Investigation of Retroreflector Characteristics using Computer-Vision Method

摘要

In a dark channel of more than 15 m, a standard A light source was used to simulate a motor vehicle's headlight, and a Nikon D750 digital camera was used as a light receiver. While the observation angle a was 0.33°, the entrance angle component β1 was -4°, the entrance angle component β2 was 0°, and the coefficients of retroreflection of the retroreflectors were measured. The entrance angle component β1 changed from -4° to 0°, and the chromaticity coordinates of retroreflectors were then measured. Experimental results show that the maximum measurement error of the coefficient of retroreflection is -2.09%, and the measured results of the chromaticity coordinates meet the national standard of retroreflective sheeting for traffic control. Obviously, the RAW data output from the camera has a linear association with the luminous flux on the surface of retroreflectors, which can be used to calculate the coefficients of retroreflection and the chromaticity coordinates.