Visual Performance And Visual Fatigue Mechanism Of Road Lighting Source

Good road lighting environment is an important factor to ensure driving safety at night. At present, the theories of new light source technology and photobiological effect are developing rapidly. In order to study and promote the application of new light source in the field of road lighting, based on the mesopic visual theory and optical biological effect theory, this paper researches and validates lighting quality of different light sources. The main contents are as follows:(1) Based on visual effect method, the paper studys the static visual effect of different lighting sources. First, the relationship between reaction time and visual performance is analyed, and reaction time test system is developed. Light, brightness, contrast, eccentric angle are used as the parameters of the static visual performance,65 groups of reaction time are designed and tested in different experiment conditions. The relationship between the reaction time and every parameter is analyzed, and the static visual performence of different light sources in different experiment conditions are obtained. The results show that the static visual performance of white light LEDs is the best.(2) Based on reaction distance, the dynamic visual performance of different lighting sources is studied. First, the relationship between reaction distance and dynamic visual effect is analyed, and speed of dynamic visual effect testing software is developed.75 groups of experiments are tested in different visual target speed and background luminance. The influence of speed on the dynamic visual effect is analyzed. The results show that the dynamic visual effect of white light LEDs is the best and the dynamic visual effect of speed at 60km/h is optimal relatively.(3) Based on critical flicker frequency, the visual fatigue mechanism in different illumination sources is reasurched. The ritical flicker frequency test system is developed, and 25 sets of experiments are tested in different experiment conditions. Based on the experiment data, the influence of light sources on visual fatigue is analyzed. The results show that high content of short wave component of LED light source help to reduce fatigue, experimental results conform to the theory of optical biological effect.(4) Based on the pupil diameter, the visual acuity in different illumination light sources is reasurched. The photographic method is used on measuring pupil diameter, and 25 sets of experiments are carried out in different experiment conditions. Based on the experiment data, the effect of light source on visual acuity in different lighting brightness is analyzed. The results show that with the increase of brightness, the pupil diameter reduces wavely, and the comprehensiveness of visual fatigue and visual acuity in middle and high color temperature LED light sources is the best relatively.