driver realises that a rear-end collision is imminent.
If speed is lower than 30km/h, the sensor watches the traffic in front of the vehicle and detects objects in front of the car’s bumper.
Based on the gap to the vehicle in front and the car’s own speed, the system makes 50 calculations per second to determine what braking force would be needed to avoid a collision. If the calculation force exceeds a certain level without the driver responding, the system determines that the risk of a collision is imminent.
The system applies the brakes only if there is a risk of a rear-end collision and the driver fails to react in time.
Volvo elaborated a test plan called World User Profile which was a worldwide test to know the various road surfaces in different countries. Volvo played all situations and found the best balance.
In the near future, Volvo plans to introduce a safety technology which detects and automatically brakes for pedestrians and a second technology which is an automatic steering in response to safety-critical oncoming cars.