Continental Sensor System in the New Volvo XC60

An infrared sensor supplies data for automatic brake application at city driving speeds to avoid rear-end collisions.

The risk of rear-end collisions is particularly great in city traffic with its constant alternation between braking and accelerating. 75 percent of accidents recorded by the police occur at speeds below 30 km/h. It is precisely at these speeds, in slow-moving or “stop and go” traffic, that this sensor system, developed and manufactured by Continental around the Closing Velocity (CV) sensor, reduces the risk of a rear-end collision. Fitted level with the inside mirror in the area cleaned by the windshield wiper, the sensor uses three infrared beams to probe the road up to some six meters 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.

If the maximum speed differential between the vehicles was 15 km/h, a rear-end collision would be avoided in most cases. And, at greater relative speeds, the severity of the impact would be considerably mitigated. 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. Like the front and side airbag initiation sensors, this is also a Continental product. According to Dr. Ralf Cramer, President of the Chassis & Safety Division, “This system will prevent numerous accidents and injuries. It is one of the important modules in our comprehensive ContiGuard(R) safety system which is bringing us one step closer to Vision Zero, our vision of road transport without accidents, without serious injuries and without fatalities.”

MK25 E1 braking system with trailer stabilization and roll-over protection functions

Even if the braking system does not intervene automatically, Continental’s CV sensor system can assist the XC60 driver. If he realizes that a rear-end collision is imminent and applies the brakes, the MK25 E1 will already have built up pressure as a precaution. The brake assist system will respond earlier, depending on how risky the situation is, shortening the stopping distance more effectively than would be possible without the CV sensor’s warning.

In addition to this interface to the environmental sensors, the braking system also has a trailer stabilization function which detects if a trailer is beginning to “fishtail” and stabilizes the car-trailer combination by brake application to individual wheels (Trailer Stability Assist, TSA). A further driving safety feature is the roll-over protection function. As well as the usual ESC sensors, the Volvo XC60’s braking system has an additional sensor which records the vehicle body’s rolling motion. If all the data it collects indicates that the vehicle is seriously at risk of overturning, the brakes are specifically applied to individual wheels. This roll sensor is built into the ESC cluster which, like the active wheel speed sensors, the brake actuation unit and the new two-piston, front axle, 2FN44 wheel brakes, is also supplied by Continental’s Chassis & Safety Division.