Influence of Beam Shape of Road Lighting Luminaire on the Visual Perception of Vehicle Driver

摘要

When driving on a lit-up road, visual perception of the vehicle driver is greatly affected by the quality of road lighting which is a combined effect of light color, glare, light level of the space, luminance uniformity of the road surface and spatial distribution of lighting.Part of these influence factors are mainly accounted in static situation, while the others could only be modeling in the dynamic situation when focusing on the aspects (e.g.perception of visual comfort) of visual perception of vehicle drivers.With the fast boost of LED application in road lighting, complaints from the vehicle drivers are reported about lower level of perceived visual comfort from LED road lighting comparing with conventional type of lighting installation such as HPS.So far, intensive researches have been done on LED specific lighting parameters such as discomfort glare, which are all based on the pre-assumption of a simplified and static background scene.Besides of the current knowledge, are there any factors influencing the drivers' visual comfort, and how does the influence work?This paper is to study the beam shape influence of road lighting luminaire on the visual comfort of the vehicle drivers.The influence of beam shape is considered as fluctuation of vertical illuminance on the eye position of the driver periodically(here-in-after named 'smack effect').As the first step, experimental set ups in the laboratory was built based on virtual reality technology to eliminate the disturbances in the reality and ensure a controllable experiment.Then, we created different stimulus of eye illuminance from selected luminaires from real applications, and invited participants to experience and rate his/her perception of visual comfort upon the given 7-points scale.Statistics analyses are performed on the experiment data.The results clearly show the influence effect of the depth of eye illuminance fluctuation on visual comfort perception.Moreover, the critical threshold of the illuminance fluctuation has been defined upon a regression model of the study.