Currently extensive research on alternative fuels is being conducted due to their increasing demand to reduce greenhouse emissions. One renewable fuel studied in this work is dimethyl ether (DME) blended with propane(C3H8) as a potential mixture for heavy-duty engines used in semi-trucks. The blend has the potential to drastically reduce particulate and greenhouse gas emissions compared to a conventional diesel engine operating under similar conditions. To develop the use of mixture, one must conduct detailed conceptual and simulation studies before progressing to detail studies in CFD, engine modifications, and live testing. For simulations, accurate high-fidelity chemical kinetic models are necessary. However, the validity of the chemical kinetic mechanism for operating conditions of a heavy-duty mixing-controlled compression (MCCI) engine was widely unknown until recent work presented here and published. In this work, we studied the ignition of DME and propane blends in a shock tube under MCCI engine conditions. Ignition delay time (IDT) gathered behind the reflected shock for DME-propane mixtures for heavy-duty compression ignition (CI) engine parameters. Testing was conducted for undiluted varieties spanning from temperatures of 700 to 1100 K at pressures ranging from 55 to 84 bar for various blends (100% CH3OCH3, 100% C3H8, 60% CH3OCH3/ 40% C3H8) of DME and propane were combusted in synthetic air (21% O2/ 79% N2). Several experiments were conducted at higher pressures (90-120 bar) to improve the model performance and accuracy. The ignition delay times (IDTs) were compared to recent mechanisms, including Aramco3.0, NUIG, and Dames et al. A common trend among the mechanisms was overpredicted experimental IDTs. Further studies were conducted by a sensitivity analysis using the Dames et al. model, and critical reactions sensitive to IDTs of DME-propane mixture near 60 bar are outlined. Chemical analysis was conducted on the NTC region to explain chemical kinetics which is critical for developing MCCI heavy duty engines.

The transportation sector has a significant impact on the environment both nationally and globally since it is a major vehicle fuel consumption and emissions contributor. These emissions are considered a major environmental threat. Consequently, decision makers desperately need tools that can estimate vehicle emissions accurately to quantify the impact of transportation operational projects on the environment. Microscopic fuel consumption and emission models should be capable of computing vehicle emissions reliably to assist decision makers in developing emission mitigation strategies. However, the majority of current state-of-the-art models suffer from two major shortcomings, namely; they either produce a bang-bang control system because they use a linear fuel consumption versus power model or they cannot be calibrated using publicly available data and thus require expensive laboratory or field data collection. Consequently, this dissertation attempts to fill this gap in state-of-the-art emission modeling through a framework based on the Virginia Tech Comprehensive Power-Based Fuel consumption Model (VT-CPFM), which overcomes the above mentioned drawbacks. Specifically, VT-CPFM does not result in a bang-bang control and can be calibrated using publicly available vehicle and road pavement parameters. The main emphasis of this dissertation is to develop a simple and reliable emission model that is able to compute instantaneous emission rates of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) for the light-duty vehicles (LDVs) and heavy-duty diesel trucks (HDDTs). The proposed extension is entitled Virginia Tech Comprehensive Power-Based Fuel consumption and Emission Model (VT-CPFEM). The study proposes two square root models where the first model structure is a cubic polynomial function that depends on fuel estimates derived solely from VT-CPFM fuel estimates, which enhances the simplicity of the model. The second modeling framework combines the cubic function of the VT-CPFM fuel estimates with a linear speed term. The additional speed term improves the accuracy of the model and can be used as a reference for the driving condition of the vehicle. Moreover, the model is tested and compared with existing models to demonstrate the robustness of the model. Furthermore, the performance of the model was further investigated by applying the model on driving cycles based on real-world driving conditions. The results demonstrate the efficacy of the model in replicating empirical observations reliably and simply with only two parameters. / Ph. D. / The transportation sector places a huge burden on our environment and is one of the major emitters of pollutants. The resulting emissions have a negative impact on human health and could be a concern for national security. Therefore, policymakers are keen to develop models that accurately estimate the emissions from on-road vehicles. Microscopic emission models are capable of estimating the instantaneous vehicle emissions from operational-level projects, and policymakers can use them to evaluate their emission reduction plans and the environmental impact of transportation projects. However, the majority of the current existing models indicate that to achieve the optimum fuel economy, the driver should accelerate at full throttle and full braking for deceleration to minimize the acceleration and deceleration times. This assumption is obviously incorrect since it requires aggressive driving which will result in increasing the fuel consumption rate. Also, the models cannot use publicly accessible and available data to estimate the emissions which require expensive laboratory or field data collection. Consequently, this dissertation attempts to fill this gap in emission modeling through a framework based on the Virginia Tech Comprehensive Power-Based Fuel consumption Model (VT-CPFM), which overcomes the above mentioned drawbacks. Specifically, VT-CPFM does not follow the mentioned assumption of aggressive driving to minimize the fuel consumption as previously explained and can use publicly available vehicle and road pavement variables to estimate the emissions. Also, it utilizes US Environmental Protection Agency (EPA) city and highway the fuel economy ratings to calibrate its parameters. The main emphasis of this dissertation is to develop a simple and reliable emission model that is able to compute instantaneous emission rates of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) for the light-duty vehicles (LDVs) and heavy-duty diesel trucks (HDDTs). The proposed extension is entitled Virginia Tech Comprehensive PowerBased Fuel consumption and Emission Model (VT-CPFEM). The study proposes two models where the first model structure that depends on fuel estimates derived solely from VT-CPFM fuel estimates, which enhances the simplicity of the model. The second modeling framework combines the VT-CPFM fuel estimates with the speed parameter. The additional speed term improves the accuracy of the model and can be used as a reference for the driving condition of the vehicle. The model framework is consistent in estimating the three emissions for LDVs and HDDTs. Moreover, the performance of the model was investigated in comparison with existing models to demonstrate the reliability of the model. Furthermore, the performance of the model was further evaluated by applying the model on driving cycles based on real-world driving conditions. The results demonstrate the capability of the model in generating accurate and reliable estimates based on the goodness of fit and error values for the three types of emissions.

Biomethane made from the anaerobic digestion of organic waste can provide several economic and environmental benefits such as: the valorisation of waste products, increased resource efficiency, increased retention of nutrients through recycling of biogas digestate (Banks, et al., 2011), reduction of greenhouse gas emissions (Börjesson, et al., 2016) as well as the reduction of nitrogen oxides and particulate matter emissions (Börjesson & Berglund, 2007).To help actors understand when and where biomethane solutions can succeed, including the qualitative and quantitative aspects of a solution, an Early Assessment Method has been developed. The categories included in the assessment are potential, feasibility, economic and environmental performance. The Early Assessment Method was developed using a multi-criteria framework and consists of 15 key areas and 24 key indicators that should be considered when assessing biomethane solutions. Each quantitative indicator can be assessed either with site-specific data or by using generic equations and average values while the qualitative indicators are given a five-grade scale to facilitate the assessment.The potential category focuses on assessing how much raw material there is in the investigated area and how much of the usable products can be produced. The final areas are: biomass potential, biomethane potential and bio-fertilizer potential. In the feasibility assessment, qualitative aspects are assessed using a five-grade scale. The key areas for feasibility include: customer demand, competing applications, strategies for renewable fuels, legislation, economic instruments and infrastructure suitability. Performance is assessed both for economic performance and environmental performance to understand how the biomethane solution would perform if implemented. Economic performance includes both an indicator for cost per unit produced and an indicator for the investment cost for each production step. The key areas included are: biogas generation cost, biogas upgrading cost and biomethane distribution cost. The environmental performance is evaluated to understand how environmental aspects would change if biomethane replaced an alternative fuel on the market in the studied region. Key areas to assess this are: climate impact, air quality and nutrient recycling. These areas highlight some important benefits of using biomethane over fossil fuels, which are the most common fuels for heavy-duty vehicles.A two-part Early Assessment Tool was also developed. The tool is included in the method, but can be used separately if the user has a basic knowledge of biomethane. It assists with information collection, through a questionnaire, and structuring and presenting data, through a spreadsheet. The design of the Early Assessment Tool favours simplicity and usability while striving to maintain relevant information. It is meant to be used both for educational and investigative purposes when providing an early assessment of biomethane solutions within a certain region. The result from the tool can aid when making decisions and help with identifying which local actors to involve and what consultancy work might be needed to realise a biomethane solution.

For Heavy-duty vehicles (HDVs), the distribution of vehicle miles traveled (VMT) by vehicle type is the most significant parameters for onroad mobile source emissions modeling used in the development of air quality management and regional transportation plans. There are two approaches for the development of the HDV VMT distribution; one approach uses HDV registration data and annual mileage accumulation rates, and another uses HDV VMT counts/observations collected with the FHWA truck classification. For the purpose of emissions modeling, the FHWA truck classes are converted to those used by the MOBILE6.2 emissions rate model by using either the EPA guidance or the National Research Council conversion factors. However, both these approaches have uncertainties in the development of onroad HDV VMT distributions that can lead to large unknowns in the modeled HDV emissions. This dissertation reports a new heavy-duty vehicle visual classification and activity estimation method that minimizes uncertainties in current HDV conversion methods and the vehicle registration based HDV VMT estimation guidance. The HDV visual classification scheme called the X-scheme, which classifies HDV/truck classes by vehicle physical characteristics (the number of axles, gross vehicle weight ratings, tractor-trailer configurations, etc.) converts FHWA truck classes into EPA HDV classes without losing the original resolution of HDV/truck activity and emission characteristics. The new HDV activity estimation method using publicly available HDV activity databases minimizes uncertainties in the vehicle registration based VMT estimation method suggested by EPA. The analysis of emissions impact with the new method indicates that emissions with the EPA HDV VMT estimation guidance are underestimated by 22.9% and 25.0% for oxides of nitrogen and fine particulate matter respectively within the 20-county Atlanta metropolitan area. Because the new heavy-duty vehicle visual classification and activity estimation method has the ability to provide accurate HDV activity and emissions estimates, this method has the potential to significantly influence policymaking processes in regional air quality management and transportation planning. In addition, the ability to estimate link-specific emissions benefits Federal and local agencies in the development of project (microscale), regional (mesoscale), and national (macroscale) level air quality management and transportation plans.

In this thesis, a combined feedforward and feedback controller for improved path tracking on autonomous heavy-duty vehicles is designed and implemented. The steering wheel is controlled in order to follow a reference curvature, computed by a higher-level MPC, responsible for minimizing the distance to a planned path. The steering dynamics, from steering wheel via wheel angles, to a measurable vehicle curvature, is modeled, and a conversion from desired curvature gain to input angle to the steering wheel is derived. Tests with an autonomous Scania R580 show that the desired curvature can be followed with satisfactory small error, both in a designed slalom path and on a more generic test track. By utilizing future curvature values computed by the MPC, a non-causal feedforward controller can reduce the delay from input to the steering wheel to a measured response in curvature, by almost two thirds, compared to the currently implemented solution. Compared to an open-loop control design, tests in simulation show that a feedback controller can reduce errors in curvature gain. However, with the identified steering dynamics and the improved conversion from steering wheel angle to curvature, no further improvement in the curvature gain was seen when implementing the feedback controller in the test vehicle. Care must also be taken not to introduce instability in the system when the feedback controller is implemented in series with a high-level MPC. / Den här rapporten beskriver design och implementering av en regulator med kombinerad framkoppling och återkoppling för förbättrad banföljning av autonoma tunga fordon. Fordonets ratt styrs för att följa en kurvaturreferens beräknad av en överordnad MPC, ansvarig för att minimera avståndet till en planerad bana. Dynamiken i styrningen, från ratten via hjulvinklarna till en mätbar kurvatur för fordonet, är modellerad. En översättning från önskad förstärkning av kurvatur till insignal för rattvinkeln är också framtagen. Tester utförda med en autonom Scania R580 visar att den önskade kurvaturen kan följas med tillfredsställande litet fel, både i en egendesignad slalombana och i en mer generisk testbana. Genom att utnyttja framtida referensvärden för kurvatur beräknade av MPC:n, kan en icke-kausal framkopplande regulator minska fördröjningen från insignal till ratten till en mätbar respons i fordonets kurvatur. Jämfört med den nuvarande lösningen minskas fördröjningen med nästan två tredjedelar. Jämfört med en öppen styrning visar tester i simulering att en återkoppling i regulatorn kan minska stationära fel i kurvatur. Med implementeringen av den identifierade styrdynamiken och den förbättrade översättningen från rattvinkel till kurvatur, syntes dock med återkoppling ingen ytterliggare förbättring i testfordonet. Implementering av den återkopplande regulatorn i serie med den överordnade MPC:n behöver också göras med omsorg för att inte introducera instabilitet i systemet.

Made available in DSpace on 2016-03-15T19:37:00Z (GMT). No. of bitstreams: 1 Dionisio Mateo Cardille.pdf: 3138784 bytes, checksum: c27dcdc2765d16f7b30f2b6a5a588e37 (MD5) Previous issue date: 2009-08-18 / This study broaches the diesel engines cylinder liners waste concepts, characterizing abrasive waste, tribo-chemical waste and scuffing, with component external factors, like adultered fuel or with high sulfur level frequently found in Brazil. It presents the modern emissioned engines and the direct causes in the cylinder liners material requirement, with the tribologic evolution of piston, piston rings and cylinder. Some concepts of cylinders internal diameter surface finish and the direct involvement in the cylinder smooth, and the blow by flux besides oil consumption. The cylinder liners are manufactured in perlitic gray casting iron, and it was compared to a bainitic gray casting iron as alternative material, in order to satisfy the modern environment laws for emissions. The experiment technical was based on a dynamometric test in a 146kw diesel engine, during 500hs, with 27,4% overpower. The liners were assembled in the engine block in an intercalated way, avoiding benefits in the cylinders closer to the water pump. After the test, the liners were dimensioned with the respective piston rings. As result, was observed that the proposal bainitic material got a better waste resistance in comparison with the perlitic material, with a better dimensional stability. The piston rings presented similar waste when applied in both materials, respecting the project original tribological pair. / Este estudo aborda os conceitos de desgaste em camisas de cilindro para motores diesel, caracterizando desgaste abrasivo, tribo-químico e "scuffing", juntamente com fatores externos ao componente como a questão dos combustíveis adulterados ou com alto teor de enxofre, freqüentemente encontrados no Brasil. Apresenta o enquadramento dos motores nas modernas leis de emissões, e suas causas diretas na exigência de materiais para camisas de cilindro, juntamente com a evolução tribológica do conjunto pistão, anéis e camisa. Definem-se também alguns conceitos de rugosidade e acabamento superficial dos cilindros e suas implicações diretas no amaciamento neste componente, além do tema passagem de gases da câmara de combustão para o cárter (blow by) e consumo de óleo lubrificante. As camisas de cilindro são em sua maioria confeccionadas em liga de ferro fundido cinzento com matriz perlítica, a qual foi objeto de comparação com uma liga proposta de matriz bainítica, como material alternativo, visando satisfazer as condições impostas pela moderna legislação ambiental. A técnica experimental empregada baseou-se em um ensaio dinamométrico em um motor diesel de 146kw, porém submetido a plena carga durante 500hs, com 27,4% de acréscimo de potência. As camisas foram montadas no motor de forma a estarem intercaladas e evitando favorecimentos em cilindros mais quentes do bloco. Após o teste, as camisas de cilindro foram dimensionadas, juntamente com os respectivos anéis de pistão. Como resultado, observou-se que o material proposto em liga com matriz bainítica teve uma melhor resposta ao desgaste em comparação com o material de matriz perlítica, inclusive com uma melhor estabilidade dimensional. Os anéis de pistão tiveram desgaste similar em ambos os materiais, respeitando o par tribológico original de projeto.

With an imminent future of fully autonomous heavy duty vehicles in offroad applications, the need for advanced control system will increase accordingly. By implementing a raster map with tiles and pixels, to which a vehicle can record slope and position data while driving, it is possible to map earth's surface. By adding a heat parameter to every pixel, i.e. the number of passings through it historically, it is possible in future visits of the same are to generate a route prediction made up by the "hottest" pixels. By fetching the slope values in the hottest pixels, it is possible to generate a slope horizon that can be utilized by control systems, e.g. when planning gear shifts in hilly offroad terrain. To mange the incrementally growing map, a memory management system was implemented. It buffers the relevant map data from the database, i.e. the vehicles closest surroundings, which is then used for route prediction and horizon generation. As the vehicle moves into other areas, new data is read from the database, and the recently passed area is written back to the database, however updated from the recent passing. The system is implemented so that it runs through another application in the telematics electrical controller unit (ECU) in a Scania vehicle. The ECU contains a GNSS module from which the vehicle fetches satellite positioning data. Slope data is fetched from a slope sensor mounted on the truck. Due to implications during testing and debugging of the resulting application developed and implemented during this thesis project, the application's performance couldn't be assessed properly. However, it is concluded that the background the application is built on is reliable, although tweaks to get the application fit for usage in offroad terrain had to be made. Mainly, the horizon length and map building techniques should not be the same as in similar applications for onroad driving.

Driving a heavy-duty distribution truck in an urban environment is an intricate task that requires atremendous effort from the driver. Even a minor error such as briefly looking away from the road for asecond could have fatal consequences. The automotive industry is heavily investing into making roads saferand innovations such as the seat belt has been able to save millions of lives. With the introduction of new lawsand regulation there is an emerging adaptation of driver monitoring systems in vehicles which aims to savemore lives and improve the driving experience. This master thesis presents the exploration and design of a holistic concept for how driver state monitoringcould be implemented in a manual heavy-duty distribution truck in the year of 2035 at Scania. The mainpurpose is to add value to drivers by finding solutions that bridge driver needs and monitoring technology.Driver state monitoring is a field that introduces abilities for the vehicle to connect and understand the driverin order to provide more efficient assists for a safer and more pleasurable driving experience. An iterative usercentered design process was initialized with user interviews, observations and literature reviews that resulted inan in-depth view of the driver’s needs and a summary of the latest research and innovations. A creative phasegenerated multiple ideas that where evaluated using qualitative feedback from drivers and experts. A final setof features was selected and by using 3D modelling and video editing, an eight minute long animated film wascreated that showcases the possibilities of driver state monitoring in a heavy-duty distribution truck in 2035. The final concept is a unified vision of 22 features in a heavy-duty electric distribution truck, utilizing hybriddriver state monitoring techniques in order to provide a safer and more pleasurable driving experience. It isinspired and created around the latest research and innovations in the automotive industry and aims to inspireScania in their future work to implement and innovate new solutions based on driver state monitoring. This isa thesis work by two Master of Science student within Industrial Design Engineering from Luleå University ofTechnology at Scania in the spring of 2020. / Att köra en distributionslastbil i stadsmiljö är en komplicerad uppgift som kräver en stor insats från föraren. Till och med ett litet misstag som att titta bort från vägen under en kort period kan få katastrofala följder.Fordonsindustrin investerar mycket inom säkerhet och innovationer som säkerhetsbältet har väldigtframgångsrikt bidragit till att rädda miljontals liv på vägarna. I och med nya lagar implementeras system ifordon som bevakar föraren, med målet att rädda fler liv och skapa en bättre körupplevelse. Det här examensarbetet syftar till att designa ett helhetskoncept som visar hur bevakning av föraren kanimplementeras i en manuell distributionslastbil på Scania år 2035. Det huvudsakliga målet är att skapa värdeför förarna genom att hitta lösningar som bryggar gapet mellan förarnas behov och tekniken som möjliggörbevakning av föraren. Genom att introducera denna typ av förarbevakningsteknik ges möjligheten förfordonet att bättre förstå sig på föraren, vilket i sin tur möjliggör ökad säkerhet och bättre körupplevelser. Eniterativ och användarcentrerad designprocess användes och inleddes med intervjuer, observationer och enlitteraturstudie, vilket resulterade i en djup förståelse för förarnas behov samt en summering av den senasteforskningen och innovationerna. En kreativ fas genererade en mängd idéer som sedan utvärderas med hjälp avkvalitativ feedback från både förare och experter. Ett slutligt urval av funktioner togs fram och visualiseradesgenom att skapa en animerad film. Den färdiga åtta minuter långa filmen visar på möjligheterna med tekniksom bevakar föraren i en distributionslastbil år 2035. Det slutliga konceptet förenar 22 funktioner i en elektrisk distributionslastbil. Ett flertal tekniker utnyttjas föratt bevaka föraren och tillsammans bidrar de till en säkrare och mer njutbar körupplevelse. Konceptet ärinspirerat av- och bygger på den senaste forskningen och de senaste innovationerna inom fordonsindustrin,med målet att inspirera Scania i framtida projekt där förarbevakningssystem utvecklas och implementeras.Detta arbete är ett examensarbete gjort av två civilingenjörsstudenter inom tekniks design från Luleå tekniskauniversitet på Scania under våren 2020.

The Swedish transport sector will need to undergo a major restructuring to achieve the established climate and environmental goals. The biggest change is that fossil fuels will be phased out and a larger part of the vehicle fleet will be electrified. This study deals with the electrification of heavy-duty trucks and how high-power charging stations affect the local electricity grid. Charging of heavy-duty trucks depends largely on the logistics of the transport system, which reduces the demand flexibility of power. High-power charging entails a risk of increased power peaks, which can affect the bus-voltage profiles, losses and loads on grid components. This thesis has been conducted as general study based on the case with the high-power charging station at Vädermotet in the area Hisingen of Gothenburg. The purpose was to build a generic model of the electricity grid at Hisingen and then investigate the consequences of high-power charging for the grid for two charging scenarios: the first scenario with four ABB Terra 360 chargers, and the second scenario with six ABB Terra 360 chargers and one MCS. The electricity network model and simulations were performed in PSS®SINCAL. The two charging scenarios, as well as the scenario before chargers were installed, were then simulated for three different system-load cases: maximum, average, and low load. The results showed that high-power charging of trucks had the biggest impacts for the voltage profiles during the case of low load. For the medium load and maximum load cases, the effect of the high-power charge decreased. Furthermore, electricity network losses increased for the low load case, but decreased slightly for the average and maximum load case. The reason was a more even load balance between the bus that connected the charging station to the grid and the rest of the network for the average and maximum load cases. In summary, the study indicated that grid implementation of a high-power charging station will have consequences for the local power system. However, the magnitude of the effects is not validated and can therefore only be regarded as indications. The outcome can be partly explained by the assumptions and simplifications of the model compared to the real system.

Hybrid-electric technologies have recently been introduced into the market for heavy-duty vehicles (HDVs). However, challenging an established technology with a new and untried technology is difficult, also under the best conditions. Forecasting is a vital tool in product portfolio management, since it provides guidance on how much resources a firm should allocate on new innovative projects and products and when and where to enter the market. Therefore, this thesis forecasts the market penetration of hybrid HDVs in Europe by usage of innovation diffusion models – based on three different market scenarios assuming no, some and considerable incentives or legislative CO2 for HDVs. Hybrid-electric, hydraulic hybrid and flywheel hybrid vehicles are considered and an analogical approach is used based on sales data for radial tyres, disc brakes and anti-lock braking systems. The result from a non-linear regression analysis indicated that innovation diffusion models of mixed influence are capable of predicting future market demand, not only of hybrid HDVs, but also of other HDVs with new innovative technologies or solutions. Therefore, it was suggested that innovation diffusion modeling should be a standard tool in the strategic planning of a HDV firm’s all new innovative products. All market scenarios resulted in a rather low diffusion speed of hybrid HDVs during the first ten years, but the speed increased then rapidly during the next ten years such that 40-50 percent of the HDV market was penetrated in 2030. In the most hybrid-friendly scenario, the market was nearly fully penetrated after 50 years since the first introduction in 2010, while in the least hybrid-friendly scenario additional ten years was needed to fully penetrate the HDV market. The forecasts may be affected by possible pre-diffusion, the emergence of a dominant design or the diffusion acceleration effect. One of the major challenges of using innovation diffusion models for sales forecasting of hybrid HDVs, was to find appropriate and sufficient analogous sales data. Therefore, Thomas (1985) analogous approach was further developed to be more focused on finding analogous sales data from internal, external or public sources.