A Study on the Night Visibility Evaluation Method of Color Temperature Convertible Automotive Headlamps Considering Weather Conditions

Abstract

This study evaluated a method of applying color temperature convertible headlamps to improve driving safety in adverse weather conditions such as fog and rain during night driving. The concept of color temperature convertible headlamps is to improve the driver’s visibility by driving with a color temperature of 6000 K on a clear night and switching to a color temperature of 3000 K with better light transmittance at night in adverse weather. Through this study, a method for evaluating the night visibility related to such color temperature convertible headlamps under bad weather at night was suggested. To this end, a method of using a facility that can implement weather conditions such as fog and rain was proposed, and evaluation conditions according to the climatic conditions and the distance of pedestrian targets were set and actual tests were conducted.

Driving in the Rain: A Survey toward Visibility Estimation through Windshields

“…where c 0 , c 1 , and c 2 are strictly positive constants, r t denotes the accumulation of rainwater on the windshield (that is, r is the intensity of the rain and t is the duration between wiper operations), and L b denotes the ambient brightness. Te authors of [74] developed a model to evaluate the efectiveness of a driver visibility system in the presence of rain at night. Te system is composed of two components: a laboratory system in which calibrated rain can be generated to imitate rain on a car's windshield in a dark tunnel with regulated lighting and a feld system in which calibrated rain can be created to replicate rain on a feld.…”

“…Ten, the computed depth estimates of the detected road objects could be adjusted before producing the object list. [19] 2022 Simulating taillights dispersion in the spray-rain medium to evaluate road visibility, and calculation of the maximum safe speed based on the stopping sight distance in low visibility Numerical simulation Critical visibility at 88, 84, 80, and 77 km/h critical and water-flm thickness of 0.5, 1.0, 2.5, and 5 mm [77] 2021 Rain rendering pipeline for evaluating computer vision algorithms under controlled amounts of rain KITTI [68] Fine-tuning improvements +21% object detection, 37% on semantic segmentation, 8% depth estimation CityScape [69] nuScenes [70] [76] 3D point clouds, road network maps, and a 3D scan of the driving environment Town01/CARLA (available at [78]) Te visibility ratio represents the actual road visibility [74] Pedestrian targets in a lab that can simulate rain at night, by comparing contrast ratio (Weber contrast)…”

“…Another limitation is that it is not clear whether the model works at night. For a night-based approach to estimating visibility, one can consider the work in [74], focusing on the intensity of the rain in 20 and 50 mm/h, corresponding to heavy and violent rain at various distances from 5 − 25 m of the target. Contrast is also considered using black and white targets, and in this study, two colour temperatures of 3000 k and…”