Abstract
Keywords - headlamp, frontlighting, AFS, beam pattern, beam control
Abstract - Headlamp system plays a very important role on safe driving at night or under darkness. A well-designed headlamp system should allow enough illumination to the oncoming road and less glare to an oncoming vehicle for a nighttime driver. A current headlamp system provides basic functions of low-beam and high-beam illumination. However, loading and body motions of a running vehicle can affect the beam direction of a headlamp. Besides, car braking and acceleration also cause vehicle pitching, and then change beam direction. Such change of beam direction results in insufficient illumination in front of a car, and reduces the safety of car driving. It also makes glare to front and oncoming vehicles. Accidents usually occur because of such insufficient illumination and glare.
This paper introduces an adaptive headlamp beam control system to solve the above-mentioned problems. With the signals from five position sensors installed on car chassis, a car can adjust angles of headlamp adaptively according to different driving conditions and environments.
In this paper, horizontal adjusting angle of headlight system is discussed first. A car turning angle is calculated based on information of front wheel turning angle and side-slip angle. Then the turning angle is used as the horizontal adjusting angle of headlight system. The vertical adjusting angle of headlight system is also discussed in details. Several conditions are considered for such adjustment. These conditions include change of car loading (i.e., passengers in backseats), car accelerating or decelerating, change of road conditions (i.e., up-hill or down-hill), change of car speed, and wet road surface in rainy days.
This study analyzes driving conditions of a car, and proposes adjusting headlight beam angles for those conditions. This adaptive headlamp will, therefore, provide enough road illumination for driver independent of the variations of car weight loadings and road conditions.