Tire Contact Research Articles

Extracting terrain elevation information in front of the vehicle based on vehicle-mounted LiDAR in dynamic environments

Abstract Point cloud maps constructed using 3D LiDAR, are widely used for robot navigation and localization. Few studies have utilized point cloud maps to extract terrain elevationinformation in front of a vehicle, which can be used as active suspension inputs to reduce vehicle bumps. In addition, the trajectories of dynamic objects in point cloud maps and global navigation satellite system (GNSS) data loss can affect the extraction of elevation information. To solve these problems, this paper proposes a framework for extracting terrain elevation information in front of the vehicle based on vehicle-mounted LiDAR in dynamic environments. The framework consists of two modules: point cloud map construction and vehicle front terrain elevation information extraction. In the point cloud map construction module, a system for simultaneous localization and mapping (SLAM) is proposed, which is capable of building point cloud maps without GNSS. Furthermore, a dynamic descriptor-based dynamic object filtering algorithm is proposed which is applied to SLAM. Therefore, the SLAM system overcomes the influence of dynamic objects on vehicle position and attitude estimation, and there are no trajectories of dynamic objects in the point cloud maps built by the system. In the vehicle front terrain elevation information extraction module, the unscented Kalman filter is utilized to predict the vehicle position at the next moment. Based on the geometric features of the tire-ground contact area, the terrain elevation information of the tire contact area at the predicted position on the point cloud map is extracted. Experiments show that the algorithm in this paper overcomes the effect of dynamic objects and builds a vehicle point cloud map without dynamic objects under GNSS data loss, which improves the accuracy of the extraction of terrain elevation information in front of the vehicle.

Development of high-efficient asphalt pavement modeling software for digital twin of road infrastructure

To develop digital twin (DT) of road infrastructure, one critical element is computation of pavement responses (strains, stresses, and deflections) under traffic and environmental loading. This study aims to develop high-efficient asphalt pavement modeling software based on semi-analytical finite element method (SAFEM) for DT application. The algorithms address important aspects in vehicle-tire-pavement interaction modeling, such as dynamic vehicular loading, three-dimensional (3-D) non-uniform tire contact stress, viscoelastic behavior of asphalt material, and interface bonding condition. The simulation accuracy is verified by comparison with full-scale test and field measurements, and the relative differences are around 5 % to 20 %. Techniques including optimized discrete Fourier transform, parallel computing, graphics processing unit (GPU) acceleration, and sparse matrices are implemented for computation efficiency. As compared to the traditional 3-D FEM, SAFEM shows significant savings in computation time and storage usage. The high efficiency and accuracy make the software full of potential to be applied for DT of roadway infrastructure.

Robust H∞ Control Design for Improving Handling and Ride Comfort in Semi-Active Suspension Systems

This study investigates the application of robust H∞ control design for semiactive suspension systems. The goal is to achieve a balance between ride comfort and handling. A quarter-car model is used to simulate the system's dynamics. The findings demonstrate that the robust H∞ control approach with μ-synthesis offers significant advantages compared to traditional passive control and nominal H∞ control methods. When compared to the passive system, the robust H∞ controller with μ-synthesis results in a 50% reduction in body displacement (from 0.04 meters to 0.02 meters) during a simulated road bump. It also achieves a 25% reduction in peak body acceleration (from 4 m/s² to 3 m/s²) and a 37.5% reduction in suspension deflection (from 0.04 meters to 0.025 meters). These improvements translate to a smoother ride with less body movement and improved handling due to better tire contact with the road. The μ-synthesis method specifically addresses uncertainties like passenger weight and road conditions. This leads to more consistent performance in real-world driving scenarios. Overall, this study highlights the effectiveness of robust H∞ control design in achieving a well-balanced suspension system that enhances both ride comfort and handling.

Impacts of bulk density and water content on the tire-soil contact area of agricultural field vehicles

We tested the hypothesis that the increase in soil stiffness, induced by variations in bulk density and water content at the tire-soil contact interface, causes a reduction in the contact area. For this, we examined the contact area from different tire-ground contact scenarios and compared the measurements and simulations using a contact area description model. Front and rear tractor tires were used for the measurement of the contact area under tilled soil, sugarcane field, unpaved road, and paved ground scenarios, which induced different bulk densities and water content levels. The results revealed that soil stiffness reduced the tire-soil contact area. The tire-soil contact area increased as the water content increased and the bulk density was reduced. For the front tractor tire, the theoretical contact area was similar to the values found for tilled soil, but there was a large difference between the measurements (2,200 cm2, for the tilled soil) and the theoretical estimates (3,100 cm2) for the rear tractor tire (likely induced by tire dimensions). Our results suggest that increases in soil stiffness reduce the tire-soil contact area. The higher the soil bulk density and the lower the soil moisture, the lower the contact area. The results also revealed that the tire tractor tread might reduce the contact at the hard surface, making the shape of the contact area more geometrically irregular and different from those predicted by models using regular geometry (e.g., cycles, ellipses, or rectangles). This study suggests that two-body (soil and tire) contact models for deformable surfaces should be used in future tire-soil contact models of agricultural field vehicles.

Fault Detection Methods for Electric Power Steering System Using Hardware in the Loop Simulation

The development of the automotive industry is associated with the rapid advancement of onboard systems. In addition, intensive development in the electronics and control systems industry has resulted in a change in the approach to the issue of assistance systems in vehicles. Classic hydraulic systems have been almost completely replaced by modern electric power steering (EPS) systems, especially in citizen vehicles. This paper focuses on fault detection algorithms for EPS, along with the available tools to aid development and verification. The article discusses in detail the current state of knowledge in this area. The principle of operation of the EPS system and the influence of the structure of the mechanical system on its operation, in particular the characteristics of the ground–tire contact, are presented. Various error identification methods are presented, including those based mainly on a combination of tests of real objects as well as those combined with modern hardware-in-the-loop (HIL) equipment and virtual vehicle environment software, enabling the development of new diagnostic methods, enhancing the security, reliability, and energy control in the vehicle. A review of the literature indicates that although many algorithms which enable fault detection at an early stage are described, their potential for use in a vehicle is highly limited. The reason lies in simplifications, including models and the operating EPS temperature range. The most frequently used simplification of the model is its linearization, which significantly reduces the calculation time; however, this significantly reduces the accuracy of the model, especially in cases with a large range of system operation. The need for methods to detect incipient faults is important for the safety and reliability of the entire car, not only during regular use but also especially during life-saving evasive maneuvers.

Suspension Based on Magnetic Effect for Vehicles

Abstract: Suspension systems are integral to vehicle performance, playing a critical role in enhancing ride comfort, stability, and handling. By absorbing shocks and vibrations, suspension systems ensure a smoother ride for occupants, improve traction, and maintain optimal tire contact with the road. Effective suspension systems also contribute to overall vehicle safety by optimizing braking performance and manoeuvrability. This research paper explores the benefits of magnetic suspension systems and their applications across various fields. Magnetic suspension offers significant advantages over traditional mechanical systems, including superior stability, quick dynamic responses, and efficient thermal management. Through detailed analysis and comparative studies, this paper highlights the potential of magnetic suspension to revolutionize modern transportation and other industries requiring precise control and stability.

RESEARCH OF THE NOISE LOAD OF VEHICLES

Noise can be viewed as an undesirable component of a signal that can affect the quality of perception or transmission of information in a system. In different contexts, the term «noise» may have different meanings, but a common feature is the random impulsive nature of this phenomenon. Automotive noise is sound energy generated by the movement of a vehicle and its components. The study of road traffic noise is an important area, especially in environments where noise can have a significant impact. This includes analyzing noise levels, identifying noise sources, assessing its impact on the environment, and developing strategies to reduce noise. This study analyzes the causes of automobile noise and their noise sources, and provides classification features. The research methodology included measuring the noise level at different points of the bus interior using a specialized acoustic sound level meter Testo 816. The Sound Meter program was additionally used to obtain current time values of noise level changes with graphical data interpretation. When the bus is idling, a monotonous noise load level in the range of 58-63 dB is observed in the cabin, which is typical for a running diesel engine, which is the main source of noise. The movement of the bus in urban conditions is accompanied by a change in traffic conditions, which in turn increases the maximum noise load to 73 dB. The movement of the bus in the city is accompanied by an increase in the noise load up to 74 dB and the equivalent up to 67 dB. This is due to an increase in speed, contact of tires with the asphalt road, interaction of the air environment with bus elements, the appearance of vibrations and other noises.Although the noise load in the bus interior is within the upper permissible limits, it requires the introduction of noise reduction measures, especially for long-distance buses for a comfortable ride for passengers. Therefore, it is important to take noise levels into account when designing and operating vehicles, as well as when planning urban infrastructure projects.

Estimation of Road Adhesion Coefficient Based on Camber Brush Model

Electric vehicles, with their distinct power systems, weight distribution, and power control strategies compared to traditional vehicles, influence the pressure distribution in the tire contact area, thereby affecting the estimation of road adhesion coefficient. In electric vehicle research, tire adhesion coefficient serves as a measure of the frictional force between the vehicle and the road surface, directly impacting the vehicle’s handling performance. The accurate estimation of the adhesion coefficient aids drivers in better understanding the vehicle’s driving state. However, the existing brush models neglect differences in ground pressure distribution along the width direction of tires during tire camber, potentially leading to inaccuracies in adhesion coefficient estimation. This study proposes a camber brush tire model that considers the width-direction pressure distribution characteristics, aiming to enhance the accuracy of adhesion coefficient estimation under camber conditions. Experimental comparisons between the improved and original models reveal a significant enhancement in estimation precision. Consequently, the findings of this study provide valuable insights for deepening our understanding of tire camber dynamics and for designing control systems for electric vehicles, thereby improving vehicle stability and safety.

Tire–road contact modelling for multibody simulations with regularised road and enhanced UA tire models

AbstractMultibody simulations play an important role in the study of the dynamic behaviour of road vehicles, being one of the key aspects the modelling of the tire-road interaction. The tire-road contact modelling is required to detect the contact between the tire and road and to obtain the tire contact forces from the tire-road relative motion. The first part of the problem is solved by a contact detection algorithm, whereas the second part is handled by a tire model. In both cases, the trade-off between accuracy and computational cost needs to be addressed in the road dynamics scenario. For the contact detection problem, this work proposes a methodology in which the road is described by a mesh of triangles while the tire is described by a toroid. The triangular mesh road input can be directly extracted from any CAD model. To avoid the geometric discontinuities due to the transition between triangular patches, a set of auxiliary points is used to obtain a continuous variation of the road surface normal, based on the method proposed by Rill (Multibody Syst. Dyn. 45:131–153, 2019. In the process of contact detection, all kinematic quantities required by the tire-road contact model are evaluated. The tire–road forces are evaluated using the enhanced UA tire model, which is a numerically stable and efficient development of the original tire model proposed by Gim and Nikravesh (Int. J. Veh. Des. 12, 1991; Int. J. Veh. Des. 12:19–39, 1991; Int. J. Veh. Des. 12:217–228, 1991). Both the contact and tire models have smooth transitions between their internal transitions, thereby reducing the need for the variable-step ODE integrators to unnecessarily decrease time steps. The advances on contact detection and the tire–road contact models, proposed here, are demonstrated with a set of road vehicle simulation scenarios in which the influence of various modelling parameters on the stability and efficiency of the simulations is addressed. The novelties of the work consist not only in the demonstration of the enhanced UA tire model in practical situations but also in the description of the new tire–road contact methodology that employs a simple description of the road geometry, to achieve smooth tire–road contact forces.

Analysis of tire-pavement interaction modeling and rolling energy consumption based on finite element simulation

Energy consumption is caused by the rolling resistance of tires as a vehicle moves forward, which contributes to resource consumption and the greenhouse effect. The objective of this paper is to investigate the variation of tire-pavement rolling energy consumption under different operating condition factors. For this purpose, a rolling finite element dynamic model was developed based on real tire and road contact. The correlation between the effective radius and free angle is determined during the free rolling process. The variations of different working conditions on rolling energy consumption under tire-road coupling were analyzed according to both tire and pavement factors, and the influence factors were analyzed by grey correlation analysis. The results show that the factors affecting the significance of rolling energy consumption in descending order are tire load, tire pressure, coefficient of friction, pavement stiffness, and rolling speed. Specifically, energy consumption can be increased by increasing the tire load or friction coefficient, the cumulative increase of rolling energy consumption reaches 68.3% and 14.51%, respectively. Energy consumption can be decreased by increasing the tire pressure or pavement stiffness, the cumulative decrease in energy consumption is 20.45% and 5%, respectively. In addition, the rolling energy consumption increases and then decreases within an increasing speed range(10–80 km/h). The speed trend inflection point is 20 km/h. The research results can provide a technical reference for the development of a low-energy consumption design scheme for tire-pavement systems. To better serve the construction needs of green low-carbon and sustainable road transportation.

A machine learning-based approach for estimation of deflection and contact area characteristics of tubeless and tube-type agricultural tyres

Support Vector Regression (SVR) models with different kernel functions (radial basis and polynomial) were developed for predicting deflection and contact area of tubeless and tube-type tractor tyres. Data were collected from experimental trials on 13.6–28 tubeless and tube-type tyres under varying loads (750–1400 kg) and inflation pressures (69–179 kPa). A displacement transducer comprising a rack-pinion arrangement and a rotary potentiometer was developed for measuring tyre deflection. A total of 168 data points were split into 70% for training and 30% for testing the SVR models. An additional 42 new data points were collected at a normal load of 900 kg for validation purpose. As compared to tube-type tyre, tubeless tyre had higher contact area at higher normal loads due to higher tyre deflection. Two SVR models were constructed by considering normal load, inflation pressure, and tyre-type as input parameters. The well-trained SVR model could predict tyre deflection with a maximum deviation of 2% from the measured values as compared to −21% in case of Wulfsohn model. Similarly, the predicted contact area had a maximum variation of 1% from the measured values as compared to 9.99% in case of Komandi model and 31% in case of Diserens model. The sensitivity analysis indicated that the proposed models ranked normal load as the highest priority followed by inflation pressure and tyre-type for estimating both tyre deflection and contact area.

Calculation and operational assessment of tyre contact areas in the tractor-and-trailer unit

Calculation and operational assessment of tyre contact areas in the tractor-and-trailer unit

Estimation of Tyre Deflection and Contact Area of Tubeless Tyre on Firm Surface for Traction Studies

Estimation of Tyre Deflection and Contact Area of Tubeless Tyre on Firm Surface for Traction Studies

Experimental validation of elliptical contact tire model with friction coefficient deduced from viscoelasticity of tread rubber

Experimental validation of elliptical contact tire model with friction coefficient deduced from viscoelasticity of tread rubber

Effects of vertical load and inflation pressure on tire-soil interaction on artificial soil

Instrumented single tire soil bin testing was conducted on a rigid surface and artificial soil by vertically loading a radial tire (LT235/75R15) to two tire vertical loads (6 kN and 8 kN) inflated to three levels of tire inflation pressure (179, 241, and 283 kPa). Lowering the tire inflation pressure by 37 % resulted in 26 % (6 kN vertical load) and 39 % (8 kN vertical load) greater contact lengths (P < 0.05). The 2-D contact area on artificial soil (initial bulk density of 1.51 Mg/m3) was significantly affected (P < 0.05) by tire inflation pressure for each load case. Increasing the load significantly affected the tire’s contact length on soil (P = 0.0010); however, tire inflation pressure did not significantly affect the contact length on soil (P = 0.0609). Soil rut depth and tire-soil deformed volume were not significantly affected by vertical load and tire inflation pressure. Measured tire contact area on soil surface was 3.3 times the contact area on the rigid surface, suggesting tire-soil interaction interface properties on deformable soil are better than using the gross flat plate for evaluating low ground pressure tire technology effects on traction and reducing soil compaction.

Thorough Analysis of the Reliability of Measurements on Chassis Roller Dynamometer and Accurate Energy Consumption Estimation for Electric Vehicles

The energy consumption of the electric test vehicle on the roller dynamometer test bench is thoroughly investigated in this work. Initially, we extensively examined the relevant testing approaches on chassis dynamometer test benches. Then, we presented the main issues and limitations of this type of testing facility. After that, an experimental analysis was performed by recording the NEDC and the WLTP-class 2 standard driving cycle test data. It was found that the power consumption associated with specific test maneuvers could be accurately simulated via the roller dynamometer system. However, the experimental test results showed some disparities compared to the expected results from the simulation models. These findings supported identifying the dynamic behavior resulting from the tire and roller contact. The LuGre friction model provided the solution, incorporating friction-related physical models such as stick-slip and the Stribeck effect. In addition, adjustments were made to the LuGre model to consider the dynamic influences of the roller on the tire. Finally, we created a systematic estimation model for energy consumption by integrating the boundary conditions of the test bench, a generic model for energy estimation of electric vehicles, and the proposed tire–roller contact model. The overall model requires only the measured traction speed of the test vehicle and the auxiliary energy losses as physical inputs. The results proved that the proposed model enabled the estimation of the total power consumption with high accuracy.

Estimating the effectiveness of electric vehicles braking when determining the circumstances of a traffic accident

In the vast majority of cases, the braking process is used to prevent traffic accidents. The effectiveness of this process depends on the design and functionality of vehicle braking systems (presence of anti-lock braking system, emergency braking system, preventive safety systems, etc.) and is limited by the amount of frictional forces in contact of tires with the road. The improvement of methodical approaches to evaluating the effectiveness of braking of cars contributes to increasing the accuracy and objectivity of establishing the circumstances of the occurrence of emergency situations. The paper analyses existing methods of evaluating the braking parameters of vehicles (including those with an electric drive) and modern methods of evaluating electric vehicle braking parameters and conducting auto-technical investigations of traffic accidents, which relate to using different methodological approaches and digital technologies at all stages of expert research. In contrast to existing models, the proposed mathematical model for estimating the trajectory of two-axle cars during braking allows for considering various types of input parameter uncertainty, reducing the range of possible modeling errors by 39%. Comparing simulation results and experimental data showed that the average relative error is 4.58%, and the maximum error did not exceed 7.82%. The performed study of the stability of the electric vehicles' movement during emergency braking with the help of developed mathematical models in the Mathcad software environment reveals the content of the algorithm of a similar calculation in specialized computer programs of auto technical examination. Conducting such calculations is relevant in the analysis of real accident situations, where specific circumstances and features that cannot be considered during modeling in specialized software must be taken into account. Simultaneously, the probability of type I errors is reduced by 2–19%, and type II errors are reduced by 43–68%.

Finite Element Analysis of Tyre Contact Interaction Considering Simplified Pavement with Different Aggregate Sizes

This study considered the effect of pavement aggregate grain size on tyre–pavement contact interaction during the late stages of pavement skid resistance. First, hemispherical shells 7, 9, and 13 mm in diameter were used to simulate coarse pavement aggregates. Subsequently, a three-dimensional finite element tyre–pavement contact model developed using ABAQUS was employed to analyse the contact interaction between each simplified pavement type and the tyre under steady–state rolling and braking conditions. Finally, the concept of occlusal depth was proposed and applied to characterise pavement skid resistance. The results showed that under steady–state rolling conditions, the peak contact stress of the simplified pavement increased with the pavement mean texture depth, whereas the contact area decreased. Under steady–state braking conditions, the effect of the contact interaction between the tyre and simplified pavement aggregates was ranked in order of superiority as aggregate grain sizes of 9, 7, and 13 mm, indicating that aggregate grain size did not exhibit any correlation with tyre–pavement contact interaction. Additionally, the squares of linear correlation coefficients between the pavement cumulative occlusal depth and horizontal braking force reached 0.921, 0.941, 0.889, and 0.894 for vehicle speeds of 30, 60, 90, and 120 km/h, respectively, indicating that they could be used to assess pavement skid resistance.

High fidelity nonlinear finite element tire modeling for dynamic analysis: Total Lagrangian formulation in rolling contact

Tire design with respect to vibrational behavior and noise emission is a challenging task due to the large number of parameters and their coupling. Therefore, accurate high fidelity nonlinear Finite Element (FE) models are needed to aid in the design process. The widely used Arbitrary Lagrangian Eulerian (ALE) models, despite their computational efficiency, are limited to rib-slicked tires and require significant effort to consider inelastic material behavior and frictional phenomena. To overcome these limitations a novel nonlinear FE tire model is presented based on the Total Lagrangian (TL) formulation. The TL model is compared to the reference ALE model for the case of stationary rolling on a smooth and a rough road surface. The observed match of the TL model with respect to the hub and contact forces proves the feasibility of using the TL formulation in the context of rolling contact tire simulations. Therefore, the TL model can be seen as a valid alternative to the frequently used ALE models.

Stability and energy-saving coordinated control strategy of six-wheel independent drive unmanned ground vehicle

During the operation of six-wheel independent drive unmanned ground vehicle (6WID UGV) in the field, the inconsistent tire contact characteristics and frequent steering maneuvers have led to increasingly prominent issues of tire excessive wear and lateral instability. Therefore, a coordinated hierarchical controller for 6WID UGV is proposed to ensure the stability of the steering process while reducing tire wear and motor energy consumption. First, a sliding mode controller (SMC) with an extended-state observer (ESO) is proposed for lateral stability control referencing the active disturbance rejection control (ADRC) technique, achieving fast response and robustness to uncertainty. Second, the lower controller constructs a Lagrangian function with tire slip energy loss and energy consumption as optimization objectives and allocates torque based on the Pareto optimal solution within the feasible domain given by the upper controller. Finally, the designed controller is tested under typical operating conditions. The results indicate that the designed coordinated controller has significant control performance and economic benefits in improving lateral stability and reducing energy loss. Compared with the torque distribution strategy based on tire vertical load, the tire slip energy is reduced by 44.8 % and 17.7 % in the process of traction/steering and braking/steering, respectively. In addition, the motor energy consumption and the friction braking energy loss are reduced by 12.1 % and 70.8 % respectively.