Rolling Radius Of Tire Research Articles

High-speed 3D digital image correlation for measuring tire rolling resistance coefficient

A novel method is proposed to measure rolling resistance coefficient of high-speed running tire. Compared with the existing rolling resistance coefficient measurement methods, the new approach is non-contact measurement based on the calculation of relative flexible principal strain rate. A high-speed stereo vision system is utilized to capture the transient deformation of high-speed rolling tire. In order to better understand the full-field dynamic distribution characteristics of high-speed rolling tire, an improved digital image correlation is proposed to accurately measure the relative coupled displacement and the relative flexible deformation. The rolling resistance mechanism of high-speed rolling tire could be clearly observed from the relative flexible principal strain rate distribution. On this basis, the tire rolling radius and rolling offset could be acquired by analyzing the relative displacement distribution and the relative flexible principal strain rate, and then the rolling resistance coefficient of high-speed rolling tire could be calculated. The experimental results demonstrate that it is feasible to measure the resistance coefficient of high-speed rolling tire by using high-speed 3D digital image correlation.

Event Data Recorder Performance during High Speed Yaw Testing Subsequent to a Simulated Tire Tread Separation Event

<div class="section abstract"><div class="htmlview paragraph">This paper presents event data from the Sensing and Diagnostic Module (SDM) of a 2004 Chevrolet Malibu during high speed yaw testing. Yaw tests were performed using tires that were intact and tires that had the tread removed. The tires that had the tread removed were placed at various wheel positions on the vehicle (e.g. leading side - front, leading side -rear, trailing side - rear). This testing simulates the loss of control phase subsequent to a tread separation. Speeds up to 117 km/h (72.9 mph) were achieved. A simple electro-mechanical device was incorporated to the dynamic testing to simulate a low-severity non-deployment event that triggered the recording of pre-crash data by the SDM. The SDM data from the tests was imaged and compared to reference data from vehicle-mounted instrumentation recording wheel speed, steering angle, measured vehicle sideslip angle and GPS calculated over the ground speed. This paper examines the dynamic effect of high sideslip angles and changes to tire rolling radius, as a result of a tread separation, as it pertains to the accuracy of EDR reported vehicle speed.</div></div>

UGV with a distributed electric driveline: Controlling for maximum slip energy efficiency on stochastic terrain

Energy saving has been a prominent concern of ground vehicle Original Equipment Manufacturers and research agencies for decades. The search for technological advances that can increase energy efficiency of vehicles has been a relentless quest. The framework of research on energy efficiency improvements has been considerably extended after the introduction of fully electric vehicles with electric motors that individually drive each wheel, i.e., In-Wheel Motors (IWM). Although incoming IWM vehicles can significantly decrease driveline power losses and, thus, improve vehicle energy efficiency compared to conventional mechanical driveline systems, one technical problem related to the vehicle-tire-terrain interaction needs to be addressed in fully electric terrain vehicles. These vehicles are still lacking strategies to manage power distribution between the drive wheels, which are not connected by a driveline system anymore, with the purpose to minimize slip power losses at all tires and maximize vehicle slip energy efficiency. Inappropriate power delivered to each of the wheels, which run in different stochastic terrain conditions, can deteriorate slip energy efficiency of a vehicle with four individually driven wheels. The research work presented in this article addresses the problem of wheel power distribution for an unmanned ground vehicle (UGV) with four IWMs.The goal of this study was to analytically establish and determine conditions for the wheel power split that corresponds to the maximum slip efficiency of the IWM UGV, design a control algorithm that implements the conditions, and verify the effectiveness of the control in experimental research of the vehicle on deformable terrain. The article presents a terramechanics-based IWM UGV mathematical modeling that integrates both vehicle, electric-motor, and wheel dynamics with stochastic soil characteristics. The control algorithm is based on the inverse dynamics approach to control the wheel angular velocity to overcome stochastic terrain load torque and to satisfy a required program of UGV motion given by a UGV velocity profile. Each wheel angular velocity is controlled by varying the wheel torque using a control-by-acceleration principle that provides each wheel with the required angular velocity and the tire rolling radius in the drive mode. Experimental research work, including lab tests at the UAB Vehicle and Robotics Engineering Lab and soil bin experiments of the IWM UGV at the USDA-ARS National Soil Dynamics Lab, was conducted to validate the analytical models and control algorithm.It was found that maximum IWM UGV slip energy efficiency is achieved if the electric motors are controlled to provide the same tire slippages at all four wheels by zeroing the kinematic discrepancy between the theoretical linear velocities of the wheels. At this condition, the total electric current drawn by all four DC motors was minimum. The maximum IWM UGV slip energy efficiency of 89.3% was achieved at a mean tire slippage value of 11.1% on Norfolk Sandy Loam (NSL) soil.

Optical 3D Deformation Measurement Utilizing Non-planar Surface for the Development of an “Intelligent Tire”

Intelligent tires, also known as smart tires, are equipped with sensors to monitor the strain of the interior surface and the rolling radius of tire, and are expected to improve the reliability of tires and tire control systems such as anti-lock braking systems (ABS). However, the high stiffness of an attached sensor like a strain gauge causes sensors to debond from the tire rubber. In the present study, a novel optical method is used for the concurrent monitoring of in-plane strain and out-of-plane displacement (rolling radius) utilizing the non-planar surface of the monitoring object. The optical method enables noncontact measurement of strain distribution. The in-plane strain and out-of-plane displacement are calculated by using image processing with an image of the interior surface of a tire that is taken with a single CCD camera fixed on the wheel rim. This new monitoring system is applied to an aluminum beam and a commercially available radial tire. As a result, the monitoring system provides concurrent measurement of in-plane strain, out-of-plane displacement and tire pressure, and is shown to be an effective monitoring system for intelligent tires.

Concurrent Monitoring of In-plane Strain and Out-of-plane Displacement of Tire Using Digital Image Correlation Method

In order to improve performance of anti lock brake system (ABS) and detect condition of road surface, intelligent tires that monitor strain of interior surface and rolling radius of tire are demanded. However, the high stiffness of an attached sensor like a strain gauge causes debonding of sensors from tire rubber. In the present study, noncontact concurrent monitoring method is proposed using digital image correlation method (DICM) and spotlight projection. In-plane strain and out-of-plane displacement (rolling radius) are calculated by using image processing with an image of interior surface of tire that is taken with a single CCD camera fixed on wheel rim. New monitoring system is applied to Al beam and commercially available radial tire. As a result, this monitoring system is proved to be able to measure in-plane strain and out-of-plane displacement with high accuracy, and confirmed to be effective for concurrent monitoring of tires.

インテリジェントタイヤ実用化のための表面形状を利用した三次元変形計測(<小特集>自動車技術を支える材料力学)

Intelligent tires, also known as smart tires, are equipped with sensors to monitor the strain of the interior surface and the rolling radius of tire, and are expected to improve the reliability of tires and tire control systems such as anti-lock braking systems (ABS). However, the high stiffness of an attached sensor like a strain gauge causes sensors to debond from the tire rubber. In the present study, a novel optical method is used for the concurrent monitoring of in-plane strain and out-of-plane displacement (rolling radius) utilizing the non-planar surface of the monitoring object. The optical method enables noncontact measurement of strain distribution. The in-plane strain and out-of-plane displacement are calculated by using image processing with an image of the interior surface of a tire that is taken with a single CCD camera fixed on the wheel rim. This new monitoring system is applied to an aluminum beam and a commercially available radial tire. As a result, the monitoring system provides concurrent measurement of in-plane strain, out-of-plane displacement and tire pressure, and is shown to be an effective monitoring system for intelligent tires.

PS29 画像解析に基づいた最適制動制御可能なインテリジェントタイヤの開発(ポスターセッション)

Intelligent tires, also known as smart tires, are equipped with sensors to monitor the strain of the interior surface and the rolling radius of tire, and are expected to improve the reliability of tires and tire control systems such as anti-lock braking systems (ABS). However, the high stiffness of an attached sensor like a strain gauge causes debonding of sensors from tire rubber. In the present study, a novel optical method is used for the concurrent monitoring of in-plane strain and out-of-plane displacement (rolling radius) utilizing the non-planar surface of the monitoring object. The optical method enables noncontact measurement of strain distribution. The in-plane strain and out-of-plane displacement are calculated by using image processing with an image of the interior surface of tire that is taken with a single CCD camera fixed on a wheel rim. This new monitoring system is applied to an aluminum beam As a result, the monitoring system provides concurrent measurement of in-plane strain and out-of-plane displacement, and is shown to be effective as the monitoring system.

Concurrent Monitoring of In-Plane Strain and Out-of-Plane Displacement of Tire Using Digital Image Correlation Method

In order to improve performance of anti lock brake system (ABS) and detect condition of road surface, intelligent tires that monitor strain of interior surface and rolling radius of tire are demanded. However, the high stiffness of an attached sensor like a strain gauge causes debonding of sensors from tire rubber. In the present study, noncontact concurrent monitoring method is proposed using digital image correlation method (DICM) and spotlight projection. In-plane strain and out-of-plane displacement (rolling radius) are calculated by using image processing with an image of interior surface of tire that is taken with a single CCD camera fixed on wheel rim. New monitoring system is applied to Al beam and commercially available radial tire. As a result, this monitoring system is proved to be able to measure in-plane strain and out-of-plane displacement with high accuracy, and confirmed to be effective for concurrent monitoring of tires.

오프로드차량의 슬립-견인력 관계의 평가에 사용되는 ASAE 제로조건에 관한 연구

Traction performance of off-road vehicles is estimated using slip-traction relationships Two zero condition accepted by ASAE have been used widely to obtain the slip-traction relationships of off-road vehicles. This study was carried out using the soil bin systems to investigate the characteristic of slip-traction curves obtained using two zero conditions defined by ASAE. which are driving and driven zero condition, and to present disadvantage of slip-traction relationship based on two zero conditions of ASAE. The results of this study are summarized as follows : 1. For the driving zero condition, the curve of slip-traction relationship shows some issues. The first question is that the slip is zero when the traction is zero. The second question is that the value of slip is smaller than that of corresponding real slip, as the rolling radius decreased f3r the setting zero condition with driving wheel. 2. For the driven zero condition. slip occurs when the traction is zero, which is more realistic results than driving zero condition. But when a zero condition is set, skid occurs and this result increased the rolling radius of tire and increased slip value f3r the specific traction value of whole slip range. This kind of trend was getting bigger as the soil is softer, or the tire inflation pressure is higher. 3. From the results of this study, it was found that slip-traction relationship obtained by two zero conditions of ASAE is not realistic in estimating the traction performance of off-road vehicles. And also slip-traction relationship obtained for the same experimental condition showed different result in accordance with chosen zero condition,