When accelerating, traction from the tyres is necessary to move the vehicle forward. If too much torque is applied to the wheels of the vehicle, the tyres will start to spin and thereby the traction will decrease. This can occur when the driver of the vehicle applies to much throttle, but can be controlled with a traction control system that prevent the tyres from spinning and keeps the tyres at maximum traction to increase acceleration. In Formula Student competitions, every tenths of a second gained is vital and a traction control could help the driver to find these tenths of a second during acceleration. The purpose of this bachelor thesis was to design a slip ratio based traction control for the KTH Formula Student car DeV17 with focus on the acceleration event from standing start. A problem with standing start is the launch of the acceleration which were investigated along with a PID-controller. The model was developed in MATLAB's SIMULINK and simulated with IPG CarMaker. Small improvements in acceleration time were seen with the PID-controller but the launch did not see any improvements.

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<p> To reduce cost of structural composites the development of more efficient manufacturing methods is of great interest. Sheet forming of thermoset prepreg, also known as hot drape forming, has been a promising manufacturing method for decades. An automatic tape layer (ATL) can be used to perform the lay-up in an efficient way. The flatly stacked unidirectional prepreg forms a sheet to be formed over a given mould. Knowledge about the materials forming behaviour is important to reach the required shape without flaws, such as wrinkles.</p><p>An experimental approach is developed to investigate the intra- (within the layer) and interply deformation. The intraply deformation properties are registered by the use of a bias-extension test and a digital image correlation (DIC) equipment. To measure the interlaminar (between the layers) friction in the prepreg/prepreg interface a specialized rig is designed and built.</p><p>The two tested materials are Cycom^® HTA/977-2 from Cytec and HexPly® T700/M21 from Hexel, which are examples of the second and third generation of carbon fibre/epoxy prepreg. Where M21 includes craze stoppers in form of thermoplastic particles, the 977-2 has the same function but in melted stage. These particles seem to influence both the intraply deformation modes and increase the level of friction between layers.</p><p>The results from the bias-extension test was compared with the theory of pin-jointed net (PJN) and it was found that M21 behaves accordingly. The measured rotation for 977-2 is less than the theoretical, this due to slippage. The rate of deformation seems to have an influence not only on the load level, but also in the mode of deformation. Both for the interlaminar and intraply deformation the resistance to motion were much larger for M21 than 977-2.</p> / KEKS (kostnadseffektiva kompositer)

AbstractSince MARPOL Annex VI took force in 1997, the limits ​​with in SECA (Sulphur EmissionControl Areas) have been stricter several times. This contributed to the vessel Peter Pan,owned by TT-Line AB, installed a scrubber in 2016. A scrubber enables the use of fuels with ahigh sulphur content and still meet the actual requirements. Since the scrubber was installed, ithas resulted in an increased workload for the crew on board. The goal of this study was toclarify if there are components in the system that cause frequent operational disturbances and ifthese can be replaced in order to reduce maintenance. To find out this a field study was doneon board the ship. This resulted in several components being observed and examined moreextensively. The compilation of the data collected during the field study showed that there areparts of the system that can be modified to extend the operating intervals. The conclusion washowever that the survey was going on for a too short period to give accurate results.

Autonomous vehicle technology is advancing at a very high pace and self-driving trucks on control-tower operated work sites is already a reality. These autonomous trucks need a highly accurate map of the surroundings for operation and navigation, and it is of great importance to be able to update that map with the ever-changing off-road work site. The autonomous fleet examined have to stop for every update of the site map, which induces unnecessary downtime when updating the site map frequently. The purpose of this work is to contribute to the development of safe configurable maps for autonomous vehicles on off-road sites by identifying and analyzing different map updating methods, proposing the best one, and suggesting how to implement it for this project's case. The result was five different map updating methods, which were evaluated with respect to efficiency and safety. Efficiency was evaluated by comparing total fleet downtime of the proposed solutions with the existing situation. Safety was evaluated by doing a fault tree analysis (FTA) for each proposed solution and comparing the relative size of the fault trees. Proposed Solution III using map tiles was chosen as the most appropriate method to implement for this project's case because it is both efficient and relatively simple. It divides the site map with a grid into smaller rectangular maps and only needs to stop vehicles which are inside the updated tile. The rest of the fleet is able to replace that tile parallel to operation and, therefore, total fleet downtime is significantly reduced. By reaching the stated goal, this work is in line with its original purpose and has contributed to the development of safe configurable maps for autonomous vehicles on off-road sites.

When buying a new car today, the customer often expects to get a vehiclewith high quality. Each vehicle or engine should therefore be checked toassure quality. The same goes for clutches and couplings. A powerful enginebecomes useless when a clutch slips. Reliable torque measurement istherefore essential to the automotive industry. The herewith Bachelor thesisproposes a new torque calibration rig for online torque measurement in couplingapplications.The concept encompasses a servo motor with its associated electronics, agearbox to create the high torques (3 kNm), a reference torque transducer,and mounting elements or adapters. From the concept generation phase, thethesis includes CAD-models of the torque calibration rig with mathematicalmodels leading to the calculation of the measurement uncertainty of the calibrationsystem.This work was performed at BorgWarner PowerDrive Systems AB in Landskronaduring eight weeks; the two remaining weeks were completed in Lulea.

When engaging a new gear in an automated manual transmission (AMT) the gear needs to be synchronized with the main shaft's angular velocity in the gearbox. This is so that the parts can be connected through a cog wheel and torque can be transferred. To synchronize the angular velocities, mechanical synchronization components can be used. These components synchronize the velocities during the engagement and can be used with larger differences in angular velocities. Should no mechanical synchronization components be used it puts higher demands on the components rotating at similar velocities to avoid mechanical wear and ensure that the gear can be engaged. In today's systems without mechanical synchronization components the gear is engaged when the angular velocities are within a certain difference. This leads to random angle connections between the cogs and gaps that are to be engaged on the gear and main shaft. This can lead to extended or incomplete engages should the components connect cog to cog. This thesis evaluates the possibility to control the angle at which the components connect by using existing sensor signals in the studied system and known parameters. A model of the system is created and simulated to evaluate the probability of predicting the system over the gear engage. Results indicate that it is possible to predict the connection angle close enough to its real value so that a control strategy could be implemented to control the angle to some level.

Pollution levels in urban areas continue to rise, with transportation being the number one cause. As cities ban fossil fuel cars access to the city center, this project looks at the delivery of packgaes from internet purchases. A three-wheeled, human-powered and electrically assisted vehicle is designed. This vehicle is dsigned to work together with last-mile logistics. A scientific design process was carried out to define the stakeholders, competition and requirements of the project, among others.The results yielded a semi-finished vehicle, comprising of the frame, general design, FEA analysis, delivery system and an optimization process for the frame. Future work includes economical or social study, design of the brakes and gear system or a design of the frame-cabin connection.

<p>In an advanced avionics system, the demand of high reliability and availability is of great importance. Testability Analysis is a method of examining this. In the project RWE Tornado GE at Saab Avitronics, they use Built-In Test (BIT), for the purpose of detecting and isolating possible failures in the equipment in question. There is however the need of verification of BIT functionality. Some of the verification tests are requested by customer EADS to be simulated and demonstrated. The objective of this thesis is to understand the Testability Analysis process as well as develop a tool to assist the Testability Demonstration preparations and result recording.</p> / <p>Kravet på hög tillförlitlighet samt tillgänglighet är av yttersta vikt inom ett avancerat avioniksystem. Testbarhetsanalys är en undersökningsmetod som man kan tillämpa. I projektet RWE Tornado GE på Saab Avitronics använder man sig av inbyggda tester - Built-In Test (BIT) - för att kunna upptäcka och isolera eventuella felmoder i en utrustning. Utöver detta vill man verifiera att BIT-funktionen faktiskt fungerar. Vissa av dessa verifieringstester måste simuleras och demonstreras i enlighet med kunden EADS begäran. Målet med examensarbetet är att förstå testbarhetsanalysprocessen samt utveckla ett verktyg för att kunna göra nödvändiga förberedelser för samt resultatinsamling under testbarhetsdemonstrationen (T-Demo).</p>

Over the past century, the automobile has become an integral part of society, with vastincreases in safety, refinement, and complexity, but most unfortunately in mass. Thetrend of increasing mass cannot be maintained in the face of increasingly stringentregulations on fuel consumption and emissions.The body of work within this thesis exists to help the vehicle industry to take a stepforward in producing vehicles for the future in a sustainable manner in terms of botheconomic and ecological costs. In particular, the fundamentally conflicting requirementsof low weight and high stiffness in a structure which should have good acousticperformance is addressed.An iterative five step design method based on the concepts of multifunctionality andmultidisciplinary engineering is proposed to address the problem, and explained witha case study.In the first step of the process, the necessary functional requirements of the systemare evaluated. Focus is placed on the overall system behavior and diverted from subproblems.For the case study presented, the functional requirements included: structuralstiffness for various loading scenarios, mass efficiency, acoustic absorption, vibrationaldamping, protecting from the elements, durability of the external surfaces,and elements of styling.In the second step of the process, the performance requirements of the system wereestablished. This involved a thorough literature survey to establish the state of theart, a rigorous testing program, and an assessment of numerical models and tools toevaluate the performance metrics.In the third step of the process, a concept to fulfil requirements is proposed. Here, amulti-layered, multi-functional panel using composite materials, and polymer foamswith varying structural and acoustic properties was proposed.In the fourth step of the process, a method of refinement of the concept is proposed.Numerical tools and parameterized models were used to optimize the three dimensionaltopology of the panel,material properties, and dimensions of the layers in a stepwisemanner to simultaneously address the structural and acoustic performance.In the fifth and final step of the process, the final result and effectiveness of the methodused to achieve it is examined. Both the tools used and the final result in itself shouldbe examined. In the case study the process is repeated several times with increasingdegrees of complexity and success in achieving the overall design objectives.In addition to the design method, the concept of a multifunctional body panel is definedand developed and a considerable body of knowledge and understanding is presented.Variations in core topology, materials used, stacking sequence of layers, effects ofperforations, and air gaps within the structure are examined and their effects on performanceare explored and discussed. The concept shows promise in reducing vehicleweight while maintaining the structural and acoustic performance necessary in the contextof sustainable vehicle development. / QC 20110311