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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Modeling and design of an electric all-terrain vehicle

Chevrefils, Adam R. 15 January 2009 (has links)
This thesis describes and evaluates the conversion of a conventional gasoline powered all-terrain vehicle (ATV) to an electric ATV. Preliminary studies are performed to obtain initial power and torque requirements for the vehicle. A detailed simulation model of the mechanical load is written and compared to manufacturer supplied data. The load model is then combined with a comprehensive electronic drive and motor simulation using an electromagnetic transient simulation program (PSCAD). A prototype of the vehicle is constructed by selecting the main components, an electric traction motor, batteries and a custom motor drive, using the simulation results. The results of both the simulation and prototypes are compared and evaluated.
12

Modeling and design of an electric all-terrain vehicle

Chevrefils, Adam R. 15 January 2009 (has links)
This thesis describes and evaluates the conversion of a conventional gasoline powered all-terrain vehicle (ATV) to an electric ATV. Preliminary studies are performed to obtain initial power and torque requirements for the vehicle. A detailed simulation model of the mechanical load is written and compared to manufacturer supplied data. The load model is then combined with a comprehensive electronic drive and motor simulation using an electromagnetic transient simulation program (PSCAD). A prototype of the vehicle is constructed by selecting the main components, an electric traction motor, batteries and a custom motor drive, using the simulation results. The results of both the simulation and prototypes are compared and evaluated.
13

A comprehensive fleet risk control system for Bill's Distributing

Spejcher, Clint. January 1998 (has links) (PDF)
Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 1998. / Includes bibliographical references.
14

Automatic vehicle detection and tracking in aerial video

Chen, Xiyan January 2016 (has links)
This thesis is concerned with the challenging tasks of automatic and real-time vehicle detection and tracking from aerial video. The aim of this thesis is to build an automatic system that can accurately localise any vehicles that appear in aerial video frames and track the target vehicles with trackers. Vehicle detection and tracking have many applications and this has been an active area of research during recent years; however, it is still a challenge to deal with certain realistic environments. This thesis develops vehicle detection and tracking algorithms which enhance the robustness of detection and tracking beyond the existing approaches. The basis of the vehicle detection system proposed in this thesis has different object categorisation approaches, with colour and texture features in both point and area template forms. The thesis also proposes a novel Self-Learning Tracking and Detection approach, which is an extension to the existing Tracking Learning Detection (TLD) algorithm. There are a number of challenges in vehicle detection and tracking. The most difficult challenge of detection is distinguishing and clustering the target vehicle from the background objects and noises. Under certain conditions, the images captured from Unmanned Aerial Vehicles (UAVs) are also blurred; for example, turbulence may make the vehicle shake during flight. This thesis tackles these challenges by applying integrated multiple feature descriptors for real-time processing. In this thesis, three vehicle detection approaches are proposed: the HSV-GLCM feature approach, the ISM-SIFT feature approach and the FAST-HoG approach. The general vehicle detection approaches used have highly flexible implicit shape representations. They are based on training samples in both positive and negative sets and use updated classifiers to distinguish the targets. It has been found that the detection results attained by using HSV-GLCM texture features can be affected by blurring problems; the proposed detection algorithms can further segment the edges of the vehicles from the background. Using the point descriptor feature can solve the blurring problem, however, the large amount of information contained in point descriptors can lead to processing times that are too long for real-time applications. So the FAST-HoG approach combining the point feature and the shape feature is proposed. This new approach is able to speed up the process that attains the real-time performance. Finally, a detection approach using HoG with the FAST feature is also proposed. The HoG approach is widely used in object recognition, as it has a strong ability to represent the shape vector of the object. However, the original HoG feature is sensitive to the orientation of the target; this method improves the algorithm by inserting the direction vectors of the targets. For the tracking process, a novel tracking approach was proposed, an extension of the TLD algorithm, in order to track multiple targets. The extended approach upgrades the original system, which can only track a single target, which must be selected before the detection and tracking process. The greatest challenge to vehicle tracking is long-term tracking. The target object can change its appearance during the process and illumination and scale changes can also occur. The original TLD feature assumed that tracking can make errors during the tracking process, and the accumulation of these errors could cause tracking failure, so the original TLD proposed using a learning approach in between the tracking and the detection by adding a pair of inspectors (positive and negative) to constantly estimate errors. This thesis extends the TLD approach with a new detection method in order to achieve multiple-target tracking. A Forward and Backward Tracking approach has been proposed to eliminate tracking errors and other problems such as occlusion. The main purpose of the proposed tracking system is to learn the features of the targets during tracking and re-train the detection classifier for further processes. This thesis puts particular emphasis on vehicle detection and tracking in different extreme scenarios such as crowed highway vehicle detection, blurred images and changes in the appearance of the targets. Compared with currently existing detection and tracking approaches, the proposed approaches demonstrate a robust increase in accuracy in each scenario.
15

Design, Development, and Modeling, of a Novel Underwater Vehicle for Autonomous Reef Monitoring

January 2020 (has links)
abstract: A novel underwater, open source, and configurable vehicle that mimics and leverages advances in quad-copter controls and dynamics, called the uDrone, was designed, built and tested. This vehicle was developed to aid coral reef researchers in collecting underwater spectroscopic data for the purpose of monitoring coral reef health. It is designed with an on-board integrated sensor system to support both automated navigation in close proximity to reefs and environmental observation. Additionally, the vehicle can serve as a testbed for future research in the realm of programming for autonomous underwater navigation and data collection, given the open-source simulation and software environment in which it was developed. This thesis presents the motivation for and design components of the new vehicle, a model governing vehicle dynamics, and the results of two proof-of-concept simulation for automated control. / Dissertation/Thesis / Masters Thesis Computer Science 2020
16

Portable automated driver for universal road vehicle dynamics testing

Mikesell, David Russell 07 January 2008 (has links)
No description available.
17

Future certification of autonomous vehicles and the use of virtual testing methods / Framtida certifiering av autonoma fordon och användning av virtuella testmetoder

Nordenström, Martin January 2020 (has links)
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.
18

Vehicle Dynamics Model for Predicting Maximum and Typical Acceleration Rates for Passenger Vehicles

Snare, Matthew C. 27 August 2002 (has links)
Effectively modeling the acceleration behavior of vehicles is an important consideration in a variety of transportation engineering applications. The acceleration profiles of vehicles are important in the geometric design of roadways and are used to model vehicle behavior in simulation software packages. The acceleration profile of the vehicle is also a critical parameter in fuel consumption and emissions models. This paper develops and validates a vehicle dynamics model to predict the maximum acceleration rates of passenger vehicles. The model is shown to be superior to other similar models in that it accurately predicts speed and acceleration profiles in all domains and for a variety of vehicle types. The paper also modifies the model by introducing a reduction factor, which enables the model to predict the typical acceleration patterns for different driver types. The reduction factors for the driving population are shown to follow a normal distribution with a mean of 0.60 and a standard deviation of 0.08. The paper also provides new data sets containing maximum and typical acceleration profiles for thirteen different vehicles and twenty different drivers. / Master of Science
19

Design and Simulation of a Towed Underwater Vehicle

Linklater, Amy Catherine 07 July 2005 (has links)
Oceanographers are currently investigating small-scale ocean turbulence to understand how to better model the ocean. To measure ocean turbulence, one must measure fluid velocity with great precision. The three components of velocity can be used to compute the turbulent kinetic energy dissipation rate. Fluid velocity can be measured using a five-beam acoustic Doppler current profiler (VADCP). The VADCP needs to maintain a tilt-free attitude so the turbulent kinetic energy dissipation rate can be accurately computed to observe small-scale ocean turbulence in a vertical column. To provide attitude stability, the sensor may be towed behind a research vessel, with a depressor fixed somewhere along the length of the towing cable. This type of setup is known as a two-part towing arrangement. This thesis examines the dynamics, stability and control of the two-part tow. A Simulink simulation that models the towfish dynamics was implemented. Through this Simulink simulation a parametric study was conducted to see the effects of sea state, towing speed, center of gravity position, and a PID controller on the towfish dynamics. A detailed static analysis of the towing cable's effects on the towfish enhanced this dynamic model. The thesis also describes vehicle design and fabrication, including procedures for trimming and ballasting the towfish. / Master of Science
20

An integrated approach to the design of moonpools for subsea operations

Day, A. H. January 1987 (has links)
The use of moonpools for the launch and retrieval of diving bells and remotely operated vehicles from a mother ship is well established, and the advantages of the moonpool approach are well known. The use of moonpools in Floating Production Systems is also becoming more common, as a means of allowing the marine riser to enter the vessel. The moonpool offers protection from wind and current forces and reduces the effects of angular motions of the vessel. The only problem with the moonpool concept is that the water column inside a badly designed moonpool may suffer from large and apparently unpredictable vertical surges, making operations through the moonpool hazardous, and in extreme cases threatening the seaworthiness of the vessel. The work described here shows how a moonpool design may be optimised for a particular vessel in order that such problems may be avoided. The dynamics of the problem are established, such that the water column oscillation and the forces on a subsea unit in the moonpool may be predicted. The effects of a variety of geometrical configurations are then studied, both mathematically and experimentally, in order to select configurations which allow large modifications of the moonpool response. A quantitative measure of moonpool performance is proposed, allowing individual designs to be ranked in terms of the long term expected downtime due to the moonpool. Finally, the understanding and results thus gained are integrated in order to produce a practical design procedure for a moonpool of any size, in any vessel, and in any operational area. A worked example based on a real design problem is presented in order to illustrate the practical application of the method.

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