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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.
1

Road user charging for heavy goods vehicles - Implementation aspects

Schelin, Eva January 2008 (has links)
Several factors have influenced the recent development in charging of heavy goods vehicles in Europe. European legislation is changed and the political will is strong in many countries. The public awareness and acceptance is large for the need to put a price and a cost on the use of infrastructure. Environmental concerns are also actuating change in this direction. Systems are being introduced to support and enhance principles of marginal cost, fair pricing, inclusion of emission factors and to support modal shift. This has laid the foundation for a payment will for good technical solutions in the field of road user charging. This licentiate thesis aims at analysing and identifying the most important factors and areas to focus on for reaching a successful implementation of a system for charging heavy goods vehicles based on distance and marginal cost. These are: - Public acceptance and use of opportunities and public opinion - The political process and most important decision points - The legal framework before and during introduction as well as for operation of a system - The institutional framework - Responsibility assignment - System procurement and implementation, including procurement strategy, technology choices, testing and demonstration and interoperability Another important contribution is the implementation process model for an introduction of a distance based system for heavy goods vehicles in a country. The model comprises of the most important aspects to consider which has been made through the study and analysis of both implemented and cancelled systems as well as planned introductions, where the Swedish work in this direction has formed the major part of the analysis. The implementation process model with its main actors, decision points and information flow between actor groups are cornerstones of the model, which can serve as a tool for future implementers to follow.
2

Road user charging for heavy goods vehicles - Implementation aspects

Schelin, Eva January 2008 (has links)
<p>Several factors have influenced the recent development in charging of heavy goods vehicles in Europe. European legislation is changed and the political will is strong in many countries. The public awareness and acceptance is large for the need to put a price and a cost on the use of infrastructure. Environmental concerns are also actuating change in this direction. Systems are being introduced to support and enhance principles of marginal cost, fair pricing, inclusion of emission factors and to support modal shift. This has laid the foundation for a payment will for good technical solutions in the field of road user charging.</p><p>This licentiate thesis aims at analysing and identifying the most important factors and areas to focus on for reaching a successful implementation of a system for charging heavy goods vehicles based on distance and marginal cost. These are:</p><p>- Public acceptance and use of opportunities and public opinion</p><p>- The political process and most important decision points</p><p>- The legal framework before and during introduction as well as for operation of a system</p><p>- The institutional framework</p><p>- Responsibility assignment</p><p>- System procurement and implementation, including procurement strategy, technology choices, testing and demonstration and interoperability</p><p>Another important contribution is the implementation process model for an introduction of a distance based system for heavy goods vehicles in a country. The model comprises of the most important aspects to consider which has been made through the study and analysis of both implemented and cancelled systems as well as planned introductions, where the Swedish work in this direction has formed the major part of the analysis. The implementation process model with its main actors, decision points and information flow between actor groups are cornerstones of the model, which can serve as a tool for future implementers to follow.</p>
3

Vision-based trailer pose estimation for articulated vehicles

de Saxe, Christopher Charles January 2017 (has links)
Articulated Heavy Goods Vehicles (HGVs) are more efficient than conventional rigid lorries, but exhibit reduced low-speed manoeuvrability and high-speed stability. Technologies such as autonomous reversing and path-following trailer steering can mitigate this, but practical limitations of the available sensing technologies restrict their commercialisation potential. This dissertation describes the development of practical vision-based articulation angle and trailer off-tracking sensing for HGVs. Chapter 1 provides a background and literature review, covering important vehicle technologies, existing commercial and experimental sensors for articulation angle and off-tracking measurement, and relevant vision-based technologies. This is followed by an introduction to pertinent computer vision theory and terminology in Chapter 2. Chapter 3 describes the development and simulation-based assessment of an articulation angle sensing concept. It utilises a rear-facing camera mounted behind the truck or tractor, and one of two proposed image processing methods: template-matching and Parallel Tracking and Mapping (PTAM). The PTAM-based method was shown to be the more accurate and versatile method in full-scale vehicle tests. RMS measurement errors of 0.4-1.6° were observed in tests on a tractor semi-trailer (Chapter 4), and 0.8-2.4° in tests on a Nordic combination with two articulation points (Chapter 5). The system requires no truck-trailer communication links or artificial markers, and is compatible with multiple trailer shapes, but was found to have increasing errors at higher articulation angles. Chapter 6 describes the development and simulation-based assessment of a trailer off-tracking sensing concept, which utilises a trailer-mounted stereo camera pair and visual odometry. The concept was evaluated in full-scale tests on a tractor semi-trailer combination in which camera location and stereo baseline were varied, presented in Chapter 7. RMS measurement errors of 0.11-0.13 m were obtained in some tests, but a sensitivity to camera alignment was discovered in others which negatively affected results. A very stiff stereo camera mount with a sub-0.5 m baseline is suggested for future experiments. A summary of the main conclusions, a review of the objectives, and recommendations for future work are given in Chapter 8. Recommendations include further refinement of both sensors, an investigation into lighting sensitivity, and alternative applications of the sensors.
4

Stationary charging infrastructure: Managing investment risks to enable charging possibilities : A case study of a future stationary charging hub in Stockholm South / Stationär laddinfrastruktur: Hanteringen av investeringsrisker för att möjliggöra laddning : En fallstudie om en framtida stationär laddningshubb i Stockholm Syd

Olsson, Anton, Notlöv, Vendela January 2022 (has links)
The electrification of heavy transport is considered a solution to climate change. Today, electrification is challenged by high investment costs for vehicles and charging, which hampers the conversion. The purpose is to investigate what investment risks occur when creating a stationary charging hub by focusing on three different charging possibilities (private, semi-public, and public) to examine the differences between them. The study is a case study with the study object Stockholm South, which is considered to be a future logistics area. The study is based on literature, documents, and interviews with actors linked to the study object. Moreover, to identify potential investment risks the study conducts a life cycle cost analysis of a stationary charging hub. The conducted interviews identified that several actors are positive to enable a charging hub, but are challenged by high investment costs, uncertainties regarding electricity network capacity, and future prospects linked to the technological development of electric trucks and charging technology. Moreover, the interviews also identified opportunities such as financial support, potential market advantages of being one of the firsts on the market, and contribution to a sustainable transport sector. The results of the cost analysis show that a stationary charging hub for heavy goods transport entails high investments and operating costs, which are affected by future aspects such as electricity prices, electricity networks, technology development, and utilisation rate. In addition, the choice of closed or open charging hub has an impact on the total cost. The analysis of the results indicates that collaboration between the involved actors can facilitate several of the identified challenges and risks. The study contributes to expanding the empirical data on stationary charging infrastructure for heavy freight transport. In addition, the study contributes with a cost analysis for a charging station that can provide inspiration and a basis for future investments. The theoretical contribution mainly concerns how new technologies in ecosystem theory are handled in relation to collaboration and business models. / Elektrifieringen av tunga transporter anses vara en lösning på klimatförändringarna. Elektrifieringen utmanas idag av höga investeringskostnader för fordon och laddning, vilket hämmar omställningen. Syftet med studien är att undersöka vilka investeringsrisker som uppstår vid skapandet av en stationär laddhubb genom att fokusera på tre olika laddningsmöjligheter (privat, semi-publik och publik) för att undersöka skillnaderna mellan dem. Studien är en fallstudie där studieobjektet är Stockholm Syd som anses vara ett framtida logistikområde. Studien baseras på litteratur, dokument och intervjuer med aktörer kopplat till studieobjektet. För att kunna identifiera investeringsriskerna har en livscykelkostnadsanalys gjorts för en stationär laddhubb. De genomförda intervjuerna identifierade att flera aktörer är positiva till att skapa en ladd hubbmen att utmaningarna framförallt ligger i höga investeringskostnader, osäkerheter angående elnätskapacitet och framtidsutsikter kopplat till den teknologiska utvecklingen av ellastbilar och laddningsteknik. Däremot identifieras även möjligheter så som finansiella stöd, potentiella marknadsfördelar med att vara en av de första på marknaden och att bidra till en hållbar utveckling av transportsektorn. Resultatet av kostnadsanalysen visar att en stationär laddhubb för tunga godstransporter medför höga investerings- och operationskostnader som påverkas av framtida aspekter så som elpris, elnät, teknikutveckling samt utnyttjandegrad. Dessutom har val av stängd eller öppen laddstation inverkan på kostnaderna. Analys av resultatet tyder på att samarbete mellan involverade aktörer kan underlätta flera av de identifierade utmaningarna och riskerna. Studien bidrar till en utökad empiri kring stationär laddinfrastruktur för tunga godstransporter. Dessutom bidrar studien med en kostnadsanalys för en laddstation som kan ge inspiration och underlag för framtida investeringar. Det teoretiska bidraget berör främst hur nya tekniker ses på inom ekosystemsteorin i förhållande till samarbete och affärsmodeller.
5

An Optimization Model for Electric Vehicle Routing with Tractor Swapping / En optimeringsmodell för ruttplanering av elektriska lastbilar med traktorbyten

Strid, Alexander, Liu, Daniel January 2022 (has links)
The purpose of this thesis is to investigate how tractor swapping can be implemented in Vehicle Routing Problems (VRP) with electric heavy goods vehicles, and to evaluate how a model that allows for tractor swapping performs, in terms of schedule cost, against a model that does not. Hence, this thesis introduces a new rich VRP variant which includes tractor swapping, as well as time windows, pickup and delivery, and electric vehicles. The model is named Electric Tractor Swap Vehicle Routing Problem (E-TSVRP) and is formulated as a mixed integer linear program. As for the solver, Gurobi is used. The results show that utilizing tractor swapping can reduce the total cost of serving customers significantly by reducing en-route charging and utilizing drivers more efficiently. Specifically, it is shown that the cost reduction comes mainly from reducing driver work time. By demonstrating how tractor swapping works and how the results can be visualized on smaller cases, this thesis aims to serve as a foundation for future research within the field. To be able to fully implement the model for large logistics problem instances however, alternative solution methods such as heuristics or metaheuristics should be developed so that the problems can be solved in a reasonable amount of time. / Syftet med denna uppsats är att undersöka hur traktorbyten kan implementeras i "Vehicle Routing Problem" (VRP) med tunga, elektriska lastfordon, och att utvärdera hur en modell som tillåter traktorbyten presterar mot en modell som inte tillåter det, med avseende på den totala schemakostnaden. I uppsatsen introduceras därför en ny och generell VRP som har stöd för traktorbyten, men som också modellerar energikonsumtion och laddning av elektriska lastbilar, samt tillåter tidsfönster för när leveranser kan levereras och hämtas upp på godtyckliga platser. Modellen kallas för "Electric Tractor Swap Vehicle Routing Problem" (E-TSVRP) och formuleras som ett linjärt, blandat heltalsprogram. Programmet löses sedan med lösaren Gurobi. Resultaten visar att utnyttjandet av traktorbyten kan märkbart minska den totala kostnaden av att leverera varor till kunder genom att minska tiden som föraren väntar på att traktorn laddar. Mer specifikt tillåts möjligheten att byta till en ny traktor när den tidigare får slut på energi, vilket möjliggör en högre utnyttjandegrad av förarna, och den fakturerade tiden associerad till förarna kan minskas. Detta sker genom en avvägning mellan å ena sidan högre hårdvarukostnader för fler traktorer och å andra sidan lägre förarkostnader. Genom att demonstrera hur traktorbyten fungerar och hur resultaten kan visualiseras på mindre transportproblem, strävar denna uppsats efter att verka som en grund för framtida forskning. För att modellen ska kunna användas för stora logistikproblem bör dock alternativa lösningsmetoder som till exempel lösningsheuristiker eller metaheuristiker utvecklas så att problemen kan lösas inom en rimlig tid.
6

Evaluation of Knee Ligament Injuries in Occupants of Heavy Goods Vehicles by Simulating Frontal Impacts using THUMS HBM / Utvärdering av knäligamentskador hos åkande i tunga fordon genom att simulera frontala islag hos THUMS HBM

Nusia, Jiota January 2019 (has links)
INTRODUCTION. Frontal collisions have been observed to cause the severe injuries on heavy goods vehicle occupants, and the lower extremities have been frequently injured. Injuries of knee joints are rarely life threatening, however they tend to give long-term consequences. AIM. Evaluate non-lethal frontal impacts towards the knee joint of Total Human Model for Safety (THUMS) v4.0 using a cylindrical barrier. The main objectives are to 1) create local injury risk functions of the knee ligaments restraining frontal impacts, 2) simulate frontal impacts towards the knee joints of THUMS and3) prepare the Hybrid III (HIII)-model for corresponding frontal impacts conducted on THUMS. The intention is for future HIII-simulations to be cross-correlated with the responses from THUMS for the ability to estimate knee ligament strains by investigating impacts on HIII. METHODS. 1) Ligament risk curves of PCL, MCL and LCL were formulated by assembling mean strain threshold values and standard deviations from literature. Virtual values were generated from these pooled strain thresholds, creating the risk curves. 2) THUMS lower body was impacted by a cylindrical steel barrier at four different locations - middle of patella, middle of knee joint, upper tibia and below tibia tuberositas. Four impact velocities ranging from 8-14 km/h were used at each location, giving a total of 16 impacts. 3) The HIII-model was prepared by removing the upper body and inserting the cylindrical steel barrier into the model file. RESULTS. The strain threshold at 50% rupture risk for PCL resulted in 23.6±4.4%, 34.2±6.0% for MCL and 26.6±6.5% for LCL. The simulated THUMS PCL strains reached between 36%-58% for the highest velocity at the impact locations where tibia was involved. Both MCL and LCL gave an approximate 5% strain outcome. The resultant knee displacement for these impacts ranged between 22 mm - 32 mm. The knee displacements at the PCL strain threshold ranged between 14 mm - 16 mm. DISCUSSION and CONCLUSION. Most of the maximal PCL strains exceeded the PCL threshold with large margins. However, the knee displacement at the PCL strain threshold resulted in outcomes comparable to the thresholds used for HIIImodel. These results supported the obtained PCL threshold to be within a reasonable range.
7

Evaluation of Thoracic Injury Risk of Heavy Goods Vehicle Occupants during Steering Wheel Rim Impacts to Different Rib Levels / Undersökning av risk för thoraxskador hos lastbilsförare vid rattislag mot olika revbensnivåer

Xu, Jia Cheng January 2019 (has links)
The interior of heavy goods vehicles (HGVs) differs from passenger cars. Both the steering wheel and the occupant are positioned differently in a HGV and increases the risk of steering wheel rim impacts. Such impact scenarios are relatively unexplored compared to passenger car safety studies that are more prevalent within the field of injury biomechanics. The idea with using human body models (HBMs) is to complement current crash test dummies with biomechanical data. Furthermore, the biofidelity of a crash dummy for loading similar to a steering wheel rimimpact is relatively unstudied and especially to different rib levels. Therefore, the aim with this thesis was to evaluate HGV occupant thoracic response between THUMS v4.0 and Hybrid III (H3) during steering wheel rim impacts with respect to different rib levels (level 1-2, 3-4, 6-7, 7-8, 9-10) with regards to ribs, aorta, liver, and spleen. To the author’s best knowledge, use of local injury risk functions for thoracic injuries is fairly rare compared to the predominant usage of global injury criteria that mainly predicts the most commonthoracic injury risk, i.e. rib fractures. Therefore, local injury criteria using experimental test datahave been developed for the ribs and the organs. The measured parameters were chest deflectionand steering wheel to thorax contact force on a global level, whilst 1st principal Green-Lagrangestrains was assessed for the rib and the organ injury risk. The material models for the liver and the spleen were remodelled using an Ogden material model based on experimental stress-strain data to account for hyperelasticity. Rate-dependency was included by iteration of viscoelastic parameters. The contact modelling of the organs was changed from a sliding contact to a tied contact to minimize unrealistic contact separations during impact. The results support previous findings that H3 needs additional instrumentation to accurately register chest deflection for rib levels beyond its current range, namely at ribs 1-2, 7-8, and 9-10. For THUMS, the chest deflection were within reasonable values for the applied velocities, but there were no definite injury risk. Fact is, the global injury criteria might overpredict the AIS3 injury risk (rib fractures) for rib level 1-2, 7-8, and 9-10. The rib strains could not be correlated with the measured chest deflections. This was explained by the unique localized loading characterized by pure steering wheel rim impact that mainly affected the sternum and the rib cartilage while minimizing rib deformation. The organ strains indicate some risk of rupture where the spleen deforms the most at rib levels 3-4 and 6-7, and the liver and the aorta at rib levels 6-7 and 7-8. This study provides a framework for complementing H3 with THUMS for HGV occupant safety with emphasis on the importance of using local injury criteria for functional injury prediction, i.e. prediction of injury risk using parameters directly related to rib fracture or organ rupture. Local injury criteria are thus a powerful safety assessment tool as it is independent on exterior loading such as airbag, steering wheel hub, or seat belt loading. It was noticed that global injury criteria with very localized impacts such as rim impacts have not been studied and will affect rib fracture risk differently than what has been studied using airbag or seat belt restraints. However, improvements are needed to accurately predict thoracic injury risk at a material level by finding more data for the local injury risk functions. Conclusively, it is clear that Hybrid III has insufficient instrumentation and is in need of upgrades to register chest deflections at multiple rib levels. Furthermore, the following are needed: better understanding of global injury criteria specific for HGV occupant safety evaluation, more data for age-dependent (ribs) and rate-dependent (organs) injury risk functions, a tiebreak contact with tangential sliding for better organ kinematics during impacts, and improving the biofidelity of the material models using data from tissue level experiments. / Förarmiljön i lastbilar gentemot personbilar är annorlunda, i detta kontext med avseende på främst ratt- och förarposition som ökar risken för islag med rattkransen för lastbilsförare. Sådana islag är relativt outforskat jämfört med passiv säkerhet för personbilar inom skadebiomekaniken. Tanken bakom användning av humanmodeller är att komplettera nuvarande krockdockor med biomekanisk information. Dessutom är biofideliteten hos en krockdocka vid rattislag relativt okänt, speciellt vid olika revbensnivåer. Därför är målet med detta examensarbete att undersöka thoraxresponsen hos en lastbilsförare genom att använda THUMS v4.0 och Hybrid III (H3) under rattislag med avseende på revbensnivåer (nivå 1-2, 3-4, 6-7, 7-8, och 9-10) och revben, aorta, lever, och mjälte. Enligt författaren verkar användning av lokala riskfunktioner för thoraxskador relativt ostuderat jämfört med den övervägande användningen av globala riskfunktioner som huvudsakligen förutser den mest vanligt förekommande thoraxskadan, nämligen revbensfrakturer. Därför har lokala riskfunktioner skapats för revben och organ, baserat på experimentell data. Uppmätta parametrar var bröstinträngning och kontaktkraft mellan ratt och thorax på global nivå, medan första Green-Lagrange huvudtöjningen användes för att evaluera skaderisken för revben och organ. Materialmodeller för lever och mjälte ommodellerades baserat på experimentell spänning-töjningsdata med Ogdens materialmodell för att ta hänsyn till hyperelasticitet. Töjningshastighetsberoendet inkluderades genom att iterera fram viskoelastiska parametrar. Kontaktmodellering av organ gjordes genom att ändra från glidande kontakt till en låsande kontakt för att minimera orealistisk kontaktseparation under islagsfallen. Resultaten stödjer tidigare studier där H3 visat sig behöva ytterligare givare för att noggrannt kunna registrera bröstinträngning vid olika revbensnivåer bortom dess nuvarande räckvidd, nämligen vid revben 1-2, 7-8, och 9-10. Uppmätt bröstinträngning i THUMS var rimliga för hastighetsfallen men gav inte någon definitiv risk för skada. Faktum är att de globala riskfunktionerna kan överskatta AIS3 risken vid revben 1-2, 7-8, och 9-10. Revbenstöjningarna kunde inte korreleras med bröstinträngningarna. Detta kunde förklaras genom de unika lastfallen som karakteriseras av rena rattislag som främst påverkar sternum och revbensbrosk som i sin tur minimerar deformation av revben. Organtöjningarna indikerar på någon risk för ruptur där mjälten deformerar som mest vid revben 3-4 och 6-7, medan för både levern och aortan sker det vid revben 6-7 och 7-8. Denna studie presenterar ett sätt att komplettera H3 med THUMS inom passiv säkerhet för lastbilsförare med fokus på lokala riskfunktioner för funktionell skadeprediktering dvs. prediktering av skaderisken med hjälp av parametrar som är direkt relaterat till revbensfraktur eller organruptur. Lokala riskfunktioner utgör en kraftfull säkerhetsbedömning som är oberoende av externa lastfall som t.ex. airbag, rattcentrum, eller bälteslast. I denna studie noterades det att de globala riskkriterierna inte har undersökts med väldigt lokala islag som rattislagen utgör och kommer därför att påverka risken för revbensfraktur annorlunda gentemot vad som har studerat, t.ex. airbag eller bältelast. Däremot behövs det mer data för de lokala riskkriterierna för att kunna prediktera thoraxskaderisken med ökad noggrannhet. Avslutningsvis, det är tydligt att Hybrid III har otillräckligt med givare och behöver förbättras för att kunna registrera bröstinträngning vid flera revbensnivåer. Vidare behövs följande: bättre förståelse för globala riskfunktioner anpassat inom passiv säkerhet för lastbilsförare, mer data för åldersberoende (revben) och töjningshastighetsberoende (organ) riskfunktioner, en ”tiebreak” kontakt med tangientiell glidning för bättre organkinematik, och ökad biofidelitet av materialmodeller genom att använda data från vävnadsexperiment.

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