Vehicle and Course Characterization Process for Indoor Tire Wear Simulation

2002 ◽  
Vol 30 (2) ◽  
pp. 100-121 ◽  
Author(s):  
D. O. Stalnaker ◽  
J. L. Turner
Keyword(s):  
Dynamic Load ◽  
Load Transfer ◽  
Longitudinal Velocity ◽  
Test Facility ◽  
Wear Rates ◽  
Tire Force ◽  
Tire Wear ◽  
Inclination Angles ◽  
Transfer Behavior ◽  
Tire Forces

Abstract An empirical methodology is described for separately characterizing vehicles and road courses for subsequent combination to predict tire force histories in tire use or testing. By building a library of vehicle and wear course characterizations, indoor wear test simulations can be selectively constructed by using any combination of “virtual” test vehicles and wear courses. A reliable transient record of vertical, lateral and fore-aft forces and inclination angles can be generated and supplied to drive the indoor wear tire loading fixture. Vehicle characterization involves mapping the basic dynamic load transfer behavior over a range of acceleration, deceleration and cornering maneuvers. A unique indoor vehicle test facility is described for efficiently capturing the tire forces and inclination angles during various maneuvers. All four tire positions can be characterized. Vehicle center of gravity (CG) accelerations and speeds are also recorded during indoor testing. An alternative to experimental measurements is the use of a vehicle computer model for mapping the basic dynamic load transfer behavior. Empirical equations relating vehicle kinematics to tire forces and inclination angles have been developed and are presented. A method of utilizing these equations together with outdoor wear course measurements for predicting transient tire force histories is presented. The method is demonstrated and validated with several vehicle case studies. The tire force component of a wear course can be characterized by measurement of a few parameters: the vehicle CG accelerations and the longitudinal velocity. Course characterization is illustrated using the Department of Transportation's Uniform Tire Quality Grading wear course in the San Angelo, TX area. The full 650 km course was characterized and combined with the laboratory characterization of a 1997 Pontiac Grand Am. Four 650 km drive files were created, one for each tire position, for an indoor wear machine. These consisted of five time-based parameters: radial load, lateral force, wheel torque (acceleration, deceleration forces), inclination angle, and velocity. By sequencing a tire through these four drive files, it was “rotated” as it would have been on the actual vehicle. Examples of tire wear rates and irregular wear are shown for a number of tire constructions, comparing the indoor to the outdoor results. Good correlation was achieved. This simulation technique permits the tire force spectrum of quite complex and lengthy routes to be accurately reproduced in the precisely controlled environment of the laboratory. Each cornering maneuver, each braking and acceleration event, every hill and town can be reproduced in real-time. Only by combining the specific vehicle dynamics of a given vehicle with that of a specific wear route can tire wear be accurately simulated. This tire-vehicle system simulation methodology is referred to as a TS-Sim model.

Influence of Truck Acceleration on Dynamic Load Transfer to Pavement

2019 ◽  
Author(s):  
Donia Savio ◽  
K. Kavinmathi ◽  
J. Murali Krishnan ◽  
Shankar C. Subramanian
Keyword(s):  
Dynamic Load ◽  
Load Transfer

Simultaneous Optimal Distribution of Lateral and Longitudinal Tire Forces for the Model Following Control

2004 ◽  
Vol 126 (4) ◽  
pp. 753-763 ◽  
Author(s):  
Ossama Mokhiamar ◽  
Masato Abe
Keyword(s):  
Lateral Force ◽  
Longitudinal Force ◽  
Equality Constraints ◽  
Steering Wheel ◽  
Slip Angle ◽  
Force Distribution ◽  
Distribution Method ◽  
Tire Force ◽  
Model Following Control ◽  
Tire Forces

This paper presents a proposed optimum tire force distribution method in order to optimize tire usage and find out how the tires should share longitudinal and lateral forces to achieve a target vehicle response under the assumption that all four wheels can be independently steered, driven, and braked. The inputs to the optimization process are the driver’s commands (steering wheel angle, accelerator pedal pressure, and foot brake pressure), while the outputs are lateral and longitudinal forces on all four wheels. Lateral and longitudinal tire forces cannot be chosen arbitrarily, they have to satisfy certain specified equality constraints. The equality constraints are related to the required total longitudinal force, total lateral force, and total yaw moment. The total lateral force and total moment required are introduced using the model responses of side-slip angle and yaw rate while the total longitudinal force is computed according to driver’s command (traction or braking). A computer simulation of a closed-loop driver-vehicle system subjected to evasive lane change with braking is used to prove the significant effects of the proposed optimal tire force distribution method on improving the limit handling performance. The robustness of the vehicle motion with the proposed control against the coefficient of friction variation as well as the effect of steering wheel angle amplitude is discussed.

Stability Regions of Vehicle Lateral Dynamics: Estimation and Analysis

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Yiwen Huang ◽  
Wei Liang ◽  
Yan Chen
Keyword(s):  
Load Transfer ◽  
Equilibrium Points ◽  
Longitudinal Velocity ◽  
Linearization Method ◽  
Stability Control ◽  
Stable Operation ◽  
Lateral Stability ◽  
Ground Vehicles ◽  
Stability Regions ◽  
Road Friction

Abstract A new method is proposed to estimate and analyze the vehicle lateral stability region, which provides a direct and intuitive demonstration for the safety and stability control of ground vehicles. Based on a four-wheel vehicle model and a nonlinear two-dimensional (2D) analytical LuGre tire model, a local linearization method is applied to estimate the vehicle lateral stability regions by analyzing the vehicle stability at each operation point on a phase plane, which includes but not limited to the equilibrium points. As the collections of all the locally stable operation points, the estimated stability regions are conservative because both vehicle and tire stability are simultaneously considered, which are especially important for characterizing the stability features of highly/fully automated ground vehicles (AGV). The obtained lateral stability regions can be well explained by the vehicle characteristics of oversteering and understeering in the context of vehicle handling stability. The impacts of vehicle lateral load transfer, longitudinal velocity, tire-road friction coefficient, and steering angle on the estimated stability regions are presented and discussed. To validate the correctness of the estimated stability regions, a case study by matlab/simulink and CarSim® co-simulation is presented and discussed.

Tire Characteristics Estimation Method Independent of Road Surface Conditions

2018 ◽  
Vol 30 (1) ◽  
pp. 138-144 ◽  
Author(s):  
Yuuki Shiozawa ◽  
◽  
Hiroshi Mouri
Keyword(s):  
Estimation Method ◽  
Surface Friction ◽  
Road Surface ◽  
Force Estimation ◽  
Tire Force ◽  
Significant Difference ◽  
Vehicle Motion ◽  
Tire Force Estimation ◽  
Tire Forces ◽  
Force Characteristics

To control vehicle behavior, it is essential to estimate tire force accurately at all times. However, it is currently difficult to detect tire performance degradation before the deterioration of vehicle dynamics in real time because tire force estimation is usually conducted by comparing the observed vehicle motion with the onboard vehicle-model motion baseline reference. Such conventional estimators do not perform well if there is a significant difference between the vehicle and the model behavior. The lack of technology to easily predict tire forces and road surface friction is concerning. In this paper, a new tire state estimation method based on tire force characteristics is proposed.

H∞ control of anti-rollover strategy based on predictive vertical tire force

2017 ◽  
Vol 40 (13) ◽  
pp. 3587-3603 ◽  
Author(s):  
Wanzhong Zhao ◽  
Lin Ji ◽  
Chunyan Wang
Keyword(s):  
Control System ◽  
Traffic Safety ◽  
Transfer Rate ◽  
Load Transfer ◽  
Strong Stability ◽  
Rear Wheel ◽  
Evaluation Index ◽  
Highway Traffic ◽  
National Highway Traffic Safety ◽  
Tire Force

The mainstream rollover evaluation index, lateral load transfer rate (LTR), is commonly used in the rollover control field. However, it is not instant enough to reflect the rollover tendency since it can only reflect the load transfer rate of one side wheels while single rear wheel leaves the ground first during rollover happens. In order to monitor the rollover tendency more instantly and improve the reliability of anti-rollover control system, a new evaluation index called predictive vertical tire force (PVTF) is proposed, which is based on the single vertical tire force and merges both iterative prediction and derivative prediction methods. Meanwhile, an optimization is taken to solve the contradiction between prediction time and deviation. Secondly, using the PVTF as the measurement output, an anti-rollover control system based on active steering is established in this paper. In order to achieve the desired tracking effect and anti-jamming capability, a two-way H∞ controller is adopted in the anti-rollover control system. Lastly, the simulation results of J-turn condition and NHTSA (national highway traffic safety administration) condition are conducted and the results indicate that the anti-rollover control system has strong stability and robustness. Meanwhile, benefit from the pre-warning function of PVTF, the controller is triggered earlier and the vertical tire forces of four wheels are controlled to be positive all the time, which is beneficial for handling stability.

Tire Wear at Controlled Slip

1962 ◽  
Vol 35 (5) ◽  
pp. 1342-1359 ◽  
Author(s):  
K. A. Grosch ◽  
A. Schallamach
Keyword(s):  
Mechanical Properties ◽  
Abrasion Resistance ◽  
Effect Of Temperature ◽  
Slip Angle ◽  
Wear Rates ◽  
Relative Wear ◽  
Tire Wear ◽  
Order Of Magnitude ◽  
The Absolute

Abstract Tire wear at controlled slip, as realized by setting the wheels of a trailer at a slip angle, obeys the theoretically predicted square law dependence on the slip angle if allowance is made for the effect of temperature and abrasion patterns on the abrasion resistance of the tread compound. The temperature of the tire surface and the intensity of the abrasion patterns increase with increasing slip angle; the severity dependence of the relative wear rating of any two types of tire is largely due to differences in temperature and abrasion pattern coefficients. This applies also to wear on wet roads. The order of magnitude of the absolute wear rates agrees well with the values calculated from the abrasion resistance of tread compounds and the mechanical properties of the tire.

Load Transfer Behavior of Rock‐Socketed Piles

1989 ◽  
Vol 115 (6) ◽  
pp. 755-768 ◽  
Author(s):  
R. Radhakrishnan ◽  
Chun F. Leung
Keyword(s):  
Load Transfer ◽  
Transfer Behavior

Dynamic analysis of laterally loaded pile groups in sand and clay

2002 ◽  
Vol 39 (6) ◽  
pp. 1358-1383 ◽  
Author(s):  
Yasser E Mostafa ◽  
M Hesham El Naggar
Keyword(s):  
Dynamic Loading ◽  
Dynamic Load ◽  
Load Transfer ◽  
Pile Group ◽  
Nonlinear Behaviour ◽  
Single Pile ◽  
Offshore Platforms ◽  
Group Effect ◽  
Pile Groups ◽  
Pile Head

Pile foundations supporting bridge piers, offshore platforms, and marine structures are required to resist not only static loading but also lateral dynamic loading. The static p–y curves are widely used to relate pile deflections to nonlinear soil reactions. The p-multiplier concept is used to account for the group effect by relating the load transfer curves of a pile in a group to the load transfer curves of a single pile. Some studies have examined the validity of the p-multiplier concept for the static and cyclic loading cases. However, the concept of the p-multiplier has not yet been considered for the dynamic loading case, and hence it is undertaken in the current study. An analysis of the dynamic lateral response of pile groups is described. The proposed analysis incorporates the static p–y curve approach and the plane strain assumptions to represent the soil reactions within the framework of a Winkler model. The model accounts for the nonlinear behaviour of the soil, the energy dissipation through the soil, and the pile group effect. The model was validated by analyzing the response of pile groups subjected to lateral Statnamic loading and comparing the results with field measured values. An intensive parametric study was performed employing the proposed analysis, and the results were used to establish dynamic soil reactions for single piles and pile groups for different types of sand and clay under harmonic loading with varying frequencies applied at the pile head. "Dynamic" p-multipliers were established to relate the dynamic load transfer curves of a pile in a group to the dynamic load transfer curves for a single pile. The dynamic p-multipliers were found to vary with the spacing between piles, soil type, peak amplitude of loading, and the angle between the line connecting any two piles and the direction of loading. The study indicated the effect of pile material and geometry, pile installation method, and pile head conditions on the p-multipliers. The calculated p-multipliers compared well with p-multipliers back-calculated from full scale field tests.Key words: lateral, transient loading, nonlinear, pile–soil–pile interaction, p–y curves, Statnamic.

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