Rozprawy doktorskie na temat „Vehicle safety”

An autonomous vehicle is a vehicle that is capable of navigating and driving with no human intervention whatsoever through the utilization of various sensors and positioning systems. The possible applications of autonomous vehicles are widespread, ranging from the aerospace industry to the mining and military sectors where the exposure of human operators to the operating conditions is hazardous to their health and safety. Automobile accidents have become the leading cause of death in certain segments of the world population. Removing the human driver from the decision-making process through automation may result in significantly safer highways. Although full autonomy may be the ultimate goal, there is huge scope for systems that aid the driver in decision making or systems that take over from the driver under conditions where the human driver fails. The aim of the longitudinal control system to be implemented on the Land Rover test vehicle in this study is to improve the vehicle’s safety by controlling the vehicle’s longitudinal behaviour. A common problem with sports-utility-vehicles is the low rollover threshold, due to a high centre of gravity. Rather than modifying the vehicle to increase the rollover threshold, the aim of the control system presented here is to prevent the vehicle from exceeding speeds that would cause the vehicle to reach its rollover threshold. In order to develop a control system that autonomously controls the longitudinal degree of freedom, a model of the test vehicle (a 1997 Land Rover Defender 110 Wagon) was developed in MSC.ADAMS/View and validated experimentally. The model accurately captures the response of the test vehicle to supply forces as generated by the engine and demand forces applied through drag, braking and engine braking. Furthermore, the model has been validated experimentally to provide reliable simulation results for lateral and vertical dynamics. The control system was developed by generating a reference speed that the vehicle must track. This reference speed was formulated by taking into account the vehicle’s limits due to lateral acceleration, combined lateral and longitudinal acceleration and the vehicle’s performance capabilities. The control system generates the desired throttle pedal position, hydraulic pressure in the brake lines, clutch position and gear selection as output. The MSC.ADAMS\View model of the test vehicle was used to evaluate the performance of the control system on various racetracks of which the GPS coordinates were available. The simulation results indicate that the control system performs as expected. Finally, the control system was implemented on the test vehicle and the performance was evaluated by conducting field tests in the form of a severe double lane change manoeuvre. The results of the field tests indicated that the control system limited the acceleration vector of the vehicle’s centre of gravity to prescribed limits, as predicted by the simulation results.<br>Dissertation (MEng)--University of Pretoria, 2013.<br>gm2014<br>Mechanical and Aeronautical Engineering<br>unrestricted

Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.<br>Includes bibliographical references (p. 83-85).<br>by Ekanterina Dolginova.<br>S.B.and M.Eng.

Motor vehicle accidents are statistically the major cause of accidental severe injuries for pregnant women and fetuses fatality. Volunteers, post mortem human surrogates, anthropomorphic crash test devices and computational occupant models are used to improve human safety in motor vehicle accidents. However, due to the ethical issues, pregnant women and their fetuses cannot be used as volunteers or post mortem human surrogates to investigate the effects of crashes on them. The only anthropomorphic test device representing pregnant women is very limited in design and lacks a fetus. There is no computational pregnant occupant model with a fetus other than 'Expecting'. This thesis focuses on understanding the risk of placental abruption for pregnant drivers involved in road accidents, hence assessing the risk to fetus fatality. An extensive review of existing models in general and pregnant women models in particular is reported. The time line of successive development of crash test dummies and their positive effect on automotive passive safety design are examined. 'Expecting', the computational pregnant occupant model with a finite element uterus and a multibody fetus, is used in this research to determine the strain levels in the uteroplacental interface. External factors, such as the effect of restraint systems and crash speeds are considered. Internal factors, such as the effect of placental location in the uterus, and the inclusion and exclusion of a fetus are investigated. The head of the multibody fetus is replaced with a deformable head model to investigate the effects of a deformable fetus head on strain levels. The computational pregnant driver model with a fetus offers a more realistic representation of the response to crash impact hence provides a useful tool to investigate fetus safety in motor vehicle accidents. Seat belt, airbag and steering wheel interact directly with the pregnant abdomen and play an important role on fetus safety in motor vehicle accidents. The results prove that the use of a three-point seat belt with the airbag offer the greatest protection to the fetus for frontal crash impacts. The model without a fetus underestimates the strain levels. The outcome of this research should assist automobile manufacturers to address the potential safety issues at the design level.

SUMMARY Light-weightiness and safety are the two most important requirements that a modern passenger car have to satisfy to stay in the current competitive market. These two targets seem to be in deep contrast one with the other as the high crashworthiness requirements and the consumer expectation for a refined and comfortable cabin, consistently increased both the mass and size of the vehicle over the decades. This trend comes out as quite problematic for the car manufacturers that, at present, are very motivated to pursue the first requirement (the lightweight) that is deeply affecting both fuel consumption and the emission performance of the vehicle. It is becoming more and more evident that by continuing to use the current conventional metallic materials for front crash structures and other vehicle components, it is more and more difficult to get a design solution capable to satisfy the conflicting interests between the vehicle light-weightiness and safety. Besides, some vehicle weight reduction techniques such as Vehicle design changes and Vehicle downsizing have an adverse effect on both customer comfort and safety, since vehicle size and occupant safety are positively related. As a response , today, researchers and car makers development departments are leaned toward finding high performance, advanced materials such as composite, which have higher Specific Energy Absorption (SEA) performance, in order to break the above mentioned conflicting relationship and truly yield to increase safety and, at the same time, reduce weight. Composite materials have the following main advantages for transportation industries • Weight reduction with improved performance ( specific strength 50% less than aluminum and 75% less than steel) • Crash worthiness/safety i.e. structure built with composite can be 6 to 8 times safer than the similar one made by metal due to higher SEA and more favorable failure mode. As a consequence less intrusion into the passenger compartment during a crash event can be achieved. • Larger number of options available to the designer. The reinforcement type and its form produce an infinite variety. Thus stiffness and strength properties can be selected in a range that is extended from mechanical properties comparable with thermoplastic materials to properties, which are greater than high performance steels. However, to implement composite materials for primary and secondary structural applications and substitution of the current traditional material is not straightforward. In fact, although modern composites introduction is dated back 1937, the rate of usage of composites in the automotive industry in all these years has been very slow and the applications have been limited. Some of the reasons are cost i.e. (raw material and manufacturing costs), volume of production (production rate) and insufficient engineering data such as data of material property, sufficient knowledge about failure behaviors, joining, damage inspection and maintenance. The study presented in this thesis is motivated and drawn from the above stated problems. It is aimed to address at some extent the effect of the material change for vehicle structures and to give research and development contributions to some of the challenges. As lack of engineering data and well established knowledge on composite damaging mechanism are major design constraints on the area, E-Glass/Epoxy composite has been selected and tensile experimental program were designed for material characterization and damage analysis. Both destructive and non destructive damage observation techniques had used to understand the damage extent in the laminate and to capture on-set total failure. Vehicles are operated under arduous conditions; therefore all components are experiencing some form of fatigue loading during most of their service life. This type of failure is usually considered as the principal mode of failure of all dynamically loaded mechanical systems and accounts approximately 90 percent service failures. Especially, when such fatigue failure occurs on some safety critical components, it will affect the vehicle integrity and could result in a complete loss of control of the vehicle that is highly risky for the life of occupants and vulnerable road users (VRU) such as pedestrians, motorcyclists and cyclists and persons in personal mobilized devices (e.g.: motorized wheelchairs and scooters). Therefore, when new advanced material is proposed for such an application it has to be accompanied by a detailed fatigue analysis. In this thesis more emphasis had given on the subject and extensive research has been conducted on the fatigue behavior of the selected material. Displacement controlled four point bending fatigue tests with R ratio of 0.1 were conducted on standard and notched specimens and damage development in the composite was continuously monitored through the decrease of bending moment during cycling. The specimens were subjected to different fatigue loading with the maximum loading level up to 75% of the material ultimate flexural strength (UFS). Having obtained an average complete diagram of the fatigue life of the material, in order to understand the type of failure mode and the possible mechanism at different stage of loading, some critical data points have been selected at various stiffness degradation rate and interrupted fatigue tests were conducted to pre-defined number of cycles . Through analyzing the pre cycled specimens using scanning electron microscope (SEM), the failure mode at the three distinctive regions of stiffness degradation regions have been identified. Furthermore, an effort has been made to study effect of notch geometry and notch size on the flexural quasi-static and fatigue performance of the selected material. Automobile safety in general is the study and practice of design, construction, equipment and regulation to minimize the occurrence and consequences of automobile accidents .It is categorized as active safety (Crash Avoidance) and passive safety (Crashworthiness). In the current work, safety is mainly referred passive safety which is measured by conducting impact physical tests or by numerical simulations at component, sled and full-scale level against a deformable or rigid barrier. The component test is aimed to determine the dynamic and/or quasi-static response to loading of an isolated component and crucial in identifying the crush mode and energy absorption capacity. Understanding their performance is also essential to the development of prototype substructures and mathematical models. Therefore, to address the issue of volume of production and production cost, as both are main constraints for transportation industries, an effort had made to identify a vehicle component where pultruded composite products can be used,( as pultrusion manufacturing technologies is relatively cheapest (due to process automation) and suitable for high volume production). After material mechanics and failure study, automotive bumper beam were identified as a suitable candidate component for the desired objective and a finite element simulations are performed using ABAQUS, in order to optimize beam section profile and beam curvature of a bumper for crashworthiness. The research activity is subdivided in two parts and compiled by six chapters. The first part contains four chapters and the second part contains two chapters. As highlighted in the previous paragraph, to understand the material failure behavior is crucial for candidating a novel material for crash absorbing components. The first part of the work is dedicated to material characterization and investigation of the failure mechanism of the selected material and the second part is extended to a component level. The first chapter covers overall introduction about composite material and its application in automotive industries. The chapters briefly discuss about type of materials that constitute composites and their behaviors, composite manufacturing techniques and the overall requirement of maternal for automotive applications. The second chapter is dedicated to material characterization and damage study on a selected composite material with and without the presence of notch. In this activity, primarily, an effort has been made to reduce the manufacturing (drilling) induced damage by closely controlling and selecting appropriate manufacturing parameters through conducting damage observations. Having relatively damage free coupon, the material is characterized and a comprehensive damage study is made through conduction of interrupted tensile tests and the material damage extent at different loading level is studied using different damage observation techniques. The third and fourth chapters cover a four points quasi- static and bending fatigue study of the same material. In chapter three, the bending fatigue behavior of fabric E-Glass/Epoxy composite is investigated. Material stiffness degradation is used as a measure of damage formation and propagation and it is continually monitored using LVDT transducer. Having obtained an average material stiffness degradation trend through conducting test up-to failure for some set of coupons, critical stiffness degradation points are identified. Then an interrupted fatigue test is conducted for a predefined number of cycles to investigate the damage extent at different stage of damage propagation. In chapter four, the effect of notch on the quasi- static and bending fatigue performance of the selected material is discussed. The effect of notch geometry, notch size and loading type are also considered for the study. The used instrumentation and damage monitoring techniques are similar to what presented in chapter three. In chapter five that is belonging to the second part a numerical study is conducted to explore the possibility of substituting the current metallic bumper beam with E-Glass/epoxy pultruded composites and its energy absorbing capability is compared with steel and E-Glass fabric composite. Since optimal design of composite crash absorber cannot be achieved by a simply material substitution, structural optimization of the beam section profile and curvature is also developed to obtain a stable flexural failure of the composite bumper beam. The analysis is done through the investigation of impact event characteristic data, such as force/time, force/deflection, energy/displacement and deflection/time curves. Finally in chapter six the main findings of the activity are briefly summarized.

While driving behavior is generally governed by the nature and the driving objectives of the driver, there are many situations (typically in crowded traffic conditions) where tacit communication between vehicle drivers and pedestrians govern driving behavior, significantly influencing transportation safety. The study aimed to formalize the tacit communication between vehicle drivers and pedestrians, in order to inform an investigation on effective communication mechanisms between autonomous vehicle and humans. Current autonomous vehicles engage in decision making primarily controlled by on-board or external sensory information, and do not explicitly consider communication with pedestrians. The study was a within subject 2x2x2 factorial experimental design. The three independent variables were driving context (normal driving vs. autonomous vehicle placard), driving route (1 vs. 2), and narration (yes vs. no). The primary outcome variable was driver-yield behavior. Each of the ten drivers completed the factorial design, requiring eight total drives. Data were collected using a data acquisition system (DAS) designed and installed on the experimental vehicle by the Virginia Tech Transportation Institute. The DAS collected video, audio, and kinematic data. Videos were coded using a proprietary software program, Hawkeye, based on an a priori data directory. Recommendations for future autonomous vehicle research and programming are provided.<br>Ph. D.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>A Flight Safety System (RAFS) for multiple, reliable Unmanned Air Vehicles (UAV’s) capable of flying Over-the-Horizon (OTH) and outside test range airspace. In addition to the flight safety application, the described full-duplex data link is suitable as a backup command and control link for UAV’s, and for sensor control & data exfiltration. The IRIDIUM satellite system was selected to provide the communications link and because of its global coverage and requisite data throughputs. A Risk Reduction activity ensued to quantify IRIDIUM performance. Hardware and software was developed to demonstrate the feasibility of using IRIDIUM in a flight safety scenario.

This thesis addresses the problem of safety in complex multi-vehicle interactions, initially in the domain of the mining industry. Operating a vehicle in a mining environment can be particularly dangerous due to the difficult environment, lack of visibility from the vehicle cabin, long shifts and many other factors that result in many accidents and near misses each year. The state of the art in vehicle safety systems do not address all of these problems. Current systems lack the ability to effectively determine the risks and threats that are important, and to be able to communicate these to an operator in a complex situation. This thesis introduces the concept of situation awareness into the mining domain. Situation awareness provides a model of the way humans take in information from their surroundings, process this information and predict the future state of the environment. Human error in vehicle accidents can be attributed to deficiencies in one or more of these components. The aim of a safety system is to improve situation awareness, while minimising or eliminating the negative impact on situation awareness caused by the introduction of the technology. The requirements for determining and distributing vehicle state information are examined and tested. The concept of context is introduced as a means of filtering out unnecessary information and false alarms to the operator, as well as providing higher level information that requires less mental bandwidth to process. This is important as false alarms and unnecessary information annoys the operators and distracts them from the important task of controlling the vehicle. The quality of the vehicle state information is shown to be improved using localisation algorithms introduced in this thesis. These algorithms utilise the context information, digitised maps and a model of the vehicle dynamics to estimate and predict vehicle state information. The theory and testing of these algorithms are an important contribution of this thesis. The methods of providing feedback to the operator are introduced, and the role of assistive, reactive and preventative feedback is discussed. A measure of vehicle safety is provided using metrics based on the known safe rules of operation within a mine. An important contribution of this thesis is the real time feedback of safety performance based on these metrics which are known to contribute to the risk of an accident. Comprehensive experimental results are provided for the concepts introduced in this thesis from system installations in several mines in Australia and Indonesia.

Road traffic safety has been a subject of worldwide concern. Dedicated short range communications (DSRC) is widely regarded as a promising enabling technology for collaborative safety applications (CSA), which can provide robust communication and affordable performance to build large scale CSA system. The main focus of this thesis is to develop solutions for DSRC QoS control in order to provide robust QoS support for CSA. The first design objective is to ensure robust and reliable message delivery services for safety applications from the DSRC networks. As the spectrum resources allocated to DSRC network are expected to be shared by both safety and non-safety applications, the second design objective is to make QoS control schemes bandwidth-efficient in order to leave as much as possible bandwidth for non-safety applications. The first part of the thesis investigates QoS control in infrastructure based DSRC networks, where roadside access points (AP) are available to control QoS control at road intersections. After analyse DSRC network capabilities on QoS provisioning without congestion control, we propose a two-phases adaptive QoS control method for DSRC vehicle networks. In the first phase an offline simulation based approach is used to and out the best possible system configurations (e.g. message rate and transmit power) with given numbers of vehicles and QoS requirements. It is noted that with different utility functions the values of optimal parameters proposed by the two phases centralized QoS control scheme will be different. The conclusions obtained with the proposed scheme are dependent on the chosen utility functions. But the proposed two phases centralized QoS control scheme is general and is applicable to different utility functions. In the second phase, these configurations are used online by roadside AP adaptively according to dynamic traffic loads. The second part of the thesis is focused on distributed QoS control for DSRC networks. A framework of collaborative QoS control is proposed, following which we utilize the local channel busy time as the indicator of network congestion and adaptively adjust safety message rate by a modified additive increase and multiplicative decrease (AIMD) method in a distributed way. Numerical results demonstrate the effectiveness of the proposed QoS control schemes.

This thesis is focused on individual wheel actuators in road vehicles intended for vehicle motion control. Particular attention is paid to electro-mechanical actuators and how they can contribute to improving vehicle dynamics and safety. The employment of individual wheel actuators at the vehicle's four corner results in a large degree of over-actuation. Over-actuation has a potential of exploiting the vehicle's force constraints at a high level and of controlling the vehicle more freely. One important reason for using over-actuated vehicles is their capability to assist the driver to experience the vehicle as desired. This thesis demonstrates that critical situations close to the limits can be handled more efficiently by over-actuation. To maximise the vehicle performance, all the available actuators are systematically exploited within their force constraints.  Therefore, force constraints for the individually controlled wheel are formulated, along with important restrictions that follow as soon as a reduction in the degrees of freedom of the wheel occurs. Particular focus is directed at non-convex force constraints arising from combined tyre slip characteristics. To evaluate the differently actuated vehicles, constrained control allocation is employed to control the vehicle. The allocation problem is formulated as an optimisation problem, which is solved by non-linear programming. To emulate realistic safety critical scenarios, highly over-actuated vehicles are controlled and evaluated by the use of a driver model and a validated complex strongly non-linear vehicle model. it is shown that, owing to the actuator redundancy, over-actuated vehicles possess an inherent capacity to handle actuator faults, with less need for extra hardware or case-specific fault-handling strategies.<br>QC 20100722

Yes<br>This article proposes an approach named SafeML II, which applies empirical cumulative distribution function-based statistical distance measures in a designed human-in-the loop procedure to ensure the safety of machine learning-based classifiers in autonomous vehicle software. The application of artificial intelligence (AI) and data-driven decision-making systems in autonomous vehicles is growing rapidly. As autonomous vehicles operate in dynamic environments, the risk that they can face an unknown observation is relatively high due to insufficient training data, distributional shift, or cyber-security attack. Thus, AI-based algorithms should make dependable decisions to improve their interpretation of the environment, lower the risk of autonomous driving, and avoid catastrophic accidents. This paper proposes an approach named SafeML II, which applies empirical cumulative distribution function (ECDF)-based statistical distance measures in a designed human-in-the-loop procedure to ensure the safety of machine learning-based classifiers in autonomous vehicle software. The approach is model-agnostic and it can cover various machine learning and deep learning classifiers. The German Traffic Sign Recognition Benchmark (GTSRB) is used to illustrate the capabilities of the proposed approach.<br>This work was supported by the Secure and Safe MultiRobot Systems (SESAME) H2020 Project under Grant Agreement 101017258.

Through a mixed methods approach this thesis investigates the road safety and operational culture of heavy vehicle drivers in Oman. The research found evidence of a low level of road safety compliance across much of the heavy vehicle industry in Oman. The research identified many unsafe driving behaviours and attitudes that were well established within the industry and its operations. Many of these behaviours and attitudes were facilitated and encouraged by lack of safety regulations and enforcement at different systems levels. The outcomes of this research have a broad range of applications in the area of road safety in Oman and similar countries.

Automotive transport unavoidably raises safety concerns for drivers, passengers, and indeed, all road users alike. Advancements in vehicle safety technologies have come a long way, and have had a major impact on the reduction of road-related accidents and fatalities. However, as the push towards autonomous vehicle systems gains momentum, assumptions must be avoided about the global application of such technologies.This paper proposes an idea for a road safety alert system, which is realized in the form of small-scale prototype, subsequently tested and evaluated to study its theoretical application to real world scenarios. The system is geared towards developing regions of the world where a reduction in road-related accidents and death is needed most. Reviews of various existing and proposed safety systems within the realm of Intelligent Transportation Systems (ITS) are conducted, with a focus on Vehicle-to-Vehicle (V2V) and non-V2V applications, which are compared to and contrasted with our proposal.We hope to foster further discussion and research into suitable technologies and their application, in regions of the world that require a different approach when trying to realistically reduce the consistent destructive trend of accidents and fatalities when humans are still behind the wheel.

Thesis (M.S.)--University of Missouri-Columbia, 2007.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 4, 2008) Includes bibliographical references.

This research contributes to the existing body of knowledge relating to crash compatibility (the minimisation of injury risk faced by all participants involved in a collision in traffic). The research focuses on the topic of structural interaction in collisions involving passenger vehicles, a phenomenon describing the efficiency of energy dissipation within existing deformation-zones of a passenger vehicle during a collision. A new definition for structural interaction was developed and several metrics to evaluate structural interaction and compatibility in car-to-car collisions were proposed, based on the commonly known Equivalent Energy Speed (EES) metric. The new EES metrics describe equivalent closing velocities for a given collision based on the energy dissipated within the front-ends (EESFF) and the entire structure (EESVV) of both vehicles involved in a head-on collision. These metrics form the basis of the new knowledge generated by this research. Additionally, a new method was developed to measure the amount of energy dissipated through structural deformation in a collision, based on accelerometer readings. This method was applied to several experimental and simulationbased car-to-car collisions and the validity of the method was proven. Based on the energy dissipation which occurred in the car-to-car collisions analysed, the degree of compatibility reached and the level of structural interaction which occurred in each collision was evaluated by applying the newly developed EESFF and EESVV metrics. Thie research also investigates the assessment of vehicles' structures in a standardized procedure with a view to improving structural interaction in the real-world. Several fixed barrier crash tests have been proposed in different configurations and with different assessment criteria. All assessments aim to evaluate the geometrical characteristics of the front-ends of passenger vehicles. A set of factors required from a compatilibility assessment focused on assessing vehicle geometry were identified. The proposed compatibility assessment procedures were evaluated based on their ability to predict the potential for structural interaction offered by passenger vehicles.

Driving through an un-signalized intersection creates multiple opportunities for missed or misunderstood information. Stop signs, in particular, can be stolen, covered by vegetation, or rotated out of place, leading to an absence of information, contributing to inappropriate decision-making and crashes. Stop controlled intersections have also been shown to be a source of unnecessary delay and emissions due to their frequent, often inappropriate use. Using connected vehicle technology, it is possible to place an electronic stop sign within the vehicle that tells the driver to stop when a conflict in the intersection is imminent, thus reducing the probability of missed information by the driver, and decreasing the amount of unnecessary delay, fuel consumption, and emissions. Before implementing any new technology, it is important to assess it from both a transportation engineering and human factors standpoint to assess the value of the system. The objective of this study was to assess several key benefits of an adaptive in-vehicle stop display as well as to determine if there are any negative safety implications with the use of this system. This assessment was accomplished through a test track experiment where participants experienced conditions where a standard R1-1 stop sign was displayed on the in-vehicle display, as well as an experimental sign, which informed them to proceed through the intersection with caution. Data collected from in-vehicle sensors was analyzed, and results indicate that the implementation of this technology reduces delay, decreases fuel consumption, and does not instigate any safety decrements.<br>Master of Science

An analysis of crash data shows that the number of fatal school bus related crashes has remained nearly constant over the past ten years, despite an increase in available safety-improving technology. One of the main concerns related to school bus safety is the issue of illegally passing a stopped school bus. To improve safety around stopped school buses, this dissertation presents a Concept of Operations for a connected vehicle application to improve safety around stopped school buses using Dedicated Short Range Communication. The focus of this application is to increase awareness of stopped school buses or bus stops that are obscured from the driver's view. An on-road naturalistic driving experiment evaluated driver response to an in-vehicle message to warn drivers that they were approaching a school bus that was stopped around a curve. The dissertation concludes by using microsimulation to evaluate the impact of implementing specialized speed control algorithms to reduce vehicle speeds near bus stops along high speed roads. The simulation evaluated the effect of the reduce speed zone on travel time and emissions when the system was considered as a pre-timed speed limit and also when the system was modeled as a connected vehicle system.<br>Ph. D.

Connected vehicles are on the cutting edge of automotive technology with applications expected to improve mobility and safety. Several studies have evaluated the mobility benefits of connected vehicle technology but there is little research on its impact on safety. The first objective of this study is to investigate the ability to evaluate the safety of a connected vehicle applications using surrogate safety measures through a combination of the micro-simulation model VISSIM and the Surrogate Safety Assessment Model (SSAM). Two connected vehicle applications are reviewed, considering two types of connected vehicle communications, specifically Vehicle-to-Vehicle and Vehicle-to-Infrastructure. The two applications are a cumulative travel time (CTT) intersection control algorithm connected vehicle environment, and a cooperative adaptive cruise control (CACC) application, facilitating vehicle platooning on a freeway. The CACC study investigates the improvement to the freeway segment through a simulated incident. The CTT study investigates the impacts of calibrating the micro-simulation model using real-world vehicle trajectory and conflict data. The CTT algorithm is applied to a signalized intersection and evaluated under three calibration scenarios: uncalibrated, first step calibrated for desired speed and vehicle arrival types, and second step calibrated for conflicts observed in the field. In both studies, a comparison of safety based on the number of conflicts at different time-to-collision thresholds is provided for the varying scenarios. Results show that the combination of VISSIM and SSAM provide an appropriate tool to use in the evaluation of changes in the level of safety of connected vehicle applications, specifically the CACC application and the CTT intersection control application. Calibration of the micro-simulation model has a significant impact on the results of the safety evaluation. However, it is inconclusive whether the results are realistic with the lack of a real-world connected vehicle implementation.<br>Applied Science, Faculty of<br>Civil Engineering, Department of<br>Graduate

One potential interaction between environmental and safety goals in transport is found within the vehicle fleet where fuel economy and safety impose conflicting requirements on vehicle design. Larger and heavier vehicles have a better secondary safety performance during a crash. On the other hand, they are associated with higher levels of fuel consumption and emissions. This issue has generated debate amongst researchers and policy makers when formulating policies to improve the environmental performance of the road transport system. An extensive review of literature reveals that arguments has often been based on either little research evidence, or research that has inadequacies in the applied methodologies. This research investigates the safety consequences of changes in vehicles mass within the vehicle fleet aimed at increasing fleet fuel economy. The partial effects of mass on fuel consumption rate and secondary safety performance were estimated using a cross-sectional analysis of mass within the British passenger car fleet. Estimation results confirmed that fuel consumption increases as mass increases and were different for different fuel and transmission types. It was shown that vehicle mass has both protective and aggressive safety effects where vehicle size only tends to have protective effects; these were estimated using a novel methodology based on a detailed analysis of two-car crashes. The estimated relationships were used to investigate partial safety and environmental effects of changes in mass distribution within the fleet using an introduced incremental approach. Results generally showed that the relationship between fuel economy and safety performance in vehicle design depends on the characteristics of the vehicle fleet, and in particular, mass distribution. It was shown that an informed change in the mass distribution not only imposes no trade-off between the fuel economy and safety goals, but also could lead to a desirable outcome in both aspects.

As vehicle manufacturers continue to increase their emphasis on safety with advanced driver assistance systems (ADAS), I propose a ubiquitous device that is able to analyze and advise on safety conditions. Mobile smartphones are increasing in popularity among younger generations with an estimated 64% of 25-34 year olds already using one in their daily lives. with over 10 million car accidents reported in the United States each year, car manufacturers have shifted their focus of a passive approach (airbags) to more active by adding features associated with ADAS (lane departure warnings). However, vehicles manufactured with these sensors are not economically priced while older vehicles might only have passive safety features. Given its accessibility and portability, I target a mobile smartphone as a device to compliment ADAS that can bring a driver assist to any vehicle without regards for any on-vehicle communication system requirements. I use the 3-axis accelerometer of multiple Android based smartphone to record and analyze various safety factors which can influence a driver while operating a vehicle. These influences with respect to the driver, vehicle and road are lane change maneuvers, vehicular comfort and road conditions. Each factor could potentially be hazardous to the health of the driver, neighboring public, and automobile and is therefore analyzed thoroughly achieving 85.60% and 89.89% classification accuracy for identifying road anomalies and lane changes, respectively. Effective use of this data can educate a potentially dangerous driver on how to operate a vehicle safely and efficiently. with real time analysis and auditory alerts of these factors, I hope to increase a driver's overall awareness to maximize safety.

Road transportation grew by 3.3 % per year over the past ten years which is faster than the economic growth of 2.3 % per year. European Commission plans for an increase of 55 % for road transportation between 2000 and 2020. This growth puts pressure on current trucking industry considering fuel consumption, emissions of green house gases, and traffic congestion.  High demand logistics industry and current pressure creates trends towards flexibility and longer vehicle combinations for efficiency and to reduce the number of engines on roads, challenging the current coupling methods of the trailers.  Primary method called 5th wheel coupling comes from a similar coupling used on 4 wheel horse-drawn carriages of the 19th century which is reliable in terms of attaching truck and trailer but has significant safety, efficiency and comfort issues for driver and the vehicles-people around.  So what if hauling setup could be safer and smarter?

Les intersections sont les zones les plus dangereuses du r��seau routier. Les ��tudes d'accidentologie montrent que la plupart des accidents aux intersections sont caus��s par des erreurs des conducteurs, et qu'une majorit�� d'accidents pourraient ��tre ��vit��s gr��ce �� l'utilisation de syst��mes d'aide �� la conduite. Dans ce cadre, les communications inter-v��hiculaire sont une technologie particuli��rement prometteuse. Le partage d'informations entre les v��hicules via des liens sans fil permet �� chaque v��hicule de percevoir son environnement au-del�� des limites de champ de vision de ses capteurs embarqu��s. Il en r��sulte une repr��sentation de l'environnement plus ��tendue dans l'espace et dans le temps, ce qui am��liore la compr��hension de situation et permet d'anticiper le danger. Cette th��se aborde le probl��me de l'estimation du risque sous un angle nouveau : elle propose une structure de raisonnement pour analyser les sc��nes routi��res et le risque de collision �� un niveau s��mantique, contrairement aux approches classiques qui raisonnent au niveau des trajectoires. Le risque est calcul�� en estimant les intentions des conducteurs et en d��tectant les conflits, sans avoir �� pr��dire les trajectoires futures des v��hicules. Plus pr��cis��ment, la d��tection des situations dangereuses est bas��e sur la comparaison entre ce que les conducteurs ont l'intention de faire et ce que les conducteurs devraient faire d'apr��s les r��gles de la circulation. Ce raisonnement est r��alis�� de mani��re probabiliste afin de prendre en compte les incertitudes sur les mesures capteur et les ambig��it��s sur l'interpr��tation de la sc��ne. En th��orie ce raisonnement peut ��tre appliqu�� �� tout type de sc��ne routi��re ; dans cette th��se nous pr��sentons son application aux intersections. Le mod��le propos�� prend en compte l'influence que la man��uvre d'un v��hicule exerce sur la man��uvre des autres v��hicules. Il incorpore aussi des informations sur l'influence de la g��om��trie et topologie de l'intersection sur le comportement d'un v��hicule. L'approche propos��e a ��t�� valid��e par des tests en environnement r��el avec des v��hicules communicants, ainsi qu'en simulation. Les r��sultats montrent que l'algorithme est capable de d��tecter les situations dangereuses et qu'il est compatible avec des applications s��curitaires temps-r��el.

The purpose of this Master thesis in Vehicle Engineering, is to study the road unevenness relation to road safety. The long term objective is to be able to prioritize which road section that is in the need of repair and maintenance prior to other road sections. This study focus on how close to an acceptable safety limit the vehicle is handled when it is run over different road surfaces. This applies to straight road sections as well as cornering, where the road surface is uneven and bumps/pits occurs. No driver behaviour or random actions are analysed but these aspects will be included in the overall discussion. The method to analyse this is through computer simulation. From a Volvo S40 a computerised vehicle model has been developed in Matlab and the effect of different road unevenness has been implemented and analysed. Forces that are generated by the unevenness of the road are compared with the normal forces that a driver needs to correct the course based on the friction between tire and road surface. On this basis, a margin to the risk of losing the grip can be estimated. In this way it can be interpreted how a road section contributes more or less, compared to another section, to whether the vehicle is closer to a safe limit from a vehicle dynamic perspective. The vehicle model has been analysed at a speed of 70 km/h with the simplification that the irregularities can be described by sinusoidal shapes. For larger bumps or dips in the road the results show that both front and rear tires can absorb side forces so that stability can be achieved. If the grip would deteriorate due to gravel, ice, etc. there is a risk that the vehicle loses steering control and/or cord leading to damage of the tyre and consequently an accident will occur. For the analysed road unevenness in the form of bumps and pits the tires do not have any ability to absorb required side forces during an avoidance manoeuvre when travelling over the road due to the tyre model used. It is therefore important that a section with varying unevenness are analysed to determine a maximum speed so that the control of the vehicle during the whole distance can be maintained regardless of whether control needs to be done in connection with the unevenness. A recommendation of future work in this area is to develop this model to make it more robust and to update the input data with relevant data for one today representative car and to carry out a more detailed full-scale modelling with also lateral simulations. If the model was verified with measured normal forces for a test car that has travelled over various bumps and pits, this would also be valuable to confirm the validity of the model. There would also be improvements if available road profile is implemented in the analysis so that realistic examples can be analysed for better real-world analysis.<br>Arbetet avser att, ur ett fordonsdynamiskt perspektiv, studera vägojämnhetens påverkan på trafiksäkerheten. Det långsiktiga målet med arbetet är att kunna prioritera vilka vägavsnitt som behöver repareras före andra. Studien behandlar hur nära en acceptabel säkerhetsgräns fordonet ligger rent fordonsdynamiskt när den färdas över vissa vägunderlag. Det gäller såväl på raksträckor som vid kurvtagning där vägytan har större ojämnheter (svackor) och gupp eller gropar. Metodiken som har använts är datasimulering. Utifrån en Volvo S40 har en fordonsmodell byggts upp i Matlab och inverkan av de olika typerna av vägojämnheter har sedan analyserats. Krafter som skapas från vägojämnheter jämförs sedan med de normalkrafter som en förare behöver för att korrigera kursen utifrån friktionen mellan däck och vägbana. Utifrån detta kan en manövermarginal uppskattas och på så sätt kan tolkning ske hur vida ett vägavsnitt bidrar mer eller mindre, jämfört med ett annat avsnitt, till att fordonet befinner sig närmare en trafiksäker gräns rent fordonsdynamiskt. Analysen har gjorts utifrån antagandet att fordonet har färdats med en hastighet på 70 km/h över de olika vägprofilerna. För större ojämnheter och svackor i vägbanan visar resultaten att både fram och bakdäck kan uppta de nödvändiga sidkrafterna för att stabilitet skall upprätthållas då goda vägförhållanden råder. Men skulle greppet försämras exempelvis av grus, halka etc. så föreligger risk att fordonet tappar styrförmåga och/eller får sladd. En begränsning i denna studie är att inga förarbeteenden eller slumpmässiga händelser kommer analyseras men däremot kommer dessa tas med i den övergripande diskussionen. Dessutom har ojämnheterna antagits vara beskrivna av sinus-funktioner och däcken har beskrivits av en modell som ej tar hänsyn till laterala egenskaper. För att kunna bestämma en maximal hastighet under vilken en kontroll över fordonet kan upprätthållas under hela sträckan oavsett manöver är det av vikt att ett vägavsnitt med varierande ojämnheter analyseras. För att vidareutveckla denna modell och göra den mer robust och aktuell rekommenderas att indata uppdateras med relevanta data för en idag representativ bil samt att modelleringen genomförs i full skala. Om modellen kan verifieras med uppmätta normalkrafter för en bil som har färdats över olika ojämnheter eller gupp vore det värdefullt. Att även implementera uppmätta vägprofiler så att realistiska exempel kan analyseras skulle dessutom ge ännu mer verklighetstrogna analyser.

The dissertation investigates communication quality issues in Vehicular Ad-hoc Network (VANET) using statistical analysis, experimental measurements, simulations and modelling. The Object of research is quality characteristics of Inter-Vehicle communication, which is based on IEEE 802.11p standard. The main objective of current research is to investigate Inter-Vehicle communication quality characteristics: packet loss and delay. Additionally propose a redundant safety message transmission method and create the confidence index concept and the calculation method. To reach these objectives following tasks have to be solved: define the boundary vehicular multi-hop transmission algorithms and investigate their performance for latency times defined in different use cases; analyze a packet loss caused by obstacles on the road and define approximation equations, for use in modelling tools; create the redundant packet transmission method for the lost safety message reduction; investigate the confidence index concept in a vehicular network and propose the confidence metrics calculation method; investigate the safe following distance dependency on road conditions and compare it to reliable communication distance. The dissertation consists of introduction, 4 chapters, conclusions and references. The introduction reveals the aim of the dissertation. The first chapter gives detailed overview of Inter-Vehicle communication environments and defines the main Inter-Vehicle communication... [to full text]<br>Disertacijoje nagrinėjama VANET ryšio kokybės problematika, analizei naudojant statistikos metodus, eksperimentinius tyrimus, modeliavimą ir simuliacijas. Tyrimų objektas yra ryšio tarp automobilių, kurio pagrindas IEEE 802.11p standartas, kokybės charakteristikos. Pagrindinis darbo tikslas – ištirti ryšio tarp automobilių kokybės charakteristikas: vėlinimus ir paketų praradimus. Papildomai pasiūlyti metodus ir algoritmus, mažinančius prarandamų saugos pranešimų skaičių. Pasiūlyti vairuotojo pasitikėjimo indekso koncepciją ir skaičiavimo metodus. Norint pasiekti šiuos tikslus, buvo spręsti sekantys uždaviniai: apibrėžti ribinius perdavimo grandine algoritmus ir ištirti jų efektyvumą perduodant pranešimus grandine; išanalizuoti duomenų paketų praradimus dėl kliūčių ir pateikti atitinkamus aproksimavimo algoritmus, tinkamus modeliavimams; sukurti dubliuotų saugos pranešimų perdavimo metodą, kuris leistų sumažinti prarandamų saugos pranešimų skaičių; sukurti vairuotojo pasitikėjimo indekso koncepciją ryšio tarp automobilių tinkle ir pasiūlyti pasitikėjimo indekso dedamųjų skaičiavimo metodus; ištirti saugaus važiavimo atstumo priklausomybę nuo kelio sąlygų ir palyginti ją su patikimo ryšio nuotolio išraiška. Disertaciją sudaro įvadas, 4 skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai. Įvade atskleidžiamas disertacijos tikslas. Pirmame skyriuje pateikiamas detalus ryšio tarp automobilių aplinkos savybių tyrimas. Yra... [toliau žr. visą tekstą]

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2007.<br>Includes bibliographical references (leaves 131-138).<br>Recent news events and statistics demonstrate the frequent occurrence of pile-up crashes on highways. A predominant reason for the occurrence of such crashes is that current vehicles (including those equipped with an Automatic Cruise Control system) do not provide the driver with advance information of events occurring far ahead of him/her. The use of inter-vehicular communication to provide advance warnings to enhance automotive safety is therefore being actively discussed in the research community. In this thesis, we investigate scenarios wherein only a subset of the vehicles in a multi-vehicle stream, are equipped with such advance warning capabilities. These vehicles (equipped with the capability to receive far-ahead information) are arbitrarily distributed among other unequipped vehicles that are capable of receiving only local, near-neighbor information. It is seen that there are conditions wherein even a partial equipment of the system can be beneficial (to both the equipped and the unequipped vehicles in a mixed vehicle stream). We demonstrate this through both simulations and a theoretical analysis. Towards this end, two distinct modeling approaches are adopted: microscopic and macroscopic.<br>(cont.) The microscopic modeling approach uses ordinary differential equations to model each driver-vehicle unit and its interactions with its neighbors. A single-lane model is employed; and the problem is formulated as a collision avoidance problem. Sufficient conditions on the number of equipped vehicles, as well as their distributions in a mixed vehicle string are obtained; under these conditions, it is guaranteed that collisions do not occur. The macroscopic modeling approach, on the other hand, uses partial differential equations that govern the average behavior of groups of vehicles. In this approach, a multi-lane formulation is employed. This thesis examines the influence of partial equipment of the advance warning system on some of the wave effects that are known to exist in traffic flows, in particular, shocks and large negative velocity gradient waves that travel unattenuated or get amplified as they pass through the traffic. We examine the influence of the equipped vehicles in attenuating such waves. The resulting velocity gradients are parametrized as a function of the percentage of equipped vehicles. A prototype of an advance warning system was also developed and road tests were conducted to test the concept. These road tests have demonstrated the system's performance to be satisfactory, subject to good communication links, for the class of scenarios tested.<br>by Animesh Chakravarthy.<br>Ph.D.

Engenharia Mecânica<br>Nos últimos anos, o número de vítimas de acidentes de tráfego por milhões de habitantes em Portugal tem sido mais elevado do que a média da União Europeia. Ao nível nacional torna-se premente uma melhor compreensão dos dados de acidentes e sobre o efeito do veículo na gravidade do mesmo. O objetivo principal desta investigação consistiu no desenvolvimento de modelos de previsão da gravidade do acidente, para o caso de um único veículo envolvido e para caso de uma colisão, envolvendo dois veículos. Além disso, esta investigação compreendeu o desenvolvimento de uma análise integrada para avaliar o desempenho do veículo em termos de segurança, eficiência energética e emissões de poluentes. Os dados de acidentes foram recolhidos junto da Guarda Nacional Republicana Portuguesa, na área metropolitana do Porto para o período de 2006-2010. Um total de 1,374 acidentes foram recolhidos, 500 acidentes envolvendo um único veículo e 874 colisões. Para a análise da segurança, foram utilizados modelos de regressão logística. Para os acidentes envolvendo um único veículo, o efeito das características do veículo no risco de feridos graves e/ou mortos (variável resposta definida como binária) foi explorado. Para as colisões envolvendo dois veículos foram criadas duas variáveis binárias adicionais: uma para prever a probabilidade de feridos graves e/ou mortos num dos veículos (designado como veículo V1) e outra para prever a probabilidade de feridos graves e/ou mortos no outro veículo envolvido (designado como veículo V2). Para ultrapassar o desafio e limitações relativas ao tamanho da amostra e desigualdade entre os casos analisados (apenas 5.1% de acidentes graves), foi desenvolvida uma metodologia com base numa estratégia de reamostragem e foram utilizadas 10 amostras geradas de forma aleatória e estratificada para a validação dos modelos. Durante a fase de modelação, foi analisado o efeito das características do veículo, como o peso, a cilindrada, a distância entre eixos e a idade do veículo. Para a análise do consumo de combustível e das emissões, foi aplicada a metodologia CORINAIR. Posteriormente, os dados das emissões foram modelados de forma a serem ajustados a regressões lineares. Finalmente, foi desenvolvido um indicador de análise integrada (denominado “SEG”) que proporciona um método de classificação para avaliar o desempenho do veículo ao nível da segurança rodoviária, consumos e emissões de poluentes.Face aos resultados obtidos, para os acidentes envolvendo um único veículo, o modelo de previsão do risco de gravidade identificou a idade e a cilindrada do veículo como estatisticamente significativas para a previsão de ocorrência de feridos graves e/ou mortos, ao nível de significância de 5%. A exatidão do modelo foi de 58.0% (desvio padrão (D.P.) 3.1). Para as colisões envolvendo dois veículos, ao prever a probabilidade de feridos graves e/ou mortos no veículo V1, a cilindrada do veículo oposto (veículo V2) aumentou o risco para os ocupantes do veículo V1, ao nível de significância de 10%. O modelo para prever o risco de gravidade no veículo V1 revelou um bom desempenho, com uma exatidão de 61.2% (D.P. 2.4). Ao prever a probabilidade de feridos graves e/ou mortos no veículo V2, a cilindrada do veículo V1 aumentou o risco para os ocupantes do veículo V2, ao nível de significância de 5%. O modelo para prever o risco de gravidade no veículo V2 também revelou um desempenho satisfatório, com uma exatidão de 40.5% (D.P. 2.1). Os resultados do indicador integrado SEG revelaram que os veículos mais recentes apresentam uma melhor classificação para os três domínios: segurança, consumo e emissões. Esta investigação demonstra que não existe conflito entre a componente da segurança, a eficiência energética e emissões relativamente ao desempenho dos veículos.<br>During the last years, the number of fatalities per million inhabitants in Portugal has always been higher than the average in the European Union. Therefore, at national level, there is a need for a more effective understanding of crash data and vehicles effects on crash severity. This research examined the effects of vehicle characteristics on severity risk, fuel use and emissions. The main goal of this research was to develop models for crash severity prediction in single vehicle-crashes and two-vehicle collisions. Furthermore, this research aimed at developing an integrated analysis to evaluate vehicle’s safety, fuel efficiency and emission performances. Crash data were collected from the Portuguese Police Republican National Guard records for the Porto metropolitan area, for the period 2006-2010. A total of 1,374 crashes were collected, 500 single-vehicle crashes and 874 two-vehicle collisions. For the safety analysis, logistic regressions were used. For single-vehicle crashes, the effect of vehicle characteristics to predict the probability of a serious injury and/or killed in vehicle occupants (designed as binary target) was explored. For two-vehicle collisions, additional binary targets were designed: one target to predict the probability of a serious injury and/or killed in vehicle V1) and another target to predict the probability of a serious injury and/or killed in vehicle V2). To overcome the challenge imposed by sample size and high imbalanced data (only 5.1% were severe crashes), research methodology was developed based on a resampling strategy and 10 stratified random samples were used for validation. During the modeling stage, the effect of vehicle characteristics, such as weight, engine size, wheelbase and age of vehicle were analyzed. For the vehicle’s fuel efficiency and emissions analysis, pollutants were estimated using CORINAIR methodology. Following, emissions data were fit into linear regression models. Finally, an integrated analysis indicator (entitled “SEG”) that provides rating classification for the evaluation of vehicle’s safety, fuel efficiency and emission performances, was developed. Regarding these results, for single-vehicle crashes, injury severity prediction model identified age of the vehicle and engine size as statistically significant, at 5% level. Model performance accuracy rate was 58.0% (S.D. 3.1). For two-vehicle collisions, when predicting injury severity in vehicle V1, the engine size of the opponent vehicle (vehicle V2) increased the risk for the occupants of the subject vehicle (vehicle V1), at 10% level. Injury severity prediction model for vehicle V1 revealed a good performance with a mean prediction accuracy rate of 61.2% (S.D. 2.4). When predicting injury severity for the other vehicle involved (vehicle V2), the engine size of the opponent vehicle (vehicle V1) increased the risk for the occupants of vehicle V2, at 5% level. Injury severity prediction model for vehicle V2 achieved a mean prediction accuracy rate of 40.5% (S.D. 2.1). The results of the integrated analysis indicator, SEG, revealed that recent vehicle achieved better rating simultaneously for all the three domains: safety, fuel efficiency and emissions performances. Newer vehicles showed a better overall safety rating, were more fuel efficient (less CO2 emissions) and reduced emissions (more environmental friendly). This research relevance showed that there is no trade-off between safety, fuel efficiency and emissions.

Safety is an important aspect of ethical, socially responsible logistics. Current U.S. motor carrier (MC) safety research topical coverage includes the effects of individual and environmental influences, carrier safety management, and regulatory compliance on carrier safety and driver fatigue/safety performance. Interestingly, little research on the subject of truck drivers' safety attitudes and behaviors exists and the underlying decision-making processes that guide drivers' safety-related behaviors have received little attention. Furthermore, researchers have not provided an integrated framework that explains individual, organizational, and regulatory factors' impact on drivers' safety decision-making and performance. Truck drivers' safety judgments, decisions, and actions must adhere to societal safety norms. To that end, ethical decision-making theory that draws from the deontological and teleological traditions in moral philosophy provides a theoretical foundation and integrated framework necessary to better understand drivers' safety decision-making processes. The current research sought to determine how drivers rely on safety norms and perceived consequences in forming safety judgments and behavioral intentions. Furthermore, the study was designed to explore how various factors (i.e., individual, organizational, and regulatory) influence drivers' safety decision-making processes. Specifically, the study sought to answer the broad question, "How do commercial motor vehicle drivers make safety-related decisions, and how do individual, organizational, and regulatory factors influence drivers' safety decision-making processes?" An experimental two-factor design (2×2) was used to manipulate safety norms (i.e., "deontologically unsafe situation" and "deontologically safe situation") and consequences (i.e., "positive consequences" and "negative consequences"). Multivariate statistical analysis revealed that drivers primarily rely on deontological evaluations in forming safety judgments. Furthermore, drivers primarily relied on safety judgments when forming behavioral intentions. Drivers' attitudes toward unsafe actions and the effectiveness of driver-related safety regulations were also influential to drivers' judgments and intentions, respectively. The empirical findings demonstrate to managers that communication and education of safety norms may be highly effective to improve safety in unique occupational contexts where employees are given high levels of responsibility with little physical supervision, and where judgment errors can have devastating consequences for multiple stakeholders.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV<br>In this paper, we present our research on using computer-vision analysis for vehicular safety applications. Our research has potential applications for both autonomous vehicles and connected vehicles. In particular, for connected vehicles, we propose three image analysis algorithms that enhance the quality of a vehicle's on-board video before inter-vehicular information exchange takes place. For autonomous vehicles, we are investigating a visual analysis scheme for collision avoidance during back up and an algorithm for automated 3D map building. These algorithms are relevant to the telemetering domain as they involve determining the relative pose between a vehicle and other vehicles on the road, or between a vehicle and its 3D driving environment, or between a vehicle and obstacles surrounding the vehicle.

The sales of all-terrain vehicles (ATVs) are increasing year by year, especially in countries like Sweden, Australia and New Zealand. With the increase in sales, a proportional rise in number of accidents involving all-terrain vehicles is also evident. Of these accidents the major cause was identified as rollover occurrence. While there are some protection devices, the lack of rollover prevention devices available is glaring. In addition to that, ATVs do not have many control units or electronic systems compared to modern-day cars. This makes it difficult to implement complicated computer technology to improve vehicle stability or act as a prevention system. In this thesis, a couple of active safety systems to prevent rollover have been proposed. Lateral Load Transfer Ratio (LLTR) is used as the primary parameter to analyse and signify rollover. First, an alarm has been proposed based on LLTR and roll angle. Two different types of alarms have been analysed, one based on real-time values and the other on predicted values. The prediction-based alarm shows better performance over the other alarm by giving the driver more time to take action. Second, to remove the flaws of the alarms and take away control from the driver, in case of impending rollover, an active braking system has been proposed. Multiple braking strategies have been simulated. The strategy where the brakes are applied on the outer wheels was found to be most effective.<br>Försäljningen av terrängfordon (ATV:s) ökar år för år, särskilt i länder som Sverige, Australien och Nya Zeeland. Som effekt av den ökande försäljningen kan man observera en proportionell ökning av antalet olyckor med terrängfordon. Bland dessa har huvudorsaken identifierats till vältningsolyckor. Även om det i dagsläget finns anordningar som skyddar förare av ATV:s vid tippning så råder det en tydlig brist på utrustning som förebygger själva vältningen. Dessutom har ATV:s inte många reglerenheter eller elektroniska system jämfört med moderna bilar. Detta gör det svårt att implementera komplicerad elektronisk teknologi för att förbättra stabilitet och förebygga uppkomsten av vältning. I denna avhandling har flera aktiva säkerhetssystem som förebygger vältning föreslagits. Lateral Load Transfer Ratio (LLTR) används som den primära parametern för att analysera och visa på risken av vältning. Först har ett varningssystem föreslagits i form av ett larm baserat på LLTR och krängningsvinkel. Två olika typer larm har analyserats, ett baserat på realtidsvärdena av dessa parametrar och det andra på deras predikterade värden. Larmet baserat på prediktering har visat bättre resultat gentemot realtidsalarmet genom att förse föraren med mer tid för att utföra en stabiliserande manöver. För att förbättra effektiviteten av säkerhetssystemet och befria föraren från att behöva vidta åtgärder har även ett aktivt bromssystem föreslagits där olika bromsstrategier simulerats. Av dessa vältningsförebyggande bromsstrategier har det som bromsar de yttre hjulen visat bäst resultat.

This thesis sought to better understand how financial pressures influence the safety of heavy truck operations in Australia. Truck driver employment (direct and outsourced) and payment methods influenced the risk of crashes and unsafe driving behaviours, and were in turn associated with companies’ perceptions of their financial performance. Improved training in financial management and monitoring of financial performance could be effective approaches to improving safety of both freight transport and those who share the roads with heavy trucks.

This research presents theoretically an automated vehicle merging control which is an important subsystem of AHS. The goal of the system is to automatically control the vehicle merging from ramp to the AHS lane in an efficient, smooth and safe manner. The entire merging process is divided the a speed adjustment stage and a lane merging stage. Three important parameters; acceptability, availability and pursuability are analyzed to characterize the AHS lane gap features. Three control guidance laws (linear, optimal and parabolic speed profile) are developed to describe the desired behaviors of the merging vehicle based on the merging quality and safety consideration. The desired states of the merging vehicle are generated through the outer loop by specified control guidance law. The tracking errors compared with desired states are eliminated by the proper design of controllers in the inner loop. Both longitudinal and lateral controller are designed using the sliding mode control theory which can handle the model nonlinearities and uncertainties of the vehicle dynamics. Two new sliding mode methods are proposed in the design of the lateral controller. The proposed system is evaluated and validated through computer simulations. The simulation results show that system performance is satisfactory under the various merging conditions for a smooth, efficient and safe merging. The system also supplies a basis for the further research on the multiple merging control system and the lane changing control system.<br>Ph. D.

One of the major challenges for automotive engineers is to provide adequate protection to motor vehicle occupants involved in side impact collisions. Although, side impacts are less frequent than frontals, to both the occupant and vehicle designer they are as serious because the number and severity of injuries per accident is greater. The objective of the current research work is to develop an approach to optimize the vehicle structure for side impact collisions and provide recommendations to enhance vehicle structural design. To achieve the above objectives, this research study was broken into five phases: Phase (1) A side impact finite element simulation package was developed as an analysis tool for use in this research. As such, this phase discusses the development and verification of the finite element simulation package based on FMVSS-214 standard compliance test configuration utilizing the LS-DYNA software. This package consists of finite element model of a U.S. Moving Deformable Barrier (MDB), a US Side Impact Dummy (SID) , and a target vehicle (1990 Ford Taurus), Phase (2) The previously developed simulation package was utilized to investigate the effect of the collision parameters on the occupant injury likelihood within this phase, Phase (3) A new criterion was developed and verified which simplifies the numerical analyses such that they are computationally cost effective, Phase (4) The critical vehicle structural components in providing side impact crashworthiness were identified, and the effects of their stiffness on the occupant injury likelihood were investigated within this phase, and Phase (5) The results of the previous phases were utilized in this phase to develop a strategy for optimizing the stiffness of the side structure elements, thus minimizing the injury likelihood. The results of this study demonstrated a successful example of the developed state-of-the-art strategy to optimize the vehicle structure to improve side impact crashworthiness. This new strategy is a significant contribution of this research, and improves upon the current design strategy in two ways: (1) this new approach recognizes the effects of the collision parameters on the occupant injury likelihood and addresses their effect on the optimization of the vehicle structure for side impact collisions, and (2) the developed strategy improves the efficiency of the design analysis tools by utilizing a new developed criterion for assessing the vehicle structural side impact crashworthiness. The development and verification of this criterion is also a significant contribution of this research, which could substantially improve the efficiency of the design process and thus should be of benefit to vehicle designers especially early in the vehicle design process. This work also provides insight information for vehicle regulators by substantiating the relative effect of various key collision parameters on the risk of occupant injury in side impact collisions in North America.<br>Applied Science, Faculty of<br>Mechanical Engineering, Department of<br>Graduate

Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, School of Engineering, System Design and Management Program, Engineering and Management Program, 2016.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 120-122).<br>As with other critical systems, space systems are also getting larger and more complex. Although Japan Aerospace Exploration Agency (JAXA) has designed various spacecraft and had not experienced any serious accident for more than 10 years, loss of an astronomical satellite finally happened in 2016 even though the development process was not drastically different from the past. The accident implies that the complexity of space systems can no longer be managed by the traditional safety analysis. Furthermore, in huge system developments, the fluidity of design is rapidly lost as the development proceeds. Thus, creating a safer system design in the early development phase that is capable of handling various undesirable scenarios will significantly contribute to the success of huge and complex system development. The goal of this thesis is to establish the way to design a safer system in the context of modern huge and complex systems and demonstrate its effectiveness in an actual JAXA future transfer vehicle design. As a solution, in this thesis a new accident model called System Theoretic Accident Model and Process (STAMP) is used. The safety analysis methods based on STAMP were invented to handle the characteristics of modem complex systems. Furthermore, detailed designs are not required in the analysis. Therefore, the issues of modern complex systems are expected to be solved by the system theoretic safety design methods. In this thesis, two types of system analysis were conducted based on STAMP: concept design analysis in the target system and incident analysis in a similar previous system. While any detailed specification was not available, various unsafe off-nominal system behaviors were derived from the concept design, and it was refined. Remarkably, off-nominal behaviors due to a new design policy being applied in the system were successfully described. Furthermore, various design flaws involving human-automation interactions were also found, which usually tends to be discussed in the later development phase. The result indicates the proposed system theoretic safety design approaches can be successfully interwoven with the early stage of development process, and systems can be fundamentally refined from a safety perspective to prevent future serious losses.<br>by Ryo Ujiie.<br>S.M. in Engineering and Management

Connected vehicles for safety applications play a significant role on reduction of the risks of road accidents. However, the performance of communication and positioning approaches is a major concern. This thesis establishes a connectivity framework based on publish-subscribe architecture for high-timeliness vehicle-to-vehicle data exchanges and determines the performance requirements for precise vehicle positioning for various safety use cases. Extensive experimental results demonstrated the performance benefits of the communication and positioning solutions for vehicle safety applications.

Object detection exists in many countries around the world after a recent growing interest for autonomous vehicles in the last decade. This paper focuses on a vision-based approach focusing on vehicles and pedestrians detection in real-time as a perception for autonomous vehicles, using a convolutional neural network for object detection. A developed YOLOv3-tiny model is trained with the INRIA dataset to detect vehicles and pedestrians, and the model also measures the distance to the detected objects. The machine learning process is leveraged to describe each step of the training process, it also combats overfitting and increases the speed and accuracy. The authors were able to increase the mean average precision; a way to measure accuracy for object detectors; 31.3\% to 62.14\% based on the result of the training that was done. Whilst maintaining a speed of 18 frames per second.

Road departure crashes are among the deadliest crash modes in the U.S. each year. In response, automakers have been developing lane departure active safety systems to alert drivers to impending departures. These lane departure warning (LDW) and lane departure prevention (LDP) systems have great potential to reduce the frequency and mitigate the severity of serious lane and road departure crashes. The objective of this thesis was to characterize lane and road departures to better understand the effect of systems such as LDW and LDP on single vehicle road departure crashes. The research includes the following: 1) a characterization of lane departures through analysis of normal lane keeping behavior, 2) a characterization of road departure crashes through the development and validation of a real-world crash database of road departures (NCHRP 17-43 Lite), and 3) develop enhancements to the Virginia Tech LDW U.S. fleetwide benefits model. Normal lane keeping behavior was found to vary with road characteristics such as lane width and road curvature. Consideration of the dynamic driving behaviors observed in the naturalistic driving study (NDS) data is important to avoid LDW false alarms and driver annoyance. Departure characteristics computed in normal driving were much less severe than the departure parameters measured in real-world road departure crashes. The real-world crash data collected in NCHRP 17-43 Lite database was essential in developing enhancements to the existing Virginia Tech LDW fleetwide benefits model. Replacement of regression model predictions with measured crash data and improvement of the injury criteria resulted in an 11-16% effectiveness for road departure crashes, and an 11-15% reduction in seriously injured drivers.<br>Master of Science

Uniformed presences are thought to create feelings of safety in people. However, do different uniformed people contribute to the same amount of safety and are there differences dependent on the situation? The present study examined the association between various types of uniformed presence and people’s feelings of safety through a questionnaire among 352 respondents (18-86 years) (49.1 % women). The questionnaire contained pictures of relatively safe and unsafe situations with or without uniformed presence. The respondents estimated how safe they thought they would feel in these situations with and without two police officers, six police officers, a police car, two security guards, or two police volunteers. The results showed that uniformed presence does not increase feelings of safety in an already relatively safe situation, making patrol unnecessary. In relatively unsafe situations however, all types of uniformed presence increase feelings of safety. Foot patrolling police increased feelings of safety the most. Security guards and police volunteers created approximately the same amount of safety; making police volunteers a cost-effective alternative, although some situation, gender and age differences were found. All types of foot patrol were better than vehicle patrol (with some gender differences), making non-police groups an alternative to vehicle patrol.

Fault-tolerant vehicle design is an emerging inter-disciplinary research domain, which is of increasedimportance due to the electrification of automotive systems. The goal of fault-tolerant systems is to handleoccuring faults under operational condition and enable the driver to get to a safe stop. This paperpresents results from an extended survey on fault-tolerant vehicle design. It aims to provide a holisticview on the fault-tolerant aspects of a vehicular system. An overview of fault-tolerant systems in generaland their design premises is given as well as the specific aspects related to automotive applications. Thepaper highlights recent and prospective development of vehicle motion control with integrated chassiscontrol and passive and active fault-tolerant control. Also, fault detection and diagnosis methods arebriefly described. The shift on control level of vehicles will be accompanied by basic structural changeswithin the network architecture. Control architecture as well as communication protocols and topologiesare adapted to comply with the electrified automotive systems. Finally, the role of regulations andinternational standardization to enable fault-tolerant vehicle design is taken into consideration.<br><p>Qc 20120730</p>

With the introduction of electronic control units to automotive vehicles, system complexity has increased. With this change in complexity, new standards have been created to ensure safety at the system level for these vehicles. Furthermore, vehicles have become increasingly complex with the push for electrification of automotive vehicles, which has resulted in the creation of hybrid electric and battery electric vehicles. The goal of this thesis is to provide an example of a hazard and operability analysis as well as a hazard and risk analysis for a hybrid electric vehicle. Additionally, the safety standards developed do not align well with educational prototype vehicles because the standards are designed for corporations. The hybrid vehicle supervisory controller example within this thesis demonstrates how to define a system and then perform system-level analytical techniques to identify potential failures and associated requirements. Ultimately, through this analysis suggestions are made on how best to reduce system complexity and improve system safety of a student built prototype vehicle.<br>Master of Science

The Master thesis has been carried out at Autoliv B.V. &amp; Co. KG in Dachau, which is a global automotive safety corporation. The objective of the thesis was to define component characteristics, which would reduce the load on a 5th percentile female dummy in a full frontal crash to achieve a five star in the new Euro NCAP full frontal crash test. Euro NCAP (voluntary vehicle safety rating system) tests new vehicles launched on the European market with the goal to encourage manufacturers to aim for more than the legislative minimum requirements. The safety performance of the vehicles is evaluated and rated in a star rating system where a maximum of five stars can be awarded depending on the impact on the dummy. The method Design of Experiments was used in the thesis and determined as a successful method to find an optimal component setting. The system with the 5th percentile female dummy was decided to be investigated in total nine parameters with different settings and eleven measured responses. The D-optimal design was considered as the most suitable design for the experiments since it was handling input parameters with different levels on the factors. Moreover, it was significantly reducing the number of required experiments. The D-optimal design was considered as suitable for optimization of parameters, however it was found as preferable to first execute a simple screening of the parameters to ensure that an appropriate range of the parameters had been selected. In this case a screening with Plackett Burman would have required 80% less experiments to investigate the selected range of the parameters. The two software programs, Minitab and Datalysor, were used to analyze the Design of Experiments. In the analysis, the main parameters, interactions and higher terms were identified, which significantly influenced the responses. Furthermore, regressions were evaluated and the programs strengths and weaknesses were compared. It was shown that the regressions made in Datalysor were more accurate and a better model of the reality. The reason for the better regression was because Datalysor had the possibility to remove different outliers and predictors for every regression, which was not possible in Minitab. From the regression model an optimal setting was found which fulfilled the requirements from Euro NCAP and five stars could be achieved.