Wiener Linien’s tram network is one of the largest and busiest of its kind worldwide. Maintaining and improving the Level of Service (LoS) is one of the major tasks of the operations division. To direct these improvements efficiently to lines and sections of lines in need, tram line performance needs to be assessed. In this master thesis a Python-based model is developed to assess tram line performance using ideal operational constraints. Furthermore, the model is capable of computing the energy consumption for this optimal case. The tool computes Undisturbed Optimal Travel Times (UOTTs) which serve as a benchmark for tram line performance. Therefor it builds on track alignment data (curves and radii, gradients and switches), speed restriction data and a set of optimal parameters (no traffic, constant acceleration, etc.). Furthermore, train resistance, curve speeds and vehicle type are taken into consideration. These parameters are investigated and selected based on literature studies, interviews with employees of Wiener Linien, as well as field tests. Finally, the model results are compared to real world data for evaluation. A discussion of the results regarding further applications and improvements is performed. / Spårvagnsnätet i Wiener Linien är ett av de största och mest trafikerade i sitt slag i världen. Att underhålla och förbättra servicenivån är en av de viktigaste uppgifterna för driftsavdelningen. För att dessa förbättringar ska kunna riktas effektivt till de linjer som mest behöver det måste spårvagnarnas prestanda bedömas. I detta exjobb utvecklas en Python-baserad modell för att bedöma spårvagnslinjens prestanda med hjälp av ideala trafikparametrar. Dessutom kan modellen beräkna energiförbrukningen för dessa optimala scenarier.Verktyget beräknar Ostörda Optimala Restider (UOTTs) som blir referenser för spårvagnslinjernas prestanda. Metoden bygger på spårutformning (kurvor och radier, lutningar och växlar), hastighetsbegränsningar, och en uppsättning optimala parametrar (ingen vägtrafik, konstant acceleration osv.). Dessutom tas hänsyn till rullmotstånd, hastighet i kurvor och fordonstyp. Dessa parametrar undersöks och väljs ut genom litteraturstudier, intervjuer med anställda vid Wiener Linien samt fälttester.Modellresultaten jämförs med uppmätta restidsdata för utvärdering av den dagliga driften. En diskussion av ytterligare tillämpningar och förbättringar förs.

This thesis aims at systematically studying the possibilities of minimising devastatingconsequences of high-speed derailments by appropriate measures and features in thetrain design, including the running gear. The course of events immediately afterderailments is studied with respect to whether the train stays upright and close to thetrack centre line or deviates laterally with probably serious consequences. There is abelief in the railway community that some trains can better cope with derailment thenothers, although this superiority is apparently hard to quantify.Firstly, an empirical database has been established containing as much relevantinformation as possible of past incidents and accidents occurred at higher speeds due tomechanical failure close to the interface between the running gear and the track, as wellas other causes that ultimately brought the train into a derailed condition. Although nevertwo derailments are the same, certain patterns appeared to crystallise after analysing thecourse of events immediately after the failure based on the descriptions available in eachincident or accident report. Ultimately, this led to that several critical vehicle parameterscould be distinguished as capable to influence the outcome of a derailment.Secondly, two of the critical vehicle features found in the first stage have been subject todetailed analysis by means of multi-body system (MBS) simulations. The first phase ofthe computer simulation program focused on studying the tendency of a wheelset toderail as a result of an axle journal failure on the outside of the wheel. The prederailmentcomputer simulation model has been validated with good results for twoauthentic Swedish events of axle journal failure.Thereafter, one of the newly found critical vehicle feature, the wheelset mechanicalrestrictions relative to the bogie frame, have been extensively studied on an X 2000power unit and trailer car model. The results show that a vertical mechanical restrictionof the wheelset relative to the bogie frame of approximately 50 to 60 mm is capable ofkeeping the wheelsets on the rails after an axle journal failure, for the studied conditions.An axle mounted brake disc constitutes the second critical vehicle feature that has thepotential to favourably influence the sequence of events in cases of wheel flangeclimbing. A minimal range of geometrical parameters for which the rail would safely fillthe gap between the brake disc and the wheel has been calculated.The third and last part of the thesis establishes the prerequisites necessary in order tostudy the remaining of the critical vehicle parameters found in the first part, whichrequires complete MBS simulations of derailed vehicles rolling on track structures, i.e.concrete sleepers. To accomplish this task, hysteresis data for the force as function ofconcrete material indentation, are aimed to be acquired by means of finite element (FE)simulations. Therefore, the intended FE model of wheel-concrete sleeper impact issubjected to a tentative validation procedure. A good agreement is observed whencomparing the FE model results with an authentic accident in terms of concrete sleeperindentation. Furthermore, preliminary results in terms of a wheelset tendency to reboundafter concrete sleeper impact are presented. / QC 20101125

Carbody tilting is today a mature and inexpensive technology allowing higher speeds in curves and thus reduced travel time. The technology is accepted by most train operators, but a limited set of issues still holding back the full potential of tilting trains. The present study identifies and report on these issues in the first of two parts in this thesis. The second part is dedicated to analysis of some of the identified issues. The first part contains Chapters 2 to 5 and the second Chapters 6 to 12 where also the conclusions of the present study are given. Chapters 2 and 3 are related to the tilting train and the interaction between track and vehicle. Cross-wind stability is identified as critical for high-speed tilting trains. Limitation of the permissible speed in curves at high speed may be needed, reducing the benefit of tilting trains at very high speed. Track shift forces can also be safety critical for tilting vehicles at high speed. An improved track standard must be considered for high speed curving. Chapters 4 and 5 cover motion sickness knowledge, which may be important for the competitiveness of tilting trains. However, reduced risk of motion sickness may be contradictory to comfort in a traditional sense, one aspect can not be considered without also considering the other. One pure motion is not the likely cause to the motion sickness experienced in motion trains. A combination of motions is much more provocative and much more likely the cause. It is also likely that head rotations contribute as these may be performed at much higher motion amplitudes than performed by the train. Chapter 6 deals with services suitable for tilting trains. An analysis shows relations between cant deficiency, top speed, tractive performance and running times for a tilting train. About 9% running time may be gained on the Swedish line Stockholm – Gothenburg (457 km) if cant deficiency, top speed and tractive performance are improved compared with existing tilting trains. One interesting conclusion is that a non-tilting very high-speed train (280 km/h) will have longer running times than a tilting train with today’s maximum speed and tractive power. This statement is independent of top speed and tractive power of the non-tilting vehicle. Chapters 7 to 9 describe motion sickness tests made on-track within the EU-funded research project Fast And Comfortable Trains (FACT). An analysis is made showing correlation between vertical acceleration and motion sickness. However, vertical acceleration could not be pointed out as the cause to motion sickness as the correlation between vertical acceleration and several other motions are strong. Chapter 10 reports on design of track geometry. Guidelines for design of track cant are given optimising the counteracting requirements on comfort in non-tilting trains and risk of motion sickness in tilting trains. The guidelines are finally compared with the applied track cant on the Swedish line Stockholm – Gothenburg. Also transition curves and vertical track geometry are shortly discussed. Chapters 11 and 12 discusses the analysis, draws conclusions on the findings and gives proposals of further research within the present area. / QC 20101119

The purpose of the thesis was to evaluate the robustness of the Hybrid A* algorithm in regards to the levels of dynamic vehicle modeling, vehicle parameters and driving velocity. The original scope of the thesis project was to alter vehicle and tire models but this was discovered to be out of the time limits of the thesis project. The new scope was to alter the parameters with close connection to the vehicle dynamics, such as tire friction, vehicle mass and driving velocity. The thesis project was performed in collaboration with Syntronic and their internal project Autodrive.  Due to the complexity of the system, tests were first performed to evaluate if the path planner and path following were deterministic. Variation of tire friction, vehicle mass, reference velocity and maximum steering was then performed during three different driving missions designed to simulate different complexity levels of realistic driving scenarios. The dependence of the varied vehicle parameters on the deterministic behaviour was also examined. Lastly, the impact of altering parameters used for smoothing of the Hybrid A* solution and parameters of the controller were explored and analysed. The position of the vehicle, the velocity profile, slip angles and angular acceleration were used in order to draw conclusions regarding the performance of Hybrid A*, the motion control and the limitations of vehicle and tire models.  The results showed that the implementation used of Hybrid A* is deterministic but fail to produce a consistent route when faced with obstacles and re-planning due to the vehicle control not being deterministic. Variation in vehicle mass and reference velocity as well as the aggressiveness of the course were concluded to impact the determinism of the path following. The best values for the smoothing parameters are dependent on the desired vehicle behaviour, but can be used to reduce the difference between the planned and followed path.  The Hybrid A* planner was concluded to be robust in regards to variations in vehicle mass, tire friction and maximum steering angles but very sensitive to a change in velocity. The slip angles were generally small, but the kinematic single-track model theoretically only hold when the slip angles are zero. The results did, however, indicate that the implementation of the Hybrid A* algorithm was able to produce a drivable and realistic path for all cases except the most extreme parameter choices. For larger velocities and unrealistically low tire friction, the dynamic single-track model is more suitable.  The choice of vehicle model is not critical except when using high driving velocities. It is important to have knowledge of the desired driving velocity when choosing a dynamic model, but the solution of the implemented path planner and path following is otherwise robust enough to handle a less advanced model. The current implementation of the Hybrid A* algorithm, using the kinematic single-track model, can therefore be concluded to be sufficient in planning a realistic path for a simulated autonomous vehicle for low driving velocities, while a more advanced model is needed when increasing the driving velocity.

The study of Heating, Ventilation and Air Conditioning (HVAC) system performance is important to understand its energy consumption, especially for electric vehicles. The purpose of this thesis is to develop a methodology to simulate the flow within the Scania S20H cab while also capturing the thermal properties of the fluid and solids within the cab. This is done by setting up a heat-up simulation of a stationary cab in STAR-CCM+ (Siemens Industry Software Inc, Plano TX,USA). The thesis speaks about the limitations with the current methodologies and delves into the theoretical aspects of such a scenario. The new method is a complete Computational Fluid Dynamics (CFD) method that involves conjugate heat transfer, shell modeling and temperature dependent Heat Transfer Coefficient (HTC). A benchmark case is run to understand the uncertainties introduced by virtue of the shell model. When its effects are understood and deemed minimal in the context of thesis, a steady state case for the full truck model is simulated. After it was found that the physics is well captured, a fully transient case is run to validate the model against the experimental data. The simulations best capture the behaviour of low insulation and low thickness areas such as the windshield. The gap between the simulation and experiment increases with increasing thickness and insulation. The model is found to perform mostly well with some variations between regions in the cab. The thesis satisfied its objectives in developing a methodology to better ease the conceptual design process. Additionally, guidelines for the workflow of the methodology are presented along with the limitations and scope for improvement.

The oceans are a key element in our society, economy and environmental system.They cover over 70% of the worlds surface and contribute substantially to ecosystemservices such as climate management as well as to economic sectors such as foodproduction and tourism. While the importance of the oceans for climate changeand the society is generally acknowledged in science and literature, it is often notreflected in policy. Integrated Assessment Models (IAMs) which are used to advicepolicy on carbon prices often systematically omit process and damages related tothe ocean such as ocean acidification, loss of biodiversity and changes in oceancurrents.The aim of this study is to give a more detailed perspective on ocean related processesand their role and importance for the economy under climate change and to testassumptions made in the development of IAMs - and more precisely the DynamicIntegrated Climate-Economy model also referred to as the DICE model. The initialresults of the DICE model resulted in a optimal temperature trajectory with amaximum of 4 ◦C contradicting the goals set with the Paris Agreement.This thesis is the first of its kind attempt in reviewing the most recentbiophysical evidence on climate change impacts with a focus on marine systemsand incorporating these damages to market and non-market sectors into the DICEmodel. The impacts from climate change are implemented into the DICE modelthrough economic valuation of the damages and an update of the damage function.The analysis is based on the damage function used in the original DICE2016R2model as well as the suggested update presented by Hänsel et al. (2020)The results show, that incorporating marine damages into the model yields in amajor increase in economic damages particularly in the temperature range up to 2◦C.These increased damages influence the results of the optimal temperature trajectoryand give a clear indication for a more stringent climate policy, drastically limitingthe maximum temperature increase compared to the original DICE model. / Haven är en viktig del av vårt samhälle, vår ekonomi och vårt miljösystem. De täcker över 70 % av jordens yta och bidrar väsentligt till ekosystemtjänster ekosystemtjänster som klimatstyrning samt till ekonomiska sektorer som livsmedels livsmedelsproduktion och turism. Havens betydelse för klimatförändringarna och samhället och samhället är allmänt erkänd inom vetenskap och litteratur, återspeglas den ofta inteåterspeglas ofta inte i politiken. Integrerade utvärderingsmodeller (IAM) som används för att geom koldioxidpriser utelämnar ofta systematiskt processer och skador relaterade tillhavet, t.ex. havsförsurning, förlust av biologisk mångfald och förändringar ihavsströmmar.Syftet med denna studie är att ge ett mer detaljerat perspektiv på havsrelaterade processeroch deras roll och betydelse för ekonomin under klimatförändringen samt att testaantaganden som gjorts i utvecklingen av IAM - och mer exakt den dynamiskaintegrerade klimat-ekonomimodellen, även kallad DICE-modellen. De förstaresultaten av DICE-modellen resulterade i en optimal temperaturbana med ettmaximalt 4 ◦C, vilket strider mot de mål som satts upp i Parisavtalet.Denna avhandling är den första i sitt slag som granskar de senastebiofysiska bevis på klimatförändringens effekter med fokus på marina systemoch införliva dessa skador på marknads- och icke-marknadssektorer i DICEmodellen. Effekterna av klimatförändringarna implementeras i DICE-modellengenom ekonomisk värdering av skadorna och en uppdatering av skadefunktionen.Analysen baseras på den skadefunktion som används i den ursprungliga DICE2016R2modellen samt den föreslagna uppdateringen som presenteras av Hänsel et al. (2020)Resultaten visar att införandet av marina skador i modellen leder till enstor ökning av de ekonomiska skadorna, särskilt i temperaturintervallet upp till 2◦C.Dessa ökade skador påverkar resultaten av den optimala temperaturbananoch ger en tydlig indikation på en mer stringent klimatpolitik, som drastiskt begränsarden maximala temperaturökningen jämfört med den ursprungliga DICE-modellen.

Both commuting to work and long-distance travelling with one's own bicycle have been intrend for years and a large market has emerged. While the reasons on the customer side aremainly sustainability and sporting activity, the companies offer customised products for manydifferent use-cases.In this master's thesis, a transport box for bicycles is being developed that can be taken on aplane, for example, and converted into a cargo trailer at the destination. A market researchshows that such a product is already available for certain folding bikes, whereas the goal is auniversal solution for utility bikes as well as mountain bikes.The methodological development follows a standard that divides the process into four phases.After the market research, main functions of the product are identified, which are "Transport abicycle as luggage" and "Carry goods during the bicycle ride". These are then divided intosub-functions in order to find different design variants for each function, combine them intodifferent drafts with the help of a morphological box and finally evaluate according totechnical and economic criteria, so that a final draft is determined at the end of this phase. It isa hard case providing enough space for different types of bicycles, that can be converted intoa trailer by mounting two wheels on the sides and a tow bar.In phase 3, the wheel size is set at 12 inches due to small space requirements and weight, andthe material is set to ABS-plastic for reasons of sustainability and mechanical properties.The final phase involves 3D design using Fusion360 with drawing derivation and validationof the model. The model shows that the requirements regarding geometry and weight havebeen implemented and that a practical transport option for bicycles has been found. In order topotentially launch the product on the market, further investigations such as FEM analysis ordynamic simulations are necessary. / Både pendling till arbetet och långväga resor med egen cykel har varit trendigt i flera år ochen stor marknad har vuxit fram. Medan anledningarna på kundsidan främst är hållbarhet ochsportaktivitet, erbjuder företagen kundanpassade produkter för många olika användningsfall.I detta examensarbete utvecklas en transportlåda för cyklar som till exempel kan tas med påett flygplan och omvandlas till en lasttrailer på destinationen. En marknadsundersökning visaratt en sådan produkt redan finns tillgänglig för vissa hopfällbara cyklar, medan målet är enuniversell lösning för både vanliga cyklar och mountainbikes.Metodutvecklingen följer en standard som delar in processen i fyra steg. Eftermarknadsundersökningen identifieras produktens huvudfunktioner, vilka är "Transportera encykel som bagage" och "Bära varor under cykelturen". Dessa delas sedan in i underfunktionerför att hitta olika designvarianter för varje funktion, kombinera dem till olika utkast med hjälpav en morfologisk box och slutligen bedöma enligt tekniska och ekonomiska kriterier, så attett slutligt utkast bestäms i slutet av denna steg. Det är en hård väska som ger tillräckligt medutrymme för olika typer av cyklar, och som kan omvandlas till en cycelkärra genom att manmonterar två hjul på sidorna och en dragkrok.I steg 3 sätts hjulstorleken till 12 tum på grund av små utrymmesbehov och vikt, ochmaterialet sätts till ABS-plast av hållbarhetsskäl och på grund av mekaniska egenskaper.Den sista steget innebär 3D-konstruktionen i Fusion360 med ritningsframtagning ochvalidering av modellen. Modellen visar att kraven på geometri och vikt har uppfyllts och attman har hittat ett praktiskt transportalternativ för cyklar. För att potentiellt kunna introduceraprodukten på marknaden krävs ytterligare undersökningar som FEM-analys eller dynamiskasimuleringar.

Nowadays, the forestry industry still uses heavy machinery damaging both the forest and the soil. The start-up AirForestry is currently developing a sustainable way to thin and harvest trees. With their 6.2m wide electric drone carrying a harvesting tool, they can reach, thin, cut and carry trees without the need for access roads. Naturally, the drone needs to be as lightweight as possible to increase its endurance and operation range. Therefore, the first version of the drone was manufactured before the thesis with a carbon fibre laminate.  The purpose of this thesis is to study and optimize the composite structure of the drone. The first step is to characterize the existing design through experiments and simulations using the software ANSYS. Static bending loads, free vibrations, and forced vibrations are investigated against a set of predefined design requirements. This study shows that the contact surfaces between each arm and with the motor holders have high-stress concentrations compared to the rest of the arm. This means that most of the arm can be made thinner to lessen the weight with some extra reinforcement on those problematic areas.  The second step is to optimize the laminate to decrease the weight of the structure. A preliminary optimization was made and manufactured at the beginning of the thesis with strict limitations on the choice of the lamina or available thicknesses. Similar bending and vibration experiments and simulations are conducted on the new design to compare it with the older model. While the mass was expected to decrease by about 30 $\%$, the final measured weight of the arms indicates a drop of only 15 $\%$ of the mass. The model is then optimized further with more freedom in the design variables. Several variables are successively optimized: the material choice for the laminae, the thickness then of the laminae, and the angles of the plies. The mass of the structure with the final laminate has an expected decrease in mass of 45$\%$, saving more than 12kg in total / I dag använder skogsindustrin fortfarande tunga maskiner som skadar både skogen och marken. Det nystartade företaget AirForestry utvecklar för närvarande ett hållbart system för att gallra och skörda träd: en 6,2 meter breda elektriska drönare som bär ett avverkningsverktyg. Med den kan de nå, gallra, avverka och bära träd utan att behöva använda tillfartsvägar. Naturligtvis måste drönaren vara så lätt som möjligt för att öka dess uthållighet och räckvidd. Därför tillverkades den första versionen av drönaren före examensarbetet med ett kolfiberlaminat.  Syftet med detta arbete är att studera och optimera drönarens kompositstruktur. Det första steget är att karakterisera den befintliga konstruktionen genom experiment och simuleringar med hjälp av programvaran ANSYS. Statiska böjningsbelastningar, fria vibrationer och påtvingade vibrationer undersöks med avseende på en uppsättning fördefinierade konstruktionskrav. Det andra steget är att optimera laminatet för att minska strukturens vikt. En preliminär optimering gjordes och tillverkades i början av arbetet med strikta begränsningar för valet av lamina eller tillgängliga tjocklekar. Liknande böjnings- och vibrationsexperiment och simuleringar utförs på den nya konstruktionen för att jämföra den med den äldre modellen. Även om massan förväntades minska med cirka 30 $\%$, visar den slutliga uppmätta vikten på armarna att den endast minskat med 15 $\%$. Modellen optimeras sedan ytterligare med större frihet i konstruktionsvariablerna. Flera variabler optimeras successivt: materialvalet för lamellerna, lamellernas tjocklek och vinklarna på skikten. Strukturen med det slutliga laminatet får då en förväntad minskning av massan med 45 $\%$, vilket innebär en total besparing på mer än 12 kg.

In this thesis work a literature survey is done to collect published data for T-welded joints with a thickness of 5-12 mm, produced in high strength steel and treated with HFMI. In addition to this, large structures are researched. The data was evaluated in nominal stress and effective notch stress and compared with the recommended FAT value from the International Institute of Welding (IIW) for post-weld improved joints. It was concluded that not sufficient data exist for T-joints in high strength steel, especially steels of grades with yield strength greater than 450 MPa, and thicknesses of 5-12mm, neither does enough data exist for large structures. The recommended fatigue strength values from the IIW were compared. / I detta arbete så kommer en litteraturstudie att genomföras för att samla data om svetsade t- balkar med en tjocklek på 5-12 mm, av materialet höghållfasta stål och behandlade med HFMI. Stora strukturer kommer även att undersökas. Den samlade datan är utvärderad i nominell spänning och effective notch stress och jämförd med International Institute (IIW) of Welding för efterbehandlade svetsar. En slutsats är att det inte finns tillräckligt med data för svetsade t-balkar i höghållfasta stål med en tjocklek mellan 5-12 mm. Data om stora strukturer bör också utvecklas. De rekommenderade utmattningshållfasthets värden från IIW jämfördes.

För att förbättra förarmiljön i Stridsbåt 90 H (CB90 H) skapades en process baseradpå IDEO.org med faser för att analysera nuvarande lösning, identifiera problem samtlösa dessa problem. Genom enkät, intervju, workshops, fokusgrupper ochdeltagande observation med en mindre grupp väldigt erfarna användare kunde fleraproblem ringas in. För att behandla dessa problem användes teori kring kognition, såsom gestaltlagar, kognitiva processer och kognitiv feedback. Även relevantastandarder för förarmiljöer i fartyg samt ergonomi tas upp. Teorin kombineradessedan med de tidigare nämnda metoderna för att komma fram till konkretalösningar. När det fanns en bra uppfattning om hur de olika instrumenten ochreglagen skapades koncept utifrån en egen metod. Metoden är en graf som plottarvikten av synlighet mot vikten av tillgänglighet. Varje enskilt instrument och reglageplaceras därefter ut på grafen där dess synlighet och tillgänglighet motsvaras.Resultatet visade att många instrument var överflödiga för de uppgifter som tillhörföraren och att flera andra placerats ogenomtänkt. Genom att använda grafentillsammans med teorin och standarderna skapades en ny layout för förarens reglageoch instrument. En enkel visualisering skapades utifrån en konstruktionsfil. Slutligendiskuteras arbetets, resultat, relevans och trovärdighet.