• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 22
  • 5
  • 2
  • 1
  • 1
  • Tagged with
  • 37
  • 13
  • 11
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 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.
1

Drivetrain Modelling and Clutch Temperature Estimation in Heavy Duty Trucks / Modellering av Drivlinan och Estimering av Kopplingstemperatur i en Tung Lastbil

Thornblad, Johan January 2014 (has links)
An existing drivetrain model with clutch temperature dynamics has been used to simulate the behaviour of a heavy duty truck. During the implementation of the model in MATLAB/Simulink modularity and simplicity was greatly emphasized. This was done in order to facilitate the use of the model in various applications as well as making it easy to understand. The main contributions of the thesis is however the adaptation of a clutch temperature and wear observer for use in an on-line application in the gearbox management system (GMS). The process of taking the observer from an off-line simulation environment to running on-line includes taking into consideration the configuration and limitations of the GMS as well as adapting the interface of the observer. Concretely this means dealing with the limitations of the available data types in the GMS, compensating for the effect of biased measurements as well as accounting for the different dynamics of the sensor-types used in the clutch.In a simulation environment the performance of the adapted observer has been studied and its ability to compensate for heat expansion and wear in the clutch shown. / En existerande drivlinemodell med temperaturdynamik i kopplingen har använts för att simulera beteendet hos en lastbil. Vid implementation av modellen i MATLAB/Simulink betonades vikten av en enkel och modulär struktur. Detta gjordes för att underlätta användning av modellen i olika applikationer samt för att göra den lätt att förstå.De huvudsakliga bidragen i uppsatsen är anpassningen av en temperatur- och slitageobeservatör på kopplingen för användning i realtid av växellådans styrenhet. För att ta observatören från simulerings- till realtidsmiljö måste styrenhetens konfiguration och begränsningar beaktas samt gränssnittet hos observatören anpassas. Konkret betyder detta att hänsyn till begränsningarna hos de olika datatyper som används i kopplingens styrenhet tagits, att den negativa inverkan som brusiga mätsignaler kan få begränsats samt att skillnader i dynamik hos de olika sensortyper som används i kopplingen kompenserats för. Med simuleringar har prestandan hos den anpassade observatören studerats samt dess förmåga att kompensera för värmeutvidgning och slitage i kopplingen visats.
2

TESTING THE EFFICIENCY OF A SERIES HYBRID DRIVETRAIN FOR AGRICULTURAL APPLICATIONS

Jackson, Joseph W. 01 January 2015 (has links)
Because of high fuel costs and rising concern over controlling motor vehicle emissions, there has been a surge in the number of hybrid passenger vehicles on roads in recent years. This transition has not yet been seen with agricultural vehicles. With this in mind, this study created a test scheme to characterize and replicate agricultural loads, and design of a hybrid drivetrain that is suitable for agricultural purposes. Torque and power data were recorded from the controller area network of a tractor performing a baling operation. The recorded data was characterized using statistical and time series analyses, and converted into a simplified torque profile that could be run on a common type of dynamometer. The prototype series hybrid drivetrain was subjected to the simplified profile developed, and drivetrain efficiency was compared to the efficiency under constant load. The effect of battery pack, and engine size was also tested. On average, the prototype developed was not more efficient than a similarly sized standard geared vehicle, but there is significant room for further optimization.
3

Reconfigurable modelling of physically based systems: Dynamic modelling and optimisation for product design and development applied to the automotive drivetrain system.

Mason, Byron A. January 2009 (has links)
The work of this thesis is concerned with the aggregation and advancement of modelling practise as used within modern day product development and optimisation environments making use of Model Based Design (¿MBD¿) and similar procedures. A review of model development and use forms the foundation of the work, with the findings being aggregated into two unique approaches for rapid model development and reconfiguration; the Plug-and-Simulate (¿PaS¿) approach and the Paradigm for Large Model Creation (¿PLMC¿); each shown to posses its own advantages. To support the MBD process a model optimisation algorithm that seeks to eliminate parameters that are of little or no significance to a simulation is developed. Eliminations are made on the basis of an energy analysis which determines the activity of a number of energy elements. Low activity elements are said to be of less significance to the global dynamics of a model and thus become targets for elimination. A model configuration tool is presented that brings together the PLMC and parameter elimination algorithm. The tool is shown to be useful for rapid configuration and reconfiguration of models and is capable of automatically running the optimisation algorithms thus producing a simulation model that is parametrically and computationally optimised. The response of the plug-and-simulate drivetrain submodels, assembled to represent a front wheel drive drivetrain, is examined. The resulting model is subjected to a torque step-input and an empirically obtained torque curve that characterises the input to a drivetrain undergoing steady acceleration. The model displays the expected response in both its full parameter and parameter reduced versions with simulation efficiency gains observed in the parameter reduced version. / EPSRC
4

An Integrated Framework of Performance Assessment and Drivetrain Prognostics for Wind Turbines

Zhao, Wenyu 20 October 2014 (has links)
No description available.
5

Reconfigurable modelling of physically based systems : dynamic modelling and optimisation for product design and development applied to the automotive drivetrain system

Mason, Byron January 2009 (has links)
The work of this thesis is concerned with the aggregation and advancement of modelling practise as used within modern day product development and optimisation environments making use of Model Based Design ('MBD') and similar procedures. A review of model development and use forms the foundation of the work, with the findings being aggregated into two unique approaches for rapid model development and reconfiguration; the Plug-and-Simulate ('PaS') approach and the Paradigm for Large Model Creation ('PLMC'); each shown to posses its own advantages. To support the MBD process a model optimisation algorithm that seeks to eliminate parameters that are of little or no significance to a simulation is developed. Eliminations are made on the basis of an energy analysis which determines the activity of a number of energy elements. Low activity elements are said to be of less significance to the global dynamics of a model and thus become targets for elimination. A model configuration tool is presented that brings together the PLMC and parameter elimination algorithm. The tool is shown to be useful for rapid configuration and reconfiguration of models and is capable of automatically running the optimisation algorithms thus producing a simulation model that is parametrically and computationally optimised. The response of the plug-and-simulate drivetrain submodels, assembled to represent a front wheel drive drivetrain, is examined. The resulting model is subjected to a torque step-input and an empirically obtained torque curve that characterises the input to a drivetrain undergoing steady acceleration. The model displays the expected response in both its full parameter and parameter reduced versions with simulation efficiency gains observed in the parameter reduced version.
6

Electricity consumption and battery lifespan estimation for transit electric buses: drivetrain simulations and electrochemical modelling

Franca, Anaissia 19 March 2018 (has links)
This thesis presents a battery electric bus energy consumption model (ECONS-M) coupled with an electrochemical battery capacity fade model (CFM). The underlying goals of the project were to develop analytical tools to support the integration of battery electric buses. ECONS-M projects the operating costs of electric bus and the potential emission reductions compared to diesel vehicles for a chosen transit route. CFM aims to predict the battery pack lifetime expected under the specific driving conditions of the route. A case study was run for a transit route in Victoria, BC chosen as a candidate to deploy a 2013 BYD electric bus. The novelty of this work mainly lays in its application to battery electric buses, as well as in the coupling of the ECONS-M and the electrochemical model to predict how long the batteries can last if the electric bus is deployed on a specific transit route everyday. An in-depot charging strategy is the only strategy examined in this thesis due to the charging rate limitations of the electrochemical model. The ECONS-M is currently being utilized in industry for the preparations of Phase I and II of the Pan-Canadian Electric Bus Demonstration & Integration Trial led by the Canadian Urban Transit Research and Innovation Consortium (CUTRIC). This project aims to deploy up to 20 battery electric buses for phase I and 60 electric buses for phase II across Canada to support the standardization of overhead fast chargers and in-depot chargers, which in a first in the world. At this time, the developed CFM can not support any final claims due to the lack of electrochemical data in the literature for the high capacity lithium-ion cells used in electric buses. This opens the door to more research in the ageing testing of batteries for heavy-duty applications. / Graduate
7

Electro-mechanical interaction in gas turbine-generator systems for more-electric aircraft

Feehally, Thomas January 2012 (has links)
Modern 'more-electric' aircraft demand increased levels of electrical power as non-propulsive power systems are replaced with electrical equivalents. This electrical power is provided by electrical generators, driven via a mechanical transmission system, from a rotating spool in the gas turbine core. A wide range of electrical loads exist throughout the aircraft, which may be pulsating and high powered, and this electrical power demand is transferred though the generators to produce a torque load on the drivetrain. The mechanical components of the drivetrain are designed for minimum mass and so are susceptible to fatigue, therefore the electrical loading existing on modern airframes may induce fatigue in key mechanical components and excite system resonances in both mechanical and electrical domains. This electro-mechanical interaction could lead to a reduced lifespan for mechanical components and electrical network instability.This project investigates electro-mechanical interaction in the electrical power offtake from large diameter aero gas turbines. High fidelity modelling of the drivetrain, and generator, allow the prediction of system resonances for a generic gas turbine-generator system. A Doubly-Fed Induction Generator (DFIG) is considered and modelled. DFIGs offer opportunities due to their fast dynamics and their ability to decouple electrical and mechanical frequencies (e.g. enabling a constant frequency electrical system with a variable speed mechanical drive). A test platform is produced which is representative of a large diameter gas turbine and reproduces the electro-mechanical system behaviour. The test platform is scaled with respect to speed and power but maintains realistic sizing between component dimensions which include: a gas turbine mechanical spool emulation, transmission driveshafts and gearbox, and accessory loads such as a generator. This test platform is used to validate theoretical understanding and suggest alternative mechanical configurations, and generator control schemes, for the mitigation of electro-mechanical interaction.The novel use of a DFIG and an understanding of electro-mechanical interaction allow future aircraft designs to benefit from the increased electrification of systems by ensuring that sufficient electrical power can be provided by a robust gas turbine-generator system.
8

Hnací ústrojí formule Dragon 3 / Drivetrain of Formula Dragon 3

Matajsz, Petr January 2013 (has links)
This master thesis deals with the structural design of the drivetrain for the formula Dragon 3. There is shown an overview of the most common design solutions used in the category Formula Student. On that basis is made my own concept of the drivetrain. Major focus is placed on the design of the final drive, differential mounting including chain tensioning mechanism and design of related components. For the designed components was made stress analysis by FEM.
9

Hnací ústrojí Formule Student / Formula Student Drivetrain

Odehnal, Jakub January 2015 (has links)
This master‘s thesis describes design of Formula Student Drivetrain, car evolution Dragon 4 and Dragon 5. There is shown an overview of the drivetrain parts used in category Formula Student. On that basis is made the new concept of drivetrain for the each car. Major focus is placed on the design of the differential mounting and chain tensioning mechanism. For the selected components was made stress analysis by FEM.
10

Analysis and simulation of centrifugal pendulum vibration absorbers

Smith, Emma January 2015 (has links)
When environmental laws are constricted and downsizing of engines has become the reality of the vehicle industry, there needs to be a solution for the rise in torsion vibrations in the drivetrain. These increased levels of torsion vibrations are mostly due to excitations from the firing pulses, which in turn have become increased due to higher cylinder pressures. One of the solutions for further dampening the system is to add a centrifugal pendulum absorber to the flywheel, and predicting the behaviour of such a device has become imperative.The intent of this thesis is to create a model that will accurately emulate the effectiveness and functionality of a centrifugal pendulum absorber, so that it can be used in simulations to predict vehicle behaviour with its addition. To validate the model, a comparison is made between simulated results, using the model created in Adams/Car and Matlab, and road measurements conducted using a prototype acquired by the industry.The results from the simulations show that, with existing theory on the subject and software provided by Scania, an accurate model can be created. The reduction of torsion vibrations is evident, and the model’s behaviour correlates to that of the prototype.Future work on the subject requires a larger insight into pendulums tuned to multiple orders, and an extension of the model geometry would be advantageous.

Page generated in 0.0668 seconds