Embedding LiDAR and smart laser headlight in a compact module for autonomous driving

Abstract

A headlight module embedding smart laser headlights and a LiDAR is presented. The headlights include blue lasers for the high beam, and blue LEDs for the low beam, each with a high efficiency glass phosphor-converter we have fabricated. The LiDAR is an indirect-mode time-of-flight 905-nm rangefinder. We used two Nichia GaN lasers emitting a total 9.5-W optical power at 445-nm for the high-beam headlight, and five OSRAM GaN LED emitting a total 12-W at 445-nm for the low-beam headlight. The yellow-converter phosphor is a glass-based Ce3+: YAG slab, 100-mm dia. and 0.2-mm thick, that we have fabricated at 750°C temperature, obtaining a high thermal stability, a high conversion efficiency, and a good color rendering index. A digital micromirror device (DMD) placed in the focus of the parabolic reflector is used to switch off sectors of the high-beam when crossing other vehicles. The 2D image of a CCD camera and the LiDAR data are fed to an image processing unit based on CNN that classifies the targets. The headlight module has a >85% detection accuracy of a pedestrian up to 20 m distance.