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

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.

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 612 ◽  
Author(s):  
Eldar Šabanovič ◽  
Vidas Žuraulis ◽  
Olegas Prentkovskis ◽  
Viktor Skrickij

Nowadays, vehicles have advanced driver-assistance systems which help to improve vehicle safety and save the lives of drivers, passengers and pedestrians. Identification of the road-surface type and condition in real time using a video image sensor, can increase the effectiveness of such systems significantly, especially when adapting it for braking and stability-related solutions. This paper contributes to the development of the new efficient engineering solution aimed at improving vehicle dynamics control via the anti-lock braking system (ABS) by estimating friction coefficient using video data. The experimental research on three different road surface types in dry and wet conditions has been carried out and braking performance was established with a car mathematical model (MM). Testing of a deep neural networks (DNN)-based road-surface and conditions classification algorithm revealed that this is the most promising approach for this task. The research has shown that the proposed solution increases the performance of ABS with a rule-based control strategy.


Author(s):  
Andrii Siedov ◽  
Olena Fomenko

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.


Author(s):  
B. E. Sabey

The control of a vehicle depends ultimately on the friction available between its tyres and the road surfaces to give adequate skidding resistance when wet under the many varied conditions of speed and road layout which are encountered in the course of normal driving. Methods of measuring the skidding resistance of road surfaces are described, with particular emphasis on the interpretation of results in relation to accident risk and on the minimum requirements for safety under different road conditions. The features of road surface texture which give these requirements are outlined and results of field surveys show the extent to which the requirements are met at the present time. The influence of tyre tread characteristics on the frictional properties of road surfaces is also discussed.


2017 ◽  
Vol 32 (3) ◽  
pp. 991-1006 ◽  
Author(s):  
Virve Karsisto ◽  
Sander Tijm ◽  
Pertti Nurmi

Abstract High-quality road condition forecasts are a prerequisite for road authorities to ensure wintertime road safety. Harsh winter conditions can cause problems for traffic not only in countries where snowy winters are common but also in regions where the temperature drops below the freezing point occasionally. This study reports on the evaluation of the Royal Netherlands Meteorological Institute’s (KNMI) new road weather forecasting model by comparing it with the Finnish Meteorological Institute’s (FMI) road weather model, both run for 321 Dutch road weather stations, four times daily (0300, 0900, 1500, and 2100 UTC) during the test period, 15 January–28 February 2015. Road surface temperature forecasts by both models were evaluated against observations. The KNMI model produced slightly more accurate forecasts than the FMI model. The main reason for the difference is probably due to the optimization of the physical properties of the KNMI model for the Netherlands, whereas the FMI model is designed for quite different Finnish wintertime meteorological conditions. However, in general the road surface temperature forecasts were of quite comparable quality.


2019 ◽  
Vol 49 (3) ◽  
pp. 323-349 ◽  
Author(s):  
Marcin Budzyński ◽  
Agnieszka Tubis

Abstract When transport is analysed for its safe delivery the focus is mainly on assessing the safety of roads and the risk of undesired events. These include road accidents, an occurrence which is relatively rare and random. Randomness means that accidents depend on several factors which are partly deterministic and partly. The authors conducted an assessment of how weather conditions affect the risk of an accident due to the factor’s significant contribution to road accidents. This case involves a combination of two sources of hazard: external conditions in the form of the weather which are beyond the driver’s control and anthropotechnical factors that address vehicle condition and driver behaviour controlled by the driver.


2018 ◽  
Vol 1 (1) ◽  
pp. 047-051
Author(s):  
Muhammad Nuh Hudawi Pasaribu ◽  
Muhammad Sabri ◽  
Indra Nasution

Tekstur permukaan jalan umumnya terdiri dari aspal dan beton. Kekasaran tekstur permukaan jalan dapat disebabkan oleh struktur perkerasan dan beban kendaraan. Kekasaran tekstur permukaan jalan, bebandan kecepatan kendaraan akan mempengaruhi koefisien gesek. Untuk mengetahui nilai koefisien gesek dilakukan penelitian dengan melakukan variasi beban mobil (Daihatsu Xenia, Toyota Avanza, Toyota Innova dan Toyota Yaris) terhadap kontak permukaan jalan (aspal dan beton) dan kecepatan kendaraan. Hasil penelitian menunjukkan bahwa massa, lebar kontak tapak ban terhadap permukaan jalan dan kecepatan sangat mempengaruhi nilai koefisien gesek kinetis. Koefisien gesek kinetis yang terbesar untuk ketiga kontak permukaan jalan (aspal lama IRI 10,1, Aspal baru IRI 6,4 dan beton IRI 6,7) dengan menggunakan mobil Daihatsu Xenia terjadi pada kondisi jalan beton yaitu 0,495 pada kecepatan 35 Km/Jam. Koefisien kinetis jalan beton > 52 % dibandingkan jalan aspal pada parameter IRI yang sama (6-8).Koefisien gesek kinetis > 0,33 diperoleh di jalan beton pada kecepatan 30 – 40 Km/Jam   The texture of road surface generally consists of asphalt and concrete. The roughness of the road surface texture could be caused by the structure of the pavement and the load of the vehicles. Roughness of road surface texture, load and speed of vehicles would affect to the coefficient of friction. This research was carried out to find out the value of the coefficient of friction by using various load of cars (Daihatsu Xenia, Toyota Avanza, Toyota Innova and Toyota Yaris) on road surface contact (asphalt and concrete) and vehicle speed. The result showed the mass, the width of the tire tread contact to the road surface, and speed very influenced the coefficient value of kinetic friction. The biggest kinetic friction coefficient for all three road surface contacts (IRI 10.1 old asphalt, IRI 6.4 and IRI 6.7) using the Daihatsu Xenia was on the concrete road condition i.e. 0.495 on a speed of 35 km/hour. The concrete road kinetic coefficient was >52% compared to the asphalt road in the same IRI parameter (6-8). The kinetic friction coefficient >0.33 was obtained on the concrete road on a speed of 30 - 40 km/hour.


2015 ◽  
Vol 5 (1) ◽  
pp. 18-35 ◽  
Author(s):  
Ulf Ahlstrom

The objective of this study was to examine the potential benefits for air traffic controllers from the use of automated weather advisories. In a part-task simulation, we used a weather support tool called Automatic Identification of Risky Weather Objects in Line of Flight (AIRWOLF) that (a) detects conflicts between aircraft and hazardous weather, (b) alerts the controller, and (c) generates automatic weather advisories. During the simulation, air traffic control (ATC) subject matter experts responded to AIRWOLF alerts and either provided weather advisories to pilots via radio in two main conditions or provided data link communication in a third control condition. Automated advisories (a) eliminate the need for a manual production of weather advisories; (b) reduce the production time, voice duration, and overall advisory duration; and (c) reduce the cognitive workload associated with the dissemination of weather advisories. The results showed that the AIRWOLF tool could support air traffic controller weather avoidance actions and provide accurate and timely weather advisories to pilots. The weather advisory tool could support en route controllers for the safe, efficient, and strategic efforts required to handle adverse weather conditions in the en route environment.


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