Tire Friction Research Articles

Microplastics in wastewater plants: A review of sources, characteristics, distribution and removal technologies

Microplastics (MPs) are widespread in everyday life, and since wastewater treatment plants (WWTPs) serve as an important route for MPs to enter natural water bodies, a thorough understanding of the distribution and removal of MPs in wastewater treatment plants is of great importance. This article provides a comprehensive overview of the measured distribution of MPs and the current status of their removal in wastewater treatment plants. The main sources of MPs in wastewater treatment plants are personal care products in domestic wastewater, textile clothing and industrial wastewater made from plastics, textile factories and the friction of road tires. The MPs that entered the sewage treatment plant were predominantly in the form of fibers, fragments, granular MPs and other types of MPs. The size of MPs is divided into three categories: <0.5 mm, 0.5–1 mm and 1–5 mm. At all treatment stages in wastewater plants, 56.8–88.4 % of MPs are removed in primary treatment, but the primary sedimentation and degreasing stages remove most MPs. The efficiency of the activated sludge process for secondary treatment is inconsistent and is generally between 42.1 and 99.2 %. The coagulation, filtration and disinfection stages of tertiary treatment all have some MPs removal capacity. In addition, novel removal technologies are also described, such as modified filtration technology, membrane separation technology, electroflocculation, sol-gel and photocatalysis. These novel removal technologies can further limit the entry of microplastics into natural water bodies through sewage treatment plants and improved sewage treatment processes help reduce the risk of MPs entering the natural environment through sewage treatment plants. This article will provide reference for the distribution and removal of microplastics in various levels of WWTPs.

The effect of load-dependent tyre friction and aerodynamic cross-flow forces on the g-g maps and minimum-lap-time of motorcycles

A three-dimensional quasi-steady-state free-trajectory method based on semi-analytical g-g maps has been recently proposed to simulate the minimum-time manoeuvring of road vehicles. A number of assumptions, such as identical tyre-road friction coefficients on front and rear tyres and negligible aerodynamic cross-flow forces (i.e. downforces and sideforces), were enforced in the case of motorcycles to keep the g-g maps semi-analytical. Such assumptions are lifted in this work and their effect on the g-g maps of single-track vehicles is analysed, together with the consequences on the related minimum-lap-time simulations. The examples of application are carried out on the Mugello circuit and compared with previous findings in the literature. It is found that different friction coefficients on tyres call for different braking strategies to extract the maximum performance of the vehicle (when compared against the case with equal friction coefficients), while aerodynamic downforces can reduce stoppie and wheelie problems, improve acceleration and braking performance and increase the maximum lateral acceleration achievable. However, if the resulting cross-flow force lies on the plane of the bike the maximum lateral performance could be reduced, depending on tyre properties.

Comprehensive Multidisciplinary Electric Vehicle Modeling: Investigating the Effect of Vehicle Design on Energy Consumption and Efficiency

In this study, an electric vehicle (EV) dynamic model is devised that amalgamates mechanical design aspects—such as aerodynamic effects, tire friction, and vehicle frontal area—with crucial components of the electrical infrastructure, including the electric motor, power converters, and battery systems. Verification of the model is executed through a comprehensive multidisciplinary analysis utilizing CATIA, ANSYS Electromagnetics, ANSYS Fluent, and MATLAB–Simulink tools, which are applied to evaluate two alternative lightweight EV prototypes. The process involves initial computations of critical inputs for the dynamic model, including aerodynamic lift (C1), drag coefficients (Cd), and frontal area (Af). Subsequent stages entail the detailed design and analysis of a 2 kW brushless permanent magnet electric motor in ANSYS Electromagnetics to map efficiency contours across various speed–torque values. Integration of these parameters into a MATLAB–Simulink dynamic model, connected with motor drive inverter and battery models, allows for simulation-based energy consumption analysis under race track slope profiles. Remarkably, the findings underscore the considerable impact of neglected parameters on energy consumption, often exceeding fifty percent of the total. Consequently, an energy-efficient EV prototype is manufactured and rigorously tested under specified drive conditions, affirming the validation of the comprehensive multidisciplinary EV dynamic model.

Simulation of the landing situation of an aircraft and the problems of diagnosing anti-skid devices

Safety is ensured, including the safe landing of the aircraft. A short landing run without a skid is achieved by the necessary preparation of the runway, a serviceable braking system, anti-skid automation and take-off and landing devices of the aircraft. Standard operation of anti-skid automatics should be able to cope with constant non-linearity of movement and atmospheric interference on the surface of the runway, as well as adjust the wheel slip coefficient to ensure reliable operation of the braking system. The need to develop technical solutions in the field of expanding the operational capabilities of diagnostic tools for anti-youth automation of the aircraft braking system is determined by regular aviation incidents, related to failures of anti-skid devices, including their incorrect setting before installation on the aircraft landing gear wheel, which leads to serious consequences – increased wear of the wheel tire surface and its possible destruction, including an emergency landing due to loss of control over the aircraft. The purpose of the work is to simulate the youth situation of the aircraft during landing, to study the problem, to increase the efficiency, reliability of the results of diagnosing devices and automata of the aircraft braking system. This article discusses the main external and operational factors affecting the dynamics and nature of the aircraft's run along the runway, the model of aircraft movement with the influence of aerodynamic forces on it, the model of tire friction on the ground, and also proposes a method for diagnosing anti-youth automation of the aircraft braking system.

Real-time integrated path tracking control using input dimensionality-reducing and asynchronous sampling methods

The integrated path tracking control (PTC) of steering and braking is crucial for enhancing the stability of autonomous vehicles under extreme conditions. In the present study, a control input dimensionality-reducing method and an asynchronous sampling method are presented to address the problem of the high computational cost of the steering and braking integrated path tracking controller (PTCer) based on model predictive control (MPC). First, based on tire friction limit and tire force utilization, the control input dimensionality-reducing method is designed and a vehicle model with reduced dimensionality of control input is derived. Second, the rolling iteration mechanism of MPC is analyzed and a variable-scale asynchronous sampling method between the control loop and prediction horizon is designed with the control horizon as the boundary. Finally, the integrated MPC-PTCer based on control input dimensionality-reducing and asynchronous sampling is designed. The real-time performance (RTP), path tracking accuracy, and vehicle stability of the proposed integrated MPC-PTC are tested and evaluated through the simulation and the hardware-in-the-loop platform. The test results of different test conditions show that the proposed integrated MPC-PTC improves the RTP by more than 70% and ensures the path tracking accuracy and lateral stability of autonomous vehicles under extreme conditions.

Path tracking of varying-velocity 4WS autonomous vehicles under tire force friction ellipse constraints

In this paper, a control scheme is presented to solve the problem of path tracking for varying-velocity autonomous vehicles with higher robust performance while friction force constraints of vehicle tires and ground are considered to avoid appearing the steering lost situation actively in the limit of the tire friction forces by using four wheel steering. To achieve these goals, a new expression of the tire forces and a new controlled system are proposed for the three degree of freedom vehicle model. A longitudinal input-saturation controller is designed to track the desired longitudinal velocity and attenuate the influence of lateral and yaw motions. The virtual control input method is used to design the input-saturation controller and get the desired steering angles to track the desired path for the lateral and yaw motions while a new control problem with desired forces tracking is considered to autonomously avoid the limit of lateral tire friction forces and the steering lost situation appearing. To test these results, lane changing, U-corner turning and straight-line driving for a varying-velocity vehicle are simulated with external disturbances and model uncertainties. Simulation results show that the higher robustness and precise path tracking performances are obtained.

Modeling and braking analyses of longitudinal-vertical coupling towbarless aircraft taxiing system

The variation of tire vertical load has effects on the vehicle braking performance, which may lead to the misjudgment of braking distance and increasement of the accident risks. In order to evaluate the braking distance of the towbarless aircraft taxiing system (TLATS) accurately, a longitudinal-vertical coupling model of the TLATS is established, in which the effects of the vertical vibration on braking dynamics is considered. An 11-degrees of freedom (DOF) dynamic model of the TLATS, which consists of the system longitudinal motion, vertical vibration, and an advanced Lugre tire model, is proposed. The tire vertical dynamic loads are obtained by calculating system vibration differential equations as the input for the Lugre tire model, in which an arbitrary pressure distribution function over the contact patch and load related parameters are used. The Lugre tire model parameters are identified based on the virtual experiment results in ADAMS/Car software through a multi-objective optimization (MOO) method. The proposed tire model is more accurate by comparing with the models using other pressure distribution functions. The advanced Lugre model is integrated into the longitudinal-vertical coupling dynamic model of the TLATS, and the fuzzy PID control method is used to achieve the optimal slip rate during the braking procedure. The tire friction and TLATS’s braking performances in terms of the slip rate, braking speed and braking distance are compared between the coupling and uncoupling models under different traction velocities and the road excitations when a same fuzzy control method is used for the system braking. The results show that the proposed longitudinal-vertical coupling TLATS dynamic model could assess the braking behaviors of the TLATS more accurately than the simplified uncoupling model, which could decrease the potential safety risk of the aircraft towing operation on the airport apron.

Direct triboelectricity from friction of wheel tires on pavements

&lt;p&gt;Energy consumption in road and street traffic is significant and increasing. A partial recovery of this energy is the objective of the research briefly presented in the present paper. The proposed technique is totally innovative and has not been investigated, even through laboratory research, anywhere else. It aims to harvest triboelectric energy generated while wheel tires are directly rubbed against a pavement surface where oppositely charged electrodes are properly attached. The laboratory testing device consists of a rotating wheel bearing a vehicle tire, set up adequately to move down to a solid bench where flat bars, rods or tubes, susceptible to being oppositely charged by pairs, are attached. Metals, such as copper, bronze and aluminum, developing high electrical conductivity, were used in most experiments, as electrodes. Triboelectricity tests, under different placement of the electrodes regarding the wheel, were conducted in the laboratory and provided noticeable values of electric potential. Even more promising seem the results obtained following an intermittent application of the wheel load. Further experimentation introducing a much bigger wheel load, a different tire texture and other test improvements are ongoing, aiming at higher values of electric potential.&lt;strong&gt;&lt;em&gt;&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;

Investigations of the city bus powertrain efficiency

Research work on the energy efficiency of vehicles is driven, among other things, by limits related to fuel consumption carbon dioxide emissions. This also applies to city buses, where fuel consumption averages between 25 and 30 dm3 per 100 km, which can be converted into approximately 87 kg CO2 per dm3. This article therefore presents the results of a study of the total efficiency of the power train of a city bus, taking into account the internal combustion engine, transmission, hydrokinetic clutch, and tyre friction on the rollers. The test object was a 12-metre city bus equipped with diesel engines and an automatic gearbox. The tests were carried out on a chassis dynamometer by implementing the World Harmonized Vehicle Cycle (WHVC). The WHVC driving test is a synthesis of the vehicle's on-road speeds and consists of three stages: Urban, Rural and Motorway. During the tests, the fuel consumption, vehicle speed and power generated at the wheels of the bus were recorded. From this, efficiency was calculated as the ratio of the power measured at the wheels of the bus to the power contained in the fuel supplied to the engine. Efficiency was shown to range from 5 to 22%.

A tyre wear modelling approach for vehicle dynamics simulation and control-oriented analyses with application to motorcycles

To increase vehicle dynamics modelling accuracy in simulation environments, in this work, we propose a model, where the mutual influence of the vehicle dynamics and tyre wear is taken into account. In this context, simulation-oriented models aim at representing the main features of the vehicle dynamics, while keeping the complexity low, making them suitable for control-oriented analyses and design. The wear model quantifies tyre wear as a tyre mass loss depending on the tyre-road interaction, derived from the vehicle dynamics and kinematics; then, the outcome of this model is consequently used to update the tyre friction characteristics, by modifying the main parameters of the Pacejka's magic formula. We also discuss the steps required to use the model in two-wheeled vehicles, where the roll dynamics plays an important role in the tyre wear. The main features of the developed model are discussed on a motorcycle, as a simulation case-study.

Data-driven and uncertainty-aware robust airstrip surface estimation

The performances of aircraft braking control systems are strongly influenced by the tire friction force experienced during the braking phase. The availability of an accurate estimate of the current airstrip characteristics is a recognized issue for developing optimized braking control schemes. The study presented in this paper is focused on the robust online estimation of the airstrip characteristics from sensory data usually available on an aircraft. In order to capture the nonlinear dependency of the current best slip on sequential slip-friction measurements acquired during the braking maneuver, multilayer perceptron (MLP) approximators have been proposed. The MLP training is based on a synthetic data set derived from a widely used tire–road friction model. In order to achieve robust predictions, MLP architectures based on the drop-out mechanism have been applied not only in the offline training phase but also during the braking. This allowed to online compute a confidence interval measure for best friction estimate that has been exploited to refine the estimation via Kalman Filtering. Open loop and closed loop simulation studies in 15 representative airstrip scenarios (with multiple surface transitions) have been performed to evaluate the performance of the proposed robust estimation method in terms of estimation error, aircraft braking distance, and time, together with a quantitative comparison with a state-of-the-art benchmark approach.

Improvement of Transfer Wheel Marker Design Using the Quality Function Deployment (QFD) Method for School Field Line Marking

The line marking of sports fieldsis a must-doactivity in every school in Malaysia since most of the schools only have one field that is used for many sports activities. Thereare many concept designs of sport line markingsin the market, but the most common designusedin Malaysia is a transfer wheel marker. However, the machine lacks many aspects, including clogging problems due to the loose grass, soil sticking to the marker wheel,and its unstable tyre, which may cause the line marking processtimebecomes longerand more difficult. Therefore, this study proposes to improve the design of the transfer wheel marker using the Quality Function Deployment (QFD) method. Based on the QFD method, a House of Quality (HoQ) in the first phase wasapplied, where a questionnaire was created using the information obtained from interviews with school teachers to quantify the needs.The collected data was then analyzed in the HoQ to determine the final ranking of engineering characteristics. With a relative weight of 14.45%, the handle height is ranked first as the characteristic that needs improvement. The second rankingorder is the amount of wasted paintat14.08% and the third rankingis tyre friction which is 11.86% relative weight. Hence, the identified three priority components will lead to the improvement of the transfer wheel markerdesign.

Hierarchical control of differential steering for four-in-wheel-motor electric vehicle.

The purpose of this paper is to study the control of differential steering for four-in-wheel-motor electric vehicles. The so-called differential steering means that the front wheel steering is realized through the differential driving torque between the left and right front wheels. With the consideration of tire friction circle, a hierarchical control method is proposed to realize the differential steering and the constant longitudinal speed simultaneously. Firstly, the dynamic models of the front wheel differential steering vehicle, the front wheel differential steering system and the reference vehicle are established. Secondly, the hierarchical controller is designed. The upper controller is to obtain the resultant forces and resultant torque required by the front wheel differential steering vehicle tracking the reference model through the sliding mode controller. In the middle controller, the minimum tire load ratio is selected as the objective function. Combined with the constraints, the resultant forces and resultant torque are decomposed into the longitudinal and lateral forces of four wheels by the quadratic programming method. The lower controller provides the required longitudinal forces and tire sideslip angles for the front wheel differential steering vehicle model through the tire inverse model and the longitudinal force superposition scheme. Simulation results show that the hierarchical controller can guarantee the vehicle to track the reference model well on both of the high and low adhesion coefficient road with all of the tire load ratios smaller than 1. It can be drawn that the control strategy proposed in this paper is effective.

Temperature elevation of aircraft tyre surface at touchdown with pre-rotations

The runway and landing gear speed difference causes non-negligible friction at touchdown, generating vital heat to raise the tyre tread temperature. The resulting material decomposition reduces tread thickness and significantly impacts flight safety and the environment. Airline operators also need to pay the cost of frequent tyre replacement. The pre-rotation strategy has been proposed to prevent high-speed friction at touchdown. Therefore, a mathematical algorithm is established on MATLAB to simulate the tyre friction and heat generation with various pre-rotation levels. The algorithm is validated by experiments, and a transient thermos-mechanical analysis on ANSYS is used as a reference. The presenting work is one of the few that uses theoretical modelling to simulate tyre heat generation. The formulas presented therein, including Laplace's equation, make the results reliable and traceable. It can be seen that the developed algorithm is capable of calculating the tyre temperature. The pre-rotation can efficiently reduce the friction strength at touchdown. However, when the pre-rotation speed is relatively low, a slight increase in maximum tyre temperature may occur, and the specific reasons for this will be in the discussion.

Investigation into high-performance tire characteristics at the limits of handling

This paper presents an investigation into high-performance tire characteristics at handling limits. Analysis of the tire characteristics has been conducted using the data obtained from indoor test rigs and vehicle tests. The test rig utilised a flat track test platform to obtain tire forces with precise controllability and measurability. As for the vehicle tests, driving data of a professional driver was obtained for repeatability through a high-performance test vehicle equipped with a wheel force transducer (WFT) at each wheel and a Differential Global Positioning System (DGPS). This study is primarily focused on obtaining a deeper insight into vehicle control through an analysis of tire force characteristics at handling limits. The analysis of indoor test data utilised the Magic Formula to obtain an appropriate model capable of describing real-world tire characteristics. An optimisation-based friction ellipse has been proposed to describe the tire force limits in particular. The solution of the proposed optimisation problem allows for an envelope to be generated that accurately reflects the tire force limits. Additionally, a normalised friction circle model has been proposed to quantify tire friction usage based on the proposed friction ellipse, providing a methodology to monitor the friction use of each wheel.

Tire Slip H∞ Control for Optimal Braking Depending on Road Condition.

Tire slip control is one of the most critical topics in vehicle dynamics control, being the basis of systems such the Anti-lock Braking System (ABS), Traction Control System (TCS) or Electronic Stability Program (ESP). The highly nonlinear behavior of tire-road contact makes it challenging to design robust controllers able to find a dynamic stable solution in different working conditions. Furthermore, road conditions greatly affect the braking performance of vehicles, being lower on slippery roads than on roads with a high tire friction coefficient. For this reason, by knowing the value of this coefficient, it is possible to change the slip ratio tracking reference of the tires in order to obtain the optimal braking performance. In this paper, an H∞ controller is proposed to deal with the tire slip control problem and maximize the braking forces depending on the road condition. Simulations are carried out in the vehicular dynamics simulator software CarSim. The proposed controller is able to make the tire slip follow a given reference based on the friction coefficient for the different tested road conditions, resulting in a small reference error and good transient response.

Development of a Runaway Vehicle Protective Barrier System Using Simulation and Full-Scale Crash Testing

Effective road safety plays an important role in achieving sustainable development goals worldwide. A large number of accidents occur on roads every year, resulting in countless losses of people, vehicles, and roads; as such, the problem of loss of vehicle control has increasingly attracted the attention of scholars. Different vehicle protective measures, such as increasing the friction of tires or applying energy-absorbing materials, have been applied; however, their application is not yet fully effective. In this paper, a flexible protective barrier system is proposed for the protection of runaway vehicles, which can successfully stop the vehicle and ensure the safety of passengers. At the same time, the system can be recycled, which means that costs can be saved, to a certain extent. Accurate finite element simulation and real vehicle tests are conducted to verify the effectiveness of the protective system. The proposed flexible protection system is found to be effective in intercepting different types of runaway vehicles, while no major damage occurred to the vehicle itself, thus indirectly ensuring the safety of the occupants. The research lays a foundation for subsequent road safety protection and maintenance of sustainable development.

A Comprehensive Vehicle Stability Assessment System Based on Enabling Tire Force Estimation

This paper presents an enabling comprehensive vehicle stability assessment system covering vehicle longitudinal, yaw and roll stability. First, the longitudinal, lateral and vertical tire forces are separately estimated using the strong tracking unscented Kalman filter and the conventional Kalman filter based on low-cost on-board sensors. Then, a comprehensive vehicle longitudinal, yaw and roll stability space is established by utilizing the normalized tire friction ellipse and the Load Transfer Ratio value. Finally, the vehicle stability is determined and predicted based on current driver's inputs. The hardware-in-loop experimental results show that the proposed vehicle stability assessment system can accurately estimate the longitudinal, lateral and vertical tire forces with the normalized root mean square errors of 1.87 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\%$</tex-math></inline-formula> , 1.07 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\%$</tex-math></inline-formula> and 1.43 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\%$</tex-math></inline-formula> , and exhibits satisfying performance for vehicle longitudinal, yaw and roll stability evaluation and prediction. This bears significance for the efficient functioning of active control systems to improve vehicle safety under critical driving conditions.

Rapid Autonomous Vehicle Drifting with Deep Reinforcement Learning

Abstract: Now days all types of vehicles run on road are upgrading to automated self-driving techniques. Drifting is a complicated procedure for autonomous vehicle control which is used for high-speed sideslip cornering. It is difficult to drift a vehicle at a high speed of 80-120 km/hr by using traditional techniques like two-state single-track model and three-state singletrack models, which depend on the knowledge of tire or road forces that are not to be known accurately due to the real-world environmental complexity. Because of these inaccuracies in these parameters there will be poor control performance and may lead to road accidents. In this scenario, this project presents a strong drift control algorithm, which is based on the most recent model-free deep reinforcement learning algorithm called soft actor-critic (SAC). SAC is used to control front-wheel drive (FWD) vehicles to drive at high speed (80– 120 km/h), and to drift through sharp corners quickly and stability which in turn helps to prevent road accidents at the time of drifting. The efficiency of this algorithm is evaluated by conducting experiments on Trajectories dataset taken from Git-Hub repository, which consists of some road maps with reference drift trajectories. The SAC algorithm can also deal with vehicle types with various actual properties, like mass, tyre friction, and so on to show its notable generalization ability.

Research on Direct Braking Force Estimation and Control Strategy Using Tire Inverse Model

With the rapid development of computer control and vehicle intelligence technology, speed and safety of vehicles have been greatly improved, and the requirements for vehicle control performance are getting higher and higher. For the direct braking force control, in the process of deceleration, a fast braking response can be obtained, which improves the braking performance and vehicle safety. This paper concentrates on direct braking force estimation and control strategy using a tire inverse model based on the antilock braking system, and to solve the problem of the existing ABS system is mainly antilock braking function, no direct braking force control function. Taking magic formula model for reference inverse model, the critical parameters under different road surfaces are obtained according to experience data. Then, the desired slip ratio corresponding to braking force can be obtained via fast tire inverse model look-up table method. The tyre friction self-adjustment decision making is obtained using the tire inverse model method. A direct braking force antilock braking system (DBF-ABS) controller is built using the nonsingular fast terminal sliding mode method. The simulation results indicated that the control strategy has adaptability and stability to the change of road conditions.