Global ETD Search

1	Kinematics, Dynamics and Control of Single-Axle, Two-Wheel Vehicles (Biplanar Bicycles) Abbott, Michael Shawn 20 April 2000 (has links) A two-wheeled, single-axle, differentially driven vehicle possesses many salient advantages when compared to traditional vehicle designs. In particular, high traction factor, zero turn radius, and inherent static and dynamic stability are characteristics of this configuration. Drive torque is provided via a swinging reaction mass hanging below the axle. While mechanically simple, the resulting nonlinear vehicle dynamics can be quite complex. Additional design challenges arise if non-pendulating platforms or hardware mounts are required. Ultimately, this vehicle class has great potential in autonomous robotic applications such as mine clearance, planetary exploration, and autonomous remote inspection. This thesis discusses the kinematic and dynamic analyses of this vehicle class and develops design tools including performance envelopes and control strategies. Further, it confronts the stable platform problem and provides one solution while suggesting alternative design concepts for other applications. / Master of Science Vehicle Dynamics Control Two-Wheel
2	Life Cycle Assessment of Lightweight Electric Motorbikes : Case Study - RIDECAKE / Livscykelbedömning av lätta elektriska motorcyklar : Fallstudie - Ridecake Englert, Savitri Visvanathan January 2023 (has links) The electric vehicle segments of companies have broadened, and their sales have increased in the past decade. The electric motorcycle sector is growing fast, with improved technology on electric powertrains, increased ranges, charging speeds, and infrastructure. Parallel to the increased sales, the electric battery sector is advancing rapidly, thereby lowering the environmental impacts of these vehicles. The competitive adventure sports sector also benefits from using electric powertrains with their incredible power-to-weight ratio and instant torque. The benefits of using electric vehicles over conventional ones can be seen during the use phase, with zero tailpipe emissions and clean, silent riding. However, with the expansion of the electric motorcycle sector rolling out new technologies and models, there are uncertainties about whether the overall lifecycle has reduced impacts on the environment. Finding and improving the most sustainable model(s) or solution(s) implies scrutinizing the effects of these motorcycles on the environment, which is the goal of CAKE 0 Emission AB, a Swedish lightweight electric motorbike manufacturer. The current project will assess the potential environmental impacts of Kalk&, an off-road electric motorcycle model certified for on-road use, designed, and manufactured by CAKE 0 Emission AB. For this purpose, Attributional Life Cycle Assessment was chosen as the method to study the impact of one whole motorbike over a lifetime of 500 battery charging cycles, used by a hypothetical example user in Stockholm, Sweden. The potential environmental impacts are focused on 12 categories using the ReCiPe Midpoint (H) method. As expected from an electric vehicle, the results show that the impacts mainly stem from the manufacturing phase of the motorbike. The hotspots in the manufacturing phase arise from producing the battery, the electric motor, and the electrical components like lights, the charger, and cables. The materials used for construction that have a high share of impact are Copper and Aluminium. Another environmental hotspot is the casting manufacturing process. Within the vehicle use phase, the impact of using solar energy in Sweden for charging the batteries is not immediately intuitive and has shown to be higher than the Swedish electricity board mix; the results argue that the choice of electricity is vital in reducing emissions. Transporting the vehicle overseas by ship instead of by flight decreases emissions by about 82% to 97% within the various impact categories. A sensitivity scenario was created for a hypothetical user in Barcelona, Spain, to better understand the influence of the selected lifetime and user behavior on the impacts. The results indicate that using an additional battery and thereby increasing the lifetime of the vehicle shows a 34% decrease in emissions per km driven within the lifetime of the motorcycle. Lastly, it is recommended whenever possible to source the numerous components of the vehicle closer to the assembly unit to reduce the transportation impacts incurred from transoceanic freight. / Företagens elfordonssegment har breddats och deras försäljning har ökat under det senaste decenniet. Den elektriska motorcykelsektorn växer snabbt, med förbättrad teknik på elektriska drivlinor, ökade räckvidder, laddningshastigheter och infrastruktur. Parallellt med den ökade försäljningen går elbatterisektorn snabbt framåt, vilket minskar miljöpåverkan från dessa fordon. Den konkurrensutsatta äventyrssportsektorn drar också nytta av att använda elektriska drivlinor med deras otroliga kraft-till-vikt-förhållande och omedelbara vridmoment. Fördelarna med att använda elfordon framför konventionella kan ses under användningsfasen, med noll avgasutsläpp och ren, tyst körning. Men med expansionen av elmotorcykelsektorn som rullar ut nya tekniker och modeller, finns det osäkerheter om huruvida den övergripande livscykeln har minskat miljöpåverkan. Att hitta och förbättra de mest hållbara modellerna eller lösningarna innebär att man granskar dessa motorcyklars effekter på miljön, vilket är målet för CAKE 0 Emission AB, en svensk lättviktstillverkare av elmotorcykel. Det aktuella projektet kommer att bedöma de potentiella miljöeffekterna av Kalk&, en terrängmodell av elektrisk motorcykel certifierad för användning på väg, designad och tillverkad av CAKE 0 Emission AB. För detta ändamål valdes Attributional Life Cycle Assessment som metoden för att studera effekten av en hel motorcykel under en livstid på 500 batteriladdningscykler, som används av en hypotetisk exempelanvändare i Stockholm, Sverige. Den potentiella miljöpåverkan är fokuserad på 12 kategorier med hjälp av metoden ReCiPe Midpoint (H). Som förväntat av ett elfordon visar resultaten att effekterna huvudsakligen härrör från motorcykelns tillverkningsfas. Hotspots i tillverkningsfasen uppstår från att producera batteriet, elmotorn och de elektriska komponenterna som lampor, laddare och kablar. De material som används för konstruktion som har en hög andel av påverkan är koppar och aluminium. En annan miljömässig hotspot är tillverkningsprocessen för gjutning. Inom fordonsanvändningsfasen är effekten av att använda solenergi i Sverige för att ladda batterierna inte direkt intuitiv och har visat sig vara högre än den svenska elkortsmixen; resultaten talar för att valet av el är avgörande för att minska utsläppen. Att transportera fordonet utomlands med fartyg istället för med flyg minskar utsläppen med cirka 82% till 97% inom de olika påverkanskategorierna. Ett känslighetsscenario skapades för en hypotetisk användare i Barcelona, Spanien, för att bättre förstå inverkan av den valda livslängden och användarbeteendet på effekterna. Resultaten indikerar att användning av ett extra batteri och därmed ökad livslängd på fordonet visar en 34% minskning av utsläppen per körd km under motorcykelns livslängd. Slutligen rekommenderas det när det är möjligt att köpa de många komponenterna i fordonet närmare monteringsenheten för att minska transportpåverkan från transoceanisk frakt. Note: The abstract has been translated to Swedish from English using Google Translate nvironmental impact two-wheel motorcycle lithium-ion battery transportation BEV (Battery Electric Vehicle) Life Cycle Assessment (LCA) miljöpåverkan våhjulig motorcykel litiumjonbatteri transport BEV (Batteri elektriskt fordon) Life Cycle Assessment (LCA) Engineering and Technology Teknik och teknologier
3	Minimization of Noise and Vibration Related to Driveline Imbalance using Robust Design Processes Al-Shubailat, Omar 17 August 2013 (has links) Variation in vehicle noise, vibration and harshness (NVH) response can be caused by variability in design (e.g. tolerance), material, manufacturing, or other sources of variation. Such variation in the vehicle response causes a higher percentage of produced vehicles to have higher levels (out of specifications) of NVH leading to higher number of warranty claims and loss of customer satisfaction, which are proven costly. Measures must be taken to ensure less warranty claims and higher levels of customer satisfactions. As a result, original equipment manufacturers (OEMs) have implemented design for variation in the design process to secure an acceptable (or within specification) response. The focus here will be on aspects of design variations that should be considered in the design process of drivelines. Variations due to imbalance in rotating components can be unavoidable or costly to control. Some of the major components in the vehicle that are known to have imbalance and traditionally cause NVH issues and concerns include the crankshaft, the drivetrain components (transmission, driveline, half shafts, etc.), and wheels. The purpose is to assess NVH as a result of driveline imbalance variations and develop a tool to help design a more robust system to such variations. program. Java quality engineering quality capability studies manufacturing processes manufacturing engineer design engineer sales profit customer concern warranty objectionable Eigen functions vectors Eigen Eigen values identity Euler differential equations differential transfer case shaft driveline static imbalance dynamic imbalance passenger customer driver inboard ear driver outboard ear steering wheel seat track variation Gamma distribution normal distribution standard deviation average variance mean phasor victor scalar linear system LTI linear time invariant transfer function output input microphone accelerometers tachometer channels order frequency frequency domain time domain convolution Transformation Fourier Transformer Fourier imaginary and real logarithmic decibel sensitivity curves run down run up two wheel drive Four Wheel Drive Nissan Truck OEM Original Equipment Manufacturers Data Acquisitions Channels Simulation Six Sigma variability Design Robust sensitivity Vibration Imbalance Noise Harshness NVH Driveline

1

Page generated in 0.0294 seconds