A Night Vision System with Spotlight / Marking Light

Dr.-Ing. Helmuth Eggers, Daimler AG Dr. Jörg Moisel, Daimler AG

Mr. Stefan Töpfer, Daimler AG Mr. Simon Tattersall, Daimler AG

1.Introduction

Imagine the scenario: you are driving at night on a dark country road and suddenly a pedestrian appears as if from nowhere – almost every driver must have encountered such a daunting moment at some point. Striking a passer-by is one of the worst things that could happen to a driver. According to research by the German Federal Highway Research Institute (BASt), five times as many pedestrians are killed on country roads at night than during the  day[3].  Another statistic from the BASt is equally as shocking: only 20 percent of car journeys take place at  night

–however this is the time when some 40 percent of fatal accidents occur[4]. Safe night-time driving would inevitably require much lower speeds that would turn any vehicle following these guidelines into a traffic hindrance[5].

Following its “Vision of Accident-free Driving” Mercedes launched its night vision system “Night View Assist” in 2005, which sports a twofold increase in vision range at night time. Its near infrared technology guarantees images that are as close as possible to images in visual   light

–those that any driver is accustomed to see. Due to a physical effect most – even darkly colouredtextiles become bright in near infrared light which makes pedestrians show up as bright shapes in the night vision images, cf. figure 1. The night vision images are displayed in the speedometer display of the car, right in front of the driver. It can be used much like a rear view mirror – a short glance from time to time assures the driver that nothing is in his path. However, the driver has to avert his gaze from the outside world and direct it towards the display. To keep this time as short as possible, an optical guidance to find pedestrians was introduced in 2009 with the Night View Assist Plus. A recognition algorithm finds pedestrians in the night vision images and flags them with rectangular marks, cf. figure 2.

In 2006 Mercedes introduced the Intelligent Light System with its fully computer controlled light functions. This system includes five lighting functions: Country mode, Motorway mode, Enhanced fog light, Active light function and Cornering light function. In 2009 the Intelligent Light System has been augmented by the Adaptive Highbeam Assist which adjusts the range of the headlamps in accordance with the distance to oncoming vehicles or vehicles travelling ahead which are detected by the multi purpose camera, separate from the night vision camera (cf. figure 3). For the first time, a fully computer controlled lighting system is available, where the headlamps could be directed towards any object to be illuminated.

Following the developments in night vision camera and headlamp design wouldn’t it be advantageous to have any pedestrian indicated by the lighting system in the outside world?

In 2009 a study showed the potentials and problems of a spotlight function directed on roadside pedestrians[1]. An internal Daimler study showed a spotlight / marker light function would be highly valued by the subjects of the study[6]. The warning character of a spotlight illumination would be highly appreciated, however no other participant of the outside traffic should be dazzled. Many subjects of the study indicated they would like to keep the lighting situation under their own control – mainly to spontaneously deactivate the automated lighting systems if necessary.