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Dissertations / Theses on the topic 'Momentum of vehicles'
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1
Akagi, Raymond. "Ram Air-Turbine of Minimum Drag." DigitalCommons@CalPoly, 2021. https://digitalcommons.calpoly.edu/theses/2261.
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The primary motivation for this work was to predict the conditions that would yield minimum drag for a small Ram-Air Turbine used to provide a specified power requirement for a small flight test instrument called the Boundary Layer Data System. Actuator Disk Theory was used to provide an analytical model for this work.
Classic Actuator Disk Theory (CADT) or Froude’s Momentum Theory was initially established for quasi-one-dimensional flows and inviscid fluids to predict the power output, drag, and efficiency of energy-extracting devices as a function of wake and freestream velocities using the laws of Conservations of Mass, Momentum, and Energy. Because swirl and losses due to the effects of viscosity have real and significant impacts on existing turbines, there is a strong motivation to develop models which can provide generalized results about the performance of an energy-extractor, such as a turbine, with the inclusion of these effects. A model with swirl and a model with losses due to the effects of viscosity were incorporated into CADT which yielded equations that predicted the performance of an energy-extractor for both un-ducted and ducted cases. In both of these models, for this application, additional performance parameters were analyzed including the drag, drag coefficient, power output, power coefficient, force coefficient, and relative efficiency.
For the un-ducted CADT, it is well known that the wake-to-freestream velocity ratio of 1/3 will give the maximum power extraction efficiency of 59.3%; this result is called the Betz limit. However, the present analysis shows that reduced drag for a desired power extraction will occur for wake-to-freestream velocity ratios higher than the value of 1/3 which results in maximum power extraction efficiency. This in turn means that a turbine with a larger area than the smallest possible turbine for a specified power extraction will actually experience a lower drag.
The model with the inclusion of swirl made use of the Moment of Momentum Theorem applied to a single-rotor actuator disk with no stators, in addition to the laws of Conservation of Mass, Momentum, and Energy from the CADT. The results from the model w/swirl showed that drag remains unchanged while power extracted decreases with the addition of swirl, with swirl effects becoming more severe for tip speed ratios below about 5. As for CADT, reduced drag for a specified power extraction can be achieved when the wake-to-freestream velocity ratio is higher that than which provides maximum power extraction efficiency. The model w/losses due to viscosity incorporated the losses into the Conservation of Energy relationship. The results from the model w/losses showed that there is a distinct wake-to-freestream velocity ratio at which minimum drag for a specified power output is achieved, and that this velocity ratio is usually—but not always—higher than that for which the power extraction efficiency is a maximum.
It was concluded that a lower drag for a specified power output of an energy-extractor can usually be achieved at a wake-to-freestream velocity ratio higher than that which produces the v maximum power extraction efficiency. The latter condition, known as the Betz limit for CADT, and which defines the minimum size for a turbine to provide a specified power extraction, is therefore not the correct target design condition to achieve lowest drag for a small Ram-Air Turbine to power BLDS.
2
Vašíček, Jiří. "Kompatibilita vozidel při čelním střetu." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-232731.
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Thesis deals with the compatibility of vehicles in a frontal collision. The first section discusses about compatibility from different views. There are the physical processes used in the mechanics of impact. The second part is focused on solving the compatibility of vehicles in a frontal collision by crash analysis using the finite element method. Firstly there are described collisions of vehicles from different vehicle classes (small cars, lower middle class, Pick up / SUV) into the fixed barrier by the US NCAP. Furthermore there are simulated head-on collisions of vehicles from different vehicle classes. In the end there is shown the possibility of using data from crash tests to determine the EES.
3
Schroll, Gregory C. (Gregory Cordner). "Design of a spherical vehicle with flywheel momentum storage for high torque capabilities." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45296.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (leaf 26).
A novel method for supplementing the propulsion of a spherical ground vehicle was conceived and developed. The addition of angular momentum storage via counter-rotating control moment gyroscopes is proposed in order to overcome significant limitations in the performance of earlier designs of spherical vehicles. Analysis and design of a fully functioning spherical vehicle incorporating such a mechanism is completed and indicates significantly increased torque capabilities for ascending steep inclines and stairs. A fully functional prototype is built and testing is ongoing to verify its capabilities.
by Gregory C. Schroll.
S.B.
4
Fojtášek, Jan. "Diferenciály s řízeným dělením momentu pro těžká užitková vozidla." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-409363.
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This work deals with the assessment of the yaw moment control via active differential effects to the heavy commercial vehicle dynamics. Summarized are the findings about design of active differential, control algorithms and theoretical assumptions about overall effects to the vehicle dynamics. According to the described theory the own concept of the active differential for experimental heavy commercial vehicle is proposed. The main part of the work is focused on the effects of the active differential on vehicle manoeuvrability, controllability, stability and limits analysis. For this purpose, multibody dynamic model of the complete vehicle with standard open differential is assembled and results of the selected manoeuvre simulations validated by measurements of the real vehicle characteristics. The validated vehicle model is then extended by the model of the active differential with control algorithm. According to the simulations results the theoretical presumptions are confirmed and the effects of the active differential on vehicle dynamics in steady and transition states are evaluated. Based on the described findings the overall improvement of the vehicle dynamics by this technology, feasibility of the proposed concept and main advantages and disadvantages are evaluated.
5
David, Regis Agenor. "A Generalized Two-Dimensional Model to Reconstruct the Impact Phase in Automobile Collisions." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2112.pdf.
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Oller, Erik D. "Forces and moments due to unsteady motion of an underwater vehicle." Thesis, Cambridge, Massachusetts. Massachusetts Institute of Technology c2003, 2003. http://hdl.handle.net/10945/11032.
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CIVINSThis research examines the effect of unsteady motion on the forces and moments experienced by an underwater vehicle in shallow water. The test platform is the REMUS Autonomous Underwater Vehicle developed by the Woods Hole Oceanographic Institution, although the results are made non-dimensional to be applicable to a wide range of similar shaped vehicles. The experimental model was moved in sinusoidal motion at various submergences, speeds, frequencies of oscillation, and amplitudes of oscillation.
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Price, William D. "Control system of a three DOF Spacecraft Simulator by vectorable thrusters and control moment GYROS." Thesis, Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion-image.exe/06Dec%5FPrice.pdf.
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Thesis (M.S. in Astronautical Engineering and Astronautical Engineer Degree)--Naval Postgraduate School, December 2007.Thesis Advisor(s): Romano, Marcello. "December 2006." Description based on title screen as viewed on March 12, 2008. Includes bibliographical references (p. 79-80). Also available in print.
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Yoon, Hyungjoo. "Spacecraft Attitude and Power Control Using Variable Speed Control Moment Gyros." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4850.
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A Variable Speed Control Moment Gyro (VSCMG) is a recently
introduced actuator for spacecraft attitude control.
As its name implies, a VSCMG is essentially a single-gimbal
control moment gyro (CMG) with a flywheel allowed to have variable spin
speed. Thanks to its extra degrees of freedom, a
VSCMGs cluster can be used to achieve additional objectives, such
as power tracking and/or singularity avoidance, as well as
attitude control.
In this thesis, control laws for an integrated power/attitude
control system (IPACS) for a satellite using VSCMGs are
introduced.
The power tracking objective is achieved by storing or releasing the kinetic energy
in the wheels. The proposed control algorithms perform both the attitude
and power tracking goals simultaneously.
This thesis also provides a singularity analysis and avoidance method using
CMGs/VSCMGs. This issue is studied for both the cases of attitude tracking with and without a power
tracking requirement. A null motion method to avoid singularities is
presented, and a criterion is developed to determine the momentum region
over which this method will successfully avoid singularities.
The spacecraft angular velocity and attitude control problem using a single
VSCMG is also addressed.
A body-fixed axis is chosen to
be perpendicular to the gimbal axis, and it is controlled to aim at an arbitrarily given inertial direction,
while the spacecraft angular velocity is stabilized.
Finally, an adaptive control algorithm for the spacecraft attitude tracking in case
when the actuator parameters, for instance the spin axis directions, are uncertain is developed.
The equations of motion in this case
are fully nonlinear and represent a Multi-Input-Multi-Output (MIMO) system.
The smooth projection algorithm is applied to keep the parameter estimates inside
a singularity-free region.
The design procedure can also be easily applied to general MIMO dynamical systems.
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Fojtášek, Jan. "Studie využití diferenciálu s řízeným dělením momentu pro těžká užitková vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231197.
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This work deals with the design of right-and-left torque vectoring systems used in heavy commercial vehicle powertrains. It is a new device for a commonly used vehicle differential. This study recommends design, kinematic and load parameters. Also the overall effect of the mechanism on vehicle dynamics and design of the experimental vehicle chassis is described. The study further describes how the mechatronic system works with necessary control systems. Purpose of this thesis is to summarize available information on a right-and-left torque vectoring and possible practical applications for further development of torque vectoring systems.
10
Yu, Zitian. "Integrated Estimation and Motion Control for Electric Vehicles." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1531778655719369.
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Rücker, Jan. "Měření hmotnostních parametrů vozidel." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-232657.
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This thesis is the first part deals with methods of determining weight parameters of vehicles. By measuring the position of center of gravity and inertia measurements. In the second part focuses on the measurement of gravity position in a selected group of vehicles Škoda and their comparison between vehicles and comparison with simulation programs PCcrach and Virtual crach.
12
Špičák, Milan. "Pokročilé algoritmy řízení pohonných jednotek." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-408015.
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This thesis describes computational control of vehicle powertrains using common variable, engine torque. The thesis is divided into three main parts. The first one shows design of methods for torque estimation using known or measured variables on the vehicle. The second part contains design of powertrain control algorithm utilizing the engine torque as a common variable among individual modules. The third part describes experimental optimization of the longitudinal acceleration of a vehicle using torque control.
13
Xu, Tongyi. "Design and Analysis of a Shock Absorber with a Variable Moment of Inertia Flywheel for Passive Vehicle Suspension." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26293.
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Conventional vehicle suspensions consist of a spring and a damper, while mass is rarely used. A mass, if properly used, can also create a damping-like effect. However, a mass has only one terminal which makes it difficult to be incorporated into a suspension. In order to use a mass to achieve the damping-like effect, a two-terminal mass (TTM) has to be designed. However, most of the reported TTMs are of fixed moment of inertia (TTM-CMI), which limits the further improvement of the suspension performance and responsiveness to changes in environment and driving conditions.
In this study, a TTM-based vibration absorber with variable moment of inertia (TTM-VMI) is proposed. The main component of the proposed TTM absorber contains a hydraulic-driven flywheel with sliders. The moment of inertia changes with the positions of the sliders in response to the driving conditions. The performance of the proposed TTM-VMI absorber has been analyzed via dynamics modeling and simulation and further examined by experiments. The analysis results indicate that the TTM-VMI absorber outperforms the TTM-CMI design in terms of body displacement; and ride comfort, tire grip and suspension deflection for zero and impulse inputs with comparable performance for sinusoidal input.
14
Holubec, Martin. "Spojka pomocného pohonu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228341.
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This thesis deal with a calculation and a construction concept of a PTO coupling used in Tatra vehicles. The coupling allows turn on an accessory machinery when the engine is on. It is designed as an multiplate clutch with a wet surrounding. The operating is managed by a pneumatic system. The construction solution was restricted mainly by space needs. The calculation includes torque issues and aslo a part considering a heat question. The construction section includes individual clutch parts design.
15
Hall, Jason S. "Design and integration of a three degrees-of freedom robotic vehicle with control moment gyro for the Autonomous Multiagent Physically Interacting Spacecraft (AMPHIS) testbed." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; National Technical Information Service [distributor], 2006. http://www.dtic.mil/dtic/.
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Thesis (M.S. in Astronautical Engineering)--Naval Postgraduate School, September 2006."September 2006." Thesis advisor: Romano, Marcello. Performed by Naval Postgraduate School, Monterey, CA. Includes bibliographical references (p. 73-74). Also available online from the Naval Postgraduate School (NPS), Dudley Knox Library site and the DTIC Online site.
16
Costa, Fabiano Tadeu Mathias. "Estimação da relação ar-combustível e do tipo de combustível utilizando o sinal de pressão no cilindro em um motor ciclo Otto alimentado com misturas de etanol e gasolina." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-23082015-131423/.
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A pesquisa realizada tratou do estudo de modelos de estimação da relação ar-combustível e de identificação do tipo de combustível usando o sinal da pressão no cilindro em um motor quatro tempos automotivo, alimentado com gasolina brasileira tipo C, etanol e misturas destes combustíveis. Foi montada uma bancada dinamométrica para realização de testes em um motor originalmente projetado para operar com etanol e que possui relação de compressão de 13,44:1. Durante os testes do motor foram coletados dados referentes às variáveis de desempenho e emissões de gases de exaustão. Os dados coletados em plena carga foram analisados utilizando parâmetros estatísticos e confrontados com os resultados esperados segundo a literatura. As variáveis independentes disponibilizadas nos testes do motor foram utilizadas em conjunto com a aplicação do método dos momentos e da razão de pressões no sinal da pressão no cilindro para o desenvolvimento de novos modelos de estimação da relação ar-combustível e de identificação do tipo de combustível. Os modelos obtidos na presente pesquisa mostraram-se capazes de estimar a relação ar-combustível, sendo sensíveis à variação da composição do combustível nesta estimativa, e de identificar o tipo de combustível utilizado no motor.This research addressed the study of models for estimating the air-fuel ratio and identifying the type of fuel by in-cylinder pressure signal in a four stroke automotive engine fueled with Brazilian gasoline C type, ethanol, and blends of these fuels. A dynamometer was assembled for tests in an engine originally designed to operate with ethanol and with a 13.44:1 compression ratio. During the engine tests, data were collected related to the performance and exhaustion gas emission variables. Data collected at full load were analyzed using statistical parameters and compared with the expected results according to the literature. The independent variables provided by the engine tests were used together with application of the method of moments and the pressure ratio for in-cylinder pressure in order to develop new models for estimating the air-fuel ratio and to identify the fuel type. The models obtained in this research proved to be capable of estimating the air-fuel ratio, being sensitive to the variation in the type of fuel used in such estimations, and of identifying the type of fuel used in the engine.
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Janiš, Libor. "Deformační měření s využitím zařízení Tritop." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228727.
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This work deal with, suggestion of measuring procedure of deformation modulus of system Tritop and his application on real instances. Also the measuring procedure of torsional stiffness of vehicle body is designed, and the models of frames including attachment of a car are elaborated, where the measuring of torsional stiffness will be done on.
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Pečeliūnas, Robertas. "Automobilio svyravimai ekstremalaus stabdymo metu." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2005. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2005~D_20050224_192006-55801.
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The suspension of the motor vehicle is one of the most important elements of the flexible mounted and inflexible mounted masses of the vehicle bodywork, and most attention is paid to its exploration and improvement. Analysis of models of equivalent oscillation systems of motor vehicles testifies that the evaluation of motor vehicle oscillations and modelling of its motion modes is still very topical and requires further research. Suspension models of motor vehicles offered in publications regard only the influence of road irregularities, and the modernisation of these models is directed towards the improvement of passengers’ comfort. However not much research has been done on the influence of oscillations of flexible mounted and inflexible mounted masses of the bodyworks of vehicles in the process of braking; also there is not much investigation of the post-accident identification of the vehicle’s movement mode corresponding to the deformations of the suspension and the longitudinal pitch of the bodywork. Research of oscillations in the conditions of emergency braking is primarily important for the work in two practical directions:
1) improvement of calculation methods of motor vehicle’s response to external impact in the conditions of real operation;
2) further improvement of research methods on the road, and analysis of fait accompli road accidents related to oscillations in the emergency braking.
Methodology defining the oscillations occurring in the braking may be applied... [to full text]
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Henry, Kevin Claude. "Soft Surface Roll Mechanics Parameters for Light Vehicle Rollover Accident Reconstruction." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1436.
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Light vehicle rollover accidents on soft surfaces can be modeled assuming constant drag with linear motion equations and other engineering principles. The concept of using segment average results to evaluate roll mechanics parameters throughout a roll sequence, and specifically, segment duration to evaluate vehicle trajectory between ground impacts is developed. The trajectory model is presented, explained and compared to values obtained by analyzing digital video of rollover crash tests. Detailed film analysis procedures are developed to obtain data from rollover crash tests that are not otherwise documented. Elevation of the center of gravity of vehicles is obtained where instrumentation does not explicitly yield this data. Instantaneous center of gravity elevation data throughout a roll sequence provides the opportunity to calculate descend distances as a vehicle travels from one ground contact to another. This data is used to quantify severity of ground impacts as a vehicle interact with the ground throughout a roll sequence. Segment average analysis is a reasonable method for determining general roll mechanics parameters. Because of the chaotic nature of rollover accidents, the range of effective drag factors for a given roll surface may be quite large. Choosing an average of typical drag factors is a reasonable approach for a first-order approximation although certain parameters may be predicted less accurately than if actual values were known. The trajectory results demonstrate the influence of drag factor descent height calculations. Typical constant drag factors tend to overestimate descent height early in a roll sequence and underestimate descent height later in the sequence. The trajectory model is a useful tool to aid in understanding rollover mechanics although a rolling vehicle may be in contact with the ground for a significant fraction of a roll segment. The model should not be used at locations in roll sequences where there are extremes in translational center of gravity decelerations. These extremes include the segments immediately following overturn where there are large angular accelerations and large differences between the tangential velocity of the vehicle perimeter and the translational velocity of the center of gravity, as well as segments that include vehicle impacts with irregular topography.
20
Hall, Jason S. "Design and integration of a three degrees-offreedom robotic vehicle with control moment gyro for the Autonomous Multiagent Physically Interacting Spacecraft (AMPHIS) testbed." Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion-image.exe/06Sep%5FHall%5FJason.pdf.
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Thesis (M.S. in Astronautical Engineering)--Naval Postgraduate School, September 2006.Thesis Advisor(s): Romano, Marcello. "September 2006." Description based on title screen as viewed on March 12, 2008. Includes bibliographical references (p. 73-74). Also available in print.
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Fišer, Petr. "Analytický řešič pro pevnostní výpočet náprav dvojkolí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230008.
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This master thesis deals with wheel set axles of rail vehicles, their design and methods of implementation stress analysis. In this work, I created a powered locomotive wheel set: axle and wheel. For the purpose of the design department of the Bonatrans Group a.s. company I developed an analytical solver, which allows creating stress analysis, which will be used for verifying finished design and in addition it allows printing of stress analysis as report for the railway´s offices. Next step was a stress analysis of this design of axle in this analytical solver.
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Luco, Nicolas, and Keren Zhu. "Energy efficient cornering : Simulation and verification." Thesis, KTH, Fordonsdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234837.
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The purpose of this master thesis is to study the energy efficiency of a vehicle when it is cornering. To achieve this, a Simulink model was built from a simple basic bicycle model and theoretically validated. This model was then analysed and successively improved by adding velocity and yaw moment control. A study of the vehicle model behaviour by changing parameters such as cornering stiffness and centre of gravity position was the nconducted. The traction force needed for a constant radius was calculated and methods such as torque vectoring have been tested using the model to obtain the lowest traction force. The model was compared with different vehicle types and further validated by comparing the simulation results with experimental data acquired from a field test. The rolling resistance and aerodynamic resistance were taken into account when the model was validated with the experimental data and the result suggest that by distributing the required traction force (using torque vectoring between inner and outer driven wheels) the energy efficiency could be improved by 10%. This report ends with recommendations for future work.
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Papp, Tomáš. "Konstrukční návrh měřicího volantu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231766.
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This diploma thesis describes construction design of a measuring steering wheel. This mechanism replaces the original steering wheel in the tested vehicle. Connection is made via steering shaft through an adapter. Measured parameters are steering torque and angular position of steering while driving. Measurements obtained during test-ride show some of the dynamic aspects of the tested vehicle.
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Derner, Petr. "Měření zkrutné tuhosti karosérie s využitím fotogrammetrického zařízení TRITOP." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228710.
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This master's thesis deals with measurement of torsional rigidity of a vehicle body with the application of TRITOP optical measuring system. The measurement was made in dynamic test-room of Škoda Auto a.s. together with a methodology used by this company. In the light of the objective comparison of both measuring methods and their accuracy, the optimal method of measurment and evaluation was made.
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Chatterton, Jacqueline Ruth. "An evaluation of the predictions of near bottom interaction forces and moments on unmanned undersea vehicles : validation, reduction, and implementation of the results of a computer code into a real-time simulation." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/37523.
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Kubica, Petr. "Zařízení pro měření výškové polohy těžiště vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232123.
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This diploma thesis deals the with measurment of the centre of gravity height position of a road vehicle and its issues. The introduction of this thesis focuses on the determining of the position of the center of gravity and the moment of inertia of a road vehicle. The next part is about creationing of a construction plan and its verification. The thesis contains a sensitivity analysis of this device including its results. The end of the thesis informs about the executed measurment in a laboratory and about recommendations for next measurments.
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Malchárek, Miroslav. "Měření torzní tuhosti vozidla s využitím 3D scanneru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231528.
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This thesis deals with the measurement of the torsional stiffness of the frame using Tritop system. There is described development of the frame due to the complexity of torsional stiffness. Further there is outlined a brief overview of the types of measurement and the effect of torsional stiffness on the driving behavior of the vehicle. The aim of the work is to develop a method for measuring torsional stiffness of the vehicle Formula Student and from the results of repeated measurements to assess the accuracy and repeatability of measurements.
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Roštek, Martin. "Estimace rychlosti vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-378739.
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Rýchlosť vozidla je jednou z kľúčových stavových premenných, ktorej znalosť je potrebná v reálnom čase a s vysokou presnosťou, aby mohla slúžiť ako vstupná veličina pre systémy kontroly dynamiky vozidla. Jej priame meranie vo vozidle je však finančne náročné. Riešením tohoto problému môže byť použitie meraní zo senzorov bežne dostupných na palube vozidla a ich následný prepočet na rýchlosť vozidla. Tieto merania sú však veľmi zaťažené procesným šumom, čo vyplýva z komplexnosti pohybu vozidla. Preto je nutné vyvinúť algoritmus so schopnosťou vysporiadať sa s týmito negatívnymi vplyvmi. Algoritmus prezentovaný v tejto práci odhaduje pozdĺžnu rýchlosť vozidla s použitím meraní uhlových rýchlostí štyroch kolies, pozdĺžnej akcelerácie, momentov motora, rýchlosti otáčania okolo zvislej osi a natočenia volantu. Algoritmus bol testovaný na veľkom počte situácií považovaných za kritické na odhad rýchlosti vozidla, ako napríklad prudká akcelerácia na vozovke s nízkym koeficientom trenia, núdzové brzdenie s aktiváciou ABS, či jazda v kopci s kolesami v preklze, prinášajúc uspokojujúce výsledky.
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Tchomgang, Angeline. "Les collisions routières chez les jeunes conducteurs les nuits de la fin de semaine : influence des facteurs humains et de l’environnement routier." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/10524.
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INTRODUCTION : Les jeunes de moins de 25 ans constituent le groupe de conducteurs le plus impliqué dans les collisions routières (CR). L’objectif de cette étude est de déterminer l’importance de certains facteurs humains et de l’environnement routier dans les collisions les nuits de la fin de semaine chez les jeunes conducteurs. Les hypothèses postulent des chances plus élevées de CR les nuits de la fin de semaine, comparativement aux CR survenant à d’autres moments de la semaine, en présence d’un seul facteur de risque et de deux facteurs de risque.
MÉTHODE : Cette étude transversale porte sur les CR ayant causé des blessures légères, graves ou mortelles au Québec chez les conducteurs âgés de 16 à 24 ans. Les informations sur les 58 478 CR survenus de 2007 à 2011 et les facteurs associés à ces CR proviennent de la banque de données de la Société de l’assurance automobile du Québec. Les CR les nuits de la fin de semaine (vendredi à samedi et samedi à dimanche de 20 h 00 à 04 h 59) sont comparées aux CR survenues aux autres moments de la semaine. L’importance des facteurs humains (p. ex., conduite avec capacités affaiblies) et de l’environnement routier (p. ex., courbes) dans ces CR est évaluée à l’aide d’analyses de régression logistique binaire et multinomiale.
RÉSULTATS : Plusieurs facteurs sont liés à une augmentation des chances de CR les nuits de la fin de semaine, comparativement aux autres moments de la semaine. Ces facteurs incluent, par ordre d’importance décroissant : la conduite avec les capacités affaiblies (rapport des cotes ajusté [RCA] = 5,05 et intervalles de confiance à 99 % [IC 99 %] = 4,53‒5,64), la fatigue et le sommeil (RCA = 2,40 ; IC 99 % = 2,12‒2,73), la présence de passagers (RCA = 1,81 ; IC 99 % = 1,69‒1,94), le genre masculin (RCA = 1,36 ; IC 99 % = 1,27‒1,46), les courbes (RCA = 1,21 ; IC 99 % = 1,11‒1,32) et la vitesse (RCA = 1,18 ; IC 99 % = 1,09‒1,28). Les résultats sur la présence de deux de ces facteurs suggèrent l’importance des capacités affaiblies. Les chances de CR sont particulièrement importantes lorsque la présence de capacités affaiblies et d’un autre facteur est comparée à l’absence de ces deux facteurs. Dans ces cas, les chances de CR s’étalent de 5,33 (IC 99 % = 4,40‒6,45) pour la combinaison avec les courbes à 7,68 (IC 99 % = 6,52‒9,05) pour la combinaison avec la présence de passagers.
CONCLUSION : Cette étude a permis de déterminer l’importance de plusieurs facteurs de risque, notamment la conduite avec capacités affaiblies, dans l’implication des jeunes conducteurs dans les CR les nuits de la fin de semaine. Les résultats suggèrent diverses stratégies afin de mieux cibler la conduite avec capacités affaiblies, incluant l’accès graduel à la conduite avec de jeunes passagers la nuit après l’obtention du permis de conduire.Abstract : INTRODUCTION: Young people under 25 represent the group of drivers most involved in motor vehicle crashes (MVC). The aim of this study is to determine the significance of certain human and road environment factors in weekend night crashes involving young drivers. The hypotheses postulate higher odds of crash occurrence on weekend nights, as compared to crashes at other times during the week, when there is the presence of a single risk factor and two risk factors. METHOD: This cross-sectional study examines MVC causing minor, severe or fatal injuries in Quebec drivers aged 16 to 24. The information pertaining to the 58 478 MVC that occurred from 2007 to 2011 and the factors associated with these MVC comes from the databank of the Société de l’assurance automobile du Québec. Weekend night MVC (Friday to Saturday and Saturday to Sunday from 8:00 p.m. to 4:59 a.m.) are compared to MVC occurring at other times of the week. The significance of human factors (e.g., driving under the influence) and road environment factors (e.g., curves) in these crashes is assessed using binary and multinomial logistic regression analyses. FINDINGS: Several factors are associated with the increased odds of an MVC occurring on weekend nights, as compared to other times of the week. These factors include, by order of decreasing significance: driving under the influence (adjusted odds ratio [AOR] = 5.05 and 99% confidence interval [99% CI] = 4.53‒5.64), fatigue and sleep (AOR = 2.40; 99% CI = 2.12‒2.73), presence of passengers (AOR = 1.81; 99% CI = 1.69‒1.94), male gender (AOR = 1.36; 99% CI = 1.27‒1.46), curves (AOR = 1.21; 99% CI = 1.11‒1.32), and speed (AOR = 1.18; 99% CI = 1.09‒1.28). The findings on the presence of two of these factors suggest the significance of driving under the influence. The odds of MVC occurrence are particularly high when the presence of driving under the influence and another factor is compared against the absence of these two factors. In such instances, the odds of MVC occurrence range from 5.33 (99% CI = 4.40‒6.45) when curves are also involved to 7.68 (99% CI = 6.52‒9.05) when passengers are also present. CONCLUSION: This study determined the significance of several risk factors, particularly driving under the influence, in young drivers’ involvement in MVC on weekend nights. The findings suggest various strategies to better target driving under the influence, including gradual access to driving with young passengers at night after obtaining a driver’s licence.
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Urban, Marek. "Návrh zavěšení kol Formule Student." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417557.
Full textAbstract:
Tato práce se se zabývá návrhem kinematiky zavěšení kol obou náprav. Na základě analýz jízdních dat, multi-body simulací v softwaru Adams Car, simulací v Matlabu a analytických kalkulací v Mathcadu, je navržena řada změn s cílem zlepšit jízdní vlastnosti vozu Formule student, tyto změny jsou následně implementovány do CAD modelu vozu. Jednotlivé změny kinematiky náprav jsou provedeny na základě analýzy konkrétního problému, který se snaží řešit. Jednou z problematik je zástavbová náročnost systému odpružení a zavěšení zadních kol, zde je cílem snížit hmotnost, výšku těžiště a moment setrvačnosti. Další problematikou je geometrie předního kola, kde je cílem zlepšit využití pneumatik a snížit síly v řízení. Dále se práce zabývá simulacemi elastokinematiky zadní nápravy, součástí je také návrh měřícího zařízení. V poslední části je zkoumán vliv provedených změn i elastokinematiky na jízdní dynamiku vozu v ustálených stavech za pomocí MM metody simulované s modelem celého vozu v Adams Car a zpracované v Matlabu.
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Mojžíšek, Dominik. "Dynamická analýza koleje." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372123.
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The diploma thesis deals with descriptions of vehicle - track dynamic interface. There are described basic analytical models of railway track. The numerical models are created by using finite element methods with moving load simulated axle of rail vehicle. The aim of thesis is to create the model which most accurately describes the dynamic phenomena in the track. The results from models are compared with data obtained by measuring in the track. Next aim of thesis is to determine dependency of rail cross-sectional characteristics on equivalent rail head wear and then on rail deflection.
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Slaběňák, Patrik. "Analýza elektrických a hybridních vozidel." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219171.
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Nowadays, oil resources start to decrease, therefore it is necessary to think about alternative sources of energy. The result of this semester project is a basic overview of the current development of electric and hybrid cars, with potential application in normal operation and the proximity of their main characteristics, such as mileage, price and service when traveling. The energy required to operate the electric stored in batteries are recharged using the power stations, which is also devoted part of the work. The thesis focuses on the design and calculation of power consumption for a defined route of four-wheel electric wheelchair. The conclusion of the thesis deals with the future development of hybrid and electric vehicles, and with the expected trends in the field of power electronics and motors and with the propagation of hybrid vehicles to the customers.
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Lojková, Lea. "Experimentální metodologie měřicího řetězce." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219052.
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This work is focused on the development of a thorough study about ISO standards focused on the vehicle dynamics, standardized tests of vehicle dynamics and measured variables that allow us to describe and model the behaviour of riding vehicles properly. In the Appendix A of the thesis, there is a list of all known ISO standards dealing with given topic. The standard ISO 15037-1 Road vehicles – Vehicle dynamics test methods, Part 1: General conditions for passenger cars is described in detail, including the forms for test reports and the Appendix C and D. In the thesis, there is also described a model of minimal needed measuring system that is still in good accordance with the standard ISO 15037-1 and fulfills all its requirements. Detailed description of all used sensors that are used to measure required variables is given, as well as a short description of all sensors that are used for measurement of other variables. After that, measurement abilities of the instrumentation of measuring system RIO used in ÚADI FSI Brno is compared and confronted with requirements given by the standard, to see, if all given criteria are properly fulfilled. Because of the fact that standard-given criteria are quite mild, while the equipment of the faculty is high-level technology, mostly made directly for measuring of dynamic parameters of the vehicles, including racing vehicles, the system is in full accordance with the standard ISO 15037-1.
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Patton, Chris. "Development of vehicle dynamics tools for motorsports." Thesis, 2013. http://hdl.handle.net/1957/37361.
Full textAbstract:
In this dissertation, a group of vehicle dynamics simulation tools is developed with two primary goals: to accurately represent vehicle behavior and to provide insight that improves the understanding of vehicle performance. Three tools are developed that focus on tire modeling, vehicle modeling and lap time simulation.
Tire modeling is based on Nondimensional Tire Theory, which is extended to provide a flexible model structure that allows arbitrary inputs to be included. For example, rim width is incorporated as a continuous variable in addition to vertical load, inclination angle and inflation pressure. Model order is determined statistically and only significant effects are included. The fitting process is shown to provide satisfactory fits while fit parameters clearly demonstrate characteristic behavior of the tire.
To represent the behavior of a complete vehicle, a Nondimensional Tire Model is used, along with a three degree of freedom vehicle model, to create Milliken Moment Diagrams (MMD) at different speeds, longitudinal accelerations, and under various yaw rate conditions. In addition to the normal utility of MMDs for understanding vehicle performance, they are used to develop Limit Acceleration Surfaces that represent the longitudinal, lateral and yaw acceleration limits of the vehicle.
Quasi-transient lap time simulation is developed that simulates the performance of a vehicle on a predetermined path based on the Limit Acceleration Surfaces described above. The method improves on the quasi-static simulation method by representing yaw dynamics and indicating the vehicle's stability and controllability over the lap. These improvements are accomplished while maintaining the simplicity and computational efficiency of the two degree of freedom method.Graduation date: 2013
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Wu, Wei-Ting, and 吳維廷. "Direct yaw moment control of Narrow-Tilting Vehicle." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/7gp2y9.
Full textAbstract:
碩士國立臺北科技大學
車輛工程系所
98
The target narrow tilting vehicle is a tricycle with two wheel motors at the rear two wheels. Without the mechanical differential, the traction forces on the right and left wheels cannot coordinate with each other to negotiate the turn. Fuzzy sliding mode control (FSMC) is used to design the direct yaw moment control (DYC) to achieve the yaw rate following for the purpose of electric differential. Work load ratio for both wheels are also balanced to prevent wheel slipping. In addition to prevent rollover during cornering, FSMC is used to design the tilting control to achieve tilting angle tracking. An angle compensation strategy is proposed in this paper to reduce the power consumption for tilting control. Yaw rate generator is modified to be non-minimum to further reduce the initial tilting torque. A nonlinear vehicle model is established using MapleSim to verify the proposed algorithms. Simulation results show that effective yaw rate following can be achieved while preventing the vehicle from rolling over and reducing the required tilting torque.
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Jeng, Jia-fong, and 鄭嘉峰. "Vehicle Rollover Prevention through Model Predictive Direct Yaw Moment Control." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/19835010779876539632.
Full textAbstract:
碩士國立臺灣科技大學
機械工程系
97
The application of differential braking or direct yaw moment control (DYC) for vehicle roll-over prevention receives increasing attentions in recent years. In this research the model predictive control (MPC) technique is employed to design the DYC for rollover prevention. The predictive nature of the MPC resembles human’s vehicle driving characteristics, and is therefore a intuitive choice for the rollover prevention control design. Due to the braking actions resulted from the DYC, the vehicle longitudinal velocity is reduced, and the reduction in vehicle speed causes significant changes in the vehicle dynamics. Therefore, how to incorporate the variation in speed in the MPC design is investigated in this research, and the modified design is evaluated using computer simulations and experiments with a scaled vehicle. The vehicle model, driver model, and the DYC are implemented as mathematical models in MATLAB/SIMULINK. The performance of the controller is evaluated by several sets of simulation scenarios, with different choices of driver models and vehicle speed settings. The simulations indicate that with a proper driver steering control model in the loop, and the internal model used in MPC updated on-line with varying speed, the DYC generates the most appropriate rollover prevention actions. The peak value of roll angle is reduced by approximately 30%, while maintaining slight improvement in lateral position tracking. The other choices may result in degradation in lateral position tracking, or even worsen the rollover motion. The DYC design is also evaluated on a scaled vehicle setup, through a human driver controlling the steering actions. The experimental results indicate that the designed DYC can provide reasonable improvement to rollover prevention under double lane change maneuver.
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Heukelman, B. J., and Brandon Jay Heukelman. "Alternating torsion and bending moment testing of a vehicle rim." Thesis, 2020. https://hdl.handle.net/10539/31229.
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A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Masters of Science in Engineering, 2020The automotive wheel is a fundamental vehicle component connecting the chassis to the road. Understanding the loading mechanism which leads to fatigue failure of a wheel is necessary to design light, safe wheels. This work characterised the strain along the length of spoke for various orientations with respect to the loading direction. Three wheel designs were tested according to the bending moment (cornering) and alternative torsion fatigue test specifications if the TUV and SAE. The results showed that the bending moment fatigue test (which reproduces the loading when cornering) is more critical than the alternating torsion fatigue test (which reproduces the loading when accelerating and decelerating). The bending moment load case produced strains that were on average 32 % higher than the torsion load case. The experimental results were compared to a finite element analysis (FEA) using commercial software (Ansys) and an analysis of the wheel which used Euler-Bernoulli beams and torsional elements of model spokes of the wheel. The FEA underestimated the peak strains 20 %, while the simplified model underestimated the peak strains by 30 %. Both the FEA and simplified model followed the same trend seen in the experimental results. The simplified model was further used to investigate the effect of spoke arrangement on the wheel's efficiency (i.e. the safety factor of the wheel normalised by the mass of the wheel). The model showed that increasing the number of spokes as well as increasing the angle of spoke to the radial increases the factor of safety (even after normalised with respect to mass)
CK2021
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Hung, Ching-Yi, and 洪靜怡. "Nonlinear Fault-Tolerant Scheme with Application to Direct Yaw Moment Control of Electric Vehicles." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/msmujh.
Full textAbstract:
碩士國立交通大學
電控工程研究所
102
This thesis investigates the fault-tolerant output tracking issues for a class of nonlinear uncertain system using a combined scheme. The combined scheme consists of integral sliding mode control (ISMC) technique and control allocation (CA) idea. It is shown that the tracking performance suffering allowable actuator faults can be totally predicted from a preselected dynamics which can be selected according to the system requirements and provides a design degree of freedom. With this scheme, the control structure under different allowable faulty situations remains the same whenever the information of fault is available, so that the complexity of the fault-tolerant controller design is greatly reduced. The analytic results are then applied to the direct yaw moment control of a four-wheel driven electric vehicle. It is shown that the presented fault-tolerant scheme not only can achieve the yaw rate tracking task even when the allowable in-wheel actuators break down, but the tracking performance of allowable faulty situations is also close to that of the preselected error dynamic. Simulation results clearly demonstrate the benefits of the proposed fault-tolerant scheme.
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Murray, William S. (William Scott). "Vehicle dynamic validation and analysis from suspension forces." Thesis, 2012. http://hdl.handle.net/1957/28477.
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Several standardized courses for Formula SAE (FSAE) testing are introduced and
described with sufficient detail to be reproduced by any Formula SAE team. Basic
analysis methods for the courses are given as well as explanations of how those
analyses could be used. On-car data from the Global Formula Racing (GFR) SAE
cars is used to verify the analysis methods, give estimates to unknown variables, and
show the relevance of the standard testing courses. Using the courses and methods
described in this paper should allow standardized comparison of FSAE car
performance, as well as provide a method to verify simulations and evaluate changes
in vehicle performance from tuning.
Instrumentation of all suspension member forces with strain gauge load cells is
shown to be an extremely powerful tool for measuring vehicle performance and
quantifying vehicle dynamic characteristics. The design and implementation of strain
gauge load cells is described in detail to provide a template for reproducing similar
results in other vehicles. Data from the GFR 2011 FSAE car is used throughout the
paper to: show the design process for making effective suspension member load
cells, show the calibration processes necessary to ensure quality data is collected,
illustrate the calculation of suspension corner forces, and show the effectiveness of
measuring vehicle dynamic characteristics with this technique. Using the methods
described in this paper should provide data that allows a more complete and
thorough understanding of on-car vehicle dynamics. This data may be used to
validate vehicle models.Graduation date: 2012