Headlights Research Articles

Bidirectional Vehicle-to-Vehicle Communication System Based on VLC: Outdoor Tests and Performance Analysis

Intelligent Transportation Systems (ITS) aim at integration of innovative technologies in next-generation vehicles in order to increase the safety and efficiency standards of vehicular traffic fluxes. Although many sensors are currently available in modern cars, mutual data exchange between vehicles in real-time will be crucial in future smart vehicles, but this domain, and in particular bidirectional Vehicle-to-Vehicle (V2V) through Visible Light Communications (VLC), remain relatively unexplored yet. In this paper we present a system for bidirectional data transmission between vehicles through VLC. Specifically, we implement for the first time a bidirectional VLC link using real motorcycle headlights (HL) and rear lights (RL), and we provide a characterization of transmission performances under direct sunlight conditions in an outdoor scenario for realistic distances (up to 30 m) and relative positions between two vehicles. The performance of the VLC system has been evaluated in terms of Signal-to-Noise (SNR) maps and Packet Error Rate (PER), measured in various configurations and for different baudrates (28 kBaud / 57 kBaud). Our result show that a bidirectional error-free communication is possible between two consecutive vehicles for distances up to 12 m, whilst successful transmission could be observed up to 21 m. Finally, we compare our bidirectional intensity and PER data in realistic ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">flat</i> ) configuration against the predictions of a physical model which considers non-ideal orientations of the receiver stage through a novel, simple technique that could also be exploited in different VLC implementations. A very good agreement between the experimental data set and the model is found on the whole measurements grid.

Automatic Headlight Intensity Control using Light Dependent Resistor

For so many years, road accidents have been a huge problem for automobile industries since they must continuously upgrade their vehicles to withstand any type of damages. In this regard, many technologies are invented to reduce the figure of accidents that happen. One of the great reasons for road accident is due to bright headlight of vehicle coming in opposite direction. High beam from the headlight causes a dangerous situation for night driving. It causes temporary blindness for the drivers that may lead to collisions or may hit people passing through the road and lives can be lost. According to the law of “Indian Roads and Transport Council”, low intensity light has to be used always, however in the time of overtaking or other mandatory situations, high beam can be turned on. But due to the driver’s ignorance and since they cannot see the long-range road in low intensity, they always drive with the high intensity light on. Automatic dipper, a circuit which controls the intensity of the head light of vehicle has been designed here. From this automatic dipper system, the intensity of headlight of the vehicle can be automatically controlled and can provide a better visible road using optimization techniques for light condition.

Simplified methods for characterizing thermal parameters of high-power automotive LEDs

This study outlines a new methodology for experimental determination of the key parameters required for designing LED thermal management hardware, using a case study of the Nichia NC5W093AT Light Emitting Diode (LED), a light used in automotive headlamps. The method provides the junction temperature, the efficiency, and the package thermal resistance of the LED. For the studied LED, it was found that efficiency decreased from 36% to 25% with increasing junction temperature from 30°C to 120°C; efficiency was also insensitive to supply current. The thermal resistance, which spanned from the LED junction to the copper base, was determined to be 3.2 K/W and was insensitive to supply current and operating temperature.

Application of rotational accelerometers on the measurement of automotive headlamp cut-off deviation

Automotive lighting products, such as Head Lamps (HL), Fog Lamps (FL), Daytime Running Lamps (DRL), face with mechanical vibrations during service life which may coincide with the resonance frequencies of the light source. When excited at resonance frequencies, especially in the case of HL’s, light beam cut-offline may deteriorate and vibration of light beam occurs. This situation is also called light flickering. This state has disturbing effect on the driver’s visibility, which is valid for both the driver and the counter drivers. Most of the automotive manufacturers have developed test specifications for evaluation of flickering state under sinusoidal frequency sweep acceleration loading and they have introduced limits for flickering angle range or displacement range of the light beam with respect to frequency measured on a screen which is put on a prescribed distance from the light source. In this study a traditional way of light beam flickering angle deviation measurement method of HL is presented. Furthermore, application of precise &amp; efficient way of measurement method by the use of quartz rotational accelerometer is inspected.

Development of Radiator with Thermoplastic Polymer and Insert-Molded Aluminum Alloy Parts for Light-Emitting Diode Headlights

The increasing popularity of electric vehicles has increased the demand for lightweight auto parts. However, the excessive weight of traditional metal heat sinks has remained a concern. Metal has excellent thermal conductivity but low radiation efficiency. Conversely, thermoplastic polymers have excellent heat radiation efficiency but poor thermal conductivity. In this study, we propose a radiator constructed using thermoplastic polymer and insert-molded aluminum alloy parts to maintain the low junction temperature of light-emitting diodes (LEDs); the radiator’s weight is reduced through a combination of aluminum alloy and a thermally conductive polymer designed for automotive headlights. At an LED thermal load of 11.48 W, the measured temperature on the LED pad is 60.8 °C. The weight of the proposed radiator is 23.37% lighter than that of a pure metal radiator. When the lightweight radiator is used in high-power LED headlights, it effectively dissipates heat within a limited space.

Types of septal deviation rate of each type morbidity and associated sinus pathology

Background Septal deviation is a common disorder and its role in pathogenesis of sinus pathology remain uncertain , Different type of septal deviation affects sinuses in different feature. Design of study : prospective study Objective Rate of each type of septal deviation . Morbidity of septal deviation . Associated sinonasal pathology . Patient and methods About 150 patients. collected from out patient clinic from AL.Yarmouk teaching hospital from April 2017 till Augest 2018 who complain from nasal obstruction, nasal discharge, facial pain others for at least 3month, patients presented without previous diagnosis. All patients collected due to symtomatic septal deviation, then examination done either by ant. Rhinoscopy using head light and killian nasal speculam, endoscopy rigid type 4mm (00&300) and fibroptic (nasopharyngeal) Doing C.T scan for each patient to observe change in each type on paranasal sinuses ,the shape of deviation which seen by endoscopy and exclude other nasal and paranasal pathology Data collected in questioner or statistic reading method using P.value . Observe rate of each type ,morbidity of septal deviation consequence of pathology of each type regarding of sinuses . Results In this current study for 150 case symptomatic septal deviation we observe : C-shape (91)60.6% S-shape (59) 39.3% we found 70 case associated with sinus pathology C-shape=32case 45.8% S-shape =38case 54.2% Conculosion Deviated nasal septum associated with significant sinonasal disease especial S-shape DNS which show statically significant correlation with sinus disease . Nasal obstruction are the main complain of septal deviation . Bilateral sinus disease more associated with S-shape &unilateral sinus disease with C-shape .

Numerical investigation of the effect of different heat sink fin structures on the thermal performance of automotive LED headlights

With the developing technology, the automotive lighting sector is also changing rapidly. Automotive lighting equipment is produced with more functionality and higher performance. However, with the increase in perfor-mance, undesirable heat generation also increases. Automotive headlights fail or perform poorly when exposed to high heat; therefore, unwanted heat has to be removed. This is accomplished with heat sinks. In this study, four different automotive light-emitting diode (LED) headlights have been designed as channelless, 4-channel, 8-channel, and 12-channel. The designed models were tested numerically at different LED powers (8, 10, 12, 14, and 16W). Thus, the impact of heat sink fin structures on the thermal performance of automotive LED headlights was investigated numerically. The heat dissipation performances of the designs were analyzed using the computational fluid dynamics software SolidWorks Flow Simulation. The simulation results showed that the designed products can be used as LED headlights. As the applied heat power increased, maximum tem-peratures also increased. While a continuous increase in performance was achieved in designs up to 8-channel, slight performance degradation was observed when the number of channels reached 12. As the applied heat power increased, the average temperatures increase whereas thermal resistance (Rth) decreased. From channel-less design to 12-channel design, Rth values decreased from 6.8 °C/W to 5.31 °C/W.

Directional emission of white light via selective amplification of photon recycling and Bayesian optimization of multi-layer thin films

Over the last decades, light-emitting diodes (LED) have replaced common light bulbs in almost every application, from flashlights in smartphones to automotive headlights. Illuminating nightly streets requires LEDs to emit a light spectrum that is perceived as pure white by the human eye. The power associated with such a white light spectrum is not only distributed over the contributing wavelengths but also over the angles of vision. For many applications, the usable light rays are required to exit the LED in forward direction, namely under small angles to the perpendicular. In this work, we demonstrate that a specifically designed multi-layer thin film on top of a white LED increases the power of pure white light emitted in forward direction. Therefore, the deduced multi-objective optimization problem is reformulated via a real-valued physics-guided objective function that represents the hierarchical structure of our engineering problem. Variants of Bayesian optimization are employed to maximize this non-deterministic objective function based on ray tracing simulations. Eventually, the investigation of optical properties of suitable multi-layer thin films allowed to identify the mechanism behind the increased directionality of white light: angle and wavelength selective filtering causes the multi-layer thin film to play ping pong with rays of light.

Study on the Influence of Opposing Glare from Vehicle High-Beam Headlights Based on Drivers’ Visual Requirements

The anti-glare facilities in median strips are designed to block opposing headlights in order to avoid disability glare, but a large amount of headlight leakage results in uncomfortable glare, to the point that drivers can barely detect dangerous obstacles or road conditions. This paper aims to explore the glare range under high-beam headlights on drivers’ visual requirements. Based on an analysis of the mechanism of headlight glare, this paper proposes a subjective headlight glare scale, and classifies glare discomfort into two categories: interference glare, and acceptability glare. Combining the scales, 24 drivers and a standard light-emitting diode automotive headlamp were used to conduct glare effect tests. The size of the laboratory that closes to scotopic vision is 12 m × 6 m. The illuminance thresholds of disability glare–interference glare (DGIG) and interference glare–acceptability glare (IGAG), along with the spatial distribution of each glare level, were collected at the longitudinal distances of 3 m, 5 m, 7 m, 10 m, and 12 m. Meanwhile, the illuminance threshold and the spatial distribution of each glare level up to a longitudinal distance of 120 m were calculated. The results indicate that disability glare is distributed in the central area, while interference glare and acceptability glare are distributed from the center to the margins. At the same longitudinal distance, the vertical illuminance of the driver’s eye under the same glare level is almost equal. In the range of a longitudinal distance of 120 m, the spatial distribution of each glare level enlarges with each increase in longitudinal distance. The results can provide scientific evidence for calculating the reasonable heights of anti-glare facilities for expressways with different alignments.

Neural Encoding of Active Multi-Sensing Enhances Perceptual Decision-Making via a Synergistic Cross-Modal Interaction.

Most perceptual decisions rely on the active acquisition of evidence from the environment involving stimulation from multiple senses. However, our understanding of the neural mechanisms underlying this process is limited. Crucially, it remains elusive how different sensory representations interact in the formation of perceptual decisions. To answer these questions, we used an active sensing paradigm coupled with neuroimaging, multivariate analysis, and computational modeling to probe how the human brain processes multisensory information to make perceptual judgments. Participants of both sexes actively sensed to discriminate two texture stimuli using visual (V) or haptic (H) information or the two sensory cues together (VH). Crucially, information acquisition was under the participants' control, who could choose where to sample information from and for how long on each trial. To understand the neural underpinnings of this process, we first characterized where and when active sensory experience (movement patterns) is encoded in human brain activity (EEG) in the three sensory conditions. Then, to offer a neurocomputational account of active multisensory decision formation, we used these neural representations of active sensing to inform a drift diffusion model of decision-making behavior. This revealed a multisensory enhancement of the neural representation of active sensing, which led to faster and more accurate multisensory decisions. We then dissected the interactions between the V, H, and VH representations using a novel information-theoretic methodology. Ultimately, we identified a synergistic neural interaction between the two unisensory (V, H) representations over contralateral somatosensory and motor locations that predicted multisensory (VH) decision-making performance.SIGNIFICANCE STATEMENT In real-world settings, perceptual decisions are made during active behaviors, such as crossing the road on a rainy night, and include information from different senses (e.g., car lights, slippery ground). Critically, it remains largely unknown how sensory evidence is combined and translated into perceptual decisions in such active scenarios. Here we address this knowledge gap. First, we show that the simultaneous exploration of information across senses (multi-sensing) enhances the neural encoding of active sensing movements. Second, the neural representation of active sensing modulates the evidence available for decision; and importantly, multi-sensing yields faster evidence accumulation. Finally, we identify a cross-modal interaction in the human brain that correlates with multisensory performance, constituting a putative neural mechanism for forging active multisensory perception.

Controllable shifting, steering, and expanding of light beam based on multi-layer liquid-crystal cells

Shaping and steering of light beams is essential in many modern applications, ranging from optical tweezers, camera lenses, vision correction to 3D displays. However, current realisations require increasingly greater tunability and aim for lesser specificity for use in diverse applications. Here, we demonstrate tunable light beam control based on multi-layer liquid-crystal cells and external electric field, capable of extended beam shifting, steering, and expanding, using a combination of theory and full numerical modelling, both for liquid crystal orientations and the transmitted light. Specifically, by exploiting three different function-specific and tunable birefringent nematic layers, we show an effective liquid-crystal beam control device, capable of precise control of outgoing light propagation, with possible application in projectors or automotive headlamps.

Active-Matrix Pixelated-LED Control System for Automotive Headlamps

This paper presents a driving circuitry system for high-resolution, pixelated-LED automotive headlamps. The system consists of an array of pixel drivers, and a row/column driver suitable for an active-matrix array configuration with the individual dimming control capabilities on each pixelated-LED. An asynchronous serial communication protocol is introduced to minimize the number of data transmission interface signals between the row/column driver and pixel drivers. The proposed pixel driver is designed to drive each pixelated-LED with constant current and pulse width modulation (PWM). It contains a memory cell for dimming data, and a sample-and-hold driver stage to minimize the static power consumption of the pixel driver. The proposed system has been fabricated by using a 0.18-μm CMOS process. The test chip includes a 2 × 16 pixel array with an embedded row/column driver. The functional operation has been verified with an 8 × 16 LED array system prototype.

Effect of headlamps on the irradiation characteristics of automotive headlights

In this study, we investigated and analyzed the correlation between high beam and low beam and the low beam irradiation characteristics of LED head lamps using a headlight tester based on each inspection standard for automotive headlights. From the experimental results, it was confirmed that the irradiation characteristics switched to the low beam did not fully satisfy the inspection criteria with respect to the appropriate irradiation direction and luminosity of the high beam. It was also found that when the halogen lamp was changed to the LED head lamp in the low beam of the 4-lamp type headlight, the change in the irradiation direction was small, but the increase in the irradiation light intensity differed depending on the vehicle.

An Intelligent Driving Assistance System Based on Lightweight Deep Learning Models

An intelligent driver assistance system is developed in this study, which is able to remind the drivers to turn on the head lights or wipers through situation recognition method when driving at night or on rainy days. Furthermore, it is also able to alarm the drivers based on the lightweight deep learning model and the distance estimation method when surrounding vehicles are too close. Experimental results show that the proposed methods and the chosen lightweight model in our proposed system obtain reliable performance and sufficient computational efficiency under limited computing resource. In conclude, our proposed system obtains high probability to be adopted for the development of advanced driver assistance systems (ADAS).

Application Research of Portable On-line Inspection System for Car Lights

In this article, a portable automotive lighting online detection system is designed, which can test various signals of car lamps online. It also can perform function and performance tests on multiple car lamps at the same time. The system has a compact structure in order to be easy to carry. It can be tested in the car light laboratory or be used for on-line testing of the production line. The system can automatically complete data collection and processing online. It can discriminate test results and print test reports easily. It has strong versatility and high measurement accuracy. This portable online detection system is convenient for detection and has good application value.

Generating Electrical Power using Movement of Various Vehicles in New Lighting Base

This work represent a proposed design to supply street lighting power using moving vehicles with an automatic system to guide the fluid flow. In the present design, wind turbines are integrated on the body of the lighting base, which can reduce the construction cost compared to previous designs and use the fluid flow of all vehicles movement with different dimensions to increase system efficiency. Also, present investigation, has been used an automatic system to direct the fluid flow to the wind turbines to increase the efficiency in supplying electricity, which was not installed in the previous designs. Other features of this system include the production of electricity in inappropriate weather and storm conditions, unlike previous designs that had to stop the wind turbine in these conditions to decrease damage. Finally, illuminating the streets and alleys, the stored energy can be used for other purposes, such as charging car batteries and lighting resort stations. Then, comparison between the best design of the third model based on lighting and second model with four vertical wind turbines (VWT) and solar panel (SP), the power generation has increased by 35.55 %. Finally, using an automatic guidance systems (AGS) of fluid flow in the third model based on lighting, the power generation was enhamced by 64.86 %.

Design of The CRONE Automatic Headlight Leveling System

Automotive headlights system represents a safety key system when it comes to drive by night. It aims to increase the comfort of the driver by providing a clear visibility in order to anticipate obstacles and follow the right path. One of the main challenges that the lighting system is facing today is its automatic leveling adjustment. Variations of load of the vehicle, its dynamics and the environment are the main sources of disturbance to the leveling system. These disturbances causes variations of vehicle pitch angle and as a result the lighting cut-off level that may glare other road users and affect the driver's visibility range. This paper proposes an innovative automatic leveling system based on an ultrasonic motor which is able to dynamically reject such disturbances on the lighting cut-off level using a robust CRONE controller.

Development Of Led Based Optical Module for Bending/Cornering Functions of Automotive Headlights

Development Of Led Based Optical Module for Bending/Cornering Functions of Automotive Headlights

Influence of different lighting and fogging system on growth, flower yield and bud opening in Nerium (Nerium oleander)

Nerium oleander an evergreen shrub is a reputed ornamental with plentiful and long lasting flowering behaviour. But the flowers open only in the early morning hoursmaking farmers harvest the unopened flower buds between mid-night and early morning with help of head lights making them prone to reptile and other poisonous insect bites. Considering the bottlenecks in the flower bud opening, the experiment is framed to understand the influence of different light and fogging system on growth, flower yield of Nerium. The experiment was conducted in farmers field at Salem district of Tamil Nadu, India with different lighting system (red, blue, white and yellow light) and water spray (fogging system) on local Nerium variety (pink coloured flowers) replicated thrice. The results of the experiments revealed that the taller Nerium plants (230.00 cm) was observed in the treatment water spray (fog) 15 min. for every one hour which was on par (242.00 cm) with the treatment blue light (450-495 nm) for overnight + water spray (Fog) 15 min. for every one hour. The flower yield was higher (129.0 g/plant) in the treatment water spray (fog) 15 min. for every one hour. All the lighting and fogging treatment does not influence the shelf life of Nerium flowers. The higher percentage of unopened flower buds after harvest (91.6) was recorded in the treatment water spray (fog) 15 min. for every one hour. Thus, for harvesting the flower buds during the evening time, the time interval for operating the fogging system must be reoriented and anthocyanin content of flowers may be measured.

Case study of liquid cooling of automotive headlights with hollow fiber heat exchanger

Thermal performance of small liquid cooling systems based on polymeric hollow fibers was experimentally studied for the cooling of automotive lighting components integrated with high power Light Emitting Diodes (LEDs). Firstly, the tests with control electric heaters on a printed circuit board (PCB) were performed to precisely measure the thermal performance. The cooling effect of liquid cooling system installed on the PCB board of Skoda Octavia 4 (SK38) and Skoda Enyaq (SK316) was tested as the second step. Results of the testing show that the proposed plastic radiators ensure efficient and uniform cooling of the PCBs and keep the LEDs operation temperature much below the recommended 110 °C. As the heat generation is relatively small for liquid cooling (tens of watts), there is only 3–10 l/h flow rate of coolant needed, allowing to operate the plastic radiator with low velocity and pressure drops (below 1 kPa). Additionally, apart from excellent cooling, the tested polymeric radiators are about ten times lighter than their aluminium passive finned competitors.