Heavy duty vehicle (HDV) platooning is currently a big topic both in the academic world and in industry. Platooning is a smart way to solve problems such as safety, traffic congestion, fuel consumption and hazardous exhaust emissions since its concept enables several vehicles to drive close to each other while maintaining all the security requisites. This way, each vehicle will use the so called slipstream effect, an atmospheric drag reduction that occurs behind a traveling vehicle, consuming less fuel and consequently reducing the exhausted gases. Furthermore, it increases the traffic flow since the distance between vehicles is significantly reduced. The concept and idea of platooning is not particularly new, but only in the last few decades new technology made it possible. HDV platooning scenarios for scale model trucks were developed in the completely renovated Smart Mobility Lab, in KTH, Stockholm. A LabVIEW application was developed giving a robust and stable control of the trucks while following and driving on a newly designed and built road network. The trucks are able to follow a predefined trajectory, change lane and road, platoon with each other with different platooning distances, overtake when the platoon master is changed in order to take the lead of the platoon and change speed to catch up, among other features. The last part of this thesis covers the analysis of the scenarios developed in the testbed. These scenarios represent several situations of HDV platooning, particularly the platoon catch-up case. The main object of this study was the saved fuel due to platooning, and the break-even point, i.e. the distance ratio when neither driving alone nor catching up a platoon ahead would be more feasible. Using real HDV models and their fuel consumption models, simulations were performed in order to check the benefits of platooning and the data got from the scenarios was analyzed. Finally, conclusions were drawn from the experiments where the parameters such as HDV weight, speed increment when catching up and intermediate distance when platooning were different in each trial. It was concluded that a single HDV has to travel 8 to 15 times more than the initial distance that separates it from the HDV(s) ahead and it can save 5 to 13% of fuel depending if catching up a single HDV or a platoon an already existing platoon. Furthermore, it is less beneficial for a platoon already formed to decide to catch up another HDV.

Diesel locomotives provide versatility to the railway system as they do not depend on electric feeding. Worldwide they constitute important parts of locomotive fleets used for various tasks such as mainline services, shunting and terminal operations. The main drawbacks are emissions of CO2, NOx and other pollutants. The emissions to air are in general controlled by legislation. The European testing and approval procedure for locomotive engines is performed with the ISO 8178-F test cycle. It is alone meant to resemble all European locomotives. Good correlation was found between mainline operations and the ISO 8178-F test cycle. A good correlation was furthermore found between shunting operations and North American shunting test cycles. However, this thesis has shown that this results in inadequate description of for instance shunting operations. Typical characteristics for shunting are relatively high ratio of transient loading, low mean power output and high amount of idling. Therefore important aspects of diesel locomotive usage are thereby disregarded in certifications. Deficient correlation between test cycle and intended operations may lead to locomotives that are not properly optimised for the type of operation they are intended for. Improperly dimensioned and optimised locomotives cause impaired fuel economy and more emissions emitted. Many Swedish diesel locomotives are to a large extent used in shunting-like conditions in yards and industries for instance. Therefore, it is recommended to supplement the present ISO test cycle with a test cycle that includes the characteristic of shunting. Knowledge about duty cycles for specific operations can be of importance in locomotive acquisition, dimensioning of new locomotives or when estimating emissions and/or fuel consumption. It is essential to make proper dimensioning of propulsion systems as it can imply lower life cycle costs as well as fewer emissions. Appropriate dimensioning of the propulsion system is particularly important for non-conventional propulsion systems. If the application range of a test cycle is narrow, its emulating capability ought to be better at describing and representing the indented application. Today's test cycles state fractional power or torque as a function of engine speed. This may result in misleading duty cycles when the same kind of operation is undertaken with different locomotives that have widespread power ratings. A more powerful locomotive used for the very same load as a less powerful locomotive will result in a different duty cycle. Non-conventional propulsion systems are gaining popularity also in the railway industry where implementation of new technology usually is slow. Dual mode and hybrid systems are two examples. Related to test and duty cycles the build-up of these new propulsion systems change the prerequisites of the propulsion systems. From a duty cycle perspective it is reasonable to implement an additional test cycle for non-conventional propulsion systems if the popularity rises. / QC 20111115

This thesis focuses on the law of self-defense in the United States, in a context of domestic violence. The starting point is the work of Cynthia Gillespie, a US attorney whose groundbreaking work in 1989 shed light on the many legal obstacles battered women defendants face in Courts while pleading self-defense to homicide charges. Gillespie argued that some of the requirements inherent to the law of self-defense create unfavorable outcomes when applied to the context of domestic violence. The aim is to understand how the issue has evolved today, through the study of a single case ruled in 2019, “People V Addimando”. The conclusion is that there are some positive evolutions even if some severe obstacles remain. Some hope is to be found with the introduction of a new bill, the DVJSA, which is retroactive.

Regarding the ground electrical connection in trucks and buses, the requirements of earthing in heavy-duty vehicles were gathered and evaluated. The most important problems in the state-of-the-art grounding devices are corrosion, electrical resistance and uncertainty in the mounting process, altogether with depreciation over time. The goal is to come up with new concepts that can give a more reliable and better ground connection into the frame with faster, easier and safer manufacturing operations. Several methods for attaching different ground connectors to the steel frame are going to be investigated, including bolted connections, press devices, soldering, brazing and local plating spots. It will be shown that the welding operation gives the best electrical results, while lowering mounting costs, time and variability. Two welded connectors are then going to be proposed as the best alternatives and a parallel investigation with both of them is going to be carried out. These new concepts, filed for patent protection, are going to be labelled as “SRM Welded ground stud” and “SRM Welded grounding nut”. The first of them consists of a plated steel threaded stud (M8 or M10) with a ring shaped contact surface built in one of the ends, where the Ø12 mm weld is to be performed onto the uncoated frame. The second concept comprises a stainless steel M10 round nut welded over a punched hole. The optimization will also cover different alternatives for plating metals, contact aid compounds and masking caps for both devices. The risk of mechanical weakening of the frame because of the new welded concepts is going to be tested for the case of the SRM Welded ground stud. The results will show an increase in fatigue resistance of at least 20% compared to the current ground screw. Furthermore, the strength of the welded interface will show higher proof load than the stud itself. The welded nuts, tested with torque loading, will show a sufficient performance as well. The electrical tests present an expected decrease in ground resistance of 40% for the welded stud and an increase of 28% for the welded nuts, compared with the current ground screw. The conclusion of this Master Thesis states the recommendation of the implementation of a new grounding method through the SRM Welded ground stud. Although, some modifications in the transportation process of the frames might be needed because of the new protruding parts, pointing an estimated distance of 20mm from the frame surface. / När det gäller jordad elanslutning i lastbilar och bussar, har kraven på jordning i tunga fordon samlats och utvärderats. De största problemen i de mest avancerade jordade enheterna är korrosion, elektriskt motstånd och osäkerhet i monteringsprocessen, sammantaget med avskrivning över tiden. Målet är att utveckla nya koncept som kan ge en bättre och mer tillförlitlig jordanslutning i ramen med snabbare, enklare och säkrare tillverkning. Flera metoder för att fästa olika mark kontakter till stålramen kommer att undersökas, bland annat skruvförband, pressanordning, lödning, hårdlödning och lokala pläteringsfläckar. Det kommer att visa att svetsning ger den bästa elektriska resultatet, samtidigt som monteringskostnader, tid och variabilitet minskar. Två svetsade kontakter kommer sedan att föreslås som de bästa alternativen och en parallell undersökning med dem båda kommer att genomföras. Dessa nya koncept, för vilka patentskydd har ansökts, kommer att märkas som “SRM Svetsade marktapp” och “SRM Svetsade jordmutter”. Den första av dem består av en pläterad stålgängad tapp med en ringformad kontaktyta byggt i en av ändarna, där svetsen skall utföras på den obelagda ramen. Det andra konceptet består av en rostfri rund mutter svetsad över ett stansat hål. Optimeringen kommer även att omfatta olika alternativ för pläterade metaller, kontaktstöds föreningar och maskeringslock för de båda enheterna. Risken för mekanisk försvagning av ramen på grund av det nya svetsade konceptet kommer att testas med avseende på fallet med SRM Svetsad bottenreglar. Resultaten visar en ökad utmattningshållfasthet på minst 20% jämfört med den nuvarande jordskruven. Dessutom kommer styrkan av den svetsade gränsytan uppvisa en högre provbelastning än tappen själv. De svetsade muttrarna, testade med momentbelastning, kommer också uppvisa en tillräcklig prestanda. De elektriska testerna presenterade en förväntad minskning av markmotståndet på 40% för svetsade tappar och en ökning med 28% för svetsade muttrar, jämfört med den nuvarande jordskruven. Slutsatsen av detta examensarbete anger en rekommendation av genomförandet av en ny jordningsmetod genom en SRM Svetsad marktapp. Trots detta kan vissa ändringar behövas i transportprocessen av ramarna på grund av de nya utskjutande delarna, vilka pekar från ramens yta med ett uppskattat avstånd av 20 mm.

This article describes the first development phase of a centrifugal compressor with variable geometry which is designed to match the needs of future heavy-duty engines. Requirements of truck engines are analyzed, and their impact on the properties of the compressor map is evaluated in order to identify the most suitable kind of variable geometry. Our approach utilizes the transformation of engine data into pressure ratio and mass flow coordinates that can be displayed and interpreted using compressor maps. One-dimensional and three-dimensional computational fluid dynamics fluid flow calculations are used to identify loss mechanisms and constraints of fixed geometry compressors. Linking engine goals and aerodynamic objectives yields specific recommendations on the implementation of the variable geometry compressor.

No description available.

Global goals to reduce the greenhouse gases and CO2 emission has challenged many industries to innovate new technologies or shift to different products. Electrification of transportation has been considered a major improvement in this respect, which affects the entire transportation value chain including the manufacturing of heavy-duty vehicles. The importance and degree of changes that shifting toward electrification imposes on the truck manufactures value chain is subject to the study with a focus on the production stage of the value chain. The research also creates some insights to understand the sources of competitive advantage in the production of BEV.    Based on the authors’ knowledge and investigations, the contribution of this study in the research field is that the concept of the value chain together with Delphi method is implemented for the first time in the BEV industry to identify the impact of technology transformation on the production activities and competitive advantage. Furthermore, it contributes to highlight the unclarities in the BEV value chain activities that need more researches in order to create a more clear technology transformation path for the heavy-duty vehicle industry. The research findings imply that electrification has a big impact on the production value chain activities. The number of employees will be reduced that in turn creates a source of cost advantage for the company by reducing the cost per vehicle production. The assembly time is also shorter that makes it easier to respond to the market dynamic faster and reduces the cost of products storage. However, the risk for production stops is considered higher in BEV compare to ICE vehicles. Another finding is that the outsourcing of the components has a negative effect on the competitive advantage of the company and production efficiency. There is no difference between the impact of production activities on the company value chain in both BEV and ICE manufacturing. There is also a consensus on the more opportunities in BEV manufacturing to increase the production efficiency and lowering the cost.

No description available.

No description available.

The increasing energy demand and its impact on the climate around the world has evoked several sectors´ efforts in order to develop and implement sustainable technologies. Political incentives and companies go toward great changes when it comes to reduction of energy sources from fossil-origins in order to reduce greenhouse gas emissions and achievement of energy security. The military organisation is strongly dependent on fossil-based energy in several units. So far, alternative energy carriers to fossil energy sources have been an uncertain option when it comes to complying with military operational requirements. It is important that new technologies do not endanger military capabilities.  However, when the market goes toward more sustainable developments for alternative energy carriers, the military sector has to follow the development in order to utilize the available assortment and to secure supply chains. The energy demand within defence is expected to increase with respect to advanced equipment and communication technologies etc. This is related to all units within the defence. This thesis has been executed on a request by the Swedish Defence Materiel Administration in order to identify alternative energy carriers for a light duty vehicle.The thesis emphasizes how the Swedish Defence Materiel Administration can consider alternative energy carriers for light duty vehicles in order to achieve energy security without endangering military capabilities from a strategic perspective. The aim is to contribute to awareness of the market direction for sustainable technologies of alternative energy carriers in order to address knowledge gaps and facilitate the Swedish Defence Materiel Administration’s decisions about future research areas. The methods for the study included both literature reviews from previous research but also interviews with persons in both the private and public sectors. Based on previous research and the interviews, the results landed on four different energy carriers: biomethane, hydrogenated vegetable oils, hydrogen and Lithium-ion batteries. These energy carriers have been studied in relation to the following mechanisms: production, storage and infrastructure needed for energy supply. The thesis found that HVO and synthetic fuels have a limited impact on military organization compared to biomethane, hydrogen and batteries. However, large-scale production of these technologies is limited by the amount of waste available. From an energy security perspective Sweden has potential to exploit both the forest and renewable electricity from wind and solar energy. However, for an establishment there is a need for a closer interplay between the private and the public sector, where political incentives are vital for development. / Det ökande behovet av energi och dess påverkan på klimatet runt om i världen har lett till initiativtagande hos flera sektorer för att implementera och utveckla nya hållbara teknologier. Politiska incitament och företag går mot en stor förändring i samband med att minska användandet av energikällor från fossilt ursprung. Detta för att minimera utsläpp av växthusgaser och uppnå energisäkerhet. Militära organisationer är starkt beroende av fossilbaserade energi i flera förband. Hittills har alternativa energibärare varit ett osäkert alternativ för att uppfylla de militära operativa kraven där det är av stor betydelse att nya teknologier inte äventyrar militär förmåga. När marknaden går mot mer hållbara alternativ måste militära organisationer följa utvecklingen för att utnyttja det tillgängliga sortimentet och säkra leveranskedjorna. Det militära energibehovet förväntas öka i samband med implementering av avancerad teknik. Denna avhandling belyser hur Försvarets Material Verk kan överväga olika alternativa energibärare för lätta fordon för att uppnå energisäkerhet från ett strategiskt perspektiv. Syftet är att bidra till medvetenhet om marknadens riktningar för hållbara teknologier av alternativa energibärare för att identifiera kunskapsluckor och underlätta framtida beslut om vidare forskningsområden. Metoden för studien omfattar litteraturstudie från tidigare forskning och intervjuer med aktörer från både privata och offentliga sektorn. Baserat på tidigare forskning och intervjuer landade resultatet på fyra olika energibärare: biometan, hydrerade vegetabiliska oljor, väte och litium-jon batterier. Dessa energibärare har studerats utifrån följande mekanismer: produktion, lagring och infrastruktur vilket är nödvändigt för energiförsörjning av lätta mark fordon. Hydrerade vegetabiliska oljor och andra syntetiska energibärare har en begränsad påverkan på den militära organisationen jämfört med biometan, väte och batterier. Storskalig produktion av denna energibärare begränsas dock av tillgängligt avfall. Från ett energisäkerhetsperspektiv har Sverige som nation möjlighet att utnyttja råvaror från skog och elproduktion från förnybara källor. För en etablering behövs dock ett samspel mellan privata och offentliga sektorn där politiska incitament är avgörande för utvecklingen.