scholarly journals Road Surface Characteristics for the Automotive 77 GHz Band

2021 ◽  
Vol 19 ◽  
pp. 165-172
Author(s):  
Vera Kurz ◽  
Hannes Stuelzebach ◽  
Florian Pfeiffer ◽  
Carlo van Driesten ◽  
Erwin Biebl

Abstract. In order to achieve a safety proof of autonomous driving using simulations, information about the environment has to be determined, which is not sufficiently available until now. This work is concerned with road surfaces and their scattering of radar signals. As it is not enough to look at geometries, as it is already done for many ray tracing approaches, also material and composition have to be investigated. Therefore, measurements are performed using a SAR setup in a laboratory as well as open space measurements using a radar evaluation board on a testing area of the Federal Highway Research Institute. The SAR setup enables a quick estimation on differences in reflection of different test objects. With the result from the latter values for the relative permittivity are calculated for different road surface types exploiting Fresnel's equations. The differences in reflection depending on material and surface structure of the road see in the measurements of both setups are discussed in the paper.

1989 ◽  
Vol 17 (1) ◽  
pp. 66-84
Author(s):  
A. R. Williams

Abstract This is a summary of work by the author and his colleagues, as well as by others reported in the literature, that demonstrate a need for considering a vehicle, its tires, and the road surface as a system. The central theme is interaction at the footprint, especially that of truck tires. Individual and interactive effects of road and tires are considered under the major topics of road aggregate (macroscopic and microscopic properties), development of a novel road surface, safety, noise, rolling resistance, riding comfort, water drainage by both road and tire, development of tire tread compounds and a proving ground, and influence of tire wear on wet traction. A general conclusion is that road surfaces have both the major effect and the greater potential for improvement.


2020 ◽  
Vol 9 (1) ◽  
pp. 922-933
Author(s):  
Qing’e Wang ◽  
Kai Zheng ◽  
Huanan Yu ◽  
Luwei Zhao ◽  
Xuan Zhu ◽  
...  

AbstractOil leak from vehicles is one of the most common pollution types of the road. The spilled oil could be retained on the surface and spread in the air voids of the road, which results in a decrease in the friction coefficient of the road, affects driving safety, and causes damage to pavement materials over time. Photocatalytic degradation through nano-TiO2 is a safe, long-lasting, and sustainable technology among the many methods for treating oil contamination on road surfaces. In this study, the nano-TiO2 photocatalytic degradation effect of road surface oil pollution was evaluated through the lab experiment. First, a glass dish was used as a substrate to determine the basic working condition of the test; then, a test method considering the impact of different oil erosion degrees was proposed to eliminate the effect of oil erosion on asphalt pavement and leakage on cement pavement, which led to the development of a lab test method for the nano-TiO2 photocatalytic degradation effect of oil pollution on different road surfaces.


2018 ◽  
Vol 51 (1) ◽  
pp. 65-81 ◽  
Author(s):  
N Strbac-Hadzibegovic ◽  
S Strbac-Savic ◽  
M Kostic

Numerous measurements have shown that the standard R classes do not represent adequately many road surfaces used nowadays. Therefore, the construction of portable reflectometers intended for on-site measurements of road surface reflection properties has been given particular attention during the last decade. This paper presents a new procedure for the improvement of the accuracy of such a portable reflectometer. Optimally extrapolating the values of the 20 luminance coefficients (q), each measured by the portable reflectometer for a set of angles of observation (α = 5°–80°), the 20 q-values referring to α = 1° are calculated. This enables their comparison with the corresponding q elements from each of the 447 reduced q-tables derived from the available r-table database, obtained by using a precise laboratory reflectometer on a wide variety of road samples. Selecting the closest reduced q-table, the corresponding r-table and the actual average luminance coefficient can be determined. In order to validate the proposed procedure, which can also be applied to other similar portable reflectometers, measurements of the luminance and overall and longitudinal luminance uniformities were carried out on eleven road-lighting installations. They showed that the results obtained by this procedure deviate only slightly from those obtained using r-tables determined by the laboratory reflectometer.


1956 ◽  
Vol 29 (4) ◽  
pp. 1425-1433 ◽  
Author(s):  
K. Knauerhase

Abstract To ensure safety from skidding, attention has up to now been devoted to building rough surface roads, to the development of the proper vehicle construction with respect to this feature, and to the factor most directly involved, the tires. Special attention has been directed in connection with this latter phase to a much more open tread patterning and to the effect of decreasing tire inflation, both of which affect the life of the tire adversely. These steps neglected to take advantage of the physical effect of adhesion, which, without lowering the durability, now makes possible an enhanced contribution to the cohesive friction by the profile grooves which are of necessity retained to keep the weight down. The goal is, therefore, to provide the smooth surfaces of the tread pattern that come in contact with the road with the greatest possible physical gripping power, or adhesion. After illustrating the interfacial magnitudes with the help of a vector diagram, we shall survey the laws of boundary surface adhesion. Here the great influence of the liquid involved in wet friction becomes clear and the particularly favorable interfacial tension property of water can be assessed. Since skidding can occur only at the interfaces : rubber-water, or water-road, the requirement is as follows : both the greatest possible wetting power between rubber and water, and also between water and road surface, that is, hydrophilic properties in the rubber and hydrophilic road surfaces, in order to reduce the danger of skidding. Good insurance against skidding requires hydrophilic rubber and a hydrophilic road surface, for a tire that has been developed to be nonskidding holds on a hydrophilic road surface and skids on a hydrophobic road surface. A hydrophobic tire, on the other hand, skids on any wet road. Although considerable advances have been made with respect to safety from skidding since rubber tires were first developed for motor vehicles, with increase of speeds this problem demands our attention to a greater and greater degree. Safety from skidding can result only from the combined efforts of road and car builders, tire makers, and the chemists and physicists of all three groups.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yuansheng Cheng ◽  
Xiaoqin Li ◽  
Xiaolan Man ◽  
Feifan Fan ◽  
Zhixiong Li

When agricultural vehicles operate in the field, the soft road excitation makes it difficult to measure the vehicle vibration. A camera-accelerator system can solve this issue by utilizing computer vision information; however, the relationship between the field road surface and the vehicle vibration response remains an unsolved problem. This study aims to investigate the correlation of the soft road excitation of different long-wave surfaces with the vehicle vibration response. Vibration equation between the vehicle and soft road surface system was established to produce an effective roughness model of the field soft road surface. In order to simulate the vehicle vibration state under different long-wave road surfaces, the soil rectangular pits with 21 kinds of different spans and depths were applied to the road surfaces, and a tractor vibration test system was built for vibration test. The frequency spectrum analysis was performed for the vibration response and the roughness signals of the road surfaces. The results showed that coefficient (R2) of frequency correlation between the roughness excitation and the original unevenness at the excitation point at the rear end of the rectangular soil pit fell within 0.9641∼0.9969. The main frequency band of the vibration response fell within 0∼3 Hz, and the phenomenon of quadruple frequency existed. The correlation of roughness excitation with quadruple frequency fell within 0.992165∼1. The primary excitation points were located at the rear end of the rectangular soil pit. In addition, it also indicated that when the vehicle was driven without autonomous power, the vehicle vibration frequency mainly depended on the excitation frequency of the field road surface and the frequency at the maximum vehicle vibration intensity was 2 or 3 times of that at the maximum field soft road excitation. These findings may provide a reference for optimal design of vibration reduction and control for agricultural vehicles.


2020 ◽  
Vol 14 (1) ◽  
pp. 39-54 ◽  
Author(s):  
Erik Heinz ◽  
Christian Eling ◽  
Lasse Klingbeil ◽  
Heiner Kuhlmann

AbstractKinematic laser scanning is widely used for the fast and accurate acquisition of road corridors. In this context, road monitoring is a crucial application, since deficiencies of the road surface due to non-planarity and subsidence put traffic at risk. In recent years, a Mobile Mapping System (MMS) has been developed at the University of Bonn, consisting of a GNSS/IMU unit and a 2D laser scanner. The goal of this paper is to evaluate the accuracy and precision of this MMS, where the height component is of main interest. Following this, the applicability of the MMS for monitoring the planarity and subsidence of road surfaces is analyzed. The test area for this study is a 6 km long section of the A44n motorway in Germany. For the evaluation of the MMS, leveled control points along the motorway as well as point cloud comparisons of repeated passes were used. In order to transform the ellipsoidal heights of the MMS into the physical height system of the control points, undulations were utilized. In this respect, a local tilt correction for the geoid model was determined based on GNSS baselines and leveling, leading to a physical height accuracy of the MMS of < 10 mm (RMS). The related height precision has a standard deviation of about 5 mm. Hence, a potential subsidence of the road surface in the order of a few cm is detectable. In addition, the point clouds were used to analyze the planarity of the road surface. In the course of this, the cross fall of the road was estimated with a standard deviation of < 0.07 %. Yet, no deficiencies of the road surface in the form of significant rut depths or fictive water depths were detected, indicating the proper condition of the A44n motorway. According to our tests, the MMS is appropriate for road monitoring.


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.


2013 ◽  
Vol 597 ◽  
pp. 193-198 ◽  
Author(s):  
Stanislaw Taryma ◽  
Jerzy A. Ejsmont ◽  
Grzegorz Ronowski ◽  
Beata Swieczko-Zurek ◽  
Piotr Mioduszewski ◽  
...  

Tire rolling resistance is one of the most important resistive forces acting on road vehicles. It depends on tire and surface characteristics as well as vehicle operating parameters. This paper deals with the influence of road surface texture on rolling resistance of passenger car tires. Results of road measurements performed on variety of road surfaces are presented.


2021 ◽  
Vol 20 (3) ◽  
pp. 216-223
Author(s):  
Yu. V. Burtyl ◽  
M. G. Salodkaya ◽  
Ya. N. Kovalev

The design of road surfaces involves application of  a sophisticated algorithm system based on mathematical calculations and engineering solutions, with the calculation of evaluation criteria.  It is precisely the observance of the standardized requirements in terms of design criteria that makes it possible to consider the design of the pavement as reliable, and the road as safe and convenient for traffic during the specified service life. When calculating the strength, based on the predicted traffic intensity and the composition of the traffic flow, calculations are carried out according to the main criteria: admissible elastic deflection, shear in layers of non-reinforced materials and in asphalt concrete, as well as the ultimate tensile stresses in cast-in-situ materials with the specified reliability level.  However, in the accepted concepts for  calculating the strength and reliability of road pavements,  only the force effect is directly taken into account. To take into account environmental factors, it is necessary to develop a comprehensive indicator of the resulting impact of all factors. The paper presents a complex of factors influencing on traffic safety, road deformations and irregularities the height of unevenness, in particular, an increase in the dynamic impact on the road and the amplitude of vibration of a car wheel on a road with an uneven surface (when detached from the road surface), the coincidence of the vibration frequency of the car with the natural frequencies of vibration of the road surface, and as a consequence, on the behavioral features of driving. The arguments have been substantiated that the predictive models do not take into account a number of factors that have a significant impact on the formation of irreversible deformation in the layers of materials of road structures.


Author(s):  
Липунов ◽  
K. Lipunov ◽  
Лемешева ◽  
E. Lemesheva ◽  
Тихомиров ◽  
...  

In this paper, an analysis of the road network and infrastructure of the Bryansk region on the example of the federal highway M-3 &#34;Ukraine&#34; (Kiev highway). The description of the state of road fabric, its length and the number of lanes. Transport-performance of the road network and bridges do not meet the stresses of modern heavy vehicles and traffic. The planned activities of the area is not considered raising technical category road. To improve the region&#180;s economy and the country&#180;s need to carry out the improvement of road infrastructure, taking into account the different methods that will reduce accidents on the roads, increase and accelerate the flow of goods through the region. It proposed a number of measures to enhance the capacity: to improve the quality of road surface with the transfer of the 1st category; adding overlapping areas; the creation of parking areas and service centers for freight transport, and installation of video cameras for control and monitoring of the road.


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