Design of Multi-module LED Headlamp of Vehicle Under Federal Motor Vehicle Safety Standard

Abstract

A light-emitting diode (LED) low-beam headlamp system was designed following the automotive headlamp regulations in Federal Motor Vehicle Safety Standard 108 (FMVSS 108). To design the system, we used the optical simulation software Light Tools. Using the focusing properties of an ellipsoidal reflector and an asymmetric light source floorboard, we enabled the light projected through the lens to form the cutoff lines that are required in regulations. The newly designed LED low-beam headlamp system can replace the shade component in conventional projector-type headlamp systems, reducing energy loss and effectively increasing light utilization efficiency. Using the concept of light pattern superposition, we superposed the light patterns of multiple modules to reduce the number of LED lights used and achieve satisfactory utilization efficiency. We used the simultaneous multiple-surface (SMS) design method to construct a high-focusing multiple-surface reflector and incorporated it into the system. By superposing the light patterns, the designed system satisfied illuminance regulations. Compared with conventional 55 W halogen low-beam headlamps, the LED low-beam headlamp systems in this study used 70% less energy.