A large number of accidents and fatalities every year occur because of human negligence. Volvo Cars aims to reduce all this by equipping its vehicles with facilities that are likely to increase safety on the road. These systems provide audio-visual warnings to the driver as and when the need arises, and may even pull the vehicle to a halt if the system believes the problem is critical enough. A look at these systems:
Collision Warning with Auto Brake (CWAB):
This is a system designed to avoid rear-end collisions. When the system sees chances of a collision, it alerts the driver and precharges the brakes. If the driver fails to take action, and a collision seems eminent, the system pulls the brakes to decrease impact or prevent collision altogether. The system also incorporates support for detection of stationary vehicles and is able to take preventive action in case a collision with a stationary vehicle becomes eminent.
CWAB employs a long-range radar (150m) and a camera (range 55m). Both these devices work in unison to make driving safer. Data fusion from the radar sensor and the camera makes the system more efficient. As the car approaches another vehicle and the driver does not react, the system activates a red warning light in the head-up display at the windscreen, along with an audible sound.
If the risk of collision increases despite these warnings, a preventive mechanism comes into play and gets ready to pull the brakes. Brakes are applied by the system only when both the devices (radar sensor and camera) agree that a collision is unavoidable.
An Adaptive Cruise Control (ACC) is also available. The driver may set speeds between 30 and 200kmph and make a choice from five time intervals that vary from 1 to 2.6 seconds. The ACC notes the speed of the car in front, and manages speed according to it.
Also present is a Distance Alert (DA). DA helps to monitor distance from the vehicle in front, when the ACC is disengaged. The driver can again choose a time gap from the five available options. If the time gap becomes less than what was chosen by the driver, visual information appears in the head-up display.
Driver Alert Control (DAC):
Here’s a DAC that is unlike systems used by other manufacturers. The DAC from Volvo does not keep looking at the eyes of the driver to see if the driver is alert; the company believes the technology for monitoring the driver’s eyes is not advanced enough.
DAC does not monitor human behavior, which may show wide variations from person to person. Instead, the system notes the car’s movements to assess whether the vehicle is under control of the driver. Monitoring the way the vehicle is driven has big advantages. The system knows whenever a potentially dangerous situation arises. This includes times when the driver loses concentration not just due to fatigue, but while using a mobile phone or being engaged in conversation with other occupants of the vehicle.
The system utilizes a camera installed between the windscreen and the interior rear-view mirror. This camera measures the distance between the car and the road lane markings. A host of sensors keep an eye on the car’s movements and feed all information to a control unit.
In case the control units assesses that the vehicle is moving out of control, it alerts the driver by means of an audible signal and a relevant text message appears on the car’s information display. DAC comes into play for speeds above 65kmph and stays active until the speed drops below 60kmph.
To further reduce chances of a mishap, Lane Departure Warning (LDW) is also included. Activated by a button on the center stack, the LDW alerts the driver through a warning sound if the car crosses road markings without the use of a turn indicator. As with the DAC, this system comes into play at speeds above 65kmph and continues till the speed goes down the 60kmph mark.
This is not a perfect world, and these systems aren’t perfect either. Environmental and weather conditions have a marked effect on the operations of these systems. Poor light, fog, snow and extreme weather conditions can make the systems become unavailable. Ironically, these are the times when you need these systems the most. These systems will be available on the S80, V70 and XC70 models for the model year 2008.
This is a move in the right direction from Volvo. All we can hope is that the automakers throughout the world come with a viable and flawless system as soon as possible.
Volvo’s safety systems Picture Gallery
[Via: Volvo]
