Headlight System Research Articles

A review of automotive intelligent and adaptive headlight beams intensity control approaches

The automotive headlight stands out as a critical vehicle component, particularly emphasized during nighttime driving. The high beam, designed for optimal driver visibility on long-distance roads, traditionally relies on manual control by the driver. However, this manual control poses challenges, particularly when the high beam light temporarily blinds oncoming drivers. The resultant dazzle for drivers of opposing vehicles is a significant concern. In response to these issues, there is a growing demand for adaptive and intelligent headlights that can autonomously adjust beam intensity. The intelligent headlight system takes on the responsibility of modifying the beam intensities without requiring explicit input from the drivers. This study aims to systematically review various approaches to controlling intelligent headlight beam intensity. The paper identifies four prominent approaches to intelligent headlight beam intensity control, recognized as widely used techniques. Furthermore, the study uncovers intriguing connections between some of these intensity control approaches. A survey on utilization rates indicates that sensor-based and machine learning (ML)-based intensity control approaches are the most commonly employed methods by automotive headlight designers. The paper concludes by providing insights into the future prospects of intelligent headlight technology, offering guidance for future researchers in this field.

Design and development of speckle-free high-power laser-driven phosphor converted compact automotive headlamp module

The applicability of diode-lasers in automobile headlights is an advanced innovation for the automobile illumination industry due to the extraordinary properties of laser light over conventional light sources, such as high brightness, wide colour gamut, high directionality, low energy consumptions and long lifetime. Lasers are highly coherent in nature, so they encounter the problem of unwanted speckles and spurious fringes and always require a high level of opto-thermal engineering along with speckle reduction mechanisms for high lumen laser applications. Targeting such challenges, in this paper, we report an innovative design and development scheme for a high lumen laser-based automotive headlamp module. The headlamp prototype comprises a set of four cylindrical diffusers which distribute the high energy laser radiation via scattering along the length of the diffusers within a metallic mirro-based pyramidal cavity reflector. The scattered laser light from cylindrical diffusers interacts with a remote phosphor layer that prevents phosphor–resin burning. The pyramidal cavity reflector plays an important role in making the laser light uniform and speckle-free, via spatial and angular diversity, as light exits from the cavity after multiple internal reflections. This reflector redirects the highly concentrated white light over a long range without using any projection lens. The design and performance of the headlight system was studied using TracePro simulation software and tested experimentally in a photometric laboratory. The International Commission on Illumination (CIE) coordinates of the light generated by the headlamp was (0.3947, 0.4908) and the correlated colour temperature was 4240 K, which represents warm white light illumination.

How do bicyclists respond to vehicles with adaptive headlamp systems? A nighttime study in an immersive virtual environment

Introduction: The risk of motor vehicle-bicyclist crashes and fatalities is greater during nighttime than daytime lighting conditions, even though there are fewer cyclists on roadways at night. Vehicle Adaptive Headlamp Systems (AHS) aim to increase the visibility of bicyclists for drivers by directing a spotlight to illuminate bicyclists on or near the roadway. AHS technology also serves to alert bicyclists to the approaching vehicle by illuminating the road beneath the rider and by projecting a warning icon on the roadway. Method: Here, we examined how bicyclists respond to different AHS designs using a large screen, immersive virtual environment. Participants bicycled along a virtual road during nighttime lighting conditions and were overtaken by vehicles with and without an AHS system. The experiment included five treatment conditions with five different AHS designs. In each design a box of white light was projected beneath the rider; in four of the designs an icon was also projected on the road that varied in color (white or red) and position (to the left of the rider at midline or to the left of the front wheel). Participants in the control condition experienced only non-AHS vehicles. Results: We found that riders in all AHS treatment conditions moved significantly farther away from overtaking vehicles with AHS systems, whereas riders in the control condition did not significantly move away from overtaking vehicles without AHS systems. Practical Applications: The experiment demonstrates that AHS has potential to increase bicycling safety by influencing riders to steer away from overtaking vehicles.

Small-size LD-based automobile headlamp design with long illumination distance and wide illumination range.

Due to the large size of an automobile headlamp that has a laser as the light source, it is difficult to reflect the advantages of high laser brightness into the effect of automobile illumination, so it has not been promoted. We propose a laser headlamp system that integrates low-beam and high-beam structures with superior illumination effects (longer illumination distance and wider illumination range) by designing freeform optical components and optical structure. The small-volume headlamp can meet the requirements of the Economic Commission for Europe regulation (ECE) R112. The structure volume of the headlamp proposed in this study is only 100∗70∗70m m 3, and the maximum luminance is 120lx (simulation result) and 78.5lx (test result). The view angle of the low beam is 13.6°, and the high beam is 15.6°, indicating that the solution is suitable for automotive illumination.

Design and implementation of an adaptive headlight system model for enhanced night-time driving safety

Driving at night poses a serious risk due to the momentary blindness brought on by oncoming traffic’s headlights. Traditional headlight designs impair vision temporarily, which increases the risk of accidents. Manual headlight settings and inadequate lighting make the issue worse. An in-depth review of the various sensors-based headlight control systems used by various automaker firms has been conducted. This study discusses a system for detecting vehicles that makes use of a camera and a regression-based machine-learning model. Using a grid formation technique on video that the on-board camera has processed, the position of the approaching vehicle is determined. A signal is then sent to a reflector system that has been specially designed to enable precise beam control with the help of a control unit made up of several electronic components, such as an Arduino UNO, a relay, and a battery. The proposed technology can increase nighttime driving safety by eliminating the Troxler effect on drivers of opposing vehicles while retaining adequate road illumination for the driver on-board.

Dynamic Model-Based Safety Margins for High-Density Matrix Headlight Systems

Real-time masking of vehicles in a dynamic road environment is a demanding task for adaptive driving beam systems of modern headlights. Next-generation high-density matrix headlights enable precise, high-resolution projections, while advanced driver assistance systems enable detection and tracking of objects with high update rates and low-latency estimation of the pose of the ego-vehicle. Accurate motion tracking and precise coverage of the masked vehicles are necessary to avoid glare while maintaining a high light throughput for good visibility. Safety margins are added around the mask to mitigate glare and flicker caused by the update rate and latency of the system. We provide a model to estimate the effects of spatial and temporal sampling on the safety margins for high-and low-density headlight resolutions and different update rates. The vertical motion of the ego-vehicle is simulated based on a dynamic model of a vehicle suspension system to model the impact of the motion-to-photon latency on the mask. Using our model, we evaluate the light throughput of an actual matrix headlight for the relevant corner cases of dynamic masking scenarios depending on pixel density, update rate, and system latency. We apply the masks provided by our model to a high beam light distribution to calculate the loss of luminous flux and compare the results to a light throughput approximation technique from the literature.

Light where it matters: IIHS headlight ratings are correlated with nighttime crash rates

Introduction: Vehicle headlights are the primary means of providing visibility illumination for drivers at night, when crash rates are several times higher than during the day. Based on research indicating a wide range of headlight performance in the passenger vehicle fleet and the absence of a comprehensive and objective consumer evaluation program, the Insurance Institute for Highway Safety (IIHS) began testing and rating headlight systems in 2015. The purpose of this study was to examine the relationship between headlight visibility, as quantified by IIHS, and real-world crash occurrence. Methods: Poisson regression was used to estimate the effects of the headlight rating and the underlying demerits on the rate of police-reported nighttime single-vehicle crashes per vehicle mile traveled. Results: Results indicate that vehicles with better headlight visibility have lower nighttime crash rates after controlling for differences in daytime rates and other factors. A reduction of 10 visibility demerits, the equivalent of one overall rating band, was estimated to reduce the nighttime crash rate by 4.6% (95% CI: 2.1%–7.0%). While statistical significance was limited by small sample sizes, good-rated headlights were estimated to reduce crash rates by 12 to 29% relative to those with poor ratings for the different types of single-vehicle crashes studied. Among different components of the IIHS rating, the assessments of low and high beam curve visibility were associated with the greatest crash rate reductions. Conclusions: This study demonstrates that the IIHS evaluation program encourages headlight designs that reduce the risk of nighttime single-vehicle crashes. Practical applications: Headlight systems have a meaningful effect on nighttime crash rates. Drivers can reduce their crash risk by selecting a vehicle with one of the best designs.

Influence of automotive headlamp systems on the visibility of targets under different road lighting conditions

Modern high-resolution headlamp systems are capable of adjusting to different driving situations. However, the existing road lighting is not yet taken into account when setting the headlamp’s light distribution. This article investigates the influence of the automotive headlamp systems on the visibility of targets in different road lighting conditions and proposes a new lighting strategy based on these results. The luminances of square targets of different surface reflectances and at different distances ahead of the vehicle were measured in road lighting designed to meet classes varying from M3 to M6. For each combination the visibility level (VL) of the targets was determined, with road lighting alone and also when additionally illuminating the scene with the car headlamps. The influence of the headlamps on target visibility was found to depend on the road lighting class, the target distance and its reflectance. In some situations, additional light from the headlamp decreased the target VL and therefore the probability that a driver would detect it. Different ranges of headlamp light distribution were proposed for different road lighting classes to bring light only where it is needed.

Piezoelectric MEMS Mirror with Lissajous Scanning for Automobile Adaptive Laser Headlights.

The emergence of smart headlights with reconfigurable light distributions that provide optimal illumination, highlight road objects, and project symbols to communicate with traffic participants further enhances road safety. Integrating all these functions in a single headlight usually suffers from issues of bulky multi-functional add-on modules with high cost or the use of conventional spatial light modulators with low optical efficiency and complex thermal design requirements. This paper presents a novel laser headlight prototype based on biaxially resonant microelectromechanical systems (MEMS) mirror light modulator for mapping blue laser patterns on phosphor plate to create structured white illumination and tunable road projection. The proposed headlight prototype system enables reconfigurable light distribution by leveraging laser beam scanning with fewer back-end lens and simple thermal design requirements. Built with thin-film lead zirconate titanate oxide (PbZrTiO3) actuators, the MEMS mirror achieved high-frequency biaxial resonance of 17.328 kHz, 4.81 kHz, and optical scan angle of 12.9°. The large mirror design of 2.0 mm facilitates more refined resolvable projection pixels, delivers more optical power, and provides moderate optical aperture to possibly serve as the common spatial light modulator of headlight and the light detection and ranging (LiDAR) towards all-in-one integration. The carefully designed bi-axial resonant frequency improves the device’s robustness by offsetting the lowest eigenmode away from the vehicle vibration. By establishing the laser headlight prototype systems of both 1D and 2D scanning modes, a mathematical model of laser modulation and MEMS electrical control principles of Lissajous scanning are proposed to tune the projection pattern density and shapes. It laid the foundation for developing a laser scanning control system with more complex project functions and prompting the application of MEMS for compact headlight system that addresses night driving visibility, eliminates glare effect, and renders interactive projection capabilities.

Adaptive Headlights System for Four Wheelers: A Review

Abstract: This paper focuses on the review of design and working of a microcontroller based Adaptive Headlight System (AHS) for automobiles. The main purpose of this system is to present a cost-effective technique to illuminate blind spots while driving in the night and during the times when the visibility is reduced significantly to make the objects visible in those darkened locations and thereby prevent accidents. The system functions in accordance to the controlled input from microcontroller unit which drives the stepper motors connected to the headlights. The system is also designed to receive input from the indicator switch wherein a full turn is achieved by the headlight mirror when the indicator input is given. Also, the adaptive headlights are automatically switched on when the amount of light measured by a photo diode falls below a threshold, thereby eliminating the need for the driver to switch on the headlights.

Predictive Headlamp Systems - Based on Driver Assistance Technology

Predictive Headlamp Systems - Based on Driver Assistance Technology

Visualization of initial bacterial colonization on dentin using fluorescence activating headlight for fluorescence enhanced theragnosis

ObjectiveTo evaluate accuracy of caries detection and the application-sensitivity of the new Designs for Vision's REVEAL™ utilizing a fluorescence activating headlight for excitation purpose. Materials and methodsREVEAL dental fluorescence loupes and headlight system were used. Occlusal enamel was removed, and mid-coronal dentine was exposed. Carious artificial lesion was created. Streptococcus mutans, Actinomyces naeslundii, and Streptococcus sanguis were used. The assessment was performed using two diagnostic methods: naked eye and Design for Vision Glasses with inter examiner blinding using two calibrated examiners. After 7 days, Raman measurements were made on dentin disc specimens with 785 nm wavelength. The bacterial counts in colony-forming units (CFU) were used to examine the growth kinetics of biofilms. The collagen fibril structure within the discs was performed using Transmission Electron Microscope. Scanning Electron Microscope was used to image samples at various magnifications. FISH was performed with specimens fixed in 4% paraformaldehyde in phosphate-buffered saline. Reproducibility was measured by Cohen kappa scores, values of which range from 0 for less than chance agreement to 1 for almost perfect agreement (p < 0.05). ResultsA significant kappa score of 0.706 showing significant reproducibility for the given diagnostic techniques, as all the teeth included in the study were spotted with the lesions. Most bacteria were detected using the CFU technique. The Raman bands scanned across the dentin surface at 960 cm−1 (P–O peak) are assigned to hydroxyapatite phosphate vibrations. FISH identified nearly all stained bacteria as days and time and dental hard tissue had a significant impact on the number of adherent bacteria. Scanning electron micrographs of polished cross sections of demineralized and non-demineralized specimens with perpendicular each tubule orientation (zone of demineralized dentin inset. ConclusionFluorescent enhanced theragnosis through Reveal vision glasses can ensure constant monitoring and diagnosis of caries progress . This may allow for a better clinical outcome.

Software Design for Adaptive Laser Headlights

Abstract: The road traffic collisions and injuries, is still a major concern in automotive field. A disproportionate number of fatal accidents happen at nighttime. The major part of the collision is contributed by the human factors. Yet the technology in automobile is continuously assisting drivers while driving. Driving in the dark is not always easy as roads aren’t always illuminated, in such cases a powerful headlight is needed to illuminate most of the road. But such headlights cause glare to the oncoming traffic and again the chances of collision increase, with risking lives of passengers. Therefore, a need of smart headlamps which can illuminate the road far ahead without glaring the oncoming traffic is generated. This research aims to build a Laser based adaptive headlight system which can fulfil the need. The headlight design is proposed using Tinkercad software in which Arduino circuit has been used and software design is presented. The system works well with responding to the steering angle and controls the intensity of light preventing oncoming traffic from getting glared. Keywords: Adaptive headlight system, laser headlights, Arduino, Arduino software design, design of headlight system, cornering lights, effects of laser headlights, Tinkercad

How do pedestrians respond to adaptive headlamp systems in vehicles? A road-crossing study in an immersive virtual environment

Three-fourths of pedestrian fatalities in the U.S. occur in the dark (National Center for Statistics and Analysis, 2020). Adaptive Headlight Systems (AHS) offer the potential to address this problem by improving the visibility of pedestrians for drivers and alerting pedestrians to approaching vehicles. The goal of this study was to investigate how pedestrians respond to different types of AHS. We conducted a mixed factor experiment with 106 college-age adults using a large-screen pedestrian simulator. The task for participants was to cross a stream of continuous traffic without colliding with a vehicle. There were four AHS treatment conditions that differed in the color (white or red) and timing of an icon projected on the roadway in front the participant as an AHS vehicle approached. Participants in the treatment conditions encountered a mix of AHS and non-AHS vehicles. There was also a control condition in which participants encountered only non-AHS vehicles. We found that the color and the timing of the icon projected on the roadway influenced the size of the gaps crossed. Participants in the red icon with early onset condition chose the largest gaps for crossing. An unexpected outcome was that participants in the AHS treatment conditions chose larger gaps even when crossing in front of non-AHS vehicles, suggesting that experiences with AHS vehicles generalized to non-AHS vehicles. We conclude that AHS can have a significant, positive impact on pedestrian road-crossing safety.

Design and Fabrication of Steering Gear Mechanism with Movable Headlights Using Embedded Systems

The main aim of any design must not solely be targeted on customer satisfaction however conjointly customer safety following this the amount of accidents are witness solely because of poor lighting facilities provided in automobiles on curved road static headlights are insufficient since they point tangential it along any point of curve instead of pointing in the vehicles direction so to avoid this problem steering controlled headlamp system has been projected which might hopefully flip out to be a boon to the individual driving through the sinusoidal roads throughout night times. Special safety features are built into cars for years some for the security of car’s occupants only, and some for the security of others. One among the alternatives available in design and fabrication of steering controlled headlight system. car safety is important to avoid automobile accidents or to minimise the harmful effect of accidents, especially as concerning human life and health. automobiles are controlled by incorporating steering controlled headlight mechanism. The Ackerman steering mechanism helps the motive force to guide the moving vehicles calls on the road by turning it right or left consistent with his needs thus a combination of the steering system and embedded system link kills the headlights within the direction as per the rotation of the steering wheel. this mechanism has been incorporated in BMW, Audi Q-7 and Benz etc., to make sure a safer drive, but our main aim is to implement the system in all vehicles at lower cost.

Adaptive Headlight Control System

This research paper focuses on the new method of a retrofittable Adaptive Headlight Control System (AHS) for automobiles like car, trucks, etc., Adaptive headlight system is the technology where the headlights can adjust their illuminating radius with respect to the steering angle and able to self-level its position depending upon the terrain and intensity of light beam changes dynamically high or low according to the oncoming vehicle. This system also considers the benefit of other motorists on the road. In the existing system, mechanical links are incorporated with the front lighting system and steering wheel, and the angle of light will change according to the requirements and the cost of this system is high which is mostly used in higher-end vehicles. In this study an attempt is made to develop a adaptive headlight system which can be retrofitted in an existing model of an automobile providing improved illuminating angles and light visibility under various terrain and road conditions. The proposed AHS system could be useful for applications like different lighting beams (low, high) and also for levelling operations. This system could be a better replacement for conventional headlights seen in low, mid-end cars and would help in the prevention of accidents especially during night driving.

Impacts of Various High Beam Headlight Intensities on Driver Visibility and Road Safety

&#x0D; &#x0D; &#x0D; Based on several studies, driving above certain speed at night while using low beam headlights has been found to result in insufficient visibility to respond to road hazards. Luckily, vehicle headlight technology has advanced so much and the system is commercially available in many parts of the world. However, the technical development for optimal photometric performance raises a few questions. The use of high beam headlight system creates a glare to drivers of oncoming and preceding vehicles (because of both oncoming headlights and preceding taillights), to the extent that it has become necessary to determine the need to put a limit on the luminous intensity of high-beam headlights. This study shall therefore summarize and investigate visual performance that allows for evaluation of the potential benefits of increased luminous intensity by considering glare rating related to safety. Two different car models; the Proton Prevé and the Perodua Myvi were used in the experiments. The results showed that the highest average illuminance [lux] for single vehicle was 17.5, 7.5, 5.0 and 1.0 for the distances of 30m, 60m, 120m and 150m. However, the average illuminance based on total number of vehicles was 1.0, 0.5, 0.0 and 0.0 at distances of 30m, 60m, 120m and 150m, which were considered below maximum recommended safety level (max. 9.0 – 11.0 lux). The current average vehicle high-beam headlight control was found at the level of acceptable glare control (glare to oncoming and preceding drivers) and below the maximum level of illuminance rate with the normal speed of 40 km/h.&#x0D; &#x0D; &#x0D;

Reliability Analysis of Accelerated Destructive Degradation Testing Data for Bi-Functional DC Motor Systems

An accelerated degradation test (ADT) has become a popular method to accelerate degradation mechanisms by stressing products beyond their normal use conditions. The components of an automobile are degraded over time or cycle due to their constant exposure to friction or wear. Sometimes, the performance degradation can be measured only by destructive inspection such as operating torques of return-springs in a bi-functional DC motor system. Plastic deformation of the return-spring causes the degradation of actuating forces for shield movement, resulting in deterioration of the shield moving speed in a headlight system. We suggest a step-by-step procedure for a reliability analysis for a bi-functional DC motor in a headlight system, based mainly on accelerated destructive degradation test (ADDT) data. We also propose nonlinear degradation models to describe the ADDT data of the return-springs. Exposure effects of high temperatures on the return-springs are quantitatively modeled through the ADDT models. We compare the estimation results from both the closed-form expression and Monte Carlo simulation to predict the failure–time distribution at normal use conditions, showing that the lifetime estimation results from the closed-form formulation are more conservative.

A Low-Cost and Fast Vehicle Detection Algorithm With a Monocular Camera for Adaptive Driving Beam Systems

The adaptive driving beam headlamp system is helpful to solve the traffic safety problems caused by the abuse of high beams at night. The fundamental problem for the adaptive driving beam system is to detect and track the vehicles at specific night environment for light shape control. This paper proposes a new and efficient algorithm for detecting and tracking based on video collected by a low-cost camera. The related automobile regulations are analyzed for classifying the application scenarios of the adaptive driving beam system and summarizing the performance requirements of the algorithm. A standard CMOS camera mounted behind windshield captures the test video from different scenarios. Some preprocessing approaches are designed to optimize the captured video so that the algorithm can work independently on specific camera. The color and morphological characteristics of the rear lights are utilized to extract the rear lamps of the vehicle. The symmetry of rear lights is checked by a correlation coefficient method to pair the rear lamps and determine the vehicle ahead preliminary. Then, the Hungarian algorithm and Kalman filter are performed to track the multiple occurrences in two consecutive frames and correct the detection results. Finally, an estimation method is given for calculating the vehicle position in real world. The experiments are designed according to referred regulations and the test video is obtained from a low-cost camera mounted on test vehicles driving in specific scenarios. The experimental results demonstrate that the algorithm can get high detection rates and adaptability to the working condition of adaptive driving beam system. Moreover, the proposed algorithm has low time cost and can be applied in embedded devices of the vehicle.

Adaptive headlight system

Adaptive headlight system