Målet med detta arbete var från början att ta fram 2-3 olika koncept som hindrar dumperns baklucka från att studsa och skapa onödigt buller. En produktutvecklingsprocess anpassades för projektet och användes för att systematiskt genomföra arbetet. Under arbetets gång gjordes valet att uppdatera målet till att ta fram en fullskalig prototyp och testa denna på en dumper. Resultatet blev en robust och ekonomisk produkt som hindrar bakluckan från att studsa och sänker dumperns bullernivå avsevärt.

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During the last decades, improved sensor and hardware technologies as well as new methods and algorithms have made self-driving vehicles a realistic possibility in the near future. Thanks to this technology enhancement, many leading automotive and technology companies have turned their attention towards developing advanced driver assistance systems (ADAS) and self-driving vehicles. Autonomous vehicles are expected to have their first big impact in closed areas, such as mines, harbors and loading/offloading sites. In such areas, the legal requirements are less restrictive and the surrounding environment is more controlled and predictable compared to urban areas. Expected positive outcomes include increased productivity and safety, reduced emissions and the possibility to relieve the human from performing complex or dangerous tasks. Within these sites, different truck and trailer systems are used to transport materials. These systems are composed of several interconnected modules, and are thus large and highly unstable while reversing. This thesis addresses the problem of designing efficient motion planning and feedback control frameworks for such systems. First, a cascade controller for a reversing truck with a dolly-steered trailer is presented. The unstable modes of the system is stabilized around circular equilibrium configurations using a gain-scheduled linear quadratic (LQ) controller together with a higher-level pure pursuit controller to enable path following of piecewise linear reference paths. The cascade controller is then used within a rapidly-exploring random tree (RRT) framework and the complete motion planning and control framework is demonstrated on a small-scale test vehicle. Second, a path following controller for a reversing truck with a dolly-steered trailer is proposed for the case when the obtained motion plan is kinematically feasible. The control errors of the system are modeled in terms of their deviation from the nominal path and a stabilizing LQ controller with feedforward action is designed based on the linearization of the control error model. Stability of the closed-loop system is proven by combining global optimization, theory from linear differential inclusions and linear matrix inequality techniques. Third, a systematic framework is presented for analyzing stability of the closed-loop system consisting of a controlled vehicle and a feedback controller, executing a motion plan computed by a lattice planner. When this motion planner is considered, it is shown that the closed-loop system can be modeled as a nonlinear hybrid system. Based on this, a novel method is presented for analyzing the behavior of the tracking error, how to design the feedback controller and how to potentially impose constraints on the motion planner in order to guarantee that the tracking error is bounded and decays towards zero. Fourth, a complete motion planning and control solution for a truck with a dolly-steered trailer is presented. A lattice-based motion planner is proposed, where a novel parametrization of the vehicle’s state-space is proposed to improve online planning time. A time-symmetry result is established that enhance the numerical stability of the numerical optimal control solver used for generating the motion primitives. Moreover, a nonlinear observer for state estimation is developed which only utilizes information from sensors that are mounted on the truck, making the system independent of additional trailer sensors. The proposed framework is implemented on a full-scale truck with a dolly-steered trailer and results from a series of field experiments are presented.

In 1999, California Air Resources Board (CARB) implemented a regulation that required all gasoline cars sold in California be fitted with an Onboard Refueling Vapor Recovery System (ORVR). The ORVR system is designed to prevent Volatile Organic Compounds (VOCs) from escaping into the atmosphere during refuelling by storing the gas vapours in a carbon canister. Due to the complex nature of the fuel system, making design changes could have large implications on the ORVR performance of the vehicle. It is therefore desirable to develop a CFD model that can predict the effects of design changes, thereby reducing the need to perform physical tests on each design iteration. This master thesis project was performed at the Fuel Systems department at Volvo Cars in order to help reduce project lead times and product development costs by incorporating CFD as a part of the fuel system development cycle. The CFD results obtained were validated through experimental tests that were also performed as part of this project. In this master thesis project, a CFD model was developed to simulate the refuelling of gasoline for a California specification Volvo XC90 with an OPW-11B pump pistol. The model was set up in STAR-CCM+ using the Eulerian Volume of Fluid model for multiphase flow, the RANS realizable k − ε turbulence model and the two layer all y + wall treatment. The effects of the carbon canister were modelled as a porous baffle interface in the simulations where viscous and inertial resistances of the porous media were adjusted to obtain a desired pressure drop across the canister. This method proved to be a suitable simplification for this study. The effects of evaporation as well as a chemical adsorption model for the carbon canister have been excluded from the project due to time limitations. It was found that the CFD simulations were in good agreement with the experimental results, especially with respect to capturing the overall behaviour of the fuel system during refuelling. It was found that resolving the flow spatially (and temporally) in the filler pipe was a crucial part in ensuring solver stability. A pressure difference between experiment and simulation was also observed as a consequence of excluding evaporation from the CFD model. After the CFD model had been verified and validated, changes to different parts of the fuel system were investigated to observe their effects on ORVR performance. These included changing the recirculation line diameter, changing the carbon canister properties and changing the angle of how the pump pistol was inserted into the capless unit. It was found that the recirculation line diameter is a very sensitive design parameter and increasing the diameter would result in fuel vapour leaking back out into the atmosphere. Similarly, increasing the back pressure by swapping to a different carbon canister would result in the leakage of fuel vapour. On the other hand, insignificant changes in system behaviour were observed when the fuel pistol angle was changed.In 1999, California Air Resources Board (CARB) implemented a regulation that required all gasoline cars sold in California be fitted with an Onboard Refueling Vapor Recovery System (ORVR). The ORVR system is designed to prevent Volatile Organic Compounds (VOCs) from escaping into the atmosphere during refuelling by storing the gas vapours in a carbon canister. Due to the complex nature of the fuel system, making design changes could have large implications on the ORVR performance of the vehicle. It is therefore desirable to develop a CFD model that can predict the effects of design changes, thereby reducing the need to perform physical tests on each design iteration. This master thesis project was performed at the Fuel Systems department at Volvo Cars in order to help reduce project lead times and product development costs by incorporating CFD as a part of the fuel system development cycle. The CFD results obtained were validated through experimental tests that were also performed as part of this project. In this master thesis project, a CFD model was developed to simulate the refuelling of gasoline for a California specification Volvo XC90 with an OPW-11B pump pistol. The model was set up in STAR-CCM+ using the Eulerian Volume of Fluid model for multiphase flow, the RANS realizable k − ε turbulence model and the two layer all y + wall treatment. The effects of the carbon canister were modelled as a porous baffle interface in the simulations where viscous and inertial resistances of the porous media were adjusted to obtain a desired pressure drop across the canister. This method proved to be a suitable simplification for this study. The effects of evaporation as well as a chemical adsorption model for the carbon canister have been excluded from the project due to time limitations. It was found that the CFD simulations were in good agreement with the experimental results, especially with respect to capturing the overall behaviour of the fuel system during refuelling. It was found that resolving the flow spatially (and temporally) in the filler pipe was a crucial part in ensuring solver stability. A pressure difference between experiment and simulation was also observed as a consequence of excluding evaporation from the CFD model. After the CFD model had been verified and validated, changes to different parts of the fuel system were investigated to observe their effects on ORVR performance. These included changing the recirculation line diameter, changing the carbon canister properties and changing the angle of how the pump pistol was inserted into the capless unit. It was found that the recirculation line diameter is a very sensitive design parameter and increasing the diameter would result in fuel vapour leaking back out into the atmosphere. Similarly, increasing the back pressure by swapping to a different carbon canister would result in the leakage of fuel vapour. On the other hand, insignificant changes in system behaviour were observed when the fuel pistol angle was changed.

<p>The objective of this thesis work was to construct and implement an algorithm into the programADAPDT to calculate the zero-lift drag profile for defined aircraft geometries. ADAPDT, shortfor AeroDynamic Analysis and Preliminary Design Tool, is a program that calculates forces andmoments about a flat plate geometry based on potential flow theory. Zero-lift drag will becalculated by means of different hand-book methods found suitable for the objective andapplicable to the geometry definition that ADAPDT utilizes.</p><p>Drag has two main sources of origin: friction and pressure distribution, all drag acting on theaircraft can be traced back to one of these two physical phenomena. In aviation drag is dividedinto induced drag that depends on the lift produced and zero-lift drag that depends on the geometry of the aircraft.</p><p>How reliable and accurate the zero-lift drag computations are depends on the geometry data thatcan be extracted and used. ADAPDT‟s geometry definition is limited to flat plate geometrieshowever although simple it has the potential to provide a huge amount of data and also delivergood results for the intended use. The flat plate representation of the geometry proved to beleast sufficient for the body while wing elements could be described with much more accuracy.</p><p>Different empirical hand-book methods were used to create the zero-lift drag algorithm. Whenchoosing equations and formulas, great care had to be taken as to what input was required sothat ADAPDT could provide the corresponding output. At the same time the equations shouldnot be so basic that level of accuracy would be compromised beyond what should be expectedfrom the intended use.</p><p>Finally, four well known aircraft configurations, with available zero-lift drag data, weremodeled with ADAPDT‟s flat plate geometry in order to validate, verify and evaluate the zeroliftdrag algorithm‟s magnitude of reliability. The results for conventional aircraft geometriesprovided a relative error within 0-15 % of the reference data given in the speed range of zero toMach 1.2. While for an aircraft with more complicated body geometry the error could go up to40 % in the same speed regime. But even though the limited geometry is grounds foruncertainties the final product provides ADAPDT with very good zero-lift drag estimationcapability earlier not available. A capability that overtime as ADAPDT continues to evolve hasthe potential to further develop in terms of improved accuracy.</p> / <p>Målet med detta examensarbete var att skapa och implementera en algoritm som införmöjligheten att beräkna nollmotstånd för givna flygplansgeometrier i programmet ADAPDT.ADAPDT, kort för AeroDynamic Analysis and Preliminary Design Tool, är ett program som,baserat på potential strömnings teori, beräknar krafter och moment på en geometri uppbyggd avplana plattor. Nollmotståndet kommer att baseras en kombination av handboksmetoder somfunnits lämpliga och applicerbara på geometridefinitionen given i ADAPDT.</p><p>Motstånd har sitt ursprung i två fysikaliska fenomen: friktion och tryckfördelning, ur vilka alltmotstånd som agerar på ett flygplan härrör. Inom flyget delar man in motståndet ilyftkraftsberoende inducerat motstånd samt geometriberoende nollmotstånd.</p><p>Hur pålitliga och noggranna motståndsberäkningarna kan förväntas vara beror på mängdengeometriska data som finns att tillgå. ADAPDT:s geometridefinition är begränsad till planaplattor men trots detta finns potential att leverera stora mängder data och resultat med rimlignoggrannhet. Plan plattgeometrin visade sig, för kroppsgeometrin, väldigt begränsad ochotillräcklig medan ving element kunde beskrivas med större noggrannhet.</p><p>En rad olika empiriska handboksmetoder användes för att skapa nollmotståndsalgoritmen. Vidvalet av formler och ekvationer var det viktigt att välja sådana som ADAPDT kunde försetillräckligt med data till. Samtidigt fick formlerna inte vara alltför simpla så att måttet avnoggrannhet i resultaten vart alltför låg mot för vad som, för ändamålet, är förväntat.</p><p>Slutligen valdes fyra kända flygplan, med nollmotståndsdata tillgängligt, att modeleras medADAPDT:s plan plattgeometri för att validera, verifiera och utvärdera algoritmens mått avtillförlitlighet. Resultaten för mer konventionella flygplanskonfigurationer visade på ett relativtfel mellan 0-15 % mot de givna referensflygplanens nollmotståndsdata inom hastigheterna 0 tillMach 1,2. För mer komplicerade konfigurationer steg det relativa felet omedelbart upp mot 40% inom samma hastighetsregim. Men även om den begränsade geometridefinitionen iADAPDT är grunden för mycket osäkerheter förser den slutliga produkten ändå programmetmed en väldigt god möjlighet till skattning av nollmotståndet som inte tidigare fanns. Enmöjlighet som över tid, allteftersom ADAPDT forstätter att utvecklas, har all potential till attförbättras med avseende på noggrannhet och tillförlitlighet.</p>

<p>Abstract</p><p>SAAB has for a long time used user controlled pilot models in ARES. ARES is a simulation tool used in the desktop environment for simulations and calculations of the JAS 39 Gripen fighter and other aircraft. ARES stands for ”Aircraft Rigid body Engineering Simulation”. To work with these pilot models has been both time-consuming and inefficient. In this master thesis, new pilot models are developed, where parameters are automatically generated, this will result in that the user doesn’t have to put a lot of work into adjusting the gains for different manoeuvres. This is called gain scheduling.</p><p>To make this possible, simple models of the aircraft were created at different points in the envelope. These models were then used to calculate optimal controllers using LQ-control and pole placement techniques. These models and controllers were then implemented in Simulink. Simulink was then used to test the controllers before they were implemented in ARES.</p><p>Control in all modes except roll attitude and speed by throttle are based on LQ-control in pitch-, roll- and yaw-angular velocity. And through these angular velocities the other angles are controlled by simple controllers, who is generating a reference in angular velocity. The roll attitude controller is based on direct pole placement based upon desired damping and undamped natural frequency, and the speed controller is based upon a model of throttle positions in trimmed states.</p><p>The new pilot models are usable to control:</p><ul><li>Roll rate</li><li>Roll attitude</li><li>Pitch rate</li><li>Pitch attitude</li><li>Angle of attack</li><li>Load factor</li><li>Yaw attitude</li><li>Course angle</li><li>Climb angle</li><li>Mach number</li><li>Climb rate</li></ul><p>These controllers can be combined so that the aircraft can perform desired maneuvers.</p>

<p>Many traffic accidents are caused by driver unawareness. This includes fatigue, drowsiness and distraction. In this thesis two systems are described that could be used to decrease the number of accidents. In the first part of this thesis a system using long-term information to warn drivers suffering from fatigue is developed. Three different versions with different criteria are evaluated. The systems are shown to handle more then 60% of the cases correctly.</p><p>The second part of this thesis examines the possibilities of developing a warning system based on the predicted time-to-lane crossing, TLC. A basic TLC model is implemented and evaluated. For short time periods before lane crossing this may offer adequate accuracy. However the accuracy is not good enough for the model to be used in a TLC based warning system to warn the driver of imminent lane departure.</p>

<p>Optical encoders are being widely suggested for precise mobile navigation. Combining such sensor information with Global Positioning System (GPS) is a practical solution for reducing the accumulated errors from encoders and moving the navigational base into global coordinates with high accuracy.</p><p>This thesis presents integration methods of GPS and optical encoders for a mobile vehicle that is controlled by microcontroller. The system analyzed includes a commercial GPS receiver, dsPIC microcontroller and mobile vehicle with optical encoders. Extended kalman filtering (EKF), real time curve matching, GPS filtering methods are compared and contrasted which are used for integrating sensors data. Moreover, computer interface, encoder interface and motor control module of dsPIC microprocessor have been used and explained.</p><p>Navigation quality on low speeds highly depends greatly upon the processing of GPS data. Integration of sensor data is simulated for both EKF and real time curve matching technique and different behaviors are observed. Both methods have significantly improved the accuracy of the navigation. However, EKF has more advantages on solving the localization problem where it is also dealing with the uncertainties of the systems.</p>

<p>A discussion regarding the alignment and measuring procedure of propeller shafts has arose due to the competing situation in the industry, and higher standards from the customers. An estimation of the deflection of shafts in different alignment situations has been made with help of FEM-analysis and beam theory. This has been analyzed and compared with the experience from Rolls-Royce AB suppliers of shafts. An evaluation of measuring protocols has been made and the result indicates that there is a correlation between the deflection of the shaft and the run out. Results from a measuring test performed by Balino, Spain, verifies this conclusion. But the main issue is considered to be the type of supports that prevent the shaft from moving in the horizontal plane. The solution to this issue is to use supports along the shaft that only prevents the deflection in the median plane.</p><p> </p><p>A recommendation to the Rolls-Royce AB is to perform changes in their measuring protocols to make them easier to use and to include more information. The sequence of the measuring points in the protocol should be re-arranged and re-named. Information of what type of support that has been used by the supplier and where they been placed should be added to the protocols to increase the traceability when questions arise. To make the measuring protocol unequivocal, the position of the measuring gauge should be marked in the protocol and the point of reference marked on the shaft.</p><p> </p><p>External expertise will participate in a workshop to educate and discuss with Rolls-Royce AB personnel how to change required references in the drawing of the shaft arrangements.</p>

Carbody tilting is today a mature and inexpensive technology that allows higher train speeds in horizontal curves, thus shortening travel time. This doctoral thesis considers several subjects important for improving the competitiveness of tilting trains compared to non-tilting ones. A technology review is provided as an introduction to tilting trains and the thesis then focuses on enhancing the benefits and strategies for less motion sickness. A tilting train may run about 15% faster in curves than a non-tilting one but the corresponding simulated running time benefit on two Swedish lines is about 10%. The main reason for the difference is that speeds are set on other grounds than cant deficiency at straight track, stations, bridges, etc. The possibility to further enhance tilting trains’ running speed is studied under identified speed limitations due to vehicle-track interaction such as crosswind requirements at high speed curving. About 9% running time may be gained on the Stockholm–Gothenburg (457 km) mainline in Sweden if cant deficiency, top speed, and tractive performance are improved compared with existing tilting trains. Non-tilting high-speed trains are not an option on this line due to the large number of 1,000 m curves. Tilting trains run a greater risk of causing motion sickness than non-tilting trains. Roll velocity and vertical acceleration are the two motion components that show the largest increase, but the amplitudes are lower than those used in laboratory tests that caused motion sickness. Scientists have tried to find models that can describe motion sickness based on one or more motion quantities. The vertical acceleration model shows the highest correlation to motion sickness on trains with active tilt. However, vertical acceleration has a strong correlation to several other motions, which precludes vertical acceleration being pointed out as the principal cause of motion sickness in tilting trains. Further enhanced speeds tend to increase carbody motions even more, which may result in a higher risk of motion sickness. However, means to counteract the increased risk of motion sickness are identified in the present work that can be combined for best effect. Improved tilt control can prevent unnecessary fluctuations in motion sickness related quantities perceived by the passengers. The improved tilt control can also manage the new proposed tilt algorithms for less risk of motion sickness, which constitute one of the main achievements in the present study. Local speed restrictions are another means of avoiding increased peak levels of motion sickness when increasing the overall speed. The improved tilt control and the proposed tilt algorithms have proven to be effective in on-track tests involving more than 100 test subjects. The new tilt algorithms gave carbody motions closer to non-tilting trains. Rather unexpectedly, however, the test case with the largest decrease in tilt gave a greater risk of motion sickness than the two test cases with less reduction in tilt. It is likely that even better results can be achieved by further optimization of the tilt algorithms; the non-linear relation between motions and motion sickness is of particular interest for further study. / QC 20110429