Real-Time Detection of Adhesion Coefficient between Tire and Road

2012 ◽  
Vol 249-250 ◽  
pp. 109-112
Author(s):  
Kui Yang Wang ◽  
Jin Hua Tang ◽  
Guo Qing Li ◽  
Chuan Yi Yuan
Keyword(s):  
Load Transfer ◽  
Detection Method ◽  
Safety Performance ◽  
Vehicle Safety ◽  
Position Sensor ◽  
Vertical Load ◽  
Adhesion Coefficient ◽  
Vehicle Load ◽  
Motion State ◽  
Brake Force

Adhesion coefficient between tire and road is one of important factors which influence vehicle safety performance. On the basis of theoretical analysis, the detection method of adhesion coefficient based on brake-by-wire is put forward. Brake force is estimated according to pedal position sensor, vehicle braking deceleration is detected through MMA6260Q acceleration sensor. Motion state of tire is distinguished according to brake force and road braking force, vertical load of tire is received in view of formula on vehicle load transfer. Adhesion coefficient used for sliding area is got and taken as adhesion coefficient of road. Analysis shows that the detection method may identify adhesion coefficient between tire and road accurately, and has certain practical value.

Theoretical Research on Ideal Brake Force Distribution of Tractor-Semitrailer Cornering Braking

2013 ◽  
Vol 467 ◽  
pp. 451-455
Author(s):  
Chen Li ◽  
Xing Hu Li ◽  
Wei Zhou ◽  
Wei Liang Dai
Keyword(s):  
Load Transfer ◽  
Lateral Acceleration ◽  
Theoretical Research ◽  
Force Distribution ◽  
Vertical Load ◽  
Traditional Design ◽  
Brake Force ◽  
Braking Control ◽  
Brake Force Distribution ◽  
The Ideal

For tractor-semitrailer, load transfer during cornering braking caused big difference of the vertical load between coaxial wheels. As a result, braking efficiency and directional stability were affected seriously, the traditional design of braking force distribution between axles couldnt meet the requirements. In this paper, a dynamic model of tractor-semitrailer was established according to the motion and force during cornering braking. The rule of vertical load changing of each wheel with longitudinal acceleration and lateral acceleration was obtained. Combining with the tire and road adhesion conditions, the ideal brake force distribution was achieved. The research could provide theoretical reference to better control strategy of tractor-semitrailer braking control system.

Image detection and parameterization for different components in cross-sections of radial tires

2021 ◽  
pp. 095440702110236
Author(s):  
Chen Liu ◽  
Yude Dong ◽  
Yanli Wei ◽  
Jiangtao Wang ◽  
Hongling Li
Keyword(s):  
Image Processing ◽  
Digital Image Processing ◽  
Cross Sections ◽  
Digital Image ◽  
Detection Method ◽  
Detection System ◽  
Practical Significance ◽  
Vehicle Safety ◽  
Wire Steel ◽  
Good Detection

The internal structure analysis of radial tires is of great significance to improve vehicle safety and during tire research. In order to perform the digital analysis and detection of the internal composition in radial tire cross-sections, a detection method based on digital image processing was proposed. The research was carried out as follows: (a) the distribution detection and parametric analysis of the bead wire, steel belt, and carcass in the tire section were performed by means of digital image processing, connected domain extraction, and Hough transform; (b) using the angle of location distribution and area relationship, the detection data were optimized through coordinate and quantity relationship constraints; (c) a detection system for tire cross-section components was designed using the MATLAB platform. Our experimental results showed that this method displayed a good detection performance, and important practical significance for the research and manufacture of tires.

A Bayesian Estimate of Vehicle Safety Performance

2005 ◽  
Author(s):  
L. Gu ◽  
G. Li ◽  
J. Abramczyk ◽  
J. Prybylski
Keyword(s):  
Safety Performance ◽  
Bayesian Estimate ◽  
Vehicle Safety

Design of Low-Noise, High-Density Signal Intelligent Detection System

2013 ◽  
Vol 380-384 ◽  
pp. 3882-3885
Author(s):  
Xiaoan Yang
Keyword(s):  
Phase Transition ◽  
Detection Method ◽  
Detection System ◽  
Low Noise ◽  
Weak Signal ◽  
High Effectiveness ◽  
Motion State ◽  
Intelligent Detection ◽  
Stable Performance ◽  
Engineering Practices

Using motion state of the equipment transducer to determine the presence of a weak signal is a common method of signal detection, whose core is to determine the system's phase change. There a many traditional ways to judge phase transition, but most of which have computational complexity and need a large amount of data which make them difficult to apply engineering practices. In order to solve these problems, this paper presents a detection method based on Lyapunov exponent classification with a small amount of data. This approach has some advantages such as requiring fewer observed values, small calculation amount, and able to automatically determine the phase transition without subjective factors involved etc. Experiments show that this method has stable performance, high effectiveness, strong practicality and promotion.

Load Transfer Mechanism of Embankment Supported by Sparse Piles

2012 ◽  
Vol 178-181 ◽  
pp. 1396-1401
Author(s):  
Hao Zhang ◽  
Ming Lei Shi ◽  
Rui Kun Zhang ◽  
Yu Zhao
Keyword(s):  
Present Method ◽  
Stress Ratio ◽  
Load Transfer ◽  
Vertical Load ◽  
Transfer Property ◽  
Arching Effect ◽  
Load Transfer Mechanism ◽  
Soil Stress ◽  
Load Effects ◽  
Piled Embankment

The load transfer property of embankment fills, cushion, pile (or with cap) and foundation soils are complicated in a piled embankment. In this paper, the vertical load effects of pile and foundation soils at the bottom of embankment were analyzed with consideration of the interaction of each component. The arching effect of embankment fills and the pile-soil interaction were respectively formulated, and then, with continuous displacements and stresses at the bottom of embankment, a calculation method of pile-soil stress ratio was presented. In addition, the influence of the setting of cushion and geosynthetic was analyzed. The present method could definite the load sharing between pile and soil, and may be applied in the engineering design of embankment supported by spares piles.

Optimization Study on Open Shaped Ribs Arrangement and Diaphragm Cutout for Steel Orthotropic Box Girder

2012 ◽  
Vol 443-444 ◽  
pp. 1072-1077
Author(s):  
Zhen Wang Wu ◽  
Kai Feng Zheng ◽  
Ying Jie Cui ◽  
Yan Bin Shui
Keyword(s):  
Finite Element ◽  
Parameter Optimization ◽  
Element Model ◽  
Vertical Load ◽  
Box Girder ◽  
Tangential Stresses ◽  
Vehicle Load ◽  
Optimization Study ◽  
Transverse Position ◽  
The Web

The ramp B of one overpass was designed as curved steel orthotropic box girder, whose deck was welded with open shaped bulb ribs in the range of driveways. Then, one detailed finite element model was built to simulate the structure. For the two arrangements of bulb towards and back to web in the cantilever, the tangential stresses of diaphragm cutout were compared under the action of vehicle load. In accordance with above research, it can be concluded that the stress will be more reasonable with the bulb back to web. After altering the transverse position of the vehicle load and calculating the tangential stress along the edge of diaphragm cutout, based on further analysis, it’s generally believed that the following two reasons made the arrangement of bulb back to web more appropriate at least. First of all, the diaphragm connected with the rib adjacent to the web could share part of vertical load. What's more, it could increase the distance from the edge of the cutout to the web center. What come next was to change the diaphragm cutout size, and that parameter optimization was carried out. The results show that a radius of 40-50mm is more applicable for the arc on the bottom of the diaphragm cutout.

scholarly journals Analysis of Vertical Load Transfer Mechanism of Assembled Lattice Diaphragm Wall in Collapsible Loess Area

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mingtan Xia ◽  
Xudong Zhang ◽  
Gengshe Yang ◽  
Liu Hui ◽  
Wanjun Ye
Keyword(s):  
Failure Modes ◽  
Load Transfer ◽  
Diaphragm Wall ◽  
Vertical Load ◽  
Soil System ◽  
Loess Area ◽  
Collapsible Loess ◽  
Negative Friction ◽  
Vertical Bearing ◽  
Soil Interface

Based on analysis of the formation mechanism and characteristics of the negative friction in collapsible loess areas, this study investigates the load transfer law of a wall-soil system under a vertical load, establishes the vertical bearing model of a lattice diaphragm wall, and analyzes the vertical bearing capacity of an assembled latticed diaphragm wall (ALDW) in a loess area. The factors influencing the vertical bearing characteristics of the ALDW in a loess area are analyzed. The vertical bearing mechanism of the lattice diaphragm wall in the loess area is investigated. The failure modes of the ALDW in the loess area are mainly shear failure of the soil around the wall and failure of the wall-soil interface. In the generation and development of negative friction, there is always a point where the relative displacement of the wall-soil interface is zero at a certain depth below the ground; at this point, the wall and soil are relative to each other. The collapsibility of loess, settlement of the wall and surrounding soil, and rate and method of immersion are the factors affecting the lattice diaphragm wall. The conclusions of this study provide a reference for the design and construction of ALDWs in loess areas.

scholarly journals Realistic Reference for Evaluation of Vehicle Safety Focusing on Pedestrian Head Protection Observed From Kinematic Reconstruction of Real-World Collisions

2021 ◽  
Vol 9 ◽  
Author(s):  
Guibing Li ◽  
Jinming Liu ◽  
Kui Li ◽  
Hui Zhao ◽  
Liangliang Shi ◽  
...  
Keyword(s):  
Head Injury ◽  
Impact Velocity ◽  
Real World ◽  
Contact Time ◽  
Injury Risk ◽  
Safety Performance ◽  
Contact Boundary ◽  
Vehicle Safety ◽  
Pedestrian Protection ◽  
Vehicle Impact

Head-to-vehicle contact boundary condition and criteria and corresponding thresholds of head injuries are crucial in evaluation of vehicle safety performance for pedestrian protection, which need a constantly updated understanding of pedestrian head kinematic response and injury risk in real-world collisions. Thus, the purpose of the current study is to investigate the characteristics of pedestrian head-to-vehicle contact boundary condition and pedestrian AIS3+ (Abbreviated Injury Scale) head injury risk as functions of kinematic-based criteria, including HIC (Head Injury Criterion), HIP (Head Impact Power), GAMBIT (Generalized Acceleration Model for Brain Injury Threshold), RIC (Rotational Injury Criterion), and BrIC (Brain Injury Criteria), in real-world collisions. To achieve this, 57 vehicle-to-pedestrian collision cases were employed, and a multi-body modeling approach was applied to reconstruct pedestrian kinematics in these real-world collisions. The results show that head-to-windscreen contacts are dominant in pedestrian collisions of the analysis sample and that head WAD (Wrap Around Distance) floats from 1.5 to 2.3 m, with a mean value of 1.84 m; 80% of cases have a head linear contact velocity below 45 km/h or an angular contact velocity less than 40 rad/s; pedestrian head linear contact velocity is on average 83 ± 23% of the vehicle impact velocity, while the head angular contact velocity (in rad/s) is on average 75 ± 25% of the vehicle impact velocity in km/h; 77% of cases have a head contact time in the range 50–140 ms, and negative and positive linear correlations are observed for the relationships between pedestrian head contact time and WAD/height ratio and vehicle impact velocity, respectively; 70% of cases have a head contact angle floating from 40° to 70°, with an average value of 53°; the pedestrian head contact angles on windscreens (average = 48°) are significantly lower than those on bonnets (average = 60°); the predicted thresholds of HIC, HIP, GAMBIT, RIC, BrIC2011, and BrIC2013 for a 50% probability of AIS3+ head injury risk are 1,300, 60 kW, 0.74, 1,470 × 104, 0.56, and 0.57, respectively. The findings of the current work could provide realistic reference for evaluation of vehicle safety performance focusing on pedestrian protection.

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