RGB LED matrix display for augmented driving for higher traffic safety

Abstract

Augmentation in manually driven vehicles can raise traffic safety significantly. The most ergonomic (eyes-on-the-road, no refocusing) solution is AR-HUD but the FOV is limited today to 10° by 5°. Transparent displays in the windshield (eyes-on-the-road, refocusing required) are costly (replacement) and hardly meet legal requirements for transparency. The cheapest solution is video-AR on dashboard displays (eyes-off-the-road, refocusing required). We report on a new approach for augmentation as compromise between ergonomics and cost: An eight-line RGB matrix display to be mounted on top of the dashboard at the bottom of the windshield. It spreads from pillar-to-pillar (150 cm, 150 x 8 pixel, RGB LED) and therefore enables augmented information along the whole windshield. In consequence, it needs less eyes-off-the road and refocusing and is a very ergonomic add-on for video-AR. We started with a single line pixelated light guide in a seating buck to measure and to evaluate the required luminance (⪆3,300 cd/m²), RGB luminance ratio (35:50:15) and perception of information from night to blinding sunlight. We optimized the RGB LED display by testing and measuring various diffusers at different distances to the LEDs for an optimum combination of sharpness and pixelation. Image quality and content such as the visualization of actual speed (including color-coding), warnings (e.g. slippery), navigation, and comfort functions (e.g. incoming call, beat mode) were evaluated by subjects via online survey and in our seating buck. The display was rated as being very helpful with significantly reduction in time for grasping the information.