Loss Of Vehicle Control Research Articles

Risk chain identification of single-vehicle accidents considering multi-risk factors coupling effect.

The real-time monitoring on the risk status of the vehicle and its driver can provide the assistance for the early detection and blocking control of single-vehicle accidents. However, complex risk coupling relationship is one of the main features of single-vehicle accidents with high mortality rate. On the basis of investigating the coupling effect among multi-risk factors and establishing a safety management database throughout the life cycle of vehicles, single-vehicle driving risk network (SVDRN) with a three-level threshold was developed, and its topology features were analyzed to assessment the importance of nodes. To avoid the one-sidedness of single indicator, the multi-attribute comprehensive evaluation model was applied to measure the comprehensive effect of characteristic indicators for nodes importance. A algorithm for real-time monitoring of vehicle driving risk status was proposed to identify key risk chains. The result revealed that improper operation, speeding, loss of vehicle control and inefficient driver management were the sequence of top four risk factors in the comprehensive evaluation result of nodes importance (mean value = 0.185, SD = 0.119). There were minor differences of 0.017 in the node importance among environmental factors, among which non-standard road alignment had the larger value. The improper operation and non-standard road alignment were the highest combination correlation of factors affecting road safety, with the support of 51.81% and the confidence of 69.35%. This identification algorithm of key risk chains that combines node importance and its risk state threshold can effectively determine the high-frequency risk transmission paths and risk factors through multi-vehicle test, providing a basis for centralization management of transport enterprises.

Lane numbers and their impact on commercial motor vehicle crash safety: An econometric perspective

This research investigates the intricate relationship between the number of lanes on highways and injury severities sustained by commercial motor vehicle (CMV) drivers. Many studies have addressed crash determinants, but the safety implications of differing numbers of lanes remain insufficiently examined, especially during the highway planning stages. Our study fills this knowledge gap by analyzing injury severity crash factors for a varied number of lane scenarios. Employing a random parameters logit modeling framework, we differentiated injury levels for 2–4 lanes and 6–10 lanes. Key factors were identified for each number of lanes, with older, loss of vehicle control, non-collision crashes, and crashes on locations where grade or hill existed being more perilous and increasing the risk of sustaining severe injuries on 2-lane highways. For 4-lane highways, factors such as non-Oregonian drivers, older drivers, crashes that occurred during the spring season, and crashes that occurred beyond shoulders were associated with an elevated probability of being involved in severe injury crashes. Regarding highways with 6 lanes and higher, driving too fast for conditions and driver error (drowsy, fatigued, inattentive, or reckless) increases the odds of being involved in higher levels of injury crashes. To enhance truck driver safety, we recommend the implementation of electronic stability control in CMVs, moderated speeds on graded sections, improved curve markers, and robust public safety campaigns.

Hügelschäffer Egg Curves as Transition Curves in Road Design

Roads and railways, as the main parts of traffic infrastructure, represent geometrically rigid elements which are hard to adapt to certain kinds of landscapes without making large changes to the terrain itself. Today, thanks to modern technology and a large number of software tools, it is possible to define new geometric curves which are easily adaptable for use as transition curves when designing roads or railways. These transition curves can be formed in such a way to make them fit in with the surrounding landscape or urban environment better, which can improve the aesthetics of the transport system. Furthermore, transition curves provide a smooth and gradual change of curvature, reducing the risk of sudden curvature changes, which can cause discomfort to passengers and create an unsafe situation, such as a loss of vehicle control or a train derailment. Accordingly, in this paper, we define the parameters for generating Hügelschäffer curves as new transition curves between two circular road segments.

Characteristics and comparison between e-scooters and bicycle-related trauma: a multicentre cross-sectional analysis of data from a road collision registry

BackgroundUrban mobility has drastically evolved over the last decade and micromobility rapidly became an expanding segment of contemporary daily transportation routines. E-scooter riders and bicyclists may share similar trauma characteristics, but this has been little explored. The objective was to describe and compare the characteristics of e-scooter and bicycle-related trauma.MethodsWe conducted a cross-sectional analysis of data from the Rhône road collision registry (January 1, 2019 to December 31, 2019). We included all e-scooter or bicycle riders injured in traffic collisions during the study period; there were no exclusion criterion.ResultsA total of 2,779 patients were included; 825 (29.7%) were e-scooter riders and 1,954 (70.3%) were bicyclists. E-scooter riders were younger (median [IQR]: 24 [20–32] vs 29 [20–45] years, p < 0.001) and less frequently male (64.2% vs 73.4%, p < 0.001). Most e-scooter and bicycle road collisions were consequent to a fall or loss of vehicle control (74.2% vs 67.7%, p < 0.001). E-scooter riders were less frequently wearing a helmet at the time of the road collision (6.1% vs 30.7%, p < 0.001) and had more frequently head (24.2% vs 19.9%, p = 0.01) and face (30.6 vs 20.5%, p < 0.001) injuries compared to bicyclists. The median injury severity score was 2 [1–4] in both groups with no significant difference (p = 0.77).ConclusionsE-scooter and bicycle-related trauma patients were mainly young males with minor injuries and most of them sustained a road collision with no third-party. However, they suffered from different injury patterns; e-scooter riders suffered more frequently face and head injuries than bicycle riders, which may be at least partly the consequence of less frequent helmet use among e-scooter riders compared to bicyclists. Hence the two groups of users should not be considered as a single trauma entity. This issue should be promptly addressed to bring down the incidence of preventable injuries and avoid healthcare costs.

Driver Preference and Level of Trust Related to Real-Time Road Freezing Risk Information

Bad weather conditions can affect normal driving by substantially hindering visibility. Among all adverse weather conditions, road freezing is probably the most dangerous to drivers because slippery roads reduce surface friction and can lead to loss of vehicle control. This paper evaluates driver preference of receiving real-time road freezing risk information and explores the factors that would most influence drivers’ trust in a future road freezing information service. A survey was conducted in the metropolitan areas of South Korea during January and February 2019. The survey was completed by 231 driver’s license holders of 18 years or older, and the results were used for statistical analysis. According to the survey results, the variable message sign (VMS) is a very important system from the perspective of public benefit. Car-navigation systems are preferred for age categories of 21∼30 and over 50. In addition, ordinal regression was used to analyze the causal relationship between the level of trust regarding road freezing risk information and its controlling factors. The ordered log odds of drivers with previous accident experience due to slippery roads exhibit a higher level of trust in road freezing risk information because the coefficient is positive. Moreover, drivers with a constant commute time show a lower level of trust in road freezing risk information. These findings provide a foundation for planning the scope of future road freezing risk information service, as well as the specific service targets and type of information, especially during the winter season.

СТРУКТУРНО – ФУНКЦІОНАЛЬНА МОДЕЛЬ РОБОТИ ЕЛЕКТРОННОЇ СИСТЕМИ КУРСОВОЇ СТІЙКОСТІ (ESP)

Розроблено імітаційну модель управління поведінкою транспортного засобу при заносах з використанням системи курсової стійкості (ESP). Створено динамічну імітацію роботи контуру гальмівної системи, яка дозволяє ознайомитись з роботою контуру в динаміці, що значно покращує розуміння процесу гальмування; розроблено інтерактивну схеми роботи ESP та АВS. Зона виводу інформації під час роботи моделі дозволяє візуалізувати проходження автомобілем тестової траси та отримувати індикацію швидкості автомобіля та повороту керма та індикацію втручання ESP. Таким чином, отримана комп’ютерна модель управління автомобілем при заносах з врахуванням роботи ESP. яка дозволяє спостерігати в динаміці роботу ESP та прослідковувати зв’язки, які виникають при роботі системи ESP та ABS. Застосування такого підходу дозволяє проводити імітаційне моделювання за різними сценаріями, залежно від формування різноманітних ситуацій, практично необмеженої складності.Ключові слова: імітаційна модель, заноси, керування транспортним засобом, ESP, АВS, контур гальмівної системи, швидкість, поворот керма.&#x0D;

Quantification of weld size parameters for throat failure prevention in a brake flange axle weld subjected to torsional loading with structural stress approach

PurposeThe brake reaction test performed on a rear axle assembly revealed that the brake flange weld could not sustain the load needed to pass the minimum requirement of the test. Evaluation of the failure mode indicated that the fracture of the weld originated at the root of the weld and cracked through the fusion zone of the weld instead of cracking through base material (toe failure). The paper aims to discuss these issues.Design/methodology/approachA computational methodology is presented to quantify the critical parameters to prevent throat failure. The torsion dominated loading created high in-plane shear stress on the weld which can contribute significantly to the premature failure.FindingsThe failure through the fusion zone, often termed as weld throat/root failure, was not accounted for during the design phase by numerical simulation which led to the wrong conclusion that the design will pass the test requirement. Although weld sizing and weld penetration depth can explain such unexpected failure modes, fatigue life of this particular failure was still over-predicted using the Master SN curve formulation of structural stress approach which is well established for Mode I type of failure. Accounting for the shear component in the structural stress approach led to good correlation with the test specimen. Weld throat depth is a significant parameter contributing to throat failure.Practical implicationsThe failure of the weld joining the brake flange and the tube of an axle is a high severity failure mode which can result in loss of vehicle control and injury or death and hence the failure should be prevented at any cost.Originality/valueMost of the previous work of welded components relates to Mode I loading. There is very few research performed to discuss the Mode III loading and failure. This research illustrates the importance of considering the throat failure mode and quantifies the weld parameters to prevent such failures in design applications.

Four-Axis Vector-Controlled Dual-Rotor PMSM for Plug-in Electric Vehicles

Dual-rotor permanent-magnet synchronous motors (PMSMs) offer the merits of higher efficiency, higher torque density, and inherent electric differential (ED). This paper proposes a novel four-axis vector-controlled dual-rotor PMSM drive for driving plug-in electric vehicles (PEVs). A four-axis d-q model of the dual-rotor PMSM is developed with the proposed three-phase to four-phase transformation. This transformation separately resolves the stator variables to the d-q-axes of the inner and outer rotor. Instead of applying back electromotive forces and rotor power angles, the d-axis fluxes are used for computing the displacement between the two d-q-axes, which is essential for the transformation. The proposed four-axis vector control of dual-rotor PMSM allows for the independent control of stator quantities corresponding to the inner and outer rotors. This facilitates ED and better control under parametric differences, such as rotor inertia and permanent magnet flux for the inner and outer rotors. The comparison of the dual-rotor PMSM-based PEV operation with the proposed control and two earlier reported schemes reveals that the proposed scheme offers effective ED without the loss of vehicle control. Furthermore, the proposed configuration is validated with different drive cycles, including the loss modeling, sensitivity analysis, and efficiency mapping.

Dynamic Responses of Experienced All-Terrain Vehicle Operators to Simulated Unexpected Terrain Changes

All-terrain vehicles (ATVs) require “active riding,” meaning operators must rapidly assess changes in vehicle stability and adjust body position to compensate. No previous studies have reported using an ATV simulator to study active riding by human subjects. An ATV was mounted to a computer-controlled platform. Ride-file programs were developed which included sudden vehicle pitch (upward/downward) and roll (side to side) movements. A motion-capture system and accelerometers collected data that were analyzed with 3D modeling software. The posture and dynamic response to simulated sudden terrain changes for five adult males with ATV riding experience were determined. This study provides proof-of-principle for the use of ATV simulation to study active riding. In addition, the response patterns of experienced adult ATV operators can now be compared to that of other groups (e.g. inexperienced operators, children, drivers with passengers) to determine potential differences that might contribute to loss of vehicle control and crashing.

Study of Cornering Maneuvers of a Pneumatic Tire on Asphalt Pavement Surfaces Using the Finite Element Method

Field experience shows that most road accidents that occur during turning maneuvers are caused by the loss of vehicle control. The loss of vehicle control is often related to a lack of sufficient friction between the tire and the pavement surface. In experiments and analytical studies, the overall antiskidding performance of a pneumatic tire has been observed to be affected by operating conditions, road texture, and surrounding temperatures. Interactions of these parameters create a complex relationship between their combined effect and the tire's ability to combat skidding. One way to analyze the cornering maneuvers of a vehicle is by means of a validated finite element tool that can carry both the tire and the pavement properties. Few computational studies have been conducted to study the cornering performance of a rolling pneumatic tire, and none of these studies included the role of pavement surface morphologies in their analysis. In this study, a thermomechanical framework was used to analyze the influence of temperature on cornering friction. The cornering friction coefficient was found to decrease with an increase in the loads and the speeds. The cornering friction coefficient was found to increase with an increase in inflation pressure, sideslip angle, and pavement surface texture depth. The proposed study contributes to an understanding of the cornering performance of passenger car tires.

Predictive Threat Assessment via Reachability Analysis and Set Invariance Theory

We propose two model-based threat assessment methods for semi-autonomous vehicles, i.e., human-driven vehicles with autonomous driving capabilities. Based on information about the surrounding environment, we introduce a set of constraints on the vehicle states, which are satisfied under “safe” driving conditions. Then, we formulate the threat assessment problem as a constraint satisfaction problem. Vehicle and driver mathematical models are used to predict future constraint violation, indicating the possibility of accident or loss of vehicle control, hence, the need to assist the driver. The two proposed methods differ in the models used to predict vehicle motion within the surrounding environment. We demonstrate the proposed methods in a roadway departure application and validate them through experimental data.

Проектирование автодорог на отрезках, подверженных влиянию аквапланирования

Pouring rain, snow melting, water condensing, fog and other natural phenomena cause the collection of water on roadway pavement, leading to the decrease of road-holding capacity of a tyre.&nbsp;When a car or a light truck is moving at a high speed on wet road pavement, the water under its wheels cannot be expelled in time.&nbsp;It results in raising of the front wheels of the vehicle above the road surface under the action of a hydrodynamic force and loss of vehicle control.&nbsp;The methods ensuring traffic safety on road sections, where vehicle’s aquaplaning is possible, should be developed by identifying and improving these sections at the stages of highway design, reconstruction and maintenance and by limiting traffic speed of vehicles. Article in Russian. Automobilių kelių ruožų projektavimas, vertinant akvaplanavimą Santrauka. Lyjant lietui, tirpstant sniegui, esant stipriam rūkui ir pan., kelio dangos paviršiuje susikaupia vandens sluoksnis. Transporto priemonei judant šlapia kelio danga dideliu greičiu minėtas vanduo ne visada išstumiamas iš po transporto priemonės ratų padangų ir kelio dangos paviršiaus sąveikos zonos. Akvaplanavimas – tai reiškinys, kai transporto priemonės ratai praranda sukibimą su kelio danga ir skrieja vandens paviršiumi, transporto priemonė praktiškai lieka nevaldoma iki tol, kol nepravažiuos šlapio kelio ruožo. Autoriai analizuoja transporto priemonių saugaus eismo keliais su šlapia danga metodus ir aptaria juos automobilių kelių projektavimo kontekste. Reikšminiai žodžiai: transporto priemonė, automobilių kelias, kelio danga, vanduo, akvaplanavimas, sukibimas. Проектирование автодорог на отрезках, подверженных влиянию аквапланирования Аннотация. Во время ливня, таяния снега, конденсации воды, при туманах и некоторых других погодных явлениях на покрытии автодороги собирается вода. Это приводит к уменьшению сцепления шины с покрытием дороги. При высокой скорости движения по мокрому покрытию вода не успевает вытесняться из-под управляемых колес легкового и легкого грузового автомобилей. Это приводит к поднятию передних колес над поверхностью автодороги под действием гидродинамической силы, и автомобиль становится неуправляемым. Следует обратить внимание на разработку методов по обеспечению безопасности движения на участках возможного аквапланирования автомобилей путём выявления и совершенствования этих участков на стадиях проектирования, реконструкции и эксплуатации автомобильных дорог, включая ограничения скоростей движения автомобилей. Ключевые слова:&nbsp; автомобиль, дорога, вода, сцепление, аквапланирование, реконструкция, эксплуатация, безопасность движения.

Using the peak heat release rate to determine the fire risk level of road tunnels

A wide range of fire incidents can occur in a road tunnel, e.g. a fire in the cargo compartment of a goods vehicle, carelessness due to discarded smoker's materials or loss of vehicle control, and a crash resulting in a multiple -vehicle fire. The number of possible fire scenarios is numerous and so, for design applications, rather than attempting to analyse every possible event using a deterministic approach, a preliminary analysis using a quantitative risk assessment approach should be considered. This paper presents a risk assessment methodology to identify the possible fire scenarios that can occur in a road tunnel in order to specify design fire requirements for smoke control systems. The analysis considers factors such as legislation, vehicle fuel load, traffic mix in the tunnel, vehicle accident rate, and causes of vehicle ignition.

Design of Simulator Scenarios to Study Effectiveness of Electronic Stability Control Systems

The mission of the National Advanced Driving Simulator is to conduct highway safety research that will reduce annual loss of life on U.S. roadways. The simulator is well suited in its ability to replicate vehicle dynamics—and associated motion and visual cues—realistically to conduct complex experiments. It is unique in its ability to study vehicle control and loss-of-control situations in a safe and controlled environment. These capabilities make it an appropriate device to study the effectiveness of electronic stability control (ESC) systems, in which proper handling during loss of vehicle control is critical to assess system efficacy. The focus of the study is on challenges associated with creating repeatable yet unexpected scenario events in which loss of control is imminent for most drivers. Scenario events designed for a large-scale experiment to study ESC systems are detailed, data derived from these scenarios are discussed, and findings of scenario effectiveness are presented. A discussion of what constitutes loss of control and how to measure its effect effectively is provided.

Design of Simulator Scenarios to Study Effectiveness of Electronic Stability Control Systems

The mission of the National Advanced Driving Simulator is to conduct highway safety research that will reduce annual loss of life on U.S. roadways. The simulator is well suited in its ability to replicate vehicle dynamics—and associated motion and visual cues—realistically to conduct complex experiments. It is unique in its ability to study vehicle control and loss-of-control situations in a safe and controlled environment. These capabilities make it an appropriate device to study the effectiveness of electronic stability control (ESC) systems, in which proper handling during loss of vehicle control is critical to assess system efficacy. The focus of the study is on challenges associated with creating repeatable yet unexpected scenario events in which loss of control is imminent for most drivers. Scenario events designed for a large-scale experiment to study ESC systems are detailed, data derived from these scenarios are discussed, and findings of scenario effectiveness are presented. A discussion of what...

Incidence of xenobiotics among drivers killed in single-vehicle crashes

The authors have performed a study of single-vehicle crashes (SVCs) in order to verify a correlation between the loss of vehicle control and the presence of drugs in the body. Overall, 129 cases were recorded and occurred in the catchment area of the Institute of Legal Medicine in Milan between 1986 to 1996. Among the 129 cases under study, respectively 121 men and eight women, 101 were car-drivers and 28 motor-cyclists. The median age was equal to 29 years, while the average age to 32.0 years (range 15–65 years). Fifty eight cases (45.0%) were “positive” for the presence of ethanol≥0.8 g/l or other drugs. The sample of “positive cases” was studied according to sex, age, day, hour and type of vehicle. Considering the cases with presence of ethanol, although under the legal limit (20 cases), the total amount of cases (78) becomes even more consistent. The amount of ethanol was found to be respectively 0.34 g/l in daily drivers and 0.87 g/l in nightly drivers ( p<0.01). Our considerations confirm the importance of toxicological analyses in the forensic investigation of traffic deaths being the sample under study recorded following criteria which minimised other possible factors effecting road accidents.

An Investigation of the Slip of a Tire Tread

Abstract Tire performance such as handling, noise, traction, wear, etc., is determined ultimately in the tire footprint. The nature of the distribution of the contact stresses within the tire footprint determine whether or not the tire tread adheres to the road or slips relative to the road surface. Loss of adhesion between the tire tread and the road can be extreme as in gross slippage resulting in the loss of vehicle control or it can be subtle as in the small magnitude slippage that promotes treadwear. This paper presents results from an experimental characterization of the slip between the tread of a free-rolling tire and a simulated road surface. Trajectories of discrete points on the tread surface were measured from the entrance to the exit of the footprint and were used to calculate the total slip of each point. The relationship between the average slip of the tire and toe angle was established. Also, the relationship between toe, camber, and the distribution of tread slip and velocity across the tire footprint, was investigated in this paper.

Travel exposure and choice of comparison crashes for examining motorcycle conspicuity by analysis of crash data

Much research has been conducted examining the problem of motorcycle road crashes. Most of this research has concluded that motorcyclists have a conspicuity problem, particularly during the day. This type of research has often involved comparing multi-vehicle motorcycle crashes with single vehicle motorcycle crashes occurring during the day and night. The aim of this paper is to point out that comparison of single and multiple vehicle motorcycle crashes juxtaposes subsets of crashes with clearly different causes (car drivers' possible failure to detect a motorcyclist against motorcyclists' loss of vehicle control). Comparing groups of crashes for which conspicuity can be posited as a common cause (car drivers' possible failure to detect a motorcyclist or car) may be a more enlightening comparison. The issue of exposure is also examined in this paper.

Pediatric head injury caused by off-road vehicle accidents.

Morbidity and mortality from pediatric head injuries associated with the use of off-road vehicles are increasing. We reviewed all such injuries admitted to acute care hospitals in the two largest urban centers in Manitoba between April 1979 and August 1986. Of 375 injured children, 83 suffered head injury, 70 boys and 13 girls. Ages ranged from 2 to 15 years, with a mean of 10.4 years. Head injury was defined as any injury involving face, scalp or nervous system. Dirtbikes were implicated in 34 accidents, snowmobiles in 28, 3-wheel ATV's in 19, and 4-wheel ATV's in 2. About 85% of accidents occurred in a rural setting. Loss of vehicle control was the most common cause of injury. Alcohol or drug abuse were not factors. Fifty (60.2%) patients suffered loss of consciousness, prolonged in 6 (7.2%). All head-injured children also suffered at least one associated injury, mainly involving the musculoskeletal system. Associated spinal injury occurred in 18%. The average hospital stay was 13 days. Three (3.6%) patients died as a result of head injury.