Adaptive driving beam system with MEMS optical scanner for reconfigurable vehicle headlight

Abstract

An adaptive driving beam (ADB) for vehicle headlights has been developed using a microelectromechanical systems optical scanner. A piezoelectric scanner is constructed using thin-film lead-zirconate-titanate oxide (PbZrTiO 3 , PZT) on a bonded silicon-on-insulator (SOI) wafer, respectively, processed by ion-milling and deep reactive ion etching. The PZT layer is laminated in metal films on the SOI layer to form a piezoelectric unimorph actuator, which are then arranged as a pair of twisting suspensions to drive the scanner at resonance. The same piezoelectric actuators are also arranged into another form of meandering suspensions to generate a large deflection angle. By the combination of these two mechanisms, two-dimensional optical scanner is constructed in a single chip. The scanner is used to draw a Lissajous pattern of a blue laser light on a phosphor material to create a structured light source that is projected forward for illumination. The lighting patterns and positions are electronically controlled and reconfigured depending upon the location of leading/oncoming vehicles, pedestrians, road signs, and the cruising speed of the vehicle. The paper discusses on the design of the piezoelectrically driven optical scanner along with the optomechanical performances. We also report on the road-test result of the developed on-vehicle ADB module. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Evaluation of IoT Based Automatic Headlight Dimmer Systems

“…From the late 1950s all the way to present year, optical system are arranged either singularly [11] or in combination with image processing systems [12] or piezoelectric systems [13] to detect illumination further down the road and send signals to the dimmer circuit for response. Towards the start of 2000s, image sensors arranged with CMOS sensors [14], micro cameras [15], and lastly multilevel thresholding [16] provide a platform to perform digital image processing which increased the sensitivity of detection of approaching vehicles to help switch beam by receiving input signals.…”

Piezoelectric MEMS Mirror with Lissajous Scanning for Automobile Adaptive Laser Headlights

“…It provides drivers with high contrast and brightness visibility at night while eliminating glare that causes temporary blindness for other drivers [ 2 , 3 , 4 ]. Unlike traditional headlights that manually switch between low and high beam modules [ 5 ], the ADB system is built on an automotive computer vision system that regulates the spatial illumination based on the cruising speed and the traffic situation (e.g., the presence of oncoming traffic, pedestrians, traffic marks, or vehicles ahead traveling in the same direction) [ 6 ]. With recent rapid advances in computer vision recognition and solid-state light source of headlight modules, it has been technically feasible for processor-control ADB systems to serve as a crucial component of automotive electronics [ 7 ].…”

“…Some commercial ADB optics employ light-emitting diode arrays to digitally regulate the projected light patterns. It is also possible to use a sliding shutter in front of the lamp to partially block the light path with mechanical movement [ 5 ]. However, due to the limited tunable degrees of freedom in such systems, the projected light is restricted by the shape without fine area adjustment capability, which even leads to over-blocking of road signs or nearby pedestrians.…”

“…The much simpler module thermal design and fewer back-end lens array requirements greatly reduce the costs. Asari et al [ 5 ] proposed a headlight system based on a piezoelectric MEMS scanner, but the relatively small mirror aperture design restricted the achievable resolution limit and the maximum delivered optical power of the system. Moreover, their low-stiffness meandering suspensions design of mirror support structure lower the 1st eigenmode frequency to below 1 kHz, which is critical for MEMS to easily react with external random vibrations of the vehicle [ 21 ].…”

Simultaneous beam steering and shaping using a single-interface optofluidic component

“…This fact combined with the ability of two-dimensional (2D) beam shaping will open up new possibilities in various application areas, such as automotive illumination systems. 27,28 2 Device and Experimental Setup…”