Using design of experiment for parameter optimization on smart headlamp optics design

Appl Opt. 2019 Oct 1;58(28):7661-7683. doi: 10.1364/AO.58.007661.

Abstract

This research focuses on the design of the optical microstructure, and the design of four kinds of light distribution for vehicles' passing beam and driving beam optical structures under the regulation ECE R123. The results show that the passing beam achieves the target light distribution with multiple light patterns superimposed by reflectors, and can meet the four segment light types under the regulations: Class C, Class V, Class E, and Class W. With the structural design method of the reflector, a cutoff line is formed under the structure without a visor to reduce the energy waste caused by the shielding structure, so that the maximum luminosity of the passing beam under the road section can reach 75,980.7 cd and the simulated maximum photometric value can reach 69,705.9 cd under Class W. The driving beam uses the total internal reflection (TIR) lens design to find the optimal 36° angle of the lens to effectively achieve the straightening and brightness enhancement of the light, and then uses the response surface methodology to optimize the optical divergence of the parameters of the microlenticular lens structure on the TIR lens to adjust the width and flatness of the light type. Among them, the radius of curvature, the thickness of the lens, and the length of the single lens are selected as the factors. Using the experimental design method of the reaction surface, the optimal solution of the driving beam design is found. The optimal solution is combined into a radius of curvature of 14.99 mm in the X direction and 25.22 mm in the Y direction, the overall thickness is 1.5 mm, and the length of a single curved surface is 2.43. Each factor is within the limit, and the maximum brightness in the center is 213,866 cd.