The Effect of Longitudinal Force on Bias and Radial Tires

1976 ◽  
Vol 4 (3) ◽  
pp. 155-168
Author(s):  
B. D. A. Phillips
Keyword(s):  
Driving Force ◽  
Lateral Force ◽  
Longitudinal Force ◽  
Radial Tire ◽  
Pressure Distributions ◽  
Braking Force ◽  
Force Characteristics

Abstract Tests were carried out to compare the effect of longitudinal force on the lateral force and aligning moment produced by a bias and a radial tire for different slip angles. Small differences occurred in the lateral force-driving force characteristics at low slip angles. Large differences occurred between the aligning moment-longitudinal force characteristics of the two tires, when the bias but not the radial tire exhibited a negative aligning moment upon the application of a braking force. These differences were caused mainly by differences in the pressure distributions in the contact patches of the two tires.

Study Ramp Steering Dynamics Problem of Small Tracked Vehicle

2012 ◽  
Vol 630 ◽  
pp. 249-252
Author(s):  
An Cheng Chen ◽  
Xi Hui Mu ◽  
Feng Po Du
Keyword(s):  
Lateral Force ◽  
Longitudinal Force ◽  
Practical Significance ◽  
Force Analysis ◽  
Tracked Vehicle ◽  
Matching Problems ◽  
Power Matching ◽  
Dynamical Characteristics ◽  
Braking Force ◽  
The Mathematical Model

The necessity and importance of studying the dynamical characteristics of ramp steering was described. After the force analysis of ramping going up, down and along the slope, Especially don‘t ignored unchanged load distribution that was caused by the longitudinal force and lateral force, Establish the mathematical model of traction and braking force. Through the simulation experiment, the result showed that the traction and braking force changed with definite rules when the tracked vehicle turned on the slope, which has practical significance for the further study of the vehicle’s power matching problems.

Computer Modeling of a Tire under Cornering Loads

1989 ◽  
Vol 17 (2) ◽  
pp. 86-99 ◽  
Author(s):  
I. Gardner ◽  
M. Theves
Keyword(s):  
Finite Element Analysis ◽  
Geometric Approach ◽  
Lateral Force ◽  
Slip Angle ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Slip Effects ◽  
Improved Accuracy ◽  
Nonlinear Geometric ◽  
Good Agreement

Abstract During a cornering maneuver by a vehicle, high forces are exerted on the tire's footprint and in the contact zone between the tire and the rim. To optimize the design of these components, a method is presented whereby the forces at the tire-rim interface and between the tire and roadway may be predicted using finite element analysis. The cornering tire is modeled quasi-statically using a nonlinear geometric approach, with a lateral force and a slip angle applied to the spindle of the wheel to simulate the cornering loads. These values were obtained experimentally from a force and moment machine. This procedure avoids the need for a costly dynamic analysis. Good agreement was obtained with experimental results for self-aligning torque, giving confidence in the results obtained in the tire footprint and at the rim. The model allows prediction of the geometry and of the pressure distributions in the footprint, since friction and slip effects in this area were considered. The model lends itself to further refinement for improved accuracy and additional applications.

scholarly journals Pavement State Recognition Method Considering Slope

2021 ◽  
Vol 2113 (1) ◽  
pp. 012080
Author(s):  
Xiuhao Xi ◽  
Jun Xiao ◽  
Qiang Zhang ◽  
Yanchao Wang
Keyword(s):  
Surface Condition ◽  
Lateral Force ◽  
Longitudinal Force ◽  
Operating Conditions ◽  
Road Surface ◽  
Tire Model ◽  
State Recognition ◽  
Adhesion Coefficient ◽  
The Road ◽  
Real Time Tracking

Abstract For the problem of road surface condition recognition, this paper proposes a real-time tracking method to estimate road surface slope and adhesion coefficient. Based on the fusion of dynamics and kinematics, the current road slope of the vehicle which correct vertical load is estimated. The effect of the noise from dynamic and kinematic methods on the estimation results is removed by designing a filter. The normalized longitudinal force and lateral force are calculated by Dugoff tire model, and the Jacobian matrix of the vector function of the process equation is obtained by combining the relevant theory of EKF algorithm. The road adhesion coefficient is estimated finally. The effectiveness of the algorithm is demonstrated by analyzing the results under different operating conditions, such as docking road and bisectional road, using a joint simulation of Matlab/Simulink and Carsim.

scholarly journals Adhesion state estimation based on improved tire brush model

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774770
Author(s):  
Bei Shaoyi ◽  
Li Bo ◽  
Zhu Yanyan
Keyword(s):  
Lateral Force ◽  
Longitudinal Force ◽  
Lateral Acceleration ◽  
Stable Range ◽  
The Road ◽  
Nonlinear Compensation ◽  
The Stability ◽  
Standard Calculation ◽  
Double Nonlinear ◽  
Brush Model

On the basis of calculating the longitudinal force using the original brush model, we simplify the tire structure and consider the lateral force generated by the lateral elasticity of the tread. At the same time, the boundary conditions between the adhesion area and the slip zone in the contact area of the tire are fully discussed. By establishing an improved tire brush model, the error caused by neglecting the sideslip characteristics is avoided, and the adaptability of the tire model is improved. A double nonlinear compensation method based on the lateral acceleration deviation and the yaw rate deviation is employed to estimate the road adhesion coefficient, which is closer to the actual attachment situation than the standard calculation. Based on this model, the vehicle stability coefficient k is defined and calculated to describe the stability of the vehicle during the driving process. The modeling results show that the value of k is always in the stable range of [0, 1]. Therefore, the vehicle that utilizes the improved tire brush model is always within the controllable range in the driving process, which verifies the effectiveness of the model.

RANS-BASED CFD PREDICTION OF THE HYDRODYNAMIC COEFFICIENTS OF DARPA SUBOFF GEOMETRY IN STRAIGHT-LINE AND ROTATING ARM MANOEUVRES

2021 ◽  
Vol 157 (A1) ◽  
Author(s):  
Z Q Leong ◽  
D Ranmuthugala ◽  
I Penesis ◽  
H D Nguyen
Keyword(s):  
Computational Cost ◽  
Turbulence Models ◽  
Lateral Force ◽  
Longitudinal Force ◽  
Independent Effect ◽  
Analysis Tool ◽  
Hydrodynamic Coefficients ◽  
Cfd Simulations ◽  
Fine Mesh ◽  
Straight Line

Computational Fluid Dynamics (CFD) simulations using Reynolds Averaged Navier-Stokes (RANS) equations are increasingly adopted as an analysis tool to predict the hydrodynamic coefficients of underwater vehicles. These simulations have shown to offer both a high degree of accuracy comparable to experimental methods and a greatly reduced computational cost compared to Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS). However, one of the major challenges faced with CFD simulations is that the results can vary greatly depending on the numerical model settings. This paper uses the DARPA SUBOFF hull form undergoing straight-line and rotating arm manoeuvres at different drift angles to analyse the hydrodynamic forces and moments on the vehicle against experimental data, showing that the selection of the boundary conditions and turbulence models, and the quality of the mesh model can have a considerable and independent effect on the computational results. Comparison between the Baseline Reynolds Stress Model (BSLRSM) and Shear Stress Transport with Curvature Correction (SSTCC) were carried out for both manoeuvres, showing that with a sufficiently fine mesh, appropriate mesh treatment, and simulation conditions matching the experiments; the BSLRSM predictions offer good agreement with experimental measurements, while the SSTCC predictions are agreeable with the longitudinal force but fall outside the experimental uncertainty for both the lateral force and yawing moment.

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.

Physics of the Slipping Wheel. I. Force and Torque Calculations for Various Pressure Distributions

1969 ◽  
Vol 42 (4) ◽  
pp. 1014-1027 ◽  
Author(s):  
D. I. Livingston ◽  
J. E. Brown
Keyword(s):  
Pressure Distribution ◽  
Lateral Force ◽  
Slip Angle ◽  
Uniform Pressure ◽  
Elliptical Distribution ◽  
Side Force ◽  
Contact Patch ◽  
Pressure Distributions ◽  
Parabolic Distribution

Abstract Slipping wheel theory has been extended to predict the dependence of the lateral force and of the aligning torque on the nature of the pressure distribution over the contact patch between the wheel and the ground. Expressions have been derived for both side force and aligning torque as functions of the slip angle under: uniform pressure distribution, which applies to the behavior of an inflated membrane wheel; elliptical distribution, which describes the behavior of a solid wheel; and parabolic distribution. All appear appropriate in some respect to the actual tire.

Evaluation of Tire and Suspension Characteristics With 6-DOF Motion Platform

2007 ◽  
Author(s):  
Taichi Shiiba ◽  
Koichiro Yamato ◽  
Kensuke Kobayashi ◽  
Tsuyoshi Okada ◽  
Keisuke Morita
Keyword(s):  
Testing Machine ◽  
Load Condition ◽  
Vertical Displacement ◽  
Lateral Force ◽  
Individual Characteristics ◽  
Suspension System ◽  
Motion Platform ◽  
Tire Force ◽  
The Individual ◽  
Force Characteristics

An accurate description of the tire characteristics is very important for vehicle dynamic analysis. However, the characteristics of a tire are very complex, and it is not easy to develop the analytical model of tire force. It is also well known that the actual tire force is greatly affected by the suspension properties. The geometry of suspension arms determines the wheel alignment specifications such as toe and camber angle, and the stiffness and damping characteristics of suspension elements influences the vertical load of each wheel. In order to investigate the suspension properties upon the tire force characteristics, the authors have developed an original tire and suspension testing machine with 6-DOF motion platform. This system is equipped with a tire, a suspension system of a passenger car, a roller conveyer, and a 6-DOF motion platform. The developed system can evaluate the relationship between the suspension system and the tire, whereas the conventional tire testing machine measures the individual characteristics of a tire. In this paper, we report some test results with developed testing system. First, the lateral force characteristics of a tire in steady-state cornering condition were evaluated with this system, and the compliance steer characteristics of a suspension caused by the lateral force were also investigated at the same time. Next, the tire force characteristics were evaluated under the varying load condition. The random vertical displacement generated by the 6-DOF motion platform was applied to the tire, and the vertical and lateral force were observed. It was shown that the developed system can realize the evaluation of tire and suspension characteristics under various conditions.

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