Tire Grip Research Articles

Альтернативні протиожеледні матеріали для боротьби з утворенням та ліквідації зимової слизькості на автомобільних дорогах

Introduction. The winter season is the most challenging for road maintenance and traffic management. Key factors affecting vehicle movement during winter include the presence of ice and snow-ice buildup, leading to a sharp decline int tyre grip, increased rolling resistance, and deteriorating surface evenness. Problem Statement. Addressing the prevention and elimination of ice on roads is a priority in all countries that experience negative temperatures annually. In our country, the salt from the “Artemsil” plant was traditionally used to combat winter slipperiness. However, the plant was destroyed at the beginning of the war, necessitating the search for alternative de-icing materials for roads and streets. Objective. To study the possibility of using alternative de-icing materials (industrial waste, local materials, etc.) for combating winter slipperiness on roads during the martial law period.

The Control of Handling Stability for Four-Wheel Steering Distributed Drive Electric Vehicles Based on a Phase Plane Analysis

For the sake of enhancing the handling and stability of distributed drive electric vehicles (DDEVs) under four-wheel steering (4WS) conditions, this study proposes a novel hierarchical control strategy based on a phase plane analysis. This approach involves a meticulous comparison of the stable region in the phase plane to thoroughly analyze the intricate influence of the front wheel angle, rear wheel angle, road adhesion coefficient, and longitudinal speed on the complex dynamic performances of DDEVs and to accurately determine the critical stable-state parameter. Subsequently, a hierarchical control strategy is presented as an integrated solution to achieve the coordinated control of maneuverability and stability. On the upper control level, a model predictive control (MPC) motion controller is developed, wherein the real-time adjustment of the control weight matrix is ingeniously achieved by incorporating the crucial vehicle stable-state parameter. The lower control level is responsible for the optimal torque allocation among the four wheel motors to minimize the tire load rate, thereby ensuring a sufficient tire grip margin. The optimal torque distribution for the four wheel motors is achieved using a sophisticated two-level allocation algorithm, wherein the friction ellipse is employed as a judgement condition. Finally, this developed control strategy is thoroughly validated through co-simulation utilizing the CarSim 2019 and Simulink 2020b commercial software, demonstrating the validity of the developed control strategy. The comparative results indicate that the presented controller ensures a better tracking capability to the desired vehicle state while exhibiting improved handling stability under both the double lane shifting condition and the serpentine working condition.

Tyre and brake thermal management in NASCAR

The need to manage race car tyres is routine faire and several academic papers have already appeared on this topic. We contribute to this literature with refined tyre grip and wear-rate models. Less well known is a methodology for managing the thermal transients in the car's braking system. This knowledge gap is addressed with a physically-based disc-and-calliper brake-heating model. The parameters in each of the models are optimised against measurement data captured on an instrumented Generation 7 (Gen 7) NASCAR driven on the Darlington speedway. These models are replicated on each corner of the vehicle. The remainder of the paper is directed to studying the minimum lap time performance of a Gen 7 NASCAR that is subject to tyre wear and temperature variations; brake heating influences are emphasised. Due to their novelty, the results focus on the performance impact of temperature variations and constraints on the front brake disc temperatures. Constraints on the brake temperatures are introduced to protect the brakes from fade and thermally-induced damage.

Recurrent Neural Network Model for On-Board Estimation of the Side-Slip Angle in a Four-Wheel Drive and Steering Vehicle

<div>A valuable quantity for analyzing the lateral dynamics of road vehicles is the side-slip angle, that is, the angle between the vehicle’s longitudinal axis and its speed direction. A reliable real-time side-slip angle value enables several features, such as stability controls, identification of understeer and oversteer conditions, estimation of lateral forces during cornering, or tire grip and wear estimation. Since the direct measurement of this variable can only be done with complex and expensive devices, it is worth trying to estimate it through virtual sensors based on mathematical models. This article illustrates a methodology for real-time on-board estimation of the side-slip angle through a machine learning model (SSE—side-slip estimator). It exploits a recurrent neural network trained and tested via on-road experimental data acquisition. In particular, the machine learning model only uses input signals from a standard road car sensor configuration. The model adaptability to different road conditions and tire wear levels has been verified through a sensitivity analysis and model testing on real-world data proves the robustness and accuracy of the proposed solution achieving a root mean square error (RMSE) of 0.18 deg and a maximum absolute error of 1.52 deg on the test dataset. The proposed model can be considered as a reliable and cheap potential solution for the real-time on-board side-slip angle estimation in serial cars.</div>

Adhesion in soft contacts is minimum beyond a critical shear displacement

The most direct measurement of adhesion is the pull-off force, i.e. the tensile force necessary to separate two solids in contact. For a given interface, it depends on various experimental parameters, including separation speed, contact age and maximum loading force. Here, using smooth contacts between elastomer spheres and rigid plates, we show that the pull-off force also varies if the contact is sheared prior to separation. For shear displacements below a critical value about 10% of that necessary to yield gross sliding, the pull-off force steadily decreases as shear increases. For larger shear, the pull-off force remains constant, at a residual value 10%–15% of its initial value. Combining force measurements and in situ imaging, we show how the unloading path leading to contact separation is modified by the initial shear. In particular, we find that the residual pull-off force prevails if the contact reaches full sliding during unloading. Based on those observations, a first modeling attempt of the critical shear displacement is proposed, involving a competition between jump instability and transition to sliding. Overall, those results offer new insights into the interplay between adhesion and friction, provide new constraints on adhesion measurements and challenge existing adhesive models. They will be useful wherever soft contacts undergo both normal and shear stresses, including tire grip, soft robotics, haptics and animal locomotion.

Tire Wear Sensitivity Analysis and Modeling Based on a Statistical Multidisciplinary Approach for High-Performance Vehicles

One of the main challenges in maximizing vehicle performance is to predict and optimize tire behavior in different working conditions, such as temperature, friction, and wear. Starting from several approaches to develop tire grip and wear models, based on physical principles, experimental data, or statistical methods available in the literature, this work aims to propose a novel tire wear model that combines physical and statistical analysis on a large number of high-performance vehicle telemetries, tracks, and road data, as well as tires’ viscoelastic properties. Another contribution of this multidisciplinary study is the definition of the functional relationships that govern the tire–road interaction in terms of friction and degradation, conducting a thorough analysis of the car’s telemetry, the track and asphalt features, and the viscoelastic properties of the tires.

Vehicle Suspension System with Integrated Inerter - Extended Analysis

Inerter devices are used in Formula 1 vehicles for a decade to reduce vertical and rolling displacement at the corner of the sharp racing curves and provide higher tire grip on racing challenges. To improve dynamics Formula SAE Car, several topological designs for suspension system are already proposed and published [1]. Based on our passive suspension system for quarter-car model, we carried out analysis for different parameters and under the impact from the road disturbance and demonstrated when integrated inerter device can increase ride comfort and decrease vertical displacement. Proposed solution system with integrated inerter mechanism can improve vehicle suspension systems development and have effects on dynamics and stability of a vehicle.

THEORETICAL APPROACHES TO RESEARCH THE ROLLING PROCESS OF THE DRIVEN WHEEL SIDE DRAWER ON A WINTER ROAD

The stability of the movement of motor vehicles in the cold season is ensured by the ability of car tires to create lateral reactions on winter roads. The lateral adhesion of the tire to the support surface is evaluated by its lateral withdrawal characteristics, which determine the coefficient of lateral adhesion and the critical angle of the tire withdrawal. With the use of chemical deicing materials, the coupling properties of tires have significantly deteriorated, especially in the lateral direction. The lack of knowledge about the processes of movement of a tire with lateral withdrawal on a winter road covered with chemical deicing materials determines the relevance of scientific research.
 The article discusses the non-stationary characteristics of the lateral withdrawal of Amtel NordMaster175/70R13 passenger friction tires, obtained from the results of their tests on a winter public road covered with rolled snow and sand-salt mixture. The graphs show that the use of sodium chloride reduces the lateral grip of friction tires and the stability of motor vehicles.
 Purpose – obtaining non-stationary characteristics of lateral withdrawal of passenger friction tires on a road covered with rolled snow and sand-salt mixture, and estimated parameters of lateral traction.
 Methodology: a road test method using the methodology and tire tester developed by the author to study the unsteady lateral withdrawal of automobile tires.
 Results: The unsteady characteristics of the lateral withdrawal of Amtel NordMaster 175/70R13 passenger friction tires were obtained, the coefficients of lateral adhesion and critical withdrawal angles were determined.
 Practical implications: the obtained results are necessary to correct the mathematical model that allows performing an analytical study of the processes of lateral withdrawal of automobile tires on roads with winter slipperiness.

Finding optimum Ackermann geometry for a car undergoing steady state cornering using tire data

For a car to have minimum lap times across a track it should be able to produce the maximum cornering force or side force in order to complete the corner at the maximum velocity possible. The grip level of a particular tire limits the maximum side/lateral force it can produce. To find the best steering geometry for a car one should know the grip limit of the tire and at which slip angle it is being produced. This paper provides a simple methodology to find the appropriate Ackermann steering geometry, which can produce the maximum lateral tire grip going through different high speed constant radius corners. Hence, reducing the time spent on-track while testing to find out the suitable steering setup and improving the overall cornering ability of the car. The raw tire data from tire testing runs of the tire: Hoosier 18.0 X 6.0 – 10 R25b is used to fit curves to the raw data using two tire models based on the Magic Formula and Data Non-dimensionalization methods respectively. The results from both of the methods are compared. These tire models are then used to find the ideal steer angles of the front tires at various constant radius steady-state turns and thus the Ackermann geometry of a Formula Student car producing the maximum possible grip.

The control optimization algorithm for automatic braking of a wheeled vehicle

Introduction (problem statement and relevance). One of the most promising and intensively developing directions in the automation field of road transport management is the creation of highly automated vehicles.The purpose of the study was to find a way to solve a wheeled vehicle safe automatic braking problem in terms of minimizing quality control of the quadratic functional and work out optimal software and hardware implementation of this system.Methodology and research methods. To solve the problem, the method of the control algorithm analytical design was used, basing on the use of the necessary conditions for minimizing the elements of the functional for the control law synthesis. The maximum deceleration value was due to the identified tire grip, and the deceleration threshold from which braking begins was selected as the minimum of the working deceleration and two decelerations depending on the rear obstacle distance.Scientific novelty and results. The tests of the developed function were carried out for the LADA Vesta vehicle equipped with an ABS valve body with the possibility of programmed control. The analysis of the research results showed that when solving the problem of safe automatic braking in front of an obstacle, the software limitation of braking deceleration did not allow wheel blocking and performed the functions of an anti-lock braking system at the permissible wheel slipping level; software backup of the distance calculation to the front obstacle from the moment of braking start allowed to prevent most of the situations with false data from the radar when the vehicle pecked during braking.Practical significance. Software tuning of mathematical models parameters of the engine, transmission and braking system allows you to adapt the automatic braking system to a wide class of vehicle models.

Understanding Test Modalities of Tire Grip and Laboratory-Road Correlations with Modeling

The present study is meant to obtain tribological insight into the interface of a rolling rubber wheel on a counter-surface disk based on the work of the previous study Salehi et al. (Tribol Lett 68(1):37, 2020), in which a new test method was developed to rapidly predict tire grip in a laboratory environment. A Laboratory Abrasion Tester (LAT100) was used and exploited as a tribometer. This opened a new cost- and time-effective horizon for tire material development in a laboratory environment rather than having to test tread compounds by building full-scale tires. The method was validated by a comprehensive study for six different tire tread compositions, by correlating the laboratory data for solid rubber wheels as LAT100 specimens with real tire results in two test modalities: lateral (α) and longitudinal (κ) sweep tests on a dry road. It was demonstrated that the LAT100 can be exploited to simulate the alpha-sweep tire tests, but not the kappa-sweep. The dynamics and physics of a rolling rubber wheel on a counter-surface disk of the LAT100 test step-up are investigated utilizing the renowned physical “brush model” in comparison to full-scale tire tests. The type of test modality leads to different friction mechanisms in the contact patch even at similar test conditions. This is substantiated by recognizing the two regions: stationary and non-stationary, in the contact area which results in different friction components and mechanisms. The behavior of the rolling wheel in lateral and longitudinal movements at the same test conditions is comparable if the contributions of the mentioned regions in the contact area are similar.

Research on the Contradiction Mechanism of Tire Rolling Resistance and Grip Performance

ABSTRACTIn order to clarify the contradictory mechanism between tire rolling resistance and grip performance, 10 205/55 R16 radial tires with different tread patterns were selected as the research objects. Based on digital image correlation method, the pressure and deformation distribution in the contact area of test tires were obtained and the relevant grounding parameters were extracted. The partial least square regression (PLSR) method was used to establish the relationship between the identified grounding parameters and tire performance indicators. Using the bootstrap resampling method, the significance test of the PLSR coefficients were carried out, and the grounding characteristic parameters with significant explanatory effect on the performances were selected, identifying the main function area for the two performances. The results show that in order to improve the grip performance of the tire, it is necessary to reduce the transverse tensile strain of the tread in the contact area and increase the longitudinal tensile strain of the tread; but, with the increase of the longitudinal tensile strain, the rolling resistance of the tire will also increase, which leads to the contradiction between tire rolling resistance and grip performance.

Análisis del diseño aerodinámico de un alerón preparado para competencia utilizando simulaciones numéricas de dinámica de fluidos computacional (DFC)

espanolLa presente investigacion analiza numericamente el comportamiento aerodinamico de vehiculo Suzuki Forsa con un aleron para competencia en pista. Para el diseno del aleron, se realiza una simulacion en ANSYS Fluent utilizando el modelo de turbulencia RANS K-e con una malla gruesa y una malla refinada. La malla refinada permitio validar los datos considerando una distancia de pared adimensional (y+=5) y una tasa de inflacion de 1,20. Con esta configuracion, se realizaron simulaciones de dinamica de fluidos computacional con distintos angulos (5o, 10o, 15o y 20o) con un tiempo de simulacion de 10 horas para cada angulo propuesto. Los resultados muestran que un angulo de 20o brinda una fuerza de sustentacion negativa (fuerza aerodinamica) adecuada para que los neumaticos tengan un mejor agarre con la superficie de rodadura y alcanzar la mejor eficiencia aerodinamica. Se concluye que la configuracion de aleron con angulo de incidencia de 20o brinda la mayor carga aerodinamica con la mejor eficiencia aerodinamica para el vehiculo Suzuki Forsa. EnglishThe present research study examines the aerodynamic behavior of a Suzuki Forsa vehicle with a racing airfoil. The ANSYS Fluent software and the RANS K-e turbulence model are used to perform a numerical simulation. A coarse and a refined mesh are used to design the airfoil. The data is validated with the refined mesh by using a normalized wall distance (y+=5) and an inflation rate of 1.20. This configuration is used to perform computational fluid dynamics simulations with different angles of attack (5o, 10o,15o, and 20o). The simulation time was 10 hours for the proposed angles of attack. The results show that the 20o angle of attack provides an adequate negative sustentation force (aerodynamic force) to improve tire grip with tread surface and achieve the most efficient aerodynamic. It is concluded that the 20o angle of attack configuration provides the most downforce and the most efficient aerodynamic configuration for Suzuki Forsa vehicles.

Study on Tire Noise and Grip Performance Based on Tread Ground Deformation Characteristics

Study on Tire Noise and Grip Performance Based on Tread Ground Deformation Characteristics

A Discrete Tire Model for Cornering Properties Considering Rubber Friction

In this paper, a discrete tire model of cornering properties for road vehicles relating to tire grip performance, which is important for driving stability and safety, is presented. The proposed tire model combines realistic rubber friction related to velocity and tire grip performance with deformation of the carcass. The model can describe the stress and strain of the carcass and tread, and the rubber friction coefficient at each point of the contact patch, which is affected by the distribution of the slip velocity. Meanwhile, the model incorporates the effects of the viscoelastic rubber material and power spectrum of the road, which are explicitly reflected in the rubber friction model. First, an improved rubber friction model based on the Persson theory of rubber friction is introduced in this paper. A discrete analytical tire model, which considers carcass compliance and the discretization of the tread, is then proposed. In addition, important phenomena of tire properties arising from the carcass compliance and rubber friction are analyzed and the effectiveness of the discrete analytical tire model is validated experimentally. The proposed model provides a new way to optimize the grip performance of a tire by adjusting the tire or rubber physical parameters even before the tire is made.

Simulating the relative influence of tire, vehicle and driver factors on forward collision accident rates

Introduction: There is currently a strong focus within the automotive industry centered on traffic safety, with topics such as distracted driving, accident avoidance technologies, and autonomous vehicles. These papers tend to focus on the possible improvements from a single factor. However, there are many factors that are present in each accident, and it is important to understand the influence of each factor on the relative accident risk in order to identify the most effective approaches for improving driver safety. Rear-end accidents tend to be the most common accident type with approximately 1.8 M cases, or 31% of all accidents, in 2012, according to NHTSA. Of the rear-end accident scenarios, approximately 18–23% occur on wet surfaces. Method: A Monte Carlo Forward Collision Simulation models the conditions of a wet rear-end accident and estimates the relative impact of various vehicle collision parameters. The model takes distributions of these parameters as inputs, and outputs a risk of collision relative to a known reference case. The parameters that can be studied include: tire grip level, road grip level, vehicle velocity, following distances, and the presence of vehicle technologies (ABS, FCW & AEB). Distributions of some of these parameters have been improved thanks to Naturalistic Driving Study data from SHRP2. Results: This study shows that these vehicle systems have a large impact on safety and can change the amount of influence attributed to other parameters such as tire grip levels. As the use of automated vehicle systems expands, so will the influence of tire grip performance levels on collision risks. Practical Applications: It is more important than ever for consumers and auto manufacturers to consider tire performance levels. Therefore, the tire industry should continue to focus on wet grip as a key performance related to safety and should strive to continue to improve tire performance.

Modeling the algorithm of the automatic emergency braking system with the prediction of the coefficient of tire grip

The problem of improving road safety is currently one of the most significant in the automotive industry. One of the promising ways to improve road safety is the development and introducing of intelligent active safety systems for automobiles. To solve the problem of improving safety, world leaders in the automotive industry are actively engaged in the development and implementation of intelligent control systems that provide control over the movement of the car and can partially intervene in driving. The article is devoted to the effectiveness of the automatic emergency braking system in accordance with the climatic and road conditions of Russia. The report discusses the problems of determining the coupling properties of the wheels of a car with a road on various surfaces, discusses the problems of predicting braking distance. Options for improving forecasting and building algorithms for the automatic emergency braking system are considered.

A New Horizon for Evaluating Tire Grip Within a Laboratory Environment

The evaluation of tire grip on the road is costly and consumes high energy and time, but is essential for safety. Prediction of tire grip on a laboratory scale is therefore always of interest and of utmost importance for research and material developments. It mostly suffers from lack of comparison with actual tire data. To involve all influencing factors on tire grip in a laboratory scale measurement is very complex. Therefore, it has always remained challenging to obtain a strong correlation between laboratory results and road data. In the present study, a new test method is developed for a Laboratory Abrasion Tester, LAT100, which enables to exploit the device as a tribometer. The objective was to develop a technique on a laboratory device to mimic the common test modalities for evaluating tire grip on the road with a trailer tester: lateral (α) and longitudinal (κ) sweep tests. The new method is validated by correlating the laboratory data with the two test modalities of real tire grip on a dry road using a trailer tester for six different tire tread compositions. For the LAT100 tests, solid rubber wheels are characterized at three different normal loads. The effects are comparable with actual tire data. The outcome of the new test method is in good agreement with actual tire trailer α-sweep tests.Graphical abstract

Optimal Tyre Management of a Formula One car

Optimal control calculations are used to study the effect of tyre wear on race car performance. This is achieved by solving a minimum lap time optimal control problem over multiple laps using a dynamical model of a Formula One car. A previously developed thermodynamic model is enhanced by adding an additional state for the carcass temperature of the tyres. The tyre grip is modelled as a function of the tyres’ wear and temperature. Grip reduces when tyres get worn, or the tyres are not operated within their optimal temperature window. Overheating the tyres can accelerate wear, which in turn, degrades performance. The optimal control problem solver needs to ‘manage’ the state of tyres throughout a race (not just a single lap) to ensure that optimal race performance is achieved. At some point during a race a pit stop may be required to change worn tyres so that tyre grip can be restored. It is essential to understand the wear characteristics of various tyre compounds in order to determine the point when the time needed for a pit stop is justified in terms of subsequent racing performance.

Simulation for rubber friction on self‐affine surface based on energy method

Here, the authors propose an energy method to obtain the friction coefficient of a rubber block sliding on self-affine substrates via simulation. Due to the multi-scale property, the rough surfaces are modelled with four harmonic rigid frictionless roads. As the rubber block is a viscoelastic solid, energy dissipation in the contact area results in friction. The authors propose a new simulation method to obtain friction coefficient through energy dissipation. With different loads and sliding velocities, the change law of friction coefficient is calculated. The authors design a test instrument to verify the friction coefficients of rubber on some certain surface. The findings of this research constitute a theoretical basis for safe tire design and tire grip improvements.