Prediction of sinkage and rolling resistance for off-the-road vehicles considering penetration velocity

1991 ◽  
Vol 28 (4) ◽  
pp. 339-347 ◽  
Author(s):  
M. Grahn
Keyword(s):  
Rolling Resistance ◽  
Road Vehicles ◽  
The Road ◽  
Penetration Velocity

Tire-Road Interactions — Harmony or Conflict?

1989 ◽  
Vol 17 (1) ◽  
pp. 66-84
Author(s):  
A. R. Williams
Keyword(s):  
Rolling Resistance ◽  
Major Effect ◽  
Road Surface ◽  
Interactive Effects ◽  
Central Theme ◽  
Water Drainage ◽  
The Road ◽  
Truck Tires ◽  
Road Surfaces ◽  
Tire Wear

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.

scholarly journals Keeping Up Textual Appearances: The Road Vehicles (Display of Registration Marks) Regulations 2001

2020 ◽  
Vol 2 (1) ◽  
pp. 91-106
Author(s):  
Thomas Giddens
Keyword(s):  
Legal Discourse ◽  
Modern State ◽  
Sovereign Power ◽  
Road Vehicles ◽  
Underlying Assumption ◽  
Visual Appearance ◽  
The Road ◽  
Intellectual Content ◽  
Practical Operation ◽  
Textual Form

In legal discourse and practice, concerns regarding the appearance of text focus almost exclusively on questions of legibility. There is little analysis of law’s textual form beyond matters of practical readability, indicating an underlying assumption that printed words are merely a vehicle for the transmission of law’s intellectual content. However, the UK’s Road Vehicles (Display of Registration Marks) Regulations 2001 (SI No 561) (the ‘2001 Regulations’) prescribe the detailed regulation of the visual appearance of registration marks (or number plates) beyond that required for their practical operation. Through analysis of these regulations, this paper overturns the assumption that the significance of textual appearance is purely pragmatic by demonstrating the widespread importance of the visual form of writing within the regulatory praxis of the modern state—of which registration marks are a part. When we read the law, when we encounter a regulatory text, we are not just decoding intellectual content but are witnessing the appearance and repetition of sovereign power.

A Laboratory Method to Comprehensively Evaluate Abrasion, Traction and Rolling Resistance of Tire Tread Compounds

2007 ◽  
Vol 80 (4) ◽  
pp. 580-607 ◽  
Author(s):  
M. Heinz ◽  
K. A. Grosch
Keyword(s):  
Friction Coefficient ◽  
Laboratory Test ◽  
Rolling Resistance ◽  
Limited Range ◽  
Slip Angle ◽  
Testing Conditions ◽  
Side Force ◽  
The Road ◽  
Wide Range ◽  
On The Road

Abstract A laboratory test method has been developed which allows the evaluation of diverse properties of tire tread compounds on the same sample. The laboratory test instrument consists of a rotating abrasive disk against which a rubber sample wheel runs under a given load, slip angle and speed. All three force components acting on the wheel during the tests are recorded. By changing the variable values over a wide range practically all severities encountered in tire wear are covered. The well-known fact that compound ratings depend on the road testing conditions is verified. Most compounds are only significantly distinguishable against a control over a limited range of testing conditions. Using a road test simulation computer program based on the laboratory data shows that not only ratings correspond to practical experience but also calculated absolute tire life times do. Tests on surfaces of different coarseness and sharpness indicate that sharp coarse surfaces give the best results with road tests, which of necessity are mostly carried out on public roads of differing constitution. The abrasive surface can be wetted with water at different temperatures and hence either the friction force at a locked wheel or the side force at a slipping wheel can be measured over a wide range of temperatures and speeds. At small slip angles the side force is dominated by dynamic cornering stiffness of the compound, at large slip angles by the friction coefficient. In this case, too, good correlations to road experience exist over a limited range of testing conditions. Low water temperatures and low slip speed settings in the laboratory produce side force ratings, which correlate closely with ABS braking on the road High and higher slip speeds give ratings in close agreement with locked wheel braking on the road. A heatable/coolable disk enables traction measurements on ice and newly abrasion measurements on surfaces at elevated surface temperature. Ice surface temperatures between −5 °C and −25 °C are possible. Friction measurements show that the difference in compound rating between summer and winter compounds is maintained over the whole temperature range. New investigations show not only a differentiation between different winter tire treads qualities but also an excellent correlation between tire and laboratory results. As a new topic side force measurements on dry surfaces highlight the correlation to dry handling of tires. The tire tread compound contributes to this performance through its shear stiffness and its friction coefficient. The shear stiffness contributes to the response of the tire in directional changes. The friction coefficient determines the maximum force, which can be transmitted. A simple operation possibility for evaluation of determined side forces is demonstrated. In addition to antecedent investigations the rolling resistance of the rubber wheel can be measured over a range of loads and speeds with the slip angle set at zero. Again for these new results good correlations are achieved with practical experience. In particular, the dependence of the rolling resistance on the velocity and loads are pointed out. Ultimately a good correlation between tire test and laboratory test results was demonstrated.

scholarly journals OPTYRE—Real Time Estimation of Rolling Resistance for Intelligent Tyres

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5119 ◽  
Author(s):  
Roveri ◽  
Pepe ◽  
Mezzani ◽  
Carcaterra ◽  
Culla ◽  
...  
Keyword(s):  
Ad Hoc ◽  
New Technology ◽  
Rolling Resistance ◽  
Time Estimation ◽  
General Context ◽  
Fibre Bragg Grating ◽  
Technical Literature ◽  
The Road ◽  
Contact Kinematics ◽  
Real Time Estimation

The study of the rolling tyre is a problem framed in the general context of nonlinear elasticity. The dynamics of the related phenomena is still an open topic, even though few examples and models of tyres can be found in the technical literature. The interest in the dissipation effects associated with the rolling motion is justified by their importance in fuel-saving and in the context of an eco-friendly design. However, a general lack of knowledge characterizes the phenomenon, since not even direct experience on the rolling tyre can reveal the insights of the correlated different dissipation effects, as the friction between the rubber and the road, the contact kinematics and dynamics, the tyre hysteretic behaviour and the grip. A new technology, based on fibre Bragg grating strain sensors and conceived within the OPTYRE project, is illustrated for the specific investigation of the tyre dissipation related phenomena. The remarkable power of this wireless optical system stands in the chance of directly accessing the behaviour of the inner tyre in terms of stresses when a real-condition-rolling is experimentally observed. The ad hoc developed tyre model has allowed the identification of the instant grip conditions, of the area of the contact patch and allows the estimation of the instant dissipated power, which is the focus of this paper.

scholarly journals Breakaway of a motor vehicle from skidding with the use of friction material on public and toting roads

2019 ◽  
Vol 135 ◽  
pp. 02005
Author(s):  
Mikhail Boyarshinov ◽  
Vitaliy Zadvorov ◽  
Andrey Kochetkov ◽  
Leonid Yankovskiy ◽  
Vladislav Chudinov
Keyword(s):  
Friction Coefficient ◽  
Motor Vehicle ◽  
Model Analysis ◽  
Friction Material ◽  
Road Vehicles ◽  
Adhesion Coefficient ◽  
The Road ◽  
Technical Effect

The goal of the paper is to provide breakaway of a motor vehicle from skidding with the use of friction material on public and toting roads.The development of an anti-skid device is reasonable because road services are not always able to maintain the proper road conditions due to overall highway mileage which leads to road icing and snow knurling, which in turn lowers the friction coefficient of tires with the road. Model analysis and practical experiments are carried out to model breakaway modes while using friction material. This process can be automated for the use in off-road vehicles with a dedicated device that will deliver large grained friction material. The mentioned device had been developed by the authors of the paper. A technical effect of increased adhesion coefficient is achieved within the research. This effect allows the increase in transportation reliability under difficult meteorological and road conditions on public and toting roads. Practical experiments showed that addition of large grain friction material when skidding modifies the surface in front of the tire into a segmented area (angled surface) that helps the vehicle to breakaway and move further without skidding.

Robust Control of Oscillations in Agricultural Tractors

2003 ◽  
Author(s):  
Torben Ole Andersen ◽  
Michael Ryygaard Hansen ◽  
Finn Conrad
Keyword(s):  
Control Strategy ◽  
Special Focus ◽  
Road Transportation ◽  
Road Vehicles ◽  
The Road ◽  
Optimization Formulation ◽  
Bounded Disturbances ◽  
Agricultural Tractors ◽  
And Control ◽  
Control Of Oscillations

This paper relates to analyses and control of the oscillations occurring in many off road vehicles, which are designed without any suspension. Without suspension, the tire is the only elastic element acting between the vehicle and the ground but the suspension and damping properties of the tires cannot meet the demands for fast, safe and comfortable road transportation. In this paper the above-mentioned phenomenon is investigated with special focus on agricultural tractors. A control strategy is developed to make the implement counteract the movement of the tractor and thereby reducing the pitching oscillation. The control strategy is based on a linear plant model with constant or slowly varying parameters. Using a frequency-response approach the disturbance rejection is made effective over a significant portion of the system bandwidth. To improve robustness with respect to bounded disturbances (from the road) natural frequencies for the vehicle and implement is identified and the controller parameters tuned adaptively based on an optimization formulation.

scholarly journals DIMENSIONAREA SISTEMULUI DE PROPULSIE AL UNUI VEHICUL ELECTRIC. STUDIU DE CAZ

2021 ◽  
Vol 2020 (1) ◽  
pp. 1-14
Author(s):  
Alexandru TURCANU ◽  
Leonard-Călin-Valentin DOBRE
Keyword(s):  
Traction Force ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Gear Ratio ◽  
Calculation Model ◽  
The Road ◽  
Electric Car ◽  
Resistive Forces ◽  
Wheel Radius ◽  
Resistance Forces

This paper aims to present to readers concrete mathematical models, transposed into simulation schemes, to calculate the forces acting on a car at its interaction with the road and the atmosphere, to properly size the electric motor and batteries of an electric car. For the calculation of these forces, a table with predefined values ​​such as vehicle mass, rolling resistance coefficient, gear ratio, wheel radius, was used throughout the work. In the second section of the paper, the values ​​of the resistance forces that oppose the movement of the vehicle and the traction force necessary to overcome these resistive forces were determined. The mathematical calculation model was compiled in Matlab and the graphs in figures 3-9 were obtained.

scholarly journals Decelerations of Passenger Vehicles on Gravel Arrester Beds

2020 ◽  
Vol 12 (5) ◽  
pp. 1761
Author(s):  
Miha Ambrož ◽  
Jovan Trajkovski ◽  
Robert Kunc
Keyword(s):  
Road Safety ◽  
Recent Past ◽  
Road Vehicles ◽  
Passenger Cars ◽  
Standard Size ◽  
Passenger Car ◽  
Safety Feature ◽  
The Road ◽  
Passenger Vehicles

Gravel-filled arrester beds, also called safety-escape ramps or vehicle run-out areas, have long been a road-safety feature for safely stopping heavy road vehicles from running off the road. In the recent past, there has been consideration given to installing these features on highway access ramps to provide safe areas to stop passenger cars driving at highway speeds. The work presented in this article was performed to investigate the behaviour of standard-size passenger cars on gravel-filled arrester beds, with a particular focus on the achievable vehicle decelerations and the ability of the arrester beds to safely stop a passenger car coasting in an uncontrolled manner. The findings show that the achievable average decelerations are in the range of 0.3 g for coasting vehicles and up to 0.9 g when the vehicles are braking. The results prove that more research is required to quantify the influence of the gravel parameters on the achievable decelerations.

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