Automatic Headlight Levelling Using Inertial Sensors

Abstract: In order to use high power headlights on heavy duty vehicles, an automatic mechanism for adjusting the level of the headlights must be used. This is in order to avoid glare while still maintaining good visibility. For headlights exceeding 2000 lumen, this control must be done automatically. The main reason for a change in the headlight level is when the truck is being loaded, and the suspension is compressed causing the headlights to point slightly up or down. Due to inherent limitations of the Scania trucks, the most commonly used approach of estimating the vehicle pitch angle is not possible to implement. Thus, a set of pitch estimation methods largely using sensors detecting acceleration are investigated and presented. Further, three methods are chosen for further study and evaluation. One method using previously recorded data about road slope as well as an on board acceleration sensor is shown to produce a high quality vehicle pitch estimate.