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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.
1

Test platform design and control of a bicycle-type two-wheeled autonomous vehicle

Wang, Xinqi 01 March 2011 (has links)
Bicycle dynamics and behaviors have been vastly studied through modeling and simulation. Due to the complexity, software models are often assumed subjecting to di erent nonholonomic constraints in order to simplify the models and control algorithms. A real life autonomous bicycle faces perturbances from the road, wind, tire deformation, slipping among other external forces. Limitations of simulations will not always allow these to apply. All these issues make the autonomous bicycle research very challenging. To study the bicycle control problems a few research results from the literature are reviewed. A nonlinear bicycle model was used to conduct control simulations. Model based nonlinear controllers were applied to simulate the balance and path tracking control. A PID controller is more practical to replace the non-linear controller for the balance control. Simulation results of the di erent controllers are compared in order to decide the proper control strategies on the hardware platform. The controller design of the platform complies with practicality based on the hardware con guration. Two control schemes are implemented on the test platform; both are developed with PID algorithms. The rst scheme is a single PID control loop in which the controller takes the roll angle feedback and balances the running platform by means of steering. If the desired roll angle is zero the controller will try to hold the platform at the upright position. If the desired roll angle is non-zero the platform will be balanced at an equilibrium roll angle. A xed roll angle will lead to a xed steering angle as the result of balance control. The second scheme is directional control with balance consisting of two cascaded PID loops. Steering is the only means to control balance and direction. To do so the desired roll angle must be controlled to achieve the desired steering angle. The platform tilts to the desired side and steering follows to the same side of the tilt; the platform can then be lifted up by the centrifugal force and eventually balanced at an equilibrium roll angle. The direction can be controlled using a controlled roll angle. Many implementation issues have to be dealt with in order for the control algorithm to be functional. Dynamic roll angle measurement is implemented with complementary internal sensors (accelerometer and gyroscope). Directional information is obtained through a yaw rate gyroscope which operates on the principle of resonance. To monitor the speed of the platform, a rotational sensor was formed by using a hard drive stepper motor attached to the axis of the vehicle's driving motor. The optoelectronic circuit plays the vital role to ensure the system functionality by isolating the electromagnetic noise from the motors. Finally, in order to collect runtime data, the wireless communication is implemented through Bluetooth/RS232 serial interface. The data is then plotted and analyzed with Matlab. Controller gains are tuned through numerous road tests. Field test results show that the research has successfully achieved the goal of testing the low level control of autonomous bicycle. The developed algorithms are able to balance the platform on semi-smooth surfaces. / UOIT
2

An advanced fuel cell simulator

Acharya, Prabha Ramchandra 01 November 2005 (has links)
Fuel cell power generation systems provide a clean alternative to the conventional fossil fuel based systems. Fuel cell systems have a high efficiency and use easily available hydrocarbons like methane. Moreover, since the by-product is water, they have a very low environmental impact. The fuel cell system consists of several subsystems requiring a lot of effort from engineers in diverse areas. Fuel cell simulators can provide a convenient and economic alternative for testing the electrical subsystems such as converters and inverters. This thesis proposes a low-cost and an easy-to-use fuel cell simulator using a programmable DC supply along with a control module written in LabVIEW. This simulator reproduces the electrical characteristics of a 5kW solid oxide fuel cell (SOFC) stack under various operating conditions. The experimental results indicate that the proposed simulator closely matches the voltage-current characteristic of the SOFC system under varying load conditions. Effects of non-electrical parameters like hydrogen flow rate are also modeled and these parameters are taken as dynamic inputs from the user. The simulator is customizable through a graphical user interface and allows the user to model other types of fuel cells with the respective voltage-current data. The simulator provides an inexpensive and accurate representation of a solid oxide fuel cell under steady state and transient conditions and can replace an actual fuel cell during testing of power conditioning equipment.
3

Preliminary design of a 1 kN liquid propellant rocket engine testing platform

Ringas, Nicolas Donovan 27 June 2022 (has links)
This work presents a preliminary design of a liquid rocket engine test platform to support research into liquid propulsion systems and rocket engine components, including injectors, ignition systems, combustion chambers and engine cooling systems. The liquid propellants, specifically liquid oxygen and ethanol, are pressure-fed using gaseous nitrogen. The test platform supports engine thrust values up to 1 kN, as well as varying oxidizer/fuel ratios up to 4.0 and varying ethanol concentrations between 70 and 100%. The test platform will integrate with a mobile control centre, which was designed concurrently, and provides remote control of the test procedures and data acquisition of all relevant pressure, temperature, mass flow and thrust data. The propellant feed assembly can support both cold and hot fire testing campaigns and is equipped with numerous safety features including inert gas purge lines, emergency drain lines and emergency shut-down and de-pressurization procedures.
4

Building a suitable testing-platform to measure impact of typographic effects on web pages

Sjöquist, Joakim January 2020 (has links)
The purpose of this study was to create a testing-platform that mea- sures the impact of typographic effects on web pages. This study chose to focus on highlighted text (text with high contrast background- color) as a typographic tool. The platform is a website, consisting of three (3) pages; (1) the first gathers test user information; (2) the sec- ond (subject-section) records time read and applies an authentication function; (3) the final page provides a multiple-choice questionnaire that records time tested, test score with same authentication method as page two. To test the platform, forty-nine participants were gathered, twenty-five participants (named Group Highlight Text) performed the test with highlight effects turned on and visible in page two (2), the remaining twenty-four (named Group Regular Text) read same page with no effects toggled or visible. Both groups were tested on page three (3) with six questions. The testing-platform fulfilled all expected requirements, with some sections requiring further development. The participation test data revealed some interesting results that could be analyzed further with assistance from social science research. In con- clusion, the test platform successfully recorded viable data that could be used in many fields, but will need additional technical work before being adopted in real-world applications. Further study could be im- plemented in collaboration with researchers from the social sciences to analyze the effects of different typographic effects. Additionally, cre- ate platforms to extract, organize and visualize gathered data would be advantageous.
5

Development and Validation of a Remote-Controlled Test Platform for Bicycle Dynamics

Gabriel, David, Baumgärtner, Daniel, Görges, Daniel 19 December 2022 (has links)
Through the electrification of bicycles, the implementation of new active and passive safety systems becomes possible. Examples for such systems are bicycle ABS, TU Delft - Fall Prevention Bicycle, Bosch Help Connect (eCall System for bicycles), airbag helmets and many others. One of the main difficulties in developing and testing such safety systems is, that test riders should not be exposed to high risks when testing early prototypes. Thus, an automated or remote-controlled test platform for the analysis of bicycle dynamics and for testing of newly developed safety systems could boost the development of such systems and make it safer. The main difficulty when developing such a test platform, which has been addressed in this work, is stabilizing it at low speeds (1.5 m/s - 4.5 m/s) and being capable of tracking a desired yaw rate, only using a steer actuator. In the following, the development of such a test platform is described and first experimental results are presented.
6

Sistema automatizado para ensaio de inversores fotovoltaicos conectados à rede em acordo com normatização brasileira / Automated test system for grid-connected photovoltaic inverter in agreeement with the brazilian standards

Figueira, Henrique Horst 03 August 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This document aims to develop an automated test platform for grid-connected photovoltaic inverters. Therefore, it was conducted a study of European, North American and Brazilian standards related in order to compare the Brazilian standard with respect to the others. A comparison between them with respect to the operating limits is presented. Further, the restrictions are evaluated for each equipment used in the testing of PV inverters certification: CA emulator source emulator PV supply, power analyzer, oscilloscope and flickermeter. Finally, it was developed a software for automation of tests, which is applied for supporting the configuration sources processes, acquisition measures and test report generation. This software is evaluated by obtaining experimental tests, whose results are compared with equivalent obtained through non-automated tests, enabling the validation of the system. / Esse trabalho tem como objetivo desenvolver uma bancada de ensaio automatizado para inversores fotovoltaicos conectados à rede elétrica. Para tanto, se realizou um estudo das normas europeias, norteamericanas e brasileiras relacionadas ao assunto com o propósito de comparar a norma brasileira com relação às demais. Uma comparação entre elas no que tange aos limites de operação é apresentado. Na sequência do trabalho são avaliadas as restrições impostas para cada equipamento utilizado no ensaio de certificação de inversores fotovoltaicos, a destacar: fonte emuladora CA, fonte emuladora FV, analisador de energia, osciloscópio e fliquerímetro. Por fim, é desenvolvido um software para automação dos ensaios que é aplicado para auxílio aos processos de configuração de fontes, aquisição de medidas e geração de relatório. Esse software é avaliado através da obtenção de ensaios experimentais, cujos resultados são comparados com equivalentes obtidos através de ensaios não-automatizados, possibilitando a validação do sistema proposto.
7

Software Testing Platform Development and Implementation / Vývoj a implementace testovací platformy

Burian, Vojtěch January 2012 (has links)
The quality is probably the most significant property of a successful software product. As experience with many software projects has already shown, leaving out testing and quality management from software development process can result in vast and critical customer issues, which usually invoke additional expenses for the software production company. In the course of time, software testing as a discipline has therefore seized an important position among other software development activities. And due to the fact that the software, thanks to rising customer demands and growing competing products portfolio, is getting more complex, the more advanced software testing procedures need to be implemented. Test strategy and iteration planning, implementation of multiple test types into the test suite, test automation, evaluation, administration and maintenance: these activities are commonly required within larger software development projects. Formalized software testing is, nevertheless, being introduced also to projects using agile management techniques which, by management decision or target user industry, are supposed to deliver products of highest quality. This initiates the high focus on the software testing discipline. The purpose of this thesis is to design and implement a new system of software testing within a real project in the CertiCon a.s. company, for which software development is the main business activity. Current issues and gaps for possible improvement, gathered both by project management and the author himself, are analyzed in the first major part of this work and transformed into testing system requirements, which should cover both process changes as well as implementation/development of needed software supporting the process. The second part of thesis is covering the design of the new software testing system, focusing mainly on the area of test management and selection of appropriate software management tool. The final part of the thesis is aimed at implementation of the designed solution within a real organization environment and evaluates its benefits against the previously set requirements.
8

Univerzální platforma pro měření inerciálních a tlakových senzorů / Universal platform for measurement of inertial and pressure sensors

Usnul, Jan January 2017 (has links)
Author describes the creation of software for the initial sensor test platform and controll computer. The platform can measure inertial and pressure sensors regardless their specific type. Measurement is provided by automatic test which is defined by the user. Also, the author describes the creation and implementation of communication protocols between control software (on Windows platform) and test platform (embedded C).
9

Development of an Automated Test Platform for Characterization and Performance Assessment of Electronic Modules in Electric Thrusters : The TESPEMET Project

Pavuluri, Sri Harsha January 2019 (has links)
There has been a sharp increase in the market for electric propulsion systems for small satellites in the recent years. Electric propulsion systems have become smaller, more efficient and cheaper, which made them ideal for small satellites because they have a low thrust requirement and benefit significantly from the high specific impulse (Isp) that is characteristic to electric thrusters. These thrusters are generally fabricated and tested manually and there is a low degree of automation in the process. As the demand for the thrusters increases, there is a need to improve the speed of the fabrication and testing process. The Test Platform for Electronics Modules in Electric Thrusters (TESPEMET) project at ThrustMe is an attempt to design a system that addresses this issue. The vision is to have a test platform that facilitates the testing of ThrustMe's Electric Thrusters by applying various source and load conditions, emulating events while performing instrumentation during the test process and generating a test report at the end of the test procedure. The development of such a test platform would enable and accelerate the test and qualification process of the thrusters significantly. This thesis presents the technical design of this test platform along with the results obtained, encountered problems and solutions. Future work and design changes have also been proposed based on the knowledge gained during the Research and Development process.
10

Metodologie pro návrh číslicových obvodů se zvýšenou spolehlivostí / Methodology of highly reliable systems design

Straka, Martin Unknown Date (has links)
In the thesis, a methodology alternative to existing methods of digital systems design with increased dependability implemented into FPGA is presented, new features which can be used in the implementation and testing of these systems are demonstrated. The research is based on the use of FPGA partial dynamic reconfiguration for the design of fault tolerant systems. In these applications, the partial dynamic reconfiguration can be used as a mechanism to correct the fault and recover the system after the fault occurrence. First, the general principles of diagnostics, testing and digital systems dependability are presented including a brief description of FPGA components and their architectures. Next, a survey of currently used methods and techniques used for the design and implementation of fault tolerant systems into FPGA is described, especially the methods used for fault detection and localization, their correction, together with the principles of evaluating fault tolerant systems design quality.  The most important part of the thesis is seen in the description of the design methodology, implementation and testing of fault tolerant systems implemented into FPGAs which uses SRAMs as the configuration memory. First, the methodology of developing and automated checker components design for digital systems and communication protocols is presented. Then, a reference architecture of a dependable system implemented into FPGA is demonstrated including several fault tolerant architectures based on the use of partial dynamic reconfiguration as the mechanism of fault correction and the recovery from it. The principles of controlling the reconfiguration process are described together with the description of the test platform which allows to test and verify the design of fault tolerant systems based on the methodology presented in the thesis. The experimental results and the contribution of the thesis are discussed in the conclusions.

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