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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Efficient Generation of Standard Customer Reports for Airbag Simulation Results

Jayanthi, Sagar 02 November 2023 (has links)
Passive safety systems like airbags have significantly improved road safety. These occupant safety systems help in reducing the severity of injuries, and save lives in the event of a road accident. The airbag systems must be configured correctly to minimize the impact of collision and protect the occupants. To configure the airbag, test crashes are performed and data is recorded. This data is simulated to find out appropriate parameters for the airbag deployment. The airbag simulation results are stored into databases. Airbag application tools are used to handle the data stored in databases. The airbag simulation results must be extracted efficiently and required computations needs to be performed. This data is then stored to reports. RSDBnext is an airbag application tool, it stands for Result Database next generation. This tool is used for extraction of data from the database. The RSDBnext tool should be adapted to generate Standard Customer Reports. These reports are to be generated based on customer requirements. The existing methodology to generate Standard Customer Reports used Excel macros, which took a lot of time to generate the reports. This method was complex and unstable. Hence, a new methodology was proposed without using macros. In the proposed method, an XML file and XSLT StyleSheet were used to generate the report in Excel using C# with Visual Studio. This approach reduces report generation time, and overcomes the drawbacks of the previous approach. From the results, this methodology to generate reports is faster, easier, and more reliable.
22

Évaluation sur simulateur de conduite du comportement humain en situation de pré-crash : application à l'amélioration des airbags / Evaluation of human behaviour on a driving simulator during the pre-crash phase : application to improvement of airbags

Robache, Frédéric 16 March 2017 (has links)
Les constructeurs automobiles sont tenus de respecter des minima sécuritaires vérifiés lors de crash-tests normalisés, d'où un nombre de scénarios de tests limité ne tenant pas compte des particularités individuelles. Ce mémoire propose d'évaluer le comportement humain réel en phase de pré-crash sur simulateur de conduite. L'expérimentation, intégrant un scénario d'accident difficilement évitable, a permis d'étudier le comportement de 76 conducteurs dont 40 sur simulateur dynamique. Pour ce groupe, 43 voies de mesures centrées sur le conducteur ont été intégrées au protocole. Parmi les résultats obtenus, on retiendra la possible détection précoce de l'accident, pour la moitié des conducteurs, sur la base de leur interaction avec le véhicule. Les manœuvres d’évitement amènent 25% des sujets à positionner l'avant-bras devant le volant au moment de l’impact. Cette situation peut compromettre l'efficacité des airbags, ce qui est vérifié sur banc statique, par le déploiement d'airbags face à un mannequin de type Hybrid III-50%. La projection du bras entraine un impact de 120g à la tête. De plus, l'intégration de membres supérieurs issus de SHPM montre que la situation provoque des fractures de l'avant-bras. Un modèle numérique a été conçu pour estimer les effets de la position atypique lors d'un crash frontal à 50km/h. L'accélération de la tête atteint 270g, synonyme de risques lésionnels élevés. Enfin, une modification technologique des airbags est proposée, basée sur l'hypothèse que la détection à distance peut permettre un déclenchement anticipé et plus lent des airbags. Testée expérimentalement et numériquement, cette évolution permet de respecter les critères lésionnels. / Automakers are lawfully required to achieve a minimum level of security which is checked during standardized crash tests. This results in a limited number of scenarios, which do not take individual specificities into account. This dissertation evaluates real human behaviour during the pre-crash phase, by means of a driving simulator. The experiment, integrating an unavoidable accident, studied the behaviour of 76 drivers, of which 40 drivers on a dynamic simulator. Concerning this group, 43 acquisition channels dedicated to drivers were added. From the results, one can retain that the crash can be predicted for half of the drivers through the observation of their behaviour and their interaction with the car. Due to swerving manoeuvres, 25% of the drivers have their forearm just in front of the steering wheel at the time of crash. This situation may compromise the efficiency of the airbags, that is verified experimentally on a static bench, by the deployment of airbags in front of a Hybrid III-50% dummy. The throwing of the arm causes an impact of 120 g to the head. In a second stage, the integration of left upper limbs from PMHS reveals that the situation is likely to generate fractures in the forearm. A numerical model has been designed to estimate the consequences of the atypical position during a frontal crash at 50km/h. The head acceleration reaches 270 g, synonymous with high lesion risks. Finally, a technological modification of the airbags is proposed to reduce this risk. The assumption is made that the use of remote sensors technologies can allow an early detection of the crash and therefore slower triggering of airbags. Tested experimentally and then numerically, this technical evolution reduces the violence of the impact to respect the injury criteria.
23

Fetus safety in motor vehicle accidents

Moustafa, Moustafa January 2014 (has links)
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.
24

Changing to polyester in airbags : A study of two test methods used for polyester fabric analyse

NYSTRÖM, ANNA-KARIN, OLSSON, JOSEFINE January 2013 (has links)
This thesis is part of an on going project within Autoliv Sweden AB to develop the process in changing the material in airbags. Most airbags are today constructed of fabric in polyamide 6.6 (PA6.6) and the thesis view the possibility of changing the material to one of three different polyesters (PET1, PET2, PET3). Both materials have different properties that have been looked into by two test methods, linear testing and dynamic testing with cold gas. The two testing methods were conducted on plain fabric and on fabric with seam to see differences in the materials when subjected to different stress caused by force or pressure. During testing the seam rupture was measured by filming the test sequences, and used for visual analysis. Tensile testing was conducted using a constant-rate-of-extension machine where the material is subjected to linear force until rupture. Dynamic testing was done with a cold nitrogen gas system using vessels to build up pressure that then releases towards the material putting it under stress. Tensile testing results for elongation do not have significant differences between testing in plain fabric or fabric with seam. PET2 have highest elongation in warp and weft. Visual analysis of specimens shows difference in how materials break, where the reference material in PA6.6 breaks more even than in PET materials. Dynamic testing show that the biggest seam opening do not occur at the highest pressure. In order to understand what is happening with the fabric during testing, three different times have been chosen in the pressure-time chart. Results in dynamic testing on fabric with seam show that PET3 have the smallest seam opening while reference material in PA6.6 has the largest opening. All PET materials have similar properties even if these are not always same as reference material in PA6.6. We can neither discard nor confirm our hypothesis of seam slippage and elongation relates equally in the same material independent of test method. From these results PET2 would not be recommended due to seam opens most at maximum force and the material has the biggest elongation. PET3 would be the recommended material, since seam opening is smallest at measured pressure. / Program: Textilingenjörsutbildningen
25

Packing Sheet Materials Into Cylinders and Prisms Using Origami-based Approaches

Bruton, Jared Thomas 01 August 2016 (has links)
Packing sheet materials into cylinders and prisms using Origami-based approaches (Soft Origami or traditional Origami) is of interest in fields where sheet materials need folded into cylinders or prisms. Fully-dense packing has application in fields where a sheet material is to be folded with minimal gaps into a cylinder or prism. Partially-dense packing is applicable to fields where gaps are required between packed surfaces or where hollow volumes are to be filled, such as in fluid filter design. Soft Origami is explored as a method for folding soft-sheet materials into fully-dense cylinders. Two fold patterns, the "flasher'' and the "inverted-cone fold,'' are explored for packing soft-sheet materials into cylindricals. An application to driver's side automobile airbags is successfully performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. In total, two origami patterns and six packing methods are examined for folding soft-sheet materials into fully-dense cylindrical prisms, and it is shown that modifying the packing method impacts deployment performance. A special case of the Miura-ori, the ninety-degree case, is briefly explored as a traditional Origami method for packing arbitrary-shaped sheet materials into fully-dense arbitrary prisms. Examples are shown and it is concluded that this pattern can be used to configure a large number of fully-dense packed prisms with configurable characteristics.Finally, patterns that fold into partially-dense cylindrical prisms are examined using traditional Origami approaches and their efficiency compared. Efficiency is defined as the ratio of the surface area of a pattern compared to an idealized high-surface-area model. Patterns include traditional (non-Origami-based) fluid filter patterns (the Basic Pleat and M-pleat) and cylindrical Origami patterns (the Accordion and Kresling). An offset crease method is used to modify the Accordion and Kresling Origami patterns so the comparison is objective. Results are presented that determine which individual pattern variations have the highest efficiency at different outside-to-inside diameter ratios. Ranges over which each pattern is most efficient are presented. It is concluded that based purely on geometry, the M-pleat provides the highest overall efficiency, but depending on other factors each pattern is viable for different purposes.
26

Meßverfahren zur Eliminierung von Erdungseinflüssen bei kapazitiven Detektoren und ihre Anwendung zur Sitzbelegungserkennung in Kraftfahrzeugen

Marschner, Christian. Unknown Date (has links) (PDF)
Techn. Universiẗat, Diss., 2004--München.
27

Utveckling av trigger för synkronisering av elektroniksystem : En praktisk tillämpning i elektroniksystem

Lundqvist, Mikael January 2006 (has links)
De triggers som idag används i Autoliv BKIs laboratorium har till uppgift att synkronisera signalerna vid simulering av krock som en intern kvalitetskontroll av produktionen. De sköter utösning av airbags och start av höghastighetskameror. Då Autoliv har flera modeller av krockkuddar används idag olika triggers och man har därför som önskemål att utveckla ett nytt system som skulle kunna ersätta de nuvarande systemen och som kan användas vid samtliga kvalitetstest. Projektet resulterade i en testad prototyp som inkluderar hårdvara, mjukvara, samt CAD-ritningar till en färdig produkt.
28

Pediatric Lower Extremities: Potential Risks and Testing Concepts

Bing, Julie Ann 20 October 2011 (has links)
No description available.
29

Normativní požadavky na činnost zádržných systémů vozidel / Normative Requirements for Automotive Restraint Systems

Kučera, Jonáš January 2010 (has links)
This diploma thesis deals with the normative requirements on the activities of restraint systems. It includes biomechanical limits of the human body, restraint systems, description of the principle of their action and legislation. Legislation, particularly regulations of ECE and EC directives defines the normative requirements on the activity of restraint systems in the context of the approval process. There are described two types of restraint systems: seat belts and airbags in details. There are created simulations of crashtests and reviewed influence of using restraint systems on elimination of negative phenomenon of car accidents.
30

Vliv prvku pasivní bezpečnosti vozidel při kolizích s chodci / The Influence of Passive Safety Features During Vehicle Collisions with Pedestrians

Mrázek, Jan January 2011 (has links)
This thesis deals with the influence of passive safety features during vehicle collisions with pedestrians. The first part focuses on introducing the basic components of active and passive vehicle safety. The second part deals with construction and usage of modern components of passive safety during vehicle collisions with pedestrians. A comparing situation model of vehicle collisions with pedestrian is introduced in the third part for which a simulation programme has been used. At the close of this part there is a result synthesis of these model situations. The last part deals with the possibility of increasing pedestrian safety.

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