Regulation-aware freeform headlamp reflector design with differentiable ray tracing
Optics Express
|July 30, 2025
Summary
This study introduces a novel, regulation-aware method for designing automotive headlamp reflectors using differentiable ray tracing. The approach efficiently optimizes freeform surfaces to meet ECE R112 standards, accelerating the design process.
Area of Science:
- Automotive Engineering
- Computational Optics
- Computer-Aided Design
Background:
- Automotive headlamp design relies on freeform reflectors to meet strict regulations.
- Manual adjustment of these surfaces is time-consuming and design-limited.
Purpose of the Study:
- To develop a regulation-aware approach for optimizing freeform headlamp reflector design.
- To utilize differentiable ray tracing for efficient and accurate simulation.
Main Methods:
- Modeling reflectors with B-spline surfaces and optimizing control points.
- Employing a custom ray tracing pipeline with triangle mesh acceleration.
- Using multi-layer perceptrons (MLPs) and regulation-based loss functions for light distribution generation.
Main Results:
- Successfully generated ECE R112-compliant passing-beam and driving-beam light distributions.
- Optimized reflector shapes in approximately 200 iterations.
- Achieved 2.5x faster simulations compared to commercial software with comparable accuracy.
Conclusions:
- The proposed neural method enables rapid, regulation-compliant freeform headlamp reflector design.
- This approach offers significant improvements in design efficiency and simulation speed.
- Optimized reflectors can be exported as CAD models for practical application.
