One of the biggest obstacles to launching autonomous vehicles is the current legislation, which currently does not cover automation level higher than level 2. Work on developing the legal requirements takes place at UN level within WP29 (The UNECE World Forum for Harmonization of Vehicle Regulations). As a world-leading vehicle manufacturer, Scania is aspiring to pave the way for sustainable transport solutions. At Scania, well-established methodologies on certification of different systems exist, although the process of certification of autonomous driving systems needs to be developed.This master thesis investigates the current situation regarding the elaboration of regulations to cover autonomous vehicles, future certification methods related to these systems, and how this applies to Scania. Particular focus is being on the investigation of virtual certification methods. This can form the basis for various departments at Scania in their work with future autonomous systems and how to get these certified.The future certification work for autonomous vehicles will be based on a validation process based on a process called the ‘Multi-pillars approach’ / ‘Three-pillars approach’. The idea is that the autonomous vehicle should be certified based on a process where the basis for certification is made by validating and justifying its systems. This will be done through simulations and other methods to ensure that the systems are satisfactory. A less extensive work should then be done in the testing of the autonomous vehicle on the test track and in traffic, where only less demanding situations must be validated.The functional requirements of the autonomous vehicle will largely control the validation process that is carried out for the ‘Multi-pillars approach’ / ‘Three-pillars approach’. For example, the definition of ODD (Operational Design Domain) is crucial for the validation that the vehicle will undergo at a later stage. / Ett av de största hindren för att lansera självkörande fordon är den nuvarande lagstiftningen som i dagsläget inte täcker automationsnivå högre än nivå 2. Arbetet med att ta fram lagkraven sker på FN nivå inom WP29 (The UNECE World Forum for Harmonization of Vehicle Regulations). Som en världsledande fordonstillverkare strävar Scania efter att bana väg för hållbara transportlösningar. På Scania finns väletablerade metoder för certifiering av olika system, men processen för certifiering av autonoma fordon måste dock utvecklas.Detta examensarbete undersöker den aktuella situationen när det gäller utformandet av regelverk för att täcka autonoma fordon, framtida certifieringsmetoder relaterade till dessa system och hur detta påverkar Scania. Särskilt fokus ligger på utredning av virtuella certifieringsmetoder. Detta kan ligga till grund för olika avdelningar på Scania i deras arbete med framtida autonoma system och hur man får dessa certifierade.Det framtida certifieringsarbetet för autonoma fordon kommer att bygga på en valideringsprocess som bygger på en process som kallas för ”Multi-pillars approach”/”Three- pillars approach”. Tanken är att fordonet ska certifieras utifrån en process där grunden till certifiering görs genom att validera och rättfärdiga sina system. Detta ska ske genom simulering och andra metoder för att säkerhetsställa att systemen är tillfredställande. Ett mindre omfattande arbete ska sedan göras i testningen av fordonen på testbana och ute i trafik, där endast mindre krävande situationer ska valideras.De funktionella kraven på fordonen kommer till stor del att styra den valideringsprocessen som görs med för ”Multi-pillars approach”/”Three-pillars approach”. Exempelvis är definierandet av ODD (Operational Design Domain) avgörande för den validering som fordonet i ett senare skede ska genomgå.

The wheel loader is a type of engineering vehicle used primarily to move crude material over shorter distances. As the vehicle is designed without wheel suspension, wheel loader drivers are exposed to high levels of whole body vibration which influences ride comfort negatively. The work presented in this thesis has the aim to investigate the potential in adding an axle suspension to a wheel loader in order to reduce vibrations and increase handling quality. While suspended axles have great potential for improving ride comfort and performance, they will also necessarily affect the vehicle dynamic behaviour which is different in many aspects from that of passenger cars or other road vehicles: the wheel loader has a large pitch inertia compared to its mass, the axle loads vary considerably with loading condition, and the vehicle uses an articulated frame steering system rather than wheel steering. These issues must all be considered in the design process for a wheel loader suspension. The effects of suspended axles on ride vibrations are analysed by simulating a multibody wheel loader model with and without axle suspension. Results from the simulations show that longitudinal and vertical acceleration levels are greatly reduced with axle suspension, but that the decrease in lateral acceleration is smaller. By reducing the roll stiffness lateral accelerations can be further reduced, although this may not be feasible because of requirements on handling stability. The pitching oscillation of the vehicle has also been studied as this is known to have a large influence on ride comfort. An analytical model is used to study the effect of front and rear suspension characteristics on the pitching response of the wheel loader, showing that a stiffer rear suspension is favourable for reducing pitching but also that a similar effect is attainable with a stiffer front suspension. Results are compared to multibody simulations which show the same trend as analytical predictions. By including a linearised representation of a hydropneumatic suspension in the models, it is also shown that favourable dynamic behaviour can be maintained when the vehicle is loaded by utilising the fact that suspension stiffness is increasing with axle load. Articulated vehicles may exhibit lateral oscillations known as "snaking" when driven at high speed. The effect of suspended axles on these oscillations are analysed using a multibody simulation model of a wheel loader with an equivalent roll stiffness suspension model. It is found that the roll motion of the sprung mass has a slightly destabilising effect on the snaking oscillations. This effect is more pronounced if the body roll frequency is close to the frequency of the snaking motion, although this loss in stability can be compensated for by increasing the equivalent stiffness or damping of the steering system. Together with existing vehicle dynamic theory and design rules, the studies reported in this work provide an insight into the specific issues related to suspension design for wheel loaders. / QC 20101119

Den alltmer växande klimatkrisen i kombination med den ständigt minskande tillgången på naturresurser motiverade EU till att införa miljömål att sänka koldioxidutsläppen med 55 % till 2030. Tung lastbilstransport stod år 2018 för 6 % av Sveriges totala utsläpp av växthusgaser och är därför en signifikant industri som måste ändras för att uppfylla miljömålen. I dagsläget använder majoriteten av lastbilsindustrin det fossila bränslet diesel som så småningom kommer att behöva bytas ut mot fossilfria alternativ för att åstadkomma en hållbar framtid. Författarna till detta arbete undersökte samt jämförde batteri- och vätgasdrift som alternativ till industristandarden diesel, för tunga lastbilar under längre distanser. Jämförelsen omfattade kategorierna miljöpåverkan, kostnad, tid samt logistik då dessa kategorier är centrala för lastbilstransport. Dessa kategorier analyserades för sträckan Stockholm - Malmö då detta är en av de vanligaste transportsträckorna i Sverige för långdistanskörning. En förstudie genomfördes för att ge kunskap om de alternativa drivsystemen vilket gav grund till jämförelsen. Resultaten från jämförelsen visade att miljöpåverkan vid användning var näst intill identisk med avseende på koldioxidutsläpp per kilometer. Vid kostnadsanalys var vätgasdrift 56 % dyrare vid tillverkning och batteridrift 11,4 % dyrare i drift, vilket tillsammans med vätgas förväntade prisökning ledde till slutsatsen att batteridrivna fordon är aningen mer kostnadseffektiva. Vid jämförelse av total körtid begränsades den batteridrivna lastbilen av ytterligare ett stopp jämfört med vätgaslastbilen på grund av räckvidden, samt utökad laddtid vilket resulterade i en 22 % längre total körtid för den valda sträckan. Under kategorin logistik undersöktes lastförmågan som visade en 19 % högre lastvikt för vätgasdrift i jämförelse med batteridrift då en maxlastad lastbil jämfördes. Denna fördel blev dock betydligt mindre väsentlig då infrastrukturen jämfördes, som visade en markant fördel för den batteridrivna lastbilen på grund av dess väletablerade laddnätverk samt dess framtida potential.

In this master thesis the dynamics of a modern main battle tank's turret traverse and gun elevation have been modelled. The models of dynamic motion have been coupled to two different types of electric motors, namely a direct-current motor and an induction motor. These have been modelled in MATLAB and SIMULINK together with the mechanical systems in the turret traverse and gun elevation. The goal of this project was to develop non-ideal models of the combined mechanical and electrical systems, but the main focus has been the dynamics of the electric motors. / I denna examensavhandling har modeller av elektriska motorer som driver tornet samt elevation av eldröret på en stridsvagn tagits fram. De två motorer som undersökts är en likströmsmotor och en induktionsmotor. Dessa har kopplats till mekaniska system som representerar rotation av stridsvagnens torn och elevation av eldröret. Modelleringen har gjorts i MATLAB och SIMULINK. Målet med denna studie var att ta fram icke-ideala modeller av både de elektriska motorerna och de mekaniska systemen för torn- och eldrörsdrift.

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As the automotive industry becomes increasingly reliant on digital systems it is of utmost importance that these systems are secure. Secure systems are of interest both for the general public as well as manufactures. This Master’s thesis evaluates potential cybersecurity solutions for a proposed damper system prototype developed by Öhlins Racing AB. A systematic literature study was performed to identify known vulnerabilities of similar systems as well as potential cybersecurity solutions. A threat model was constructed using vehicleLang, the Meta Attack Language, and securiCAD. The model was created utilizing preexisting assets from vehicleLang and a newly implemented Bluetooth asset. The result from the systematic literature study was used to validate preexisting attack steps and also to create the Bluetooth asset. To validate the model, experts in the field of automotive security and/or threat modeling were asked to assess the model. Using Cochran’s Equation, a target of eight expert evaluations were decided. Unfortunately, only seven evaluations were obtained, equivalent to an increase in the error margin from 25% to 26.6%. However, of the seven expert evaluations obtained none indicated the existence of critical flaws within the model. The model was therefore considered a good reflection of the damper system and its security aspects. Critical defenses included the utilization of cryptography, mutual authentication, and on-the-fly decryption. These defenses were shown to prevent unauthorized modifications of firmware and protect Öhlins intellectual property in form of source code. While it was not possible to defend against all attacks the identified defenses would increase the safety and security of the system, benefiting not only Öhlins but also overall road users. / Allt eftersom fordonsindustrins beroende av digitala system ökar är det av yttersta vikt att dessa system är säkra. Säkra system är av intresse för både allmänheten likväl som för systemtillverkarna. Denna masteruppsats evaluerar potentiella cybersäkerhetslösningar för en föreslagen stötdämparprototyp utvecklad av Öhlins Racing AB. En systematisk litteraturöversikt skapades med syfte att identifiera kända sårbarheter av liknande system och potentiella cybersäkerhetslösningar. En hotmodell skapades med hjälp av vehicleLang, the Meta Attack Language, och securiCAD. Hotmodellen skapades med existerande komponenter från vehicleLang och en nyskapad Bluetooth komponent. Resultaten från den systematiska litteraturöversikten användes för att validera existerande komponenter från vehicleLang och för implementationen av Bluetooth komponenten. För att evaluera modellen bads experter inom fordonssäkerhet och/eller hotmodellering utvärdera modellen. Genom Cochran’s ekvation beslutades att åtta expert utvärderingar skull införskaffas. Tyvärr erhölls enbart sju utvärderingar, vilket motsvarar en ökning av felmarginalen från 25% till 25.6%. Av de sju experter som utvärderade modellen identifierades dock inga kritiska brister. Kritiska säkerhetslösningar inkluderade användandet av: kryptografi, ömsesidig autentisering, och on-the-fly decryption. Dessa försvar anses kunna skydda mot obehörig modifiering av programvara, samt skydda Öhlins intellektuella egendom i form av källkod. Trots att det inte var möjligt att förhindra alla attacker skulle de identifierade försvaren öka systemets säkerhet, vilket är fördelaktigt inte bara för Öhlins utan även trafikanter i allmänhet.

Construction machines, also referred to as engineering vehicles or earth movers, are used in a variety of tasks related to infrastructure development and material handling. While modern construction machines represent a high level of sophistication in several areas, their suspension systems are generally rudimentary or even nonexistent. This leads to unacceptably high vibration levels for the operator, particularly when considering front loaders and dump trucks, which regularly traverse longer distances at reasonably high velocities. To meet future demands on operator comfort and high speed capacity, more refined wheel suspensions will have to be developed. The aim of this thesis is therefore to investigate which factors need to be considered in the fundamental design of suspension systems for wheeled construction machines. The ride dynamics of wheeled construction machines are affected by a number of particular properties specific to this type of vehicle. The pitch inertia is typically high in relation to the mass and wheelbase, which leads to pronounced pitching. The axle loads differ considerably between the loaded and the unloaded condition, necessitating ride height control, and hence the suspension properties may be altered as the vehicle is loaded. Furthermore, the low vertical stiffness of off-road tyres means that changes in the tyre properties will have a large impact on the dynamics of the suspended mass. The impact of these factors has been investigated using analytical models and parameters for a typical wheel loader. Multibody dynamic simulations have also been used to study the effects of suspended axles on the vehicle ride vibrations in more detail. The simulation model has also been compared to measurements performed on a prototype wheel loader with suspended axles. For reasons of manoeuvrability and robustness, many construction machines use articulated frame steering. The dynamic behaviour of articulated vehicles has therefore been examined here, focusing on lateral instabilities in the form of “snaking” and “folding”. A multibody dynamics model has been used to investigate how suspended axles influence the snaking stability of an articulated wheel loader. A remote-controlled, articulated test vehicle in model-scale has also been developed to enable safe and inexpensive practical experiments. The test vehicle is used to study the influence of several vehicle parameters on snaking stability, including suspension, drive configuration and mass distribution. Comparisons are also made with predictions using a simplified linear model. Off-road tyres represent a further complication of construction machine dynamics, since the tyres’ behaviour is typically highly nonlinear and difficult to evaluate in testing due to the size of the tyres. A rolling test rig for large tyres has here been evaluated, showing that the test rig is capable of producing useful data for validating tyre simulation models of varying complexity. The theoretical and experimental studies presented in this thesis contribute to the deeper understanding of a number of aspects of the dynamic behaviour of construction machines. This work therefore provides a basis for the continued development of wheel suspensions for such vehicles. / QC 20110531

This project was conducted as a case study at Öhlins Racing AB, a manufacturer of suspension systems for automotive applications. Öhlins usually manufacture their components by traditional methods such as forging, casting, and machining. The project aimed to investigate how applicable Additive Manufacturing (AM) is to manufacture products for suspension systems to add value to suspension system components. For this, a proof of concept was designed and manufactured. The thesis was conducted at Öhlins in Upplands Väsby via the consultant firm Combitech.  A product catalog was searched, screened, and one part was selected. The selected part was used as a benchmark when a new part was designed for AM, using methods including Topology Optimization (TO) and Design for Additive Manufacturing (DfAM). Product requirements for the chosen part were to reduce weight, add functions, or add value in other ways.  Methods used throughout the project were based on traditional product development and DfAM, and consisted of three steps: Product Screening, Concept Development, and Part Design. The re-designed part is ready to be manufactured in titanium by L-PBF at Amexci in Karlskoga.  The thesis result shows that at least one of Öhlin's components in their product portfolio is suitable to be chosen, re-designed, and manufactured by AM. It is also shown that value can be added to the product by increased performance, in this case mainly by weight reduction. The finished product is a fork bottom, designed with hollow structures, and is ready to print by L-PBF in a titanium alloy.