Normalization of Tire Force and Moment Data

1993 ◽  
Vol 21 (2) ◽  
pp. 91-119 ◽  
Author(s):  
H. S. Radt ◽  
D. A. Glemming
Keyword(s):  
Surface Water ◽  
Lateral Force ◽  
Slip Angle ◽  
Inflation Pressure ◽  
Slip Ratio ◽  
Tire Force ◽  
Camber Angle ◽  
Potential Benefits ◽  
Overturning Moment ◽  
Semi Empirical

Abstract Semi-empirical theories of tire mechanics are employed to determine appropriate means to normalize forces, moments, angles, and slip ratios. Force and moment measurements on a P195/70R 14 tire were normalized to show that data at different loads could then be superimposed, yielding close to one normalized curve. Included are lateral force, self-aligning torque, and overturning moment as a function of slip angle, inclination angle, slip ratio, and combinations. It is shown that, by proper normalization of the data, one need only determine one normalized force function that applies to combinations of slip angle, camber angle, and load or slip angle, slip ratio, and load. Normalized curves are compared for the effects of inflation pressure and surface water thickness. Potential benefits as well as limitations and deficiencies of the approach are presented.

Study on Cornering Properties of Tire and Vehicle

1990 ◽  
Vol 18 (3) ◽  
pp. 136-169 ◽  
Author(s):  
H. Sakai
Keyword(s):  
Load Distribution ◽  
Driving Forces ◽  
Slip Angle ◽  
Inflation Pressure ◽  
Slip Ratio ◽  
Side Force ◽  
Camber Angle ◽  
Tire Wear ◽  
Main Factors ◽  
Tire Friction

Abstract This paper presents theoretical analysis on the cornering properties of tire and vehicle. First, the side force, braking driving forces and self-aligning torque on the tire are shown as functions of slip angle, slip ratio, camber angle and load. Next, the steady cornering properties of the vehicle using these tires are analyzed with the rolling conditions. Slip angle, slip ratio, camber angle and load, and forces and moments of the four tires are calculated. Effects of main factors on the above vehicle properties such as the load distribution, camber/roll ratio, front/rear drive ratio, tire size, tire wear, tire inflation pressure and tire friction are discussed.

Investigation and Comparison of Tires Perfomance on Ice

2017 ◽  
Author(s):  
Andrius Ružinskas ◽  
Henrikas Sivilevicius
Keyword(s):  
Lateral Force ◽  
Operating Conditions ◽  
Slip Angle ◽  
Transmission Measurement ◽  
Force Transmission ◽  
Force Coefficient ◽  
Slip Ratio ◽  
The Road ◽  
Tire Force ◽  
Main Component

The risk of accident increases significantly when tire rolls on ice comparing to the dry surface. The vehicle tire becomes the main component of force transmission to the road and necessity of investigating the tire behavior becomes of high importance. This paper presents results of tire force transmission measurement with two different winter tires at the same operating conditions. Longitudinal and lateral force coefficient characteristics as the functions of slip ratio and slip angle are presented and discussed. The results showed a different lateral and longitudinal performance because of different tread pattern and rubber compound.

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.

Relationship Between Tire Tread Physical Properties and Tire Force and Moment Properties

1989 ◽  
Vol 17 (2) ◽  
pp. 109-125 ◽  
Author(s):  
M. G. Pottinger ◽  
A. M. Fairlie
Keyword(s):  
Physical Properties ◽  
Lateral Force ◽  
Hysteresis Effect ◽  
Design Parameters ◽  
Slip Angle ◽  
Tire Force ◽  
Torque Curve ◽  
Driving Range ◽  
Important Design

Abstract Tire lateral force and aligning torque are the most significant determinants of automotive handling. Tread compound physical properties are important design parameters for determination of tire lateral force and aligning torque behavior. This paper extends the published knowledge of the effects of tread compound physical properties on force and moment to cover the entire range of slip angles encountered in driving. Below 10 degrees slip angle lateral force increases with increasing compound stiffness and hysteresis. At and above 10 degrees slip angle there is a change in the general trend. In this range it appears that an optimal compound stiffness exists and that the hysteresis effect reverses. Aligning torque shows two distinctly different behaviors. One, like that governing lateral force in the general driving range, is valid below the peak of the aligning torque curve. The other, valid above the peak of the aligning torque curve, shows decreasing aligning torque with increasing tread stiffness and no hysteresis effect.

Physical Understanding of Transient Generation of Tire Lateral Force and Aligning Torque

2019 ◽  
Vol 47 (4) ◽  
pp. 308-333 ◽  
Author(s):  
Pavel Sarkisov ◽  
Günther Prokop ◽  
Jan Kubenz ◽  
Sergey Popov
Keyword(s):  
Cross Sections ◽  
Physical Simulation ◽  
Optical Measurement ◽  
Structural Parameters ◽  
Lateral Force ◽  
Slip Angle ◽  
Contact Patch ◽  
Physical Description ◽  
Patch Shape ◽  
Tire Force

ABSTRACT Increasing vehicle performance requirements and virtualization of the development process require more understanding of the physical background of tire behavior, especially in transient rolling conditions with combined slip. The focus of this research is the physical description of the transient generation of tire lateral force and aligning torque. Apart from tire force and torque measurements, two further issues were investigated experimentally. Using acceleration measurement on the tire inner liner, it was observed that the contact patch shape of the rolling tire changes nonlinearly with slip angle and becomes asymmetric. Optical measurement outside and inside the tire has clarified that carcass lateral bending features both shear and rotation angle of its cross sections. A physical simulation model was developed that considers the observed effects. The model was qualitatively validated using not only tire force and torque responses but also deformation of the tire carcass. The model-based analysis explained which tire structural parameters are responsible for which criteria of tire performance. Change in the contact patch shape had a low impact on lateral force and aligning torque. Variation of carcass-bending behavior perceptibly influenced aligning torque generation.

Stabilization of a Steer-by-Wire Vehicle at the Limits of Handling Using Feedback Linearization

2005 ◽  
Author(s):  
Yung-Hsiang (Judy) Hsu ◽  
J. Christian Gerdes
Keyword(s):  
Control System ◽  
Feedback Linearization ◽  
Control Algorithm ◽  
State Feedback ◽  
Threshold Value ◽  
Lateral Force ◽  
Tire Force ◽  
Operating Region ◽  
Steer By Wire ◽  
Potential Benefits

As a vehicle approaches the limits of handling (the operating region defined by the peak lateral tire force), the vehicle response may be oscillatory or unstable. This paper develops a control system to allow the driver to approach the limits of handling safely. The control algorithm uses a new method that applies recent advances in vehicle sensing to estimate tire cornering stiffness and coefficient of friction in real-time. The controller employs state feedback linearization to cancel nonlinearities in the system using steer-by-wire steering inputs. Once the lateral force surpasses a threshold value, the driver steering input is saturated to keep the vehicle in the linearizable handling region and to alert the driver of approaching limits. Simulation results and preliminary experimental work performed on a steer-by-wire research vehicle demonstrate the potential benefits of this control system.

Effect of Tire Wear on Tire Force and Moment Characteristics

2010 ◽  
Vol 38 (1) ◽  
pp. 47-79 ◽  
Author(s):  
D. F. Tandy ◽  
R. J. Pascarella ◽  
J. W. Neal ◽  
J. M. Baldwin ◽  
J. D. Rehkopf
Keyword(s):  
Lateral Force ◽  
Controlled Environment ◽  
Tire Force ◽  
Lateral Forces ◽  
Physical Testing ◽  
Tire Wear ◽  
Overturning Moment ◽  
Load Conditions

Abstract In repeated physical testing of vehicles at or near their handling limit, shoulder wear occurs that is not typical of normal customer use. It has been observed for decades that this type of severe cornering induced tire wear can have a significant effect on the force and moment characteristics of tires. In this study, this shoulder wear effect was isolated by testing tires in a controlled environment and objectively assessed for a number of tires of various brands and sizes. This testing shows how a tire’s lateral force and overturning moment capacities increase significantly as the number of runs on a tire accumulates. Additionally, one particular tire make and model was placed on a vehicle to acquire 1000 miles of normal customer driving and then evaluated under the same simulated load conditions. The results confirmed that, irrespective of a tire break-in procedure, the increases in lateral forces of the tire in repeated limit handling maneuvers were a product of the test induced atypical shoulder wear generated during the limit handling maneuver.

Measurement of Uncoupled Lateral Carcass Deflections With a Wireless Piezoelectric Sensor and Estimation of Tire Road Friction Coefficient

2010 ◽  
Author(s):  
Gurkan Erdogan ◽  
Lee Alexander ◽  
Rajesh Rajamani
Keyword(s):  
Friction Coefficient ◽  
Leading Edge ◽  
Piezoelectric Sensor ◽  
Lateral Force ◽  
Slip Angle ◽  
Contact Patch ◽  
Tire Force ◽  
Coefficient Estimation ◽  
Road Friction ◽  
Road Friction Coefficient

A new tire-road friction coefficient estimation approach based on lateral carcass deflection measurements is proposed. The unique design of the developed wireless piezoelectric sensor decouples lateral carcass deformations from radial and tangential carcass deformations. The estimation of the tire-road friction coefficient depends on the estimation of the slip angle and the lateral tire force. The tire slip angle is estimated as the slope of the lateral deflection curve at the leading edge of the contact patch. The lateral tire force is obtained by using a parabolic relationship with the lateral deflections in the contact patch. The estimated slip angle and lateral force are then plugged into a tire brush model to estimate the tire-road friction coefficient. A specially constructed tire test-rig is used to experimentally evaluate the performance of the tire sensor and the developed approach. Experimental results show that the proposed tire-road friction coefficient estimation approach is quite promising.

State Estimation of a Robotic Vehicle With Six In-Wheel Drives Using Kalman Filter

2020 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Se-Woong Oh ◽  
Youngshik Kim
Keyword(s):  
Kalman Filter ◽  
Dynamic Model ◽  
Angular Acceleration ◽  
Estimation Algorithm ◽  
Slip Angle ◽  
Test Environment ◽  
Slip Ratio ◽  
Tire Force ◽  
Robotic Vehicle ◽  
Tire Forces

Abstract This paper describes an estimation algorithm for a robotic vehicle with articulated suspension (RVAS) to estimate the vehicle velocity and acceleration states, and the tire forces. The RVAS is an unmanned ground vehicle based on a skid steering using an independent in-wheel motor at each wheel. The estimation algorithm consists of five parts. In the first part, a wheel state estimator estimates the wheel rotational speed and its angular acceleration using Kalman filter, which is used to estimate the longitudinal tire force distribution in the second part. The third part is to estimate respective longitudinal, lateral, and vertical speeds of the vehicle and wheels. Based on these speeds, the slip ratio and slip angle are estimated in the fourth part. In the fifth part, the vertical tire force is then estimated. For a simulation test environment, the RVAS dynamic model is developed using Matlab and Simulink. The RVAS model consists of five main parts which include in-wheel motor model, wheel dynamic model, Fiala tire model, arm dynamic model, and the sprung mass dynamic model. The estimation algorithm is then validated using the vehicle test data and different test scenarios. It is found from simulation results that the proposed estimation algorithm can estimate the vehicle states, longitudinal tire forces, and vertical tire forces efficiently.

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.

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