Virtual Simulation and Design Optimization of Bi-Functional Projector Headlamp for Nighttime Visibility of Overhead Signs

For safe driving function, signs must be visible. Sign visibility is function of its luminance intensity. During day, due to ambient light conditions sign luminance is not a major concern. But during night, due to absence of sun light sign board retro-reflectivity plays a crucial role in sign visibility. The vehicle headlamp color, beam pattern, lamp installation position, the relative seating position of driver and moon light conditions are important factors. Virtual simulation approach is used for analyzing the sign board visibility. Among various factors for example the headlamp installation position from ground, distance between two lamps and eye position of driver are considered for analyzing the sign board visibility in this paper. Many automotive organizations have widely varying requirements and established testing guidelines to ensure visibility of signs in head lamp physical testing but there are no guidelines during design stage for headlamp for sign visibility.

In this paper, among several other considerations focus is given on enhancing the driver’s ability to truly control the driving experience using Ansys VRXperience night drive simulator capability. Bifunctional LED projector headlamp CAD is used for generating light intensity files in Lucid Shape. These light intensity ray files (IES file format) which is output from Lucid Shape software is used as input to Ansys VRXperience for in scenario driving simulation and to understand the real time visibility of signs while driving. The nighttime sign visibility simulation process is established for virtual verification of lamp installation position and consequently its impact on driving experience in early design phase. This helps in addressing last minute changes in design and costly prototype mockups required to check the safety aspect.