INVESTIGATION OF THE INFLUENCE OF CORRELATED COLOR TEMPERATURE OF LED illuminatorS AS A FACTOR OF SAFETY LIGHTING OF HIGHWAYS FOR DIFFICULT WEATHER CONDITIONS

2021 ◽  
Vol 56 ◽  
pp. 89-96
Author(s):  
V. S. Kretulis ◽  
Keyword(s):  
Spectral Distribution ◽  
Spectral Dependence ◽  
Weather Conditions ◽  
Road Surface ◽  
Atmospheric Environment ◽  
Color Temperature ◽  
Visible Range ◽  
Reflection Coefficients ◽  
Flight Safety ◽  
Scattering Index

A investigation of the dependence of relative horizontal illumination level and brightness of the most common types of road surface in Ukraine when using LED illuminators with different spectral distribution of radiation in the presence of aerial aerosols of different optical densities (strong, moderate, weak fog and haze) is performed. Mathematical models of LED illuminators with correlated color temperature Tcc = (2200÷8400) K in the visible range of the spectrum λ = (380÷780) nm have been created. Their use together with the selected model of the spectral dependence of the scattering index β (λ) (Ferdinandоv’s model) of the atmospheric environment with the presence of aqueous aerosols, which cause a limited meteorological range of visibility MOR = (0.1÷3) km, showed a slight (1%) advantage in creation of illumination from lamps of a warm spectrum of radiation (TCC = 2200 K) in comparison with cold (Tcc = 8400 K) for cases of strong fogs with MOR = 100 m. Calculations involving the analysis of mathematical modeling of the spectral distribution of the reflection coefficients for two types of road surface (new and worn asphalt) proved that when using warm spectrum illuminators the brightness of the most common in Ukraine old asphalt pavement in the conditions of MOR = 100 m by 5% exceeds the corresponding value of the cold spectrum emitters. This difference gradually decreases as visibility is improved due to the weaker spectral dependence of β (λ) and at MV = 3 km is 4.5%. The advantage of using warm spectrum illuminators will be significantly enhanced for the case of estimating the brightness of the coverage over long distances, for example, airfield runways, which will significantly improve flight safety.

ASSESSMENT OF ADVERSE METEOROLOGICAL CONDITIONS FOR DISPERSION OF POLLUTANTS IN THE ATMOSPHERIC AIR OF CHERKASSY CITY

2016 ◽  
Author(s):  
Olga Khrystoslavenko ◽  
Ingrida Chemerys
Keyword(s):  
Pollution Index ◽  
Anthropogenic Pollution ◽  
Weather Conditions ◽  
Multiple Correlation Coefficient ◽  
Atmospheric Environment ◽  
Atmospheric Air ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Reduce Emissions ◽  
The City

Nowadays there is a tendency towards increasing of anthropogenic pollution in the atmospheric air in the large cities. Therefore, important measures have to be taken for the improvement of the atmospheric environment. In order to optimize the quality of air in the city and reduce emissions from stationary and mobile sources, it is important to predict of the state of the atmospheric air of the city, which is based on the analysis of the characteristics of adverse weather conditions conducive to the accumulation of harmful impurity in a lower (ground) layer of air. The paper identifies and analyzes the conditions in the Cherkassy city (Ukraine) for the period of 2011–2015, provides correlation and regression analysis of air pollution index with adverse weather conditions (the multiple correlation coefficient R = 0.55–0.87). The current research shows that the maximum number of days with adverse weather conditions is in autumn (77.20±4,96) and the lowest number is in spring (58.60±4.40), the greatest number of days matching several adverse weather conditions were found in January and October (4.80±0.20 and 4.60±0.24, respectively). Recommendations to reduce the content of harmful impurities in the atmospheric air of the city are suggested.

scholarly journals COMPARISONAL ANALYSIS OF MANUEVERING AND BRAKING

2010 ◽  
Vol 2 (6) ◽  
pp. 90-93 ◽  
Author(s):  
Artūras Žukas ◽  
Jurijus Zaranka ◽  
Kristina Kemzūraitė
Keyword(s):  
Traffic Accident ◽  
Weather Conditions ◽  
Road Surface ◽  
Movement Speed ◽  
Surface Type ◽  
Dangerous Situation ◽  
Road Surfaces ◽  
Road Distance

This article covers the possibility of avoiding a traffic accident considering a car driver who is fallen in a dangerous situation. In such a case, the driver can choose one of the following ways: hard braking or one of the types of maneuvering, including turning off, turning with straightening or changing a line regarding road surface type (dry asphalt, wet asphalt or snowy asphalt). The article also proposes formulas for calculating road distance the car travels till dead stop. Moreover, the tables display theoretical values taking into account various car speeds and road surfaces. The pictures help with determining the most suitable type of action in light of road and weather conditions as well as car speed. The pictures clearly show the dependence of road length on movement speed. At the end of the article, conclusions are proposed.

scholarly journals REDUCING INFLUENCE OF ADVERSE EXTERNAL CONDITIONS IN THE LOCAL AIRPORTS

2018 ◽  
Vol 21 (3) ◽  
pp. 101-114
Author(s):  
A. L. Rybalkina ◽  
A. S. Spirin ◽  
E. I. Trusova
Keyword(s):  
Mobile Network ◽  
Weather Conditions ◽  
Civil Aviation ◽  
Successful Implementation ◽  
Flight Safety ◽  
Electric Discharges ◽  
Aviation Accidents ◽  
Factors Affecting ◽  
Adverse Weather ◽  
Unfavorable Weather

The problem of the unfavorable weather conditions impact on aircraft, including electric discharges on aircraft, continues to be relevant. For the successful implementation of flights, aviation as a type of transport should ensure safety, regularity and economy of air transportation. The aerial meteorology always takes an active part in above problems solution, since flight safety depends on timely prediction of unfavorable weather conditions. Modern airfield and aircraft equipment, as well as a new meteorological technique, helped to improve flight safety and reduce the number of accidents associated with adverse weather conditions, but this did not solve all the problems of civil aviation meteorological support. This problem is especially acute in small airports, where there are often no means of meteorological support and warnings about dangerous weather phenomena or they are insufficient. The article analyzes various unfavorable weather conditions, their influence on aircraft, provides statistics related to unfavorable weather conditions of aviation accidents, and shows the proportion of meteorological conditions among the factors affecting safety. Particular attention is paid to the problem of electric discharges to aircraft. The consequences of electric discharges on aircraft, as well as weather conditions contributing to electric discharges, are analyzed. In order to improve flight safety at local airports, it is proposed to create mobile units for collecting, processing and transmitting meteorological information that is territorially spread over the aerodrome zone; it allows to create mobile meteorological radar network. The structural scheme of the deployment of the mobile network for meteorological radars is given.

scholarly journals Investigation of the wear of asphalt concrete pavement taking into account the influence of temperature, moisture of the pavement and the presence of an aggressive environment

2021 ◽  
Vol 2 (92) ◽  
pp. 68
Author(s):  
Andrii Siedov ◽  
Olena Fomenko
Keyword(s):  
Asphalt Concrete ◽  
High Speed ◽  
Climatic Factors ◽  
Load Capacity ◽  
Weather Conditions ◽  
Road Surface ◽  
Winter Period ◽  
Influence Of Temperature ◽  
The Road ◽  
Industrial Enterprises

Abstract. The emergence of a large number of modern high-speed cars with improved dynamic characteristics and an increase in the share of cars, especially large load capacity, have significantly accelerated the destruction of asphalt roads. Plastic deformations, tracks and cracks are more and more often observed on asphalt concrete pavements of roads, their wear is accelerated. As a result, the transport and operational condition of roads deteriorates, the speed of traffic decreases, the cost of road transport increases, and increasing costs are required for road repairs. Thus, the conditions of traction of the wheels of the car with the road surface are influenced by the service life of the coating, traffic intensity, the amount of harmful emissions of industrial enterprises and climatic factors. At the same time uneven change of conditions of coupling in cross and longitudinal profiles of the highway comes to light. Analyzing the natural and climatic factors, we can establish that different weather conditions have different effects on the condition of the road surface. In summer, the condition of the surface is dry and clean, so the driving conditions are safe. Taking into account all the factors that lead to the destruction of the coating with the formation of residual deformations and irreversible changes, requires the study of wear of the coating surface. he wear of the coating largely depends on the friction force in the area of contact of the tire with the surface of the coating, the type of tires and the pressure in the tires. But the random nature of changes in the intensity and composition of traffic, seasons, temperature, humidity, rainfall affects the amount of wear over a period of operation of the road surface. The presence of water or solutions in the pores of the coating leads to the separation of mineral particles from the layer under the action of impact force from the wheels of vehicles. It is experimentally established that the wear of asphalt concrete in the dry and wet state increases with increasing temperature. One of the main types of damage to road surfaces is their premature wear under the influence of vehicle wheels, in combination with changing weather conditions. Analyzing the natural and climatic factors, we can establish that different weather conditions have different effects on the condition of the road surface. The article considers the influence of temperature, humidity and the presence of solutions of chloride anti-icing materials on the process of abrasion of asphalt pavement in the autumn-winter period. Occurrence of big differences of temperature and humidity accelerates processes of aging of materials from which layers are made, influencing their durability and wear resistance.

scholarly journals Adjustable light source for low light level with nearly constant correlated color temperature

2022 ◽  
Vol 2149 (1) ◽  
pp. 012016
Author(s):  
Z F Wu ◽  
L Li ◽  
C H Dai ◽  
Y F Wang ◽  
Q T Cheng ◽  
...  
Keyword(s):  
Light Source ◽  
Spectral Distribution ◽  
Light Level ◽  
Color Temperature ◽  
Spectral Radiance ◽  
Integrating Sphere ◽  
Spectral Difference ◽  
Low Light ◽  
Light Levels ◽  
Variable Aperture

Abstract Low light level (LLL) calibration becomes more and more important since the rapid growth of remote sensing. The spectral radiance at normal higher light levels can be calibrated with good accuracy, while LLL spectral radiance cannot. If an adjustable light source can be designed at nearly constant correlated color temperature (CCT) covering several orders of magnitude, low light level spectral radiance can be obtained with the help of a photodetector. Whether or not the spectral distribution of an integrating sphere based light source is nearly constant is investigated. By adjusting the diameter of the variable aperture between the integrating sphere and tungsten lamp, the spectral radiance can be varied over 6 orders of magnitude. However, the relative spectrum in the red region increases notably when the spectral radiance is decreased to 1/100000. If the spectral radiance is decreased further, the spectral difference can be more than 300% and CCT decreases more than 250 K. By using baffles and another integrating sphere, low light level radiation source at nearly constant spectral distribution is obtained. The variation of CCT is less than 50 K over 6 orders of magnitude.

scholarly journals A Study on the Night Visibility Evaluation Method of Color Temperature Convertible Automotive Headlamps Considering Weather Conditions

2021 ◽  
Vol 11 (18) ◽  
pp. 8661
Author(s):  
Ho-Joon Kang ◽  
Seong-Jin Kwon
Keyword(s):  
Evaluation Method ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Light Transmittance ◽  
Color Temperature ◽  
Driving Safety ◽  
Clear Night ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Bad Weather

This study evaluated a method of applying color temperature convertible headlamps to improve driving safety in adverse weather conditions such as fog and rain during night driving. The concept of color temperature convertible headlamps is to improve the driver’s visibility by driving with a color temperature of 6000 K on a clear night and switching to a color temperature of 3000 K with better light transmittance at night in adverse weather. Through this study, a method for evaluating the night visibility related to such color temperature convertible headlamps under bad weather at night was suggested. To this end, a method of using a facility that can implement weather conditions such as fog and rain was proposed, and evaluation conditions according to the climatic conditions and the distance of pedestrian targets were set and actual tests were conducted.

scholarly journals METHODS FOR DETERMINING THE FRICTION COEFFICIENT OF THE ROAD SURFACE / TRINTIES KOEFICIENTO SU KELIO DANGA NUSTATYMO METODAI

2019 ◽  
Vol 11 (0) ◽  
pp. 1-6
Author(s):  
Elena Perova ◽  
Evgeniya Ugnenko ◽  
Gintas Viselga ◽  
Ina Tetsman
Keyword(s):  
Friction Coefficient ◽  
Literature Review ◽  
Weather Forecasting ◽  
Weather Conditions ◽  
Air Traffic ◽  
Road Surface ◽  
The Road ◽  
Frictional Properties ◽  
Air Traffic Controllers ◽  
Comprehensive Literature Review

In spite of advances in aviation technology, operational procedures and weather forecasting, safe winter runway operations remain a challenge for airport operators, air traffic controllers, airlines and pilots who must coordinate their actions under rapidly-changing weather conditions. The paper analyses most popular methods for determining the friction coefficient of the road surface. Their advantages, disadvantages and comparison of their modern instruments for measuring the frictional properties of airfields is shown. Most of the information was derived from a comprehensive literature review. Santrauka Nepaisant aviacijos technologijų pažangos, operacinių procedūrų ir oro prognozių, saugios kilimo ir tūpimo tako operacijos žiemą išlieka iššūkiu oro uostų valdytojams, skrydžių vadovams, oro linijoms ir pilotams, kurie turi koordinuoti savo veiksmus sparčiai besikeičiančiomis oro sąlygomis. Straipsnyje analizuojami populiariausieji kelio dangos trinties koeficiento nustatymo metodai. Pateikiami jų privalumai, trūkumai ir lyginami jų modernūs prietaisai, skirti aerodromų trinties savybėms matuoti. Didžioji dalis informacijos buvo gauta iš išsamios literatūros apžvalgos.

scholarly journals ATMOSPHERIC ENVIRONMENT DETECTION METHOD BASED ON MULTI-ROTOR UAV PLATFORM

2018 ◽  
Vol XLII-3/W5 ◽  
pp. 67-71
Author(s):  
A. Shen ◽  
S. Zhou ◽  
S. Peng
Keyword(s):  
Detection Method ◽  
Center Of Gravity ◽  
Atmospheric Environment ◽  
Detection Accuracy ◽  
Flight Safety ◽  
Rotor Speed ◽  
Gradual Process ◽  
The Stability ◽  
Environment Detection ◽  
Improve Stability

<p><strong>Abstract.</strong> For the method of atmospheric detection based on multi-rotor UAV, the effects of flight safety and airflow on detection accuracy are analyzed. The detector mounted on the multi-rotor drone should be highly symmetrical and the center of gravity should be on the same vertical line as the center of gravity of the drone. Mounting the detector above the drone's fuselage will reduce the stability of the drone, and lowering it will improve stability, but for models with high stability, placing it below will affect the maneuverability of the drone. The airflow interference in the area where the detector can be placed near the fuselage is related to the drone: the faster the rotor speed, and the closer the rotor is to the fuselage, the stronger the airflow interference. At the same time, the influence of airflow disturbance on temperature and humidity has a gradual process. Waiting for a period of time after starting the drone can change the error into a fixed error for post-processing. This method was used to detect a pollution process and achieved good results.</p>

Robust LIDAR localization using multiresolution Gaussian mixture maps for autonomous driving

2017 ◽  
Vol 36 (3) ◽  
pp. 292-319 ◽  
Author(s):  
Ryan W Wolcott ◽  
Ryan M Eustice
Keyword(s):  
Autonomous Vehicle ◽  
Probabilistic Method ◽  
Three Dimensional ◽  
Weather Conditions ◽  
Autonomous Driving ◽  
Gaussian Mixture ◽  
Road Surface ◽  
Vehicle Localization ◽  
Adverse Weather ◽  
Self Driving Cars

This paper reports on a fast multiresolution scan matcher for local vehicle localization of self-driving cars. State-of-the-art approaches to vehicle localization rely on observing road surface reflectivity with a 3D light detection and ranging (LIDAR) scanner to achieve centimeter-level accuracy. However, these approaches can often fail when faced with adverse weather conditions that obscure the view of the road paint (e.g. puddles and snowdrifts), poor road surface texture, or when road appearance degrades over time. We present a generic probabilistic method for localizing an autonomous vehicle equipped with a three-dimensional (3D) LIDAR scanner. This proposed algorithm models the world as a mixture of several Gaussians, characterizing the [Formula: see text]-height and reflectivity distribution of the environment—which we rasterize to facilitate fast and exact multiresolution inference. Results are shown on a collection of datasets totaling over 500 km of road data covering highway, rural, residential, and urban roadways, in which we demonstrate our method to be robust through heavy snowfall and roadway repavements.

Sign in / Sign up

Export Citation Format

Share Document