Drive better in the dark
BMW's new driver assistance systems have been designed to make driving in the dark a far less strenuous or dangerous experience.
How does BMW Night Vision work? A thermal imaging camera covers an area up to 300m in front of the vehicle creating an image of objects ahead of the vehicle but out of "sight" of the headlights. The more brilliantly the object the on the central monitor is displayed, the greater the warmth registered by the camera.
Thus people (pedestrians at the edge of the road) and animals (domestic and wild animals crossing the road), because of their high infrared heat signature, would thus be the brightest areas of the image — at the same time these are the most important points to concentrate on when driving responsibly.
BMW engineers opted for the innovative Far Infrared (FIR) technology since it best meets the goal of detecting people, animals and objects at night. Scientific studies also prove that FIR is a more suitable technology than Near Infrared (NIR) for performing this function.
In addition to the fundamental advantages of FIR, BMW has extended the technology by adding other functional features. For example, the image section follows the course of the road (panning) and objects in the distance can be enlarged (zoom). BMW Night Vision is activated/deactivated simply by means of a switch next to the light switch, and is planned to be available, both locally and internationally, in the BMW 7 Series as of fourth quarter 2005.
The thermal imaging camera is installed in the front bumper at the left in its own housing. It is protected by impact-resistant glass and a fine grid. The camera cleaner jet is activated along with the windscreen washer system and ensures a clear view at all times; at outside temperatures below + 5 degrees, the glass cover is heated.
The camera operates with a resolution of 320 x 240 pixels and a range of some 300 m, the image sensor registers heat radiated from people and objects within a wave band of 8 – 14 µm. At speeds below 80km/h, the large horizontal aperture angle of the camera of 36 degrees means that not only the road can be identified but also the areas at the side of the road and surroundings (pedestrians, animals).
The control unit receives data from the camera and converts it into an image on the central monitor. Depending on outside conditions, the image is electronically brightened or darkened.
At a medium road speed, the section shown on the monitor covers an angle of 24 degrees, at the same time this section moves as the road turns — up to six degrees to the left or right. This so-called panning movement is controlled by the steering angle of the front wheels. From a higher speed, a digital zoom can be activated which displays objects at a greater distance in 1.5:1 enlargement.
BMW Night Vision provides the driver with the night vision image as a contrasting black-and-white display on the central monitor in the instrument panel. Use of the Head-Up Display was considered by BMW. However, tests showed that the superimposition of real and virtual image information causes irritation and is therefore not optimum.
With High-Beam Assist, also available from fourth quarter 2005 in the BMW 5 Series, 6 Series and 7 Series, a camera sensor integrated in the rear mirror casing registers activity on the road and automatically controls the activation and deactivation of the high beam. The system identifies the headlights and rear lights of vehicles, as well as the surrounding road lighting.
The high beam switches on in the absence of vehicles on the road ahead or oncoming traffic, provided the road itself is not sufficiently illuminated. BMW is the first European premium manufacturer to offer such a system.
A scientific study in the US has shown that the high beam is used very rarely, although such use is possible and even desirable in many situations. High-Beam Assist makes a significant contribution to ensuring the high-beam is used more frequently. It also prevents other road users from being dazzled if the driver switches to low beam too late or not at all. At the same time it relieves the driver and increases comfort. All in all, High-Beam Assist increase driver safety immeasurably.
The high beam is automatically deactivated in the following situations:
In the case of oncoming traffic (including motorcycles). Here the system recognises the high or low beam of vehicles.
In the case of vehicles driving ahead. The red rear lights of vehicles are recognised.
In the case of sufficient street lighting, i.e. in built-up areas.
At low speeds, when driving with the high beam does not provide any increase in safety.
The system also analyses the brightness and light colour of the light source so as to imitate human use of the high beam as closely as possible. It is designed so that road users within a range of up to around 1000m are detected.
High-Beam Assist does not require additional switches or operating elements. It is activated by means of the light control unit by putting the rotational knob on automatic (same position as for the activation of the light sensor for automatic control of the low beam). In addition, the direction indicator lever must be pushed towards high beam, if currently on low beam. A control lamp in the instrument panel indicates that High-Beam Assist is activated.
BMW Night Vision and High-Beam Assist represent the current high point of an initiative by BMW to make night-time driving safer for all road users and to offer the driver increased comfort.
Xenon light, which provides significantly increased headlight brilliance and range, was introduced in 1991 (Bi-Xenon for low and high beam in 2001). It was followed by the Adaptive Headlight in 2003, whose horizontally swivelling headlamps ensure considerably improved illumination of the road ahead.
The function of BMW driver assistance systems is to support the driver in certain situations without taking away his responsibility. The driver remains the sole "master" of the vehicle. On the one hand, driver assistance systems serve the purpose of providing the driver with improved information on potential dangers or giving him an early warning.
On the other hand they provide relief by taking on simple, repetitive tasks. In general, more information is a bonus in road traffic: up to 50 percent of all serious accidents are caused by the fact that the driver did not have information early enough.
A linear increase in the quantity of information is not the aim, however. Important information must be qualitatively processed and made available at the right moment. Therefore, in addition to increasing safety for vehicle occupants and other road users, BMW driver assistance systems also increase driving pleasure, ensuring that BMW remains the ultimate driving machine