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Neal, Terance (Terance K. )., and David Hill. "Frontal collision analysis of City Car." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/63031.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 39).
This experiment tests the proposed crash system of the CityCar. The car is to fold during the crash to help decrease the impact force experienced by the passengers. The experiment was conducted by running a simulation of the car crashing into a wall compared to that of a rigid car with no folding, and by building a one-fifth scale wooden model of the CityCar, running it into a wall, and measuring the force upon impact. The simulation was ran at 20 mph, 50 mph, and 80 mph, with weight ratios between the front and back of the car respectively of 1:1, 1:2, 1:3, 2:1, and 3:1, as well as three variations in the damping of the folding process. Both experiments show that the folding car experienced lower forces than the rigid car. The variations done in the simulation suggest that a back heavy car with considerable damping is best, but these results were a bit inconsistent and unclear and, therefore, will be tested more completely in the future. Results suggest that folding during a crash provides significant help, but this experiment only provides preliminary feedback useful for future analysis of the CityCar.
by Terance Neal [and] David Hill.
S.B.
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Happian-Smith, J. "Motorcycle and rider dynamics in frontal collision, simulation and verification." Thesis, Brunel University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234975.
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Kuehbeck, Thomas. "Pre-crash extraction of the constellation of a frontal collision between two motor vehicles." Thesis, Staffordshire University, 2017. http://eprints.staffs.ac.uk/4571/.
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One of the strategic objectives of the European Commission is to halve the number of road traffic fatalities by 2020. In addition, in 2010, the United Nations General Assembly initiated the "Decade of Action for Road Safety 2011-2020" to reduce the number of fatalities and decrease the number of road traffic injuries. To address the scourge of road traffic accidents, this thesis presents a research study which has devised and evaluated a novel algorithm for extracting the constellation of an unavoidable frontal vehicle-to-vehicle accident. The primary research questions addressed in this work are: • What are the most significant collision parameters which influence the injury severity for a frontal collision between two motor vehicles? • How to extract the constellation of a crash before the accident occurs? In addition, the secondary research questions given below were addressed: • How to integrate physical constraints, imposed on the rate of acceleration of a real vehicle, together with data from vehicle-to-vehicle (V2V) communication, into the crash constellation extraction algorithm? • How to integrate uncertainties, associated with the data captured by sensors of a real vehicle, into a simulation model devised for assessing the performance of crash constellation extraction algorithms? Statistical analysis, conducted to determine significant collision parameters, has identified three significant crash constellation parameters: the point of collision on the vehicle body and the relative velocity between the vehicles; and the vehicle alignment offset (or vehicle overlap). The research reported in this thesis has also produced a novel algorithm for analysing the data captured by vehicle sensors, to extract the constellation of an unavoidable vehicle-to-vehicle frontal accident. The algorithm includes a model of physical constraints on the acceleration of a vehicle, cast as a gradual rise and eventual saturation of vehicle acceleration, together with the acceleration lag relative to the timing of information received from V2V communication. In addition, the research has delivered a simulation model to support the evaluation of the performance of crash constellation extraction algorithms, including a technique for integrating (into the simulation model, so that the simulation can approach real-world behaviour) the uncertainties associated with the data captured by the sensors of a real vehicle. The results of the assessment of the soundness of the simulation model show that the model produces the expected level of estimation errors, when simulation data is considered on its own or when it is compared to data from tests performed with a real vehicle. Simulation experiments, for the performance evaluation of the crash constellation extraction algorithm, show that the uncertainty associated with the estimated time-to-collision decreases as vehicle velocity increases or as the actual time-to-collision decreases. The results also show that a decreasing time-to-collision leads to a decreasing uncertainty associated with the estimated position of the tracked vehicle, the estimated collision point on the ego vehicle, and the estimated relative velocity between the two vehicles about to collide. The results of the performance assessment of the crash constellation extraction algorithm also show that V2V information has a beneficial influence on the precision of the constellation extraction, with regards to the predicted time-to-collision, the predicted position and velocity of the oncoming vehicle against which a collision is possible; the predicted relative velocity between the two vehicles about to collide, and the predicted point of collision on the body of the ego vehicle. It is envisaged that the techniques, developed in the research reported in this thesis, will be used in future integrated safety systems for motor vehicles. They could then strongly impact passenger safety by enabling optimal activation of safety measures to protect the vehicle occupants, as determined from the estimated constellation of the impending crash.
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Delcaillau, Bernard. "Evolution géomorphostructurale d'un piémont frontal de chaîne de collision intracontinentale les Siwalik de l'Himalaya du Népal oriental." Lille 3 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37597020c.
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Delcaillau, Bernard. "Evolution geomorphostructurale d'un piemont frontal de chaine de collision intracontinentale : les siwalik de l'himalaya du nepal oriental." Toulouse 2, 1986. http://www.theses.fr/1986TOU20091.
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Les siwalik representent la partie la plus ancienne (mio-pleistocene) du piemont himalayen. Ils sont constitues par une succession de crets orientes ese - wnw a front tourne vers le sud et separes par des depressions longitudinales (les duns). Tailles dans les molasses mio-pleistocenes, ces reliefs sont apparus consecutivement au jeu de chevauchements imbriques. Au nord, le m. B. T. Est le plus ancien de ces chevauchements, le m. D. T. Lui succede plus au sud, enfin le m. S. T. , le plus recent met en superposition les materiaux et reliefs siwalik sur les alluvions de la plaine gangetique. Cette structuration progressive des siwalik et du front himalayen con- trole l'apparition successive des reliefs et des duns qui les separent ; elle a ete enregistree par la sedimentation molassique siwalik. Cet ensemble constitue un prisme d'accretion tectonique associe a une collision intracontinentale. Dans ce memoire, sont abordees successivement l'etude sedimentologique des series siwalik et des depots du pleistocene, puis l'etude de la deformation de ces mate- riaux menee depuis l'echelle regionale jusqu'a l'echelle de l'affleurement. Apres avoir defini le regime des contraintes, un modele d'evolution geodynamique du prisme siwalik est proposeSouth of the himalayas, the siwalik range, developped in the mio-pleistocene molassic deposits, is composed of ese-wnw trending hogbacks. The geomorphological structural and sedimentological datas show that the orogenic movements are under the strict dependance of the thrusting dynamic : the reliefs are linked to thrusts which appeared successively from north to south : the m. B. T. Appeared first, then the m. D. T. And finally, the m. S. T. . This successive appearence of thrusts and reliefs more and more recent from north to south, can be assimilated to a piggy back thrust sequence. The siwalik area is closely comparable to a tectonic accretionary wedge linked to an intracontinental collision. In this survey, we'll successively analysed the siwalik and post-siwalik sedimentation and the deformation of these materials inside each thrusting set. The stress pattern is analysed and compared with the morphostructural organisation of the siwalik. In conclusion, a geodynamic evolutionary model of this intracontinental tectonic prism has been proposed in this analysis
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Peck, Louis Raymond. "Dynamic Failure Properties of the Porcine Medial Collateral Ligament: Predicting Human Injury in High Speed Frontal Automotive Collisions." Link to electronic thesis, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-050207-155719/.
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Kullgren, Anders. "Validity and reliability of vehicle collision data : crash pulse recorders for impact severity and injury risk assessments in real-life frontal impacts /." Stockholm, 1998. http://diss.kib.ki.se/1998/91-628-3280-8/.
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Albert, Devon Lee. "Biomechanical Responses of Human Surrogates under Various Frontal Loading Conditions with an Emphasis on Thoracic Response and Injury Tolerance." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/100947.
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Frontal motor vehicle collisions (MVCs) resulted in 10,813 fatalities and 937,000 injuries in 2014, which is more than any other type of MVC. In order to mitigate the injuries and fatalities resulting from MVCs, new safety restraint technologies and more biofidelic anthropomorphic test devices (ATDs) have been developed. However, the biofidelity of these new ATDs must be evaluated, and the mechanisms of injury must be understood in order to accurately predict injury. Evaluating the biomechanical response, injury mechanisms, and injury threshold of the thorax are particularly important because the thorax is one of the most frequently injured body regions in MVCs. Furthermore, sustaining a severe thoracic injury in an MVC significantly increases mortality risk.
The overall objective of this dissertation was to evaluate the biomechanical responses of human surrogates under various frontal loading conditions. This objective was divided into three sub-objectives: 1) to evaluate the biofidelity of the current frontal impact ATDs, 2) to evaluate the effect of different safety restraints on occupant responses, and 3) to evaluate rib material properties with respect to sex, age, structural response, and loading history.
In order to meet sub-objectives 1 and 2, full-scale frontal sled tests were performed on three different human surrogates: the 50th percentile male Hybrid III (HIII) ATD, the 50th percentile male Test Device for Human Occupant Restraint (THOR-M) ATD, and approximately 50th percentile male post-mortem human surrogates (PMHS). All surrogates were tested under three safety restraint conditions: knee bolster (KB), KB and steering wheel airbag (KB/SWAB), and knee bolster airbag and SWAB (KBAB/SWAB). The kinematic, lower extremity, abdominal, thoracic, and neck responses were then compared between surrogates and restraint conditions. In order to assess biofidelity, the ATD responses were compared to the PMHS responses. For both the kinematic and thoracic responses, the HIII and THOR-M had comparable biofideltiy. However, the HIII responses
were slightly more biofidelic. The ATDs experienced similar lower extremity kinetics, but very different kinetics at the upper and lower neck due to differences in design. Evaluation of the different restraint conditions showed that the SWAB and KBAB both affected injury risk. The SWAB decreased head injury risk for all surrogates, and increased or decreased thoracic injury risk, depending on the surrogate. The KBAB decreased the risk of femur injury, but increased or decreased tibia injury risk depending on the surrogate and injury metric used to predict risk.
In order to meet sub-objective 3, the tensile material properties of human rib cortical bone and the structural properties of whole ribs were quantified at strain rates similar to those observed in frontal impacts. The rib cortical bone underwent coupon tension testing, while the whole ribs underwent bending tests intended to simulate loading from a frontal impact. The rib material properties accounted for less than 50% of the variation observed in the whole rib structural properties, indicating that other factors, such as rib geometry, were also influencing the structural response of whole ribs. Age was significantly negatively correlated with the modulus, yield stress, failure strain, failure stress, plastic strain energy density, and total strain energy density. However, sex did not significantly influence any of the material properties. Cortical bone material properties were quantified from the ribs that underwent the whole rib bending tests and subject-matched, untested (control) ribs in order to evaluate the effect of loading history on material properties. Yield stress and yield strain were the only material properties that were significantly different between the previously tested and control ribs.
The results of this dissertation can guide ATD and safety restrain design. Additionally, this dissertation provides human surrogate response data and rib material property data for the validation of finite element models, which can then be used to evaluate injury mitigation strategies for MVCs.PHD
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Vašíček, Jiří. "Kompatibilita vozidel při čelním střetu." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-232731.
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Thesis deals with the compatibility of vehicles in a frontal collision. The first section discusses about compatibility from different views. There are the physical processes used in the mechanics of impact. The second part is focused on solving the compatibility of vehicles in a frontal collision by crash analysis using the finite element method. Firstly there are described collisions of vehicles from different vehicle classes (small cars, lower middle class, Pick up / SUV) into the fixed barrier by the US NCAP. Furthermore there are simulated head-on collisions of vehicles from different vehicle classes. In the end there is shown the possibility of using data from crash tests to determine the EES.
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Heath, Douglas. "Factors Affecting Occupant Risk of Knee-Thigh-Hip Injury in Frontal Vehicle Collisions." Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-theses/422.
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Every year, millions of people are killed or injured in motor vehicle accidents in the United States. Although recent improvements to occupant restraint systems, such as seatbelts and airbags, have significantly decreased life threatening injuries, which usually occur to the chest or head, they have done little to decrease the occurrence of lower extremity injuries. Although lower extremity injuries are not usually life threatening, they can result in chronic disability and high psychosocial cost. Of all lower extremity injuries, injuries to the knee-thigh-hip (KTH) region have been shown to be among the most debilitating. This project used a finite element (FE) model of the KTH region to study injury. A parametric investigation was conducted where the FE KTH was simulated as a vehicle occupant positioned to a range of pre-crash driving postures. The results indicate that foot contact force and knee kinematics during impact affects the axial force absorbed by the KTH region and the likelihood of injury. The results of the study could be used to reevaluate the lower extremity injury thresholds currently used to regulate vehicle safety standards. Also, the results could be used to provide guidelines to vehicle manufacturers for developing safer occupant compartments.
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Xie, Bingqian. "Lane Departure and Front Collision Warning System Using Monocular and Stereo Vision." Digital WPI, 2015. https://digitalcommons.wpi.edu/etd-theses/274.
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Driving Assistance Systems such as lane departure and front collision warning has caught great attention for its promising usage on road driving. This, this research focus on implementing lane departure and front collision warning at same time. In order to make the system really useful for real situation, it is critical that the whole process could be near real-time. Thus we chose Hough Transform as the main algorithm for detecting lane on the road. Hough Transform is used for that it is a very fast and robust algorithm, which makes it possible to execute as many frames as possible per frames. Hough Transform is used to get boundary information, so that we could decide if the car is doing lane departure based on the car's position in lane. Later, we move on to use front car's symmetry character to do front car detection, and combine it with Camshift tracking algorithm to fill the gap for failure of detection. Later we introduce camera calibration, stereo calibration, and how to calculate real distance from depth map.
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SONG, DONGGANG. "Contribution a la modelisation de l'occupant implique dans des collisions frontales de voitures." Paris, ENSAM, 1993. http://www.theses.fr/1993ENAM0003.
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Deux modeles mathematiques ont ete elabores pour simuler sur ordinateur la reponse dynamique d'un occupant implique dans des collisions frontales de voitures. Le premier modele est une approche bidimensionnelle de type corps rigides. Dans ce modele, l'occupant est simule par un systeme de corps rigides articules. Des ellipses et des segments de droite sont utilises pour representer respectivement le volume de l'occupant et la structure de l'habitacle, et modeliser les contacts entre les deux. Une combinaison de ressorts permet de simuler l'interaction occupant/ceinture. Le deuxieme modele est une approche tridimensionnelle de type elements finis. Dans ce modele, un systeme compose d'elements plaques, de ressorts et de corps rigides est propose pour modeliser d'une facon plus fine l'occupant et son environnement vehicule. Une attention particuliere est portee sur la modelisation de l'interaction occupant/ceinture, avec la prise en compte de la deformation du thorax et du bassin sous l'action de la sangle. Le glissement de la ceinture sur le mannequin est aussi simule. Ces deux modeles ont ete valides a l'aide d'une serie d'essais de reference. Ils permettent d'aider a la conception des moyens de protection de l'homme soumis aux accidents de voiture
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Rosenblatt, Nicolas. "Contribution à la conception robuste de véhicules en choc frontal : détection de défaillances en crash." Thesis, Ecully, Ecole centrale de Lyon, 2012. http://www.theses.fr/2012ECDL0014/document.
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Ce mémoire s’intéresse à la conception robuste de systèmes complexes dans le cadre de l’ingénierie système et de la méthode First Design. Ces travaux s’appliquent plus particulièrement aux prestations en choc frontal de véhicules de la gamme Renault. L’objectif principal de ces travaux est de proposer une méthode de conception robuste basée sur la modélisation numérique des prestations crash du véhicule. Cette stratégie vise à assurer la robustesse du produit dès la phase de conception, afin d’éviter des modifications de conception tardives et coûteuses, conséquences d’apparition de problèmes durant le cycle de validation ou la vie série du véhicule. Les spécificités du crash sont le coût important des simulations, la forte non linéarité du phénomène, ainsi que les bifurcations de comportement. Ces particularités rendent les méthodes classiques de conception robuste peu efficaces ou très couteuses. Afin de répondre à ce problème, nous développons une méthode originale, baptisée détection de défaillances, permettant d’identifier les problèmes de robustesse en crash, afin de les corriger dès le cycle de conception. Cette méthode est basée sur l’utilisation des techniques d’optimisation par les plans d’expériences. La méthode développée vise aussi à intégrer l’expertise des concepteurs crash afin de localiser rapidement les défaillances, ce qui permet de limiter le nombre de simulations nécessaires. La contrepartie d’une méthode de conception robuste reposant sur la simulation numérique est la nécessité d’avoir un bon niveau de confiance dans les résultats du modèle. On propose donc dans ce mémoire des améliorations des modèles éléments finis des véhicules Renault, afin d’améliorer la qualité de la simulation. Ces travaux vont dans le sens d’un remplacement des prototypes physiques par des prototypes numériques dans l’industrie, enjeu majeur permettant la réduction des coûts et des délais de développement. Cet enjeu est particulièrement important dans un secteur automobile très concurrentiel, où la survie d’un constructeur dépend de ses coûts et de sa réactivité face au marchéThis PhD thesis deals with robust design of complex products, within the framework of system engineering methods, such as First Design. This work focuses on frontal crashworthiness of Renault vehicles. The main goal of this PhD is to develop a robust design method based on crashworthiness numerical simulation. This method aims at ensuring the robustness of a vehicle crashworthiness right from the design stage of the product, in order to avoid costly design modifications, necessary when problems are found during the validation cycle or the life cycle of the product. Characteristics of crashworthiness phenomena are a high cost of numerical simulation, highly non-linear and bifurcative behaviour. Due to this behaviour, classic robust design methods would be unefficient or very expensive to use. In order to face this problem, we develop an original robust design method, based on optimization using design of experiments method. The goal of this method is to identify crash failures as soon as possible in the design stage, in order to correct them. This method also aims at integrating knowledge from the crash engineers, in order to find crash failures quickly, using as few simulations as possible. A challenge we meet when using numerical simulation of the crashworthiness is the need to trust the results of the model. This thesis also deals with improvements in the crash models at Renault. This work is well suited for a very competitive industry such as the automotive, where car manufacturers need to replace physical prototypes with numerical ones, in order to reduce design costs and be more reactive
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Poulard, David. "Influence de l’âge et du morphotype sur la réponse mécanique du thorax : étude expérimentale in vivo et analyse numérique à l'aide de modèles EF personnalisés du corps humain." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10332/document.
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Cette étude aborde le problème de l’aggravation du risque de fractures de côtes chez les automobilistesâgés en choc frontal. L’analyse de la bibliographie fait ressortir que les moyens actuels d’évaluationdu risque de fractures ne permettent pas de prendre en compte les différences anatomiques et depropriétés mécaniques du thorax observées chez les personnes âgées. Les modèles éléments finis (EF)personnalisés du corps humain offrent un grand potentiel en tant qu’outil avancé d’évaluation durisque de blessures. Toutefois, des données expérimentales sont nécessaires pour valider ces modèlesdans des conditions réalistes. De plus, le choix du niveau de personnalisation et la sensibilité de laréponse du modèle à celle-ci doivent être évaluées.Des expérimentations in vivo menés sur des volontaires ceinturés en choc léger, de différents âges etanthropométries, ont été réalisées. Ces tests ont permis d’étudier l’influence de l’âge et de lacorpulence sur la réponse mécanique du thorax et ont permis l’obtention de corridors nécessaires à lavalidation de modèles EF personnalisés. La géométrie du modèle numérique THUMS a été adaptée àcelle des volontaires et les propriétés mécaniques du thorax ont été modifiées au vu du vieillissementpour effectuer une analyse similaire dans le domaine lésionnel. Les simulations numériques ont mis enévidence un risque accru de fracture de côtes pour certains modèles personnalisés.Cette étude devrait permettre de mieux estimer le risque de blessure pour les automobilistesvulnérables. Elle devrait contribuer ainsi à promouvoir les modèles personnalisés du corps humaincomme outil avancé d’évaluation du risque de blessuresThis study deals with the topic of increased risk of rib fractures among elderly drivers infrontal impact. The analysis of the literature reveals that actual thorax injury assessment tools do nottake into account for the differences in anatomical features and biological material properties observedbetween adults and elderly. Personalized human body finite element (FE) models have great potentialas improved thorax injury assessment tools. However, experimental data are needed to validate thesemodels under real-world conditions. In addition, the choice of the level of personalization of the modeland the sensibility of the model response to this personalization must be assessed to predict thoracicinjury risk.In vivo sled tests were performed on belted volunteers of various anthropometries and age. These testswere used to assess the influence of age and corpulence on thorax mechanical response and allowed toobtain corridor responses needed to validate personalized FE models. The geometry of the FE modelTHUMS was adapted to the volunteers and the thorax material properties were modified consideringaging to carry out a similar analysis in the injurious domain. Numerical simulations highlighted anincreased risk of rib fractures for specific personalized models.This study should help to better estimate the injury risk for car occupants. It should contribute topromote personalized human body models as attractive thorax injury assessment tool ofvulnerable individuals
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ABDALLAH, NIZAR. "Methode de simulation logico-temporelle de circuits numeriques complexes prenant en compte le front des signaux et les collisions dans le cadre de la simulation mixte analogique-numerique." Paris 6, 1998. http://www.theses.fr/1998PA066001.
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Elmarakbi, Ahmed. "Dynamic modeling and analysis of vehicle's smart front-end structure for frontal collision improvement." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=94735&T=F.
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Joshi, Aditya Umakant. "Finite element modeling of low floor mass transit bus and analysis of frontal impact scenarios." Thesis, 2006. http://hdl.handle.net/10057/653.
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There is no international regulation for the frontal collision of the buses, protecting their occupants and partners in traffic. There are some regulation such as ECE R-80 which deals with strength of seat structure of the coaches and their anchorages strength. There is increasing need to focus issues like occupant protection and full scale crash testing regulation for buses. This thesis attempts to collect possible subjects required for international regulation required for crashworthiness of transit buses.
This research attempts to develop and validate a model of transit bus for all three impact conditions. The full finite element model is developed with help hypermesh software and its validation and analysis is done with help Ls-Dyna nonlinear finite element solver. The cost of actual testing and secrecy maintained by manufacturers make research process difficult and increase the importance of computer simulations. To boost the research of crash worthiness of transit need for computer model is felt.
This thesis examines several frontal crash test procedures and evaluates how well each procedure meets the objective. This validated model is used to analyze various real world impact scenarios and its analysis with European and federal regulation. This validated model is used to extract crash pulses of various impact scenarios at the center of gravity of the bus. These extracted crash pulses are applied to the madymo model to estimate the injuries to occupants of the bus. This thesis discusses the design aspects of bus frontal impact behavior as one of the main subjects of bus crashworthiness and results of previous full scale tests comparing the Fem simulation results carried out on the transit bus.Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering
"December 2006."
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Nakaza, Edward Takeshi Safety Science Faculty of Science UNSW. "Assessment of injury risks associated with wearing the enhanced combat helmet and night vision goggle - driver: frontal vehicle collision study." 2007. http://handle.unsw.edu.au/1959.4/40484.
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The requirement to operate vehicles in low light and/or night environments whilst wearing night vision goggle (NVG) systems has become increasingly common during military operations. There is very limited research investigating injury risks associated with these systems during ground vehicle collisions. This study examined the injury risks associated with wearing the Australian Defence Force - Enhanced Combat Helmet (ECH) and NVG system, in frontal vehicle collisions. This project consisted of two components: (1) crash tests using a sled and (2) numerical simulations of impacts. Four dynamic sled tests were conducted using a 50th percentile, male, Hybrid III dummy positioned on a rigid seat. Frontal impact tests were performed at a 40 km/h change in velocity (*v) and 20 g deceleration. The test configurations were as follows: (a) Base; (no helmet or additional equipment); (b) ECH; and, (c) ECH and NVG. Condition (c) was carried out twice, to determine repeatability. The sled test protocols were reconstructed precisely with the numerical simulation package MADYMO and the simulations were shown to correlate well with the experimental results. Using this validated model, four parametric studies were undertaken to assess the influence of counterweights, seat cushion, seatbelt pre-tensioner, and the vehicle's *v and acceleration on injury risks. The study found that neck loads were within acceptable limits, with the exception of the neck extension moment, which was exceeded for all NVG conditions. Based on the parametric studies, no major improvements were observed in the neck extension moments with the use of counterweights or a seat cushion. In contrast the use of a seatbelt pre-tensioner was observed to decrease greatly this neck injury risk in certain scenarios. The study also identified that a *v of 15 km/h and peak acceleration of up to 14 g were required to keep the neck extension moment below the prescribed injury criteria. However, the high neck extension moment values may have been partially attributable to the stiff Hybrid III neck. This study identified a possible injury mechanism for soldiers using the ECH and NVG system during specific impact scenarios. The method applied in this project was designed to be repeatable.
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Chen, Hua-Wen, and 陳華玟. "High-resolution Sequence Stratigraphic Analysis of Late Quaternary Deposits of the Changhua Coastal Plain in the Frontal Arc-Continent Collision Belt of Central Taiwan." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/62963660051899695257.
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博士國立臺灣師範大學
地球科學系
98
For the aim to reconstruct the depositional evolution and solve the impacts of eustacy and tectonic on relative sea-level change of the Late Quaternary foreland basin- Changhua Coastal Plain, detailed sequence stratigraphic analysis of 30 cores from the Late Quaternary deposits of the Changhua Coastal Plain that provides a 40 ka high resolution record of the depositional history of a region situated in the frontal arc-continent collision belt of Taiwan. Twenty-five lithofacies and nine facies associations are recognized in the cores. Three depositional systems are from terrestrial system (alluvial fan and fluvial) to marginal marine (estuarine, shoreface, lagoon, tidal flat, marsh) and shallow shelf (offshore-transition) systems. Sedimentology and sequence stratigraphic analysis shows that the sedimentation of study area reflects two main cycles (sequence 1 and Sequence 2) of sea-level falls and rises. Transgressive (TST) and highstand (HST) deposits can be differentiated in sequence 1 (SQ1, 0-16 ka) and sequence 2 (SQ2, 20-40 ka). Sequence boundary 1 (SB 1) is an unconformity. The Late Pleistocene to Holocene (0-40 ka) depositional evolution of the study area is summarized as follows. Fluvial sedimentation prevailed before 40 ka, and then a differential tectonic activity was recorded in regions north and south of the HT well with a wide and shallow incised valley formed in the middle area of Changhua Coastal Plain in this period. Since 40 ka, estuary (middle area) and shelf (southernmost area) deposits formed the lower TST during 40-35 ka. Between 35–30 ka was characterized by retrogradation of shelf and marginal marine systems (upper TST), and then sea-level reached maximum (MFS2) at about 30 ka. HST (30-20 ka) was characterized by shelf, marginal marine, and fluvial–alluvial fan progradation. HST phase was followed by non-deposition and erosion during the Last Glacial Maximum unconformity (SB1), except the western margin of Pakua tableland. Between 16 and 6 ka, the Changhua Coastal Plain experienced rising sea-level with retrogradational deposition. From 16 to 10 ka, estuarine deposits (lower TST) were deposited. From 10 to 6 ka, shelf and marginal marine (upper TST) deposited. By about 7–6 ka, sea level reached its peak (MFS1), and shelf and marginal marine sediments covered most of the study area. After 6 ka, the highstand was dominated by progradation of shelf, marginal marine and terrestrial deposits. About 1 ka, fluvial deposits were preserved in the central part of the Changhua Coastal Plain. Since then, fluvial channels shifted southward to the present-day Chuoshuei River. The depositional patterns of SQ1 and SQ2 in this tectonically active area reflected the complex interplay between high-frequency sea-level fluctuations, tectonics (subsidence and uplift), and autocyclic processes. The study area was relatively speaking in tectonic quiescence during Holocene but sediments accumulation rate in this period was about 3 times of before which may indicate the depositional pattern of Changhua Coastal Plain in the last interglacial was majorly controlled by eustacy, and fast sediment supply made that southeastern area only recorded the terrestrial sediments in this period. But the accommodation for the SQ2 deposits was largely created by tectonic subsidence since regional tectonism was very active during late last glacial.
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WANG, HUAI-MU, and 王淮慕. "Visual of Front Collision Warning System by Deep Learning." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/v2f9w2.
Full textAbstract:
碩士國立中正大學
電機工程研究所
107
For an autonomous driving cars, visual preception is of great significance to recognize the surrounding scenes. It consists of front depth information of scenes and object detection. For adaptation of real environment in front collision, FCWS should be effective and efficient enough, and has strong ability to detect small objects. Especially detecting small objects like faraway pedestrians and traffic signs is crucial to driving. Besides, performance of detection is another important factor, since real-time object detection can help self-driving cars avoid obstacles in time. In general ADAS employs popular active sensors such as LIDAR, Time-of-Flight (ToF) to infer depth by perturbing the sensed environment according to different technologies. In this thesis we utilized passive sensors. They are cheaper and more lightweight than active sensors. Moreover, passive depth sensors do not have moving parts like LIDAR and do not require to perturb the sensed environment thus avoiding interference with other devices.
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Tsai, Tsung-Yu, and 蔡宗祐. "The Front Vehicle Distance and Time to Collision Warning System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/46677718924414253040.
Full textAbstract:
碩士明志科技大學
電子工程系碩士班
103
When the vehicle is traveling on the road, driving from the safety would become very important, if the driver do not to keep a safe distance on the road, is not only dangerous to themselves, the surrounding is very unsafe drivers. The front vehicle detection and alarm system proposed by this article can be applied to Forward Collision Warning（FCW）, Forward Distance Estimation（FDE）, and Time to Collision（TTC）estimation. Using the CCD camera to capture the road image in front for the image processing algorism, the image processing algorism is the key point which decides the accuracy and reliability of vehicle safety systems. This system we proposed is mainly used on freeway, and it can estimate the relative distance of host vehicle and the preceding vehicle. This paper will be achieved over the system to image in Texas Instruments DPS Platform DM6437 among and combine FlashBurn development board to reality appropriate usage. The effective distance is about 7 to 40 meters. It will alarm the driver when the TTC is less than 1.5 seconds and the distance is less than 15 meters. After the experiment, this system can correctly detect the relative distance and the time to collision for both of daytime and nighttime, and the system can be carried out during the daytime and the nighttime sky based on the current status of the system switches.
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Chuang, Wang-Lin, and 莊旺霖. "RF Front-end Passive Components of 79GHz Automobile Rear Anti-collision Radar." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/msy8p3.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
105
In recent years, the Advanced Driver Assistance Systems (ADAS) are the smart vehicle technology that the vehicular manufacturers actively develop. The automotive radars are important parts in the ADAS. In this paper, we study the passive components used in parking anti-collision radar system, including the rat race coupler and wide half-power-beam-width parasitic patch antenna. We proposed a new method to improve the equivalent circuit model of transmission line section for T-coil structure, and we used lumped circuits to design the rat race coupler on integrated passive component process and re-distribution layer of wafer level package process to achieve the compact circuit size. At the same time, we design the patch antenna on the package substrate to make the whole radar system integrated on a substrate. We used the grounded parasitic components to enhance the half power beam-width of E-plane of the patch antenna to increase the detection angle of the system.
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Liang, Jui-Hung, and 梁瑞宏. "A front vehicle collision warning system using lane detection technique on higyways." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/49969167899695224682.
Full textAbstract:
碩士國立臺灣師範大學
資訊工程研究所
100
The main purpose of this thesis is to develop a front-vehicle collision warning system. Drivers are easy to affect by the unexpected behaviors of neighboring vehicles and sometimes cause traffic accidents. Therefore, many driving assistance systems have been developed by car companies to protect drivers. The lane marking detection and front-vehicle detection system on the highway is one of the driving assistance systems. The lane marking detection system can detect abnormal lane change behaviors of the host vehicle, and monitor the road region in front of the host vehicle for safety. The front-vehicle collision warning system can warn the drivers when they are in dangerous traffic situations, for example, “the left-side or right-side vehicles suddenly enter to the host lane” or “the front vehicle is too close to the host vehicle.” In this study a recorder is set on front windshield to obtain the input sequences. The proposed system can be divided into two sub-systems, one is the lane marking detection sub-system and the other is the front-vehicle detection sub-system. The lane marking detection sub-system uses Sobel edge detection and Hough transform technique to extract the lane marking. The front vehicle detection sub-system can process two different situations, the daytime and the nighttime or raining day. This system uses Otsu’s method to find the suitable threshold to extract the vehicle’s shadow, and uses a horizontal edge detection to detect vehicle’s horizontal features in daytime. Combine these two features, the system can verify the locations of front vehicles. On the other hand, the system uses Cr component of YCrCb color model and Hue component of HSI color model to extract the light features in nighttime or raining. Moreover, the system uses the property of the symmetry of brake lights to verify the location of front vehicles. The experimental results show that the proposed system has great stability and usability. Although the front-vehicle detection system obtains lower correct rate in the tunnel, it still works when raining or extreme bad sight in nighttime. Finally, we hope the proposed system can be embedded into driving assistance systems installed in every vehicle in the future. Index terms—Otsu’s method, lane detection, vehicle detection
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Jung-PingKuo and 郭容平. "A Robust Driving Assistance System with Combined Lane Departure and Front Collision Warning Technologies." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/26244x.
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Liao, Ming-Wei, and 廖明威. "Front-Tracking Method and Volume of Fluid Method Numerical Simulations for Binary Droplet Collision." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/23198302899923379656.
Full textAbstract:
碩士國立臺灣大學
機械工程學研究所
97
This study focuses on numerical simulation for binary droplets collision. We compare the numerical results with the experimental ones by front-tracking method and volume of fluid (VOF) method. Front-tracking method is controlled artificially by prescribing the rupture of the inter-drop film in multiphase flow, and the simulation results are consistent with the experimental ones. In high-speed droplet collision, the surface tension force damping option in VOF increases the viscosity in the vicinity of the interface, which damps the capillary wave effect that is invariably generated at the interface by the surface tension. In the view of physics, the droplets are not supposed to rupture in the separation regime. Therefore, if the surface tension force damping option is selected, the droplet does not rupture during the collision. The simulation condition of head-on collision of binary equal-size droplets is set. Water and tetradecane are used to be the liquid phases to predict the phenomena of droplet collision under the atmosphere. We examine the feasibility of droplet collision simulation with VOF in CFD-ACE solver. The 3D simulation results of high-speed droplet collision are obtained by VOF.
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Wang-Zhu, lu, and 盧旺助. "Simulation and Test Analysis Study for Drive-by-Wire Vehicle Front Anti-Collision Controlled System." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/16929424365612126842.
Full textAbstract:
碩士大葉大學
機械與自動化工程學系
97
The purpose of this study is to integrate the methodologies for simulation by object-oriented program and By-Wire control for the vehicle Front Anti-Collision Control (FACC) system. The objective of this study focuses on the control of FACC system active braking and accelerating so that the FACC vehicle can maintain the safe distance with the preceding vehicle. The relative velocity and distance between the FACC and preceding vehicle are the inputs for the Fuzzy Logic Collision (FLC) controller, while the different safety algorithm calculations can be applied to assure the safe distance is maintained. Simulation for different vehicle acceleration and deceleration conditions can be established to test the FACC system electronic throttle and active braking dynamic response under safe vehicle speed specifications. This study established the vehicle dynamic model from the combination of first-order transfer functions which can simulate vehicle response faster. The results were compared with vehicle dynamic simulation software CarSim to assure the safe requirement under different driving and handling conditions for the FACC vehicle. When the expected dangers are introduced in the simulation, the program simulated vehicle response speed and result for whether or proportion for active braking were justified to validate the controller parameter set up for both straight and turning drive conditions. The FACC system specifications from ISO 15622 and SAE J2399 standards were compared to check the controller output performance. The result from the simulation showed the FACC vehicle with FLC can satisfy both ISO and SAE safe requirements under different driving conditions.
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Wu, Chung-Hung, and 吳中宏. "W Band Front-End System for Collision Avoidance Vehicle Radar and Ku Band Analog Phase Shifter." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/31242669919688626222.
Full textAbstract:
碩士國立交通大學
電信工程系所
94
In this thesis, a 77 GHz front-end system for collision avoidance vehicle radar and a 12.45 GHz analog phase shifter for phased array antenna are proposed. In the first part of this thesis, each individual circuit of the RF front-end, integration of the RF front-end, and measurement of the RF front-end and each individual circuit are described. The conversion loss of the RF front-end is about 9.3 to 13.3 dB and the RF output power is about 3.2 to 4.4 dBm.The whole circuits are integrated with CPW on an Al2O3 substrate with a dielectric constant of 9.8, a thickness of 15 mil. In the second part of this thesis, the design and measurement of reflective phase shifter are presented. The maximal phase shift is larger than 120 degree. A unit circuit of phased array is implemented and measured, which includes an analog phase shifter, a coupler, and a phase compensation transmission line. The mainbeam of the array can be switched between 35 to 60 degree in vertical direction. The whole circuits are fabricated with microstrip line on a RO4003 substrate with a dielectric constant of 3.38, a thickness of 20 mil.
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Ho, Tan-Hsiung, and 何丹雄. "Development of Vehicle Collision Warning Radars and Short-Range Communication RF Front-End With New Quadrature Hybrid Based Circuits." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/94220453259309495838.
Full textAbstract:
博士國立交通大學
電信工程研究所
98
This dissertation discusses the development of vehicle collision warning radars and short-range communication RF front-end with new quadrature hybrid composed circuits. A new radar and a communication RF front-end architectures using the proposed circuits are presented with simplified circuit complexity. In the first part of this dissertation, three new quadrature hybrid composed circuits are presented. A new LO transparent hybrid mixer is proposed, which is composed of a branch-line coupler and two Schottky diodes. The new hybrid mixer can transmit the LO power to the antenna. Then, a LO transmissive quadrature hybrid mixer is proposed. The quadrature hybrid mixer is composed of two hybrid mixer, 45° delay lines, and branch-line couplers. The proposed quadrature hybrid mixer can receive signal with phase. Moreover, the proposed mixer shows high transmission efficiency to pass LO power to antenna and no received power wasted in the oscillator port. A novel full-duplex bi-directional amplifier is then presented. The bi-directional amplifier is composed of a quadrature hybrid and two reflection type amplifiers. The proposed amplifier can enhance the signals in both transmitting and receiving directions, which can be used in a transceiver front-end without using the signal switches. In the second part, a 10.5 GHz Doppler radar using the proposed LO transmissive quadrature hybrid mixer is presented. The proposed architecture offers higher local power usage efficiency than the conventional ones and simplifies the front-end complexity. A defected-ground-structure local oscillator along with the phase-lock-loop frequency synthesizer is used in the system to provide better phase noise and good frequency stability. The designed transceiver can be operated from 10.36 to 10.74 GHz with output power level of 6 dBm. Compare to the conventional quadrature radar, the proposed one offers 3.3 dB received power more when the LO power is 10 dBm, and 16.2 dB more when the LO power is 0 dBm. The implemented radar can measure the speed and moving direction with 0.25 km/hr resolution. In the third part, two complete FMCW 24 GHz collision warning radars are presented. The 24 GHz radars are designed for sideway-looking and the forward-looking applications. In the 24GHz radar systems, a 6 GHz VCO, two frequency doublers, a 12 GHz gain block, and a sub-harmonic mixer are developed. In the sideway-looking application, a patch-fed horn antenna is designed. All the RF circuits, antenna, and base-band signal processor are integrated into a dimension of 60 × 45 × 30 mm3. This size is ready to be installed under the back-mirror of a small car. The developed radar shows a capability to detect a human in 8 meters and a small car located in 15 meters away. In 24 GHz forward-looking radar, a planar 9x8 series-fed patch antenna array is developed. The antenna has an antenna gain of 18.5 dBi, and the half power beam widths are 10.5 and 11.2 degrees, in E- and H-plane respectively. The radar transceiver shows an output EIRP of 23 dBm with only 0.7 dB power deviation within the whole modulation bandwidth. A frequency linearizer mechanism is presented. The frequency linearizer improves the modulation frequency deviation from 9 % to 0.3 %. A 2D-FFT signal processing algorithm is implemented to estimate the object speed and distance, simultaneously. From the experiment, the radar can detect a human up to 15 meters away and measure the relative speed with 0.7 km/h resolution. In the end of this dissertation, a full-duplex communication RF front-end using the new bi-directional amplifier is presented. A 10 GHz bi-directional amplifier is developed, which has transmission gains of 14 and 13 dB in two directions. A planar Yagi-antenna is adopted. The antenna shows a gain of 12 dBi and half-power beam width 40 degrees. A ring mixer is used as the up / down converter to convert the signal between RF and base-band. The integrated transceiver shows the overall up / down conversion gain of 17 dB and output EIRP 15.5 dBm.