Tech Product

Emergency Brake – a system that saves lives

2017-07-07

Text: Alastair MacDuff Illustration: Dan Hambe

Collision Warning with Emergency Brake is the result of Volvo Trucks’ pioneering work with active safety systems. Here we take a look at the technology behind Emergency Brake, how it protects the driver and makes traffic environments safer.

Emergency Brake in action — Using a camera and a radar, Collision Warning with Emergency Brake continuously monitors objects ahead. If a collision is imminent, a warning is issues, and if the driver fails to respond, the emergency brake is automatically activated.

Accidents where one vehicle drives into the back of another are all too common. Such accidents usually occur when the driver of the following vehicle is not paying attention to the road. When trucks are involved, it is obviously even more dangerous due to the vehicle’s size and weight.

Continuous testing of the emergency brake system ensures that the truck can stop, or mitigate possible collisions and resulting injuries. Modification takes place in order to keep up with legal requirements, but it is most vital to maintain a proud commitment to making all traffic environments involving Volvo trucks as safe as possible.

1. Camera and radar
The camera identifies distance and the type of object ahead of the truck. The radar measures how fast the object ahead of the truck is moving and the distance to the object. It is important that drivers can trust the system and don’t receive too many false alarms, so the camera and radar work together to provide warnings only when necessary.

2. Sensor fusion
Sensor fusion occurs when two sensors (radar and camera) provide input to a processor in order to better understand a situation. Sensors working together are crucial, as they help distinguish between real vehicles and objects that are not a real threat, like an empty can, for instance. After all, you see more detail with two eyes than one.

3. Control unit
All information from the camera, radar, truck and driver behaviour is collected in the control unit. Software analyses this information and activates the warning system and the truck braking system if an accident is about to occur.

4. Braking system
The braking system is activated when the driver has not reacted to the collision warnings. The vehicle first brakes lightly, the gearbox is decoupled and the truck slows down. The braking system is now active and if the danger is critical, the truck is braked with full force and the brake lights flash. The parking brake is activated if there has been no reaction from the driver.

How emergency brake is activated

Emergency Brake is the last phase in the sequence of events that occur when Collision Warning with Emergency Brake is activated.

Firstly, a pre-warning signal is given if the system senses that the truck is in a dangerous situation. The driver is warned by a red LED light, reflected on the front windshield. This is followed by a flashing light and an alarm if there is still no reaction from the driver.

The emergency brake is then activated if the driver still hasn’t acted on these warnings.