Integrated estimation of vehicle states, tire forces, and tire-road friction coefficients

Road friction coefficients are highly effective for advanced vehicle control technologies, although the estimation at four individual tires has not been practically used for ordinary vehicles. This study describes the essential relation between the tire forces and the aligning torque that can be rearranged as an estimation equation for the grip margin. The grip margin is readily convertible into the friction coefficient. The brush model is reanalyzed, beginning from the conventional simple physical model, and intrinsic expressions are derived. The grip margin, which is defined as the residual tire force normalized by the radius of friction circle, was estimated using three components of the tire forces and the aligning torque. A simple cubic equation is obtained as a grip margin equation for an isotropic brush model. Previous studies assumed an anisotropic brush model and obtained an imperfect quintic equation. In the present study, a new term is added to the algebraic equation, which was shown to be consistent with the isotropic model. The solutions to the equations are approximated by Chebyshev polynomials. The estimation methods are tested by numerical simulations using CarSim, which is a popular vehicle simulation software application. The estimated friction coefficients agree well with the values that are set during each run of the simulations, especially for the cases of smaller grip margins and lower friction conditions.

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A Modified Dugoff Tire Model for Combined-slip Forces

Tire Science and Technology ◽

10.2346/1.3481696 ◽

2010 ◽

Vol 38 (3) ◽

pp. 228-244 ◽

Cited By ~ 19

Author(s):

Nenggen Ding ◽

Saied Taheri

Keyword(s):

Vehicle Dynamics ◽

Tire Model ◽

Magic Formula ◽

Model Based ◽

Proposed Model ◽

Road Friction ◽

On Line ◽

Double Lane Change ◽

Tire Forces ◽

Tire Models

Abstract Easy-to-use tire models for vehicle dynamics have been persistently studied for such applications as control design and model-based on-line estimation. This paper proposes a modified combined-slip tire model based on Dugoff tire. The proposed model takes emphasis on less time consumption for calculation and uses a minimum set of parameters to express tire forces. Modification of Dugoff tire model is made on two aspects: one is taking different tire/road friction coefficients for different magnitudes of slip and the other is employing the concept of friction ellipse. The proposed model is evaluated by comparison with the LuGre tire model. Although there are some discrepancies between the two models, the proposed combined-slip model is generally acceptable due to its simplicity and easiness to use. Extracting parameters from the coefficients of a Magic Formula tire model based on measured tire data, the proposed model is further evaluated by conducting a double lane change maneuver, and simulation results show that the trajectory using the proposed tire model is closer to that using the Magic Formula tire model than Dugoff tire model.

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Tire Friction on Wet Roads

Rubber Chemistry and Technology ◽

10.5254/1.3534982 ◽

1976 ◽

Vol 49 (3) ◽

pp. 862-908 ◽

Cited By ~ 16

Author(s):

K. A. Grosch ◽

A. Schallamach

Keyword(s):

Hydrodynamic Lubrication ◽

Vehicle Control ◽

Critical Conditions ◽

Frictional Properties ◽

Road Surfaces ◽

Road Friction ◽

Tire Forces ◽

The One ◽

Tire Friction ◽

Contact Pressures

Abstract Evidence accumulates that tire forces on wet roads, particularly when the wheel is locked, are determined by the dry frictional properties of the rubber on the one hand and by hydrodynamic lubrication in the contact area on the other. The probable reason why they are so clearly separable is that water is a poor lubricant, tending to separate into globules and dry areas under relatively small pressures. Road surfaces and tire profiles are, therefore, designed to create easy drainage and high local contact pressures. The influence of road friction on vehicle control well below the critical conditions is becoming more clearly understood; but more Investigations are required here, in particular under dynamic conditions.

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Estimation of Nonlinear Tire Forces and Road Friction for Modeling and Control

IFAC Proceedings Volumes ◽

10.1016/s1474-6670(17)42171-9 ◽

1998 ◽

Vol 31 (1) ◽

pp. 17-22

Author(s):

Laura R. Ray

Keyword(s):

Modeling And Control ◽

Road Friction ◽

Tire Forces ◽

And Control

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Study on Road Friction Database for Automated Driving - Fundamental Consideration of Measuring Device for Road Friction Database -

10.20944/preprints202111.0268.v1 ◽

2021 ◽

Author(s):

Tetsunori Haraguchi ◽

Ichiro Kageyama ◽

Yukiyo Kuriyagawa ◽

Tetsuya Kaneko ◽

Motohiro Asai ◽

...

Keyword(s):

Friction Coefficient ◽

Traffic Safety ◽

Surface Condition ◽

Automated Driving ◽

Friction Coefficients ◽

Measuring Device ◽

The Road ◽

Road Friction ◽

Road Friction Coefficient ◽

Fundamental Consideration

This research deals with the possibility for construction of the database on the braking friction coefficient for actual roads from the viewpoint of traffic safety especially for automated driving such as level 4 or higher. In an automated driving such levels, the controller needs to control the vehicle, but the road surface condition, especially the road friction coefficient on wet roads, snowy or icy roads, changes greatly, and in some cases, changes by almost one order. Therefore, it is necessary for the controller to constantly collect environment information such as the road friction coefficients and prepare for emergencies such as obstacle avoidance. However, at present, the measurement of the road friction coefficients is not systemically performed, and a method for accurately measuring has not been established. In order to improve this situation, this study examines a method for continuously measurement for the road friction characteristics such as μ-s characteristics.

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Adaptive Vehicle Stability Control With Optimal Tire Force Allocation

Volume 11: Transportation Systems ◽

10.1115/imece2012-87560 ◽

2012 ◽

Author(s):

Mustafa Ali Arat ◽

Kanwar Bharat Singh ◽

Saied Taheri

Keyword(s):

Stability Control ◽

Crash Risk ◽

Slip Angle ◽

Vehicle Stability ◽

Successful Implementation ◽

Tire Force ◽

Vehicle Stability Control ◽

Saturation Region ◽

Road Friction ◽

Tire Forces

Vehicle stability control systems have been receiving increasing attention, especially over the past decade, owing to the advances in on-board electronics that enables successful implementation of complex algorithms. Another major reason for their increasing popularity lies in their effectiveness. Considering the studies that expose supporting results for reducing crash risk or fatality, organizations such as E.U. and NHTSA are taking steps to mandate the use of such safety systems on vehicles. The current technology has advanced in many aspects, and undoubtedly has improved vehicle stability as mentioned above; however there are still many areas of potential improvements. Especially being able to utilize information about tire-vehicle states (tire forces, tire-slip angle, and tire-road friction) would be significant due to the key role tires play in providing directional stability and control. This paper presents an adaptive vehicle stability controller that makes use of tire force and slip-angle information from an online tire monitoring system. Solving the optimality problem for the tire force allocation ensures that the control system does not push the tires into the saturation region where neither the driver nor the controller commands are implemented properly. The proposed control algorithm is implemented using MATLAB/CarSim® software packages. The performance of the system is evaluated under an evasive double lane change maneuver on high and low friction surfaces. The results indicate that the system can successfully stabilize the vehicle as well as adapting to the changes in surface conditions.

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Determination of Tire-Road Friction Coefficients for Skid Mark Analysis

Tire Science and Technology ◽

10.2346/1.2150987 ◽

1985 ◽

Vol 13 (1) ◽

pp. 41-64

Author(s):

W. R. Garrott ◽

D. A. Guenther

Keyword(s):

Experimental Study ◽

Coefficient Of Friction ◽

Friction Coefficients ◽

Pickup Truck ◽

The Road ◽

Heavy Trucks ◽

Road Friction ◽

Brake Application ◽

The Coefficient Of Friction

Abstract An experimental study was made to compare the validities of methods currently used by accident reconstructionists to determine the coefficient of friction between the road and the vehicle tires at the time of an incident. This value could then be used in conjunction with skid mark length and vehicle weight to calculate the prebraking speed of the vehicle. Three automobiles and three trucks with a variety of tires and loadings were used on a variety of pavements. The accuracy and area of applicability of each of four methods for obtaining friction coefficients were determined by relating the prebraking speed calculated from each to the actual speed at the time of brake application. All four methods were satisfactory for automobiles and the pickup truck used, but only two were acceptable for heavy trucks. The most valid coefficients are obtained from skid mark lengths obtained under conditions duplicating those in an incident.

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Wireless Piezoelectric Sensor for the Measurement of Tire Deformations and the Estimation of Slip Angle

ASME 2009 Dynamic Systems and Control Conference, Volume 1 ◽

10.1115/dscc2009-2627 ◽

2009 ◽

Cited By ~ 1

Author(s):

Gurkan Erdogan ◽

Lee Alexander ◽

Rajesh Rajamani

Keyword(s):

Friction Coefficient ◽

Piezoelectric Sensor ◽

Slip Angle ◽

Lateral Deformation ◽

Test Rig ◽

Slip Ratio ◽

Lateral Deflection ◽

Road Friction ◽

Tire Forces ◽

Road Friction Coefficient

This paper introduces a wireless piezoelectric tire sensor whose readings can be utilized for the estimation of various tire variables such as slip angle, slip ratio, tire forces and tire road friction coefficient. In this paper, the proposed sensor is demonstrated for the estimation of tire slip angle. Lateral deformation of the tire is decoupled from radial and longitudinal tire deformations using a special sensor design. The decoupled lateral deflection profile of the tire is employed to estimate the slip angle. A new tire test rig is constructed to experimentally evaluate the performance of the developed sensor. Results show that the tire sensor can accurately estimate slip angles up to values of 5.0 degrees.

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