Dissertations / Theses on the topic 'Dual adaptive brake system'

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.22.02 – автомобілі та трактори. Національний технічний університет "Харківський політехнічний інститут". – Харків, 2017. З метою розширення області застосування АБС за рахунок зниження вартості модулятора тиску досліджено процес осциляційної модуляції тиску. Запропоновано конструкцію осциляційного модулятора, який задовольняє всі висунуті до нього вимоги, та доведено можливість його застосування в якості виконавчого елемента у складі дуальних адаптивних гальмівних системах. Порівняльний аналіз відомих способів модуляції тиску в гідравлічному гальмівному приводі показав, що тільки спосіб осциляційної модуляції не вимагає для своєї реалізації дорогих конструктивних елементів (електромагнітних клапанів, насосів, що підкачують, крокових електродвигунів і т.п.), що дозволяє знизити вартість модуляторів при їх застосуванні. Моделювання процесу осциляційної модуляції та лабораторні випробування осциляційного модулятора показали: – принципову можливість осциляційної модуляції у всьому необхідному діапазоні зміни тиску від 0 до 10 МПа; – працездатність запропонованої конструкції модулятора і його відповідність усім пред’явленим до модулятору АБС вимогам. Дослідження роботи осциляційного модулятора у складі дуальної адаптивної гальмівної системи, виконані шляхом моделювання процесу гальмування автомобіля при різних станах дорожньої поверхні та режимах руху підтвердили, що застосування осциляційного модулятора не погіршують показники ефективності гальмування, стійкості і керованості у порівнянні з відомими.
The dissertation on competition of a scientific degree of candidate of technical sciences, speciality 05.22.02 – cars and tractors. National technical university "Kharkiv polytechnic institute". – Kharkiv, 2017. With the of expanding the field of application of anti-block system by reducing the value of the pressure modulator investigated the process of the oscillating modulation of the pressure. The proposed design of the oscillating modulator that meets all applicable requirements and proved the possibility of its use as an clement in the composition of the dual adaptive brake systems. Comparative analysis of the known methods of modulation of the pressure in the hydraulic brake drive showed that the only way of oscillating modulation does not require expensive structural elements (solenoid valves, booster pumps, stepper motors, etc.) that can reduce the cost of modulators in its application. Modeling of oscillating modulation process and laboratory tests of oscillating modulator showed: – principle possibility of oscillating modulation in all the required range of pressure changes from 0 to 10 МПА; – the efficiency of the proposed design of the modulator and its compliance with all requirements to the anti-block system modulator. Research work of oscillating modulator comprising a dual adaptive brake system, made by modeling the process of deceleration of the vehicle under different conditions of road surface and driving conditions confirmed that the application of an oscillating modulator does not degrade the braking efficiency, stability and controllability with the known.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.22.02 – автомобілі та трактори. Національний технічний університет "Харківський політехнічний інститут". – Харків, 2017. З метою розширення області застосування АБС за рахунок зниження вартості модулятора тиску досліджено процес осциляційної модуляції тиску. Запропоновано конструкцію осциляційного модулятора, який задовольняє всі висунуті до нього вимоги, та доведено можливість його застосування в якості виконавчого елемента у складі дуальних адаптивних гальмівних системах. Порівняльний аналіз відомих способів модуляції тиску в гідравлічному гальмівному приводі показав, що тільки спосіб осциляційної модуляції не вимагає для своєї реалізації дорогих конструктивних елементів (електромагнітних клапанів, насосів, що підкачують, крокових електродвигунів і т.п.), що дозволяє знизити вартість модуляторів при їх застосуванні. Моделювання процесу осциляційної модуляції та лабораторні випробування осциляційного модулятора показали: – принципову можливість осциляційної модуляції у всьому необхідному діапазоні зміни тиску від 0 до 10 МПа; – працездатність запропонованої конструкції модулятора і його відповідність усім пред’явленим до модулятору АБС вимогам. Дослідження роботи осциляційного модулятора у складі дуальної адаптивної гальмівної системи, виконані шляхом моделювання процесу гальмування автомобіля при різних станах дорожньої поверхні та режимах руху підтвердили, що застосування осциляційного модулятора не погіршують показники ефективності гальмування, стійкості і керованості у порівнянні з відомими.
The dissertation on competition of a scientific degree of candidate of technical sciences, speciality 05.22.02 – cars and tractors. National technical university "Kharkiv polytechnic institute". – Kharkiv, 2017. With the of expanding the field of application of anti-block system by reducing the value of the pressure modulator investigated the process of the oscillating modulation of the pressure. The proposed design of the oscillating modulator that meets all applicable requirements and proved the possibility of its use as an clement in the composition of the dual adaptive brake systems. Comparative analysis of the known methods of modulation of the pressure in the hydraulic brake drive showed that the only way of oscillating modulation does not require expensive structural elements (solenoid valves, booster pumps, stepper motors, etc.) that can reduce the cost of modulators in its application. Modeling of oscillating modulation process and laboratory tests of oscillating modulator showed: – principle possibility of oscillating modulation in all the required range of pressure changes from 0 to 10 МПА; – the efficiency of the proposed design of the modulator and its compliance with all requirements to the anti-block system modulator. Research work of oscillating modulator comprising a dual adaptive brake system, made by modeling the process of deceleration of the vehicle under different conditions of road surface and driving conditions confirmed that the application of an oscillating modulator does not degrade the braking efficiency, stability and controllability with the known.

In this study, the Dual Beam Phased Array Antenna System designed for COST260* project is upgraded to have the abilities of beam steering, tracking and direction finding by providing the necessary computer codes using C++ Programming Language. The functions of new prototype are tested to verify the operation. *COST260 project was an adaptive phased array receiving antenna system for satellite communication, which was operating at 11.49-11.678 GHz band.

The cells and molecules that comprise the immune system are essential for mounting an effective response against microbes. A successful immune response limits pathology within the host while simultaneously eliminating the pathogen. The key to this delicate balance is the correct recognition of the pathogen and the appropriate response of immune cells. Cellular activation originates through receptors that relay information about the state of the microenvironment to different compartments within the cell. The rapid relay of information is called signal transduction and employs a network of signaling mediators such as kinases, phosphatases, adaptor molecules, and transcription factors. IL-2 inducible T cell kinase (Itk) is a non-receptor tyrosine kinase that is an integral component of signal transduction downstream of many immunoreceptors. This dissertation describes two distinct pathways that utilize Itk in both phases of the immune response. T cells use the TCR to sense a multitude of peptide-based ligands and to transmit signals inside the cell to activate cellular function. In this regard, the diversity of ligands the T cells encounter can be portrayed as analog inputs. Once a critical threshold is met, signaling events transpire in close proximity to the plasma membrane to activate major downstream pathways in the cell. The majority of these pathways are digital in nature resulting in the on or off activation of T cells. We find, however, that altering the TCR signal strength that a T cell receives can result in an analog-based response. Here, the graded expression of a transcription factor, IRF4, is modulated through the activity of Itk. We link this graded response to an NFAT-mediated pathway in which the digital vs. analog nature has been previously uncharacterized. Finally, we demonstrate that the repercussions of an analog signaling pathway is the altered expression of a second transcription factor, Eomes, which is important in the differentiation and function of T cells. These results suggest that Itk is crucial in the modulation of TCR signal strength. Mast cells primarily rely on the IgE-bound FcεR1 for pathogen recognition. Crosslinking this receptor activates mast cells and results in degranulation and cytokine production via an expansive signaling cascade. Upon stimulation, Itk is recruited to the plasma membrane and phosphorylated. Little else is known about how Itk operates inside of mast cells. We find that mast cells lacking Itk are hyperresponsive to FcεR1-mediated activation. This is most apparent in the amount of IL-4 and IL-13 produced in comparison to wild-type mast cells. Increased cytokine production was accompanied by elevated and sustained signaling downstream of the FcεR1. Finally, biochemical evidence demonstrates that Itk is part of an inhibitory complex containing the phosphatase SHIP-1. These results indicate a novel function for Itk as a negative regulator in FcεR1- mediated mast cell activation.

The cells and molecules that comprise the immune system are essential for mounting an effective response against microbes. A successful immune response limits pathology within the host while simultaneously eliminating the pathogen. The key to this delicate balance is the correct recognition of the pathogen and the appropriate response of immune cells. Cellular activation originates through receptors that relay information about the state of the microenvironment to different compartments within the cell. The rapid relay of information is called signal transduction and employs a network of signaling mediators such as kinases, phosphatases, adaptor molecules, and transcription factors. IL-2 inducible T cell kinase (Itk) is a non-receptor tyrosine kinase that is an integral component of signal transduction downstream of many immunoreceptors. This dissertation describes two distinct pathways that utilize Itk in both phases of the immune response. T cells use the TCR to sense a multitude of peptide-based ligands and to transmit signals inside the cell to activate cellular function. In this regard, the diversity of ligands the T cells encounter can be portrayed as analog inputs. Once a critical threshold is met, signaling events transpire in close proximity to the plasma membrane to activate major downstream pathways in the cell. The majority of these pathways are digital in nature resulting in the on or off activation of T cells. We find, however, that altering the TCR signal strength that a T cell receives can result in an analog-based response. Here, the graded expression of a transcription factor, IRF4, is modulated through the activity of Itk. We link this graded response to an NFAT-mediated pathway in which the digital vs. analog nature has been previously uncharacterized. Finally, we demonstrate that the repercussions of an analog signaling pathway is the altered expression of a second transcription factor, Eomes, which is important in the differentiation and function of T cells. These results suggest that Itk is crucial in the modulation of TCR signal strength. Mast cells primarily rely on the IgE-bound FcεR1 for pathogen recognition. Crosslinking this receptor activates mast cells and results in degranulation and cytokine production via an expansive signaling cascade. Upon stimulation, Itk is recruited to the plasma membrane and phosphorylated. Little else is known about how Itk operates inside of mast cells. We find that mast cells lacking Itk are hyperresponsive to FcεR1-mediated activation. This is most apparent in the amount of IL-4 and IL-13 produced in comparison to wild-type mast cells. Increased cytokine production was accompanied by elevated and sustained signaling downstream of the FcεR1. Finally, biochemical evidence demonstrates that Itk is part of an inhibitory complex containing the phosphatase SHIP-1. These results indicate a novel function for Itk as a negative regulator in FcεR1- mediated mast cell activation.

A city is considered as a complex system. It consists of numerous interactivesub-systems and is affected by diverse factors including governmental landpolicies, population growth, transportation infrastructure, and market behavior.Land use and transportation systems are considered as the two most importantsubsystems determining urban form and structure in the long term. Meanwhile,urban growth is one of the most important topics in urban studies, and its maindriving forces are population growth and transportation development. Modelingand simulation are believed to be powerful tools to explore the mechanisms ofurban evolution and provide planning support in growth management. The overall objective of the thesis is to analyze and model urban growth basedon the simulation of land-use changes and the modeling of road networkexpansion. Since most previous urban growth models apply fixed transportnetworks, the evolution of road networks was particularly modeled. Besides,urban growth modeling is an interdisciplinary field, so this thesis made bigefforts to integrate knowledge and methods from other scientific and technicalareas to advance geographical information science, especially the aspects ofnetwork analysis and modeling. A multi-agent system was applied to model urban growth in Toronto whenpopulation growth is considered as being the main driving factor of urbangrowth. Agents were adopted to simulate different types of interactiveindividuals who promote urban expansion. The multi-agent model with spatiotemporalallocation criterions was shown effectiveness in simulation. Then, anurban growth model for long-term simulation was developed by integratingland-use development with procedural road network modeling. The dynamicidealized traffic flow estimated by the space syntax metric was not only used forselecting major roads, but also for calculating accessibility in land-usesimulation. The model was applied in the city centre of Stockholm andconfirmed the reciprocal influence between land use and street network duringthe long-term growth. To further study network growth modeling, a novel weighted network model,involving nonlinear growth and neighboring connections, was built from theperspective of promising complex networks. Both mathematical analysis andnumerical simulation were examined in the evolution process, and the effects ofneighboring connections were particular investigated to study the preferentialattachment mechanisms in the evolution. Since road network is a weightedplanar graph, the growth model for urban street networks was subsequentlymodeled. It succeeded in reproducing diverse patterns and each pattern wasexamined by a series of measures. The similarity between the properties of derived patterns and empirical studies implies that there is a universal growthmechanism in the evolution of urban morphology. To better understand the complicated relationship between land use and roadnetwork, centrality indices from different aspects were fully analyzed in a casestudy over Stockholm. The correlation coefficients between different land-usetypes and road network centralities suggest that various centrality indices,reflecting human activities in different ways, can capture land development andconsequently influence urban structure. The strength of this thesis lies in its interdisciplinary approaches to analyze andmodel urban growth. The integration of ‘bottom-up’ land-use simulation androad network growth model in urban growth simulation is the major contribution.The road network growth model in terms of complex network science is anothercontribution to advance spatial network modeling within the field of GIScience.The works in this thesis vary from a novel theoretical weighted network modelto the particular models of land use, urban street network and hybrid urbangrowth, and to the specific applications and statistical analysis in real cases.These models help to improve our understanding of urban growth phenomenaand urban morphological evolution through long-term simulations. Thesimulation results can further support urban planning and growth management.The study of hybrid models integrating methods and techniques frommultidisciplinary fields has attracted a lot attention and still needs constantefforts in near future.

QC 20130514

Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.05.06 – гірничі машини. – Державний вищий навчальний заклад «Національний гірничий університет» Міністерства освіти і науки, молоді та спорту України, Дніпропетровськ, 2013.
Диссертация на соискание учетной степени доктора технических наук по специальности 05.05.06 – горные машины. – Государственное высшее учебное заведение «Национальный горный университет» Министерства образования и науки, молодежи и спорта Украины, Днепропетровск, 2013.
У дисертаційній роботі розв'язана актуальна наукова проблема обґрунтування методів управління силою тертя в робочих процесах гальма за величиною і у функції швидкості ковзання, показниками ефективності гальма та гальмування рухомого складу рейкового транспорту шахт на основі ідентифікації спільного збудження кінематично вимушених коливань за рахунок дискретності і конструктивних зв'язків контакту тертя з фрикційними коливаннями, застосування адаптивного механізму змінної структури гальма і варіаційного формулювання у вигляді квазіваріаційної нерівності нелінійної динамічної задачі з тертям.
Система подземного транспорта при развитии подразумевает объединение преимуществ рельсового и конвейерного транспорта. Электровозная откатка относится к объектам с наиболее благоприятными предпосылками роботизации. Внедрение робототехнического комплекса откатки наиболее эффективно в магистральных выработках с интенсивными грузопотоками от очистных и подготовительных работ, кольцевой схемой движения, погрузкой и разгрузкой состава по ходу и требует оптимизации эффективности тяги и торможения поездов. На шахтных локомотивах, где размещается тормозное оборудование поезда, за счет изменения силы трения тормозного механизма от скорости движения и тормозного нажатия мощность его при скорости начала торможения 3 м/с уменьшается в 3 раза, при 5 м/с – 11 раз. В диссертационной работе решена научная проблема обоснования методов управления силой трения в рабочем процессе тормоза по величине и в функции скорости скольжения, показателями эффективности тормоза и торможения подвижного состава рельсового транспорта шахт на основе идентификации совместного возбуждения кинематически вынужденых колебаний за счёт дискретности и конструктивных связей контакта трения с фрикционными колебаниями, применения адаптивного механизма переменной структуры тормоза и вариационной формулировки в виде квазивариационного неравенства нелинейной динамической задачи с трением. Функционально-морфологический анализ позволяет классифицировать структуру тормоза с напряженным замкнутым кинематическим контуром, в ко- тором тормозная передача относится к неассуровым группам отрицательного порядка, тормоз является адаптивным механизмом с переменной структурой, структурно-неопределенной трибологической системой и обладает видом структурной неопределенности по количеству и составу входных переменных в моделях зависимости силы (коэффициента) трения. Разработана регрессионная модель кинетической характеристики трения колодочно-колесного тормоза шахтных локомотивов в условиях структурной неопределенности. Задача регрессионного анализа поставлена в широком смысле. Выполнен спектральный анализ усилий и перемещений масс в тормозном механизме, экспериментально определены спектрограммы виброперемещений тормозной колодки и переменных составляющих нормальных и тангенциальных усилий нагружения тормозного механизма. Частота и амплитуда высоко- частотных колебаний до 1 кГц изменяется в зависимости от параметров тормозного режима, упругих и диссипативных сил нагружения, что в состоянии тормоза выражается изменением коэффициентов регрессии в статистической модели характеристики трения тормоза. Разработаны основные положения теории тормозной колодки для определения структуры и параметров динамической модели тормозного механизма, измерительного и обрабатывающего комплекса аппаратуры. Разработана математическая модель тяги и движения шахтных поездов с учетом неравнозамедленного движения при торможении. Для идентификации исследуемого состояния управляемого движения шахтных поездов выполнено решение задачи классификации, в которой из двух совокупностей показателей тяги и торможения построено классификационное правило, позволяющее установить технический уровень подвижного состава по принадлежности к одной совокупности. Для интегральной оценки использования сцепной массы локомотива при торможении шахтных поездов на остановку определен коэффициент полезного действия тормоза. Разработаны динамические модели тормоза с учетом дискретности контакта поверхности трения тормозной колодки, конструктивных связей и распределения усилий по шероховатым поверхностям, установившихся и неустановившихся режимов движения. Вариационная формулировка в виде квазивариационного неравенства колебательной системы при использовании разностных схем позволяет получить при определенных значениях весовых коэффициентов решения нелинейной динамической задачи с трением. Экспериментальными методами периодических и промышленных испытаний шахтного подвижного состава с использованием планирования экспериментов и статистического моделирования для идентификации параметров и состояний динамических моделей тормоза и математической модели тяги и движения шахтных поездов получены тягово-энергетические и виброшумовые характеристики локомотивов, расчетные нормативные значения ходовых качеств вагонов. Классификация показателей назначения тормоза, алгоритм и программное обеспечение для моделирования тяги и движения шахтных поездов, метод определения технического уровня подвижного состава по эффективности тяги и торможения позволяет повысить производительность и безопасность локомотивного транспорта и расширить область применения на профиле пути от 0,005 до 0,050. Разработан алгоритм и программное обеспечение моделирования фрикционных колебаний в тормозе для управления силой трения по величине и в функции скорости движения, что позволяет получить рабочие характеристики в соответствии с его назначением, повысить КПД и надежность тормоза. Результаты работы внедрены в отраслевой стандарт Минуглепрома Украины СОУ 10.1.00155790.007:2006, нашли практическое использование на ОАО «Дружковский машзавод» и ДонУГИ при разработке и испытаниях опытных образцов электровозов АРВ10ГЭ, АВ8Т и АП8Т с гидротормозной системой и внедрены в учебный процесс при подготовке специалистов по специальностям «Горное оборудование» и «Разработка месторождений полезных ископаемых» в Государственном ВУЗ «Национальный горный университет». Внедрение результатов работы имеет социальный эффект за счет повышения технического уровня, надежности и безопасности локомотивной откатки на нормальном и тяжелом профиле рельсового пути.
The dissertation has solved burning scientific problem of justifying methods of control of frictional force under the exploitation conditions of brake in magnitude, and as a function of slipping motion velocity, measures of mine rail haulage brake efficiency as well as its braking on the basis of identifying general excitation of kinematically forced oscillations owing to dimensional resolution and ratio of friction contact and friction oscillations; use of adaptive mechanism of shiftable structure and variational definition in terms of quasivariational inequality of nonlinear dynamic problem with friction.

碩士
大葉大學
車輛工程學系碩士班
96
This study established the integration technology and methodology for vehicle Adaptive Cruise Control (ACC) active brake control subsystems. Experimental data including the brake pedal position and force, master and slave cylinder pressure and travel were incorporated to build and to validate the active brake system dynamic model developed by object oriented software Matlab/Simulink®. The brake system dynamic simulation model was integrated to the vehicle longitudinal dynamic program to calculate the vehicle deceleration response to the active brake and driver brake command. The slave cylinder brake pressure from each wheel simulated and measured can then be used to calculate the resulting brake force and the corresponding vehicle deceleration which can be later validated. The developed vehicle dynamic model considered the variation of brake force of the front and rear wheels in ACC vehicle. Since the ACC system requires vehicle follow the preceding vehicle with a safe distance on either straight line or turning drive condition, the active brake and radar signal must integrated to assure their performance can satisfy the requirement of ISO 15622 ACC system standard. This integration methodology can reduce the time and expanse for establishing the research and development capacity for ACC system and active brake controller thus increase the vehicle safety and reliability.

碩士
國立屏東科技大學
車輛工程系碩士班
93
This thesis addresses the problem of controlling a vehicle motion system by continuously adjusting the brake torque. In order to satisfy these specifications, firstly a deceleration trajectory must be planned, before the controller desired. At braking process, the vehicle velocity and deceleration will track the trajectory. An full-order model which consists of the vehicle motion subsystem, wheel dynamics, and servo hydraulic dynamics is under consideration. There are two kinds of design scenarios proposed in this thesis. In the first type of scenario is to design the controllers separately according to two dynamic conditions which are arising from different values of slip ratio. Then these two separately designed controllers are incorporated based on fuzzy concept. For the second controller design, besides, the different dynamic models stemming from different road conditions are first merged using TSK model approximation method. On the basis of the developed model, an adaptive sliding model control scheme is then proposed. After the mechanical part of the full-order system is achieved. The controller for hydraulic counterpart is finally fimished by adopting adaptive control approach. Lyapunov functions for the two types of control are proposed to guarantee the asymptotical stability of the vehicle motion systems. To demonstrate the validity of the design, several simulations are also performed and discussed.

碩士
南台科技大學
機械工程系
93
The requirements of high speed and high accuracy become more demanding in the trend of industry development. Positioning systems of high accuracy and great tracking performance, such as X-Y stages in wafer transportation, play an important role therewith. Such a system can be realized by a magnetic levitation (maglev) stage, driven by voice coil motors (VCM). The magnetic levitation endows it with the contact-free characteristics, which makes it suitable in clean room and vacuum operation. Nevertheless, the controller used must be robust enough in the presence of uncertainties. Therefore, we first build a model of a dual-axis maglev system, for which we design a suitable controller to meet the requirements of high tracking performance. Both backstepping method and sliding mode control are used for comparison. Finally, direct adaptive control laws are implemented into either controller to ensure sufficient robustness to parameter variation. Convergence is guaranteed since every controller is derived using the Lyapunov stability theorem. The MATLAB simulation demonstrates that the dual-axis maglev system settles very fast with negligible errors for arbitrary trapezoidal trajectories using any of the proposed adaptive controllers.

碩士
國立臺灣大學
工程科學及海洋工程學研究所
106
This paper presents a dual-microphone method based on the Microphone Array theorem, which develops a system that can be applied to a microphone device for communication purposes. The main purpose is to eliminate the ambient noise and the echo of the speaker due to time delay (Come from one''s own way or each other) ,in order to create a more comfortable communication environment. Least Mean Squares filter(LMS filter), Normalized Least Square filter(NLMS filter) and Recursive Least Square filter(RLS filter) are used with deep learning to find the most suitable parameters and algorithm to optimize the anti-noise effect. To compare with a method which is the more intuitive way to eliminate noise, we call it''s ingle microphone method" in this paper. In the anti-noise system, the filter works mainly through two pairs of relevant signals to match, find and eliminate the noise part of the noise, and the greater the correlation between the more accurate, the more accurate to find Out of the noise section. Compared to the single-microphone method, the dual-microphone method is used to compare the two signals because of the same space and the time difference is extremely short, so the correlation is large, can more effectively find the noise and eliminate. The default of the study is the case of remote meetings, during communication, sometimes the both sides speak at the same time. At this point the microphone will receive our voice, as well as the sound of dialogue that comes from the speaker of communication equipment. After the transmission the other party will receive our message and their own echo, both sounds mixed together makes the signal blurred, so the communication cannot proceed smoothly. This article calls this situation as "Double Talk" which cause the communication interference. The dual-microphone device is used to solve such problems. The results of the experiment can be proved that the dual-microphone method has good results in dealing with the call, whether it is single talk or double talk, after the treatment by the dual-microphone system can effectively anti-noise.

碩士
國立中正大學
電機工程所
94
In the modern society, the number of old people is gradually raised, the teenagers are used to personal stereo earphones, and the hearing lose of the newborns is still out of control. All of these factors contribute to the continuously increase in the need of hearing aids. To those Dysaudia patients who can't be clinically treated but still has remaining hearing, they can improve the hearing ability by wearing hearing aids. For the hearing aid researchers, “noise＂ has always been a problem to solve. In real life, background noise always interferes the ability of people to distinguish and understand the voice, this kind of interference is even more severe to the hearing loss patients. In daily life, background noise includes not only the wideband noise but also the sinusoidal noise, such as ventilating fan or engine noise. In recent years, dual microphone system has been widely used on digital hearing aids. This paper proposes two dual-input noise cancellation systems based on ANC and ALE, each of which corresponds to different background noise. By using these two systems, we can eliminate the background noise from the signal. The noise-elimination power of the two systems are compared in the study. In low SNR experiments(-20～0 dB SNR), the average SNR of system II improves 7.56 dB, while system I only improves 6.96 dB. Moreover system I outperforms system II in reducing sinusoidal noise, while System II has better performance in more complex noisy environments. Therefore, we can conclude that system II has better iii average performance, but an suitable scheme may be suggested to switch the hearing aid in different mode to cope with different noise types.

碩士
國立東華大學
電機工程學系
94
Wide-band CDMA is a promising technique in the third generation cellular system. The 3GPP WCDMA system is an essential standard in the third generation mobile system, which includes the Frequency Division Duplex (FDD) operational mode and the Time Division Duplex (TDD) operational mode. In this thesis, we propose a dual-mode channel estimation architecture for the 3GPP WCDMA system. The proposed dual-mode architecture contains an adjustable digital filter, a velocity estimator, and a control unit. The adjustable digital filter and the velocity estimation are used to adaptively estimate the channel impulse response. The control unit is utilized to make the switch of the FDD mode and the TDD mode. We evaluate the proposed dual-mode channel estimation architecture by computer simulations. The BER performance and the statistical mean square error are presented in this thesis. According to the simulation results, the dual-mode channel estimation architecture performs well under different channel conditions. The dual-mode channel estimation architecture has low complexity for the dual-mode WCDMA receiver design.

碩士
國立成功大學
系統及船舶機電工程學系碩博士班
100
This thesis presents an adaptive vehicle rotate angle system using dual MEMS inertia sensor, which can apply to underwater environment. The system consist of vehicles rotate angle estimation module and driving module. The angle estimation module calculate the vehicle steering angle model by the two accelerometers. The design of vehicle steering angle model can be divided into three parts, including the roll angle correction method, turning radius calculation method and driving module rotate angle. Turning roll angle correction method calibrate the influence of gravity in centripetal acceleration by the accelerometer multi-axis sensing characteristics. Turning radius calculation method calculate the turning radius by the difference value between two accelerometers distance. The rotate angle and maximum rotate angle of driving module is calculated by illuminating distance, light angle and Turning radius. Driving module is composed of two core components: symmetrical piezoelectric element and trussed preload structure which can improve the general linear preload track design into torque track design. The truss structure utilized a triangular structure to provide a normal force as preload. The software LabVIEW is used to control the adaptive vehicle rotate angle system, and link up driving module and vehicle rotate angle estimation module. The design of active vehicle rotation angle estimation system could be combined with the lighting design and camera, the concept and has been estimated in various applications, such as adaptive front lighting system and unmanned aerial vehicle or autonomous underwater vehicle camera.

碩士
國立成功大學
系統及船舶機電工程學系
104
This proposal presents an adaptive vehicle rotate angle system using dual micro-inertial sensor, which can apply to underwater environment. The system consists of vehicle rotate angle estimation module and PZT driving module to form adaptive front LED lighting system. Driving module is composed of two core components: symmetrical piezoelectric element and trussed preload structure. The design of the symmetrical piezoelectric element is utilizing the finite element analysis to simulate its motion characteristics, in order to get the fixed point and the driving point. The piezoelectric actuator of the preload structure design improves the general linear preload track type into torque track type, to further simplify the linear preload track into rotation track and introduce the truss structure component concept to ameliorate preload skew problem, and design a triangular truss-type preload mechanism, and then to integrate with SPE as a driving module. Finally realizing the active dynamic feedback sensing concept and enhance AUV or ROV in underwater exploration technology capability.

碩士
國立交通大學
電機與控制工程系所
97
In this paper, a sub-1V input single-inductor dual-output (SIDO) DC-DC converter with an adaptive load-tracking control (ALTC) technology is proposed for single-cell-powered portable devices. Through the minimized number of switch and the optimum current sequence, the ALTC technique adaptively and accurately adjusts storage energy in form of inductor current according to the actual load condition without wasting surplus charge and increasing cross-regulation. Moreover, a current-mode ring oscillator with a self-bias current source (SBCS) circuit is proposed to replace the conventional startup ring oscillator to produce a nearly constant system clock. Owing to the proposed current-mode ring oscillator operates in the startup process and steady-state of SIDO DC-DC converter, a simplified design efficiently addresses high switching frequency losses at startup process and reduces chip area and power consumption. The proposed sub-1V input SIDO DC-DC converter was fabricated by TSMC 0.25 μm 2.5 V/5 V BCD process and the experimental results show a high efficiency of 92 % and a good cross-cross regulation smaller than 10 mV.

Process variations and circuit aging continue to be main challenges to the power-efficiency of VLSI circuits, as considerable power budget must be allocated at design time to mitigate timing variations. Modern designs incorporate adaptive techniques for variation compensation to reduce the extra power consumption. The efficiency of existing adaptive approaches, however, is often significantly attenuated by the fine-grained nature of variations in nanometer technology such as random dopant fluctuation, litho-variation, and different rates of transistor degradation due to non-uniform activity factors. This dissertation addresses the limitations from existing adaptation techniques, and proposes new adaptive approaches to effectively compensate the fine-grained variations. Adaptive supply voltage (ASV) is one of the effective adaptation approaches for power-performance tuning. ASV has advantages on controlling dynamic and leakage power, while voltage generation and delivery overheads from conventional ASV systems make their application to mitigate fine-grained variations demanding. This dissertation presents a dual-level ASV system which provides ASV at both coarse-grained and fine-grained level, and has limited power routing overhead. Significant power reduction from our dual-ASV system demonstrates its superiority over existing approaches. Another novel technique on supply voltage adaptation for variation resilience in VLSI interconnects is proposed. A programmable boostable repeater design boosts switching speed by raising its internal voltage rail transiently and autonomously, and achieves fine-grained voltage adaptation without stand-alone voltage regulators or additional power grid. Since interconnect is a widely recognized bottleneck to chip performance and tremendous repeaters are employed on chip designs, boostable repeater has plenty of chances to improve system robustness. A low cost scheme for delay variation detection is essential to compose an efficient adaptation system. This dissertation presents an area-efficient built-in delay testing scheme which exploits BIST SCAN architecture and dynamic clock skew control. Using this built-in delay testing scheme, a fine-grained adaptation system composed of the proposed boostable repeater design and adaptive clock skew control is proposed, and demonstrated to mitigate process variation and aging induced timing degradations in a power as well as area efficient manner.

The low latitude tropical ionosphere has been investigated by various researchers using Global Positioning System (GPS). Presently for many civil aviation applications, the ionospheric modeling of the tropical region has gained importance, in particular for flight safety. Since ionosphere is dispersive in nature, dual frequency (L1 = 1575.42 MHz and L2 = 1227.60 MHz) GPS observations can be used to obtain Ionospheric Total Electron Content (TEC). Since TEC varies with local time and geomagnetic latitude, an Ionospheric Modeling Technique using spatial linear approximation of vertical TEC over receiver station has been implemented following Sardon et al. The effects of all the systematic errors due to the satellite plus the receiver (SPR) instrumental biases can reach upto several nanoseconds. (1 TEC is 1016 electrons/m2, 1 ns = 2.86 TEC and 1 TEC = 0.16 m). Hence, to have an accurate estimation of ionospheric TEC, the instrumental biases must also be estimated. This thesis describes a heuristic adaptive Kalman Filtering scheme developed to estimate the TEC, the constants in the linearisation scheme, as well as the above total instrumental biases. The Kalman filter implementation is basically an optimization problem of minimizing the Cost Function J based on the difference between the model output and the measurement, called as the ‘innovation’, scaled by its covariance. In order to obtain the best possible results using the Kalman Filter approach, it is essential to provide appropriate values for the initial state, process and measurement noise covariances (P0, Q and R) respectively, which in general may not be known. Usually manual tuning of the filter parameter is carried out without using the above cost function J! The filter estimates can be highly sensitive to the above chosen statistics and thus these will have to be estimated carefully. Hence, we have utilized the Adaptive Kalman Filtering procedure of Myers and Tapley extended by Gemson and Ananthasayanam. The minimization is carried out by simultaneously estimating the above statistics and the unknown parameters, which include the TEC and the instrumental bias. In addition, A Constant Gain Kalman Filter approach using Genetic Algorithm (GA) has also been developed for the above requirement. It is observed that the steady state gains in KF and AKF approaches are in good match with the constant gains obtained from Genetic Algorithm. Using the above Adaptive Kalman Filtering technique and Constant Gain Kalman Filter approach, vertical TEC values and SPR biases have been estimated from the IGS receiver observations stationed at ISTRAC/ISRO, Bangalore, India. A diurnal TEC variation over Bangalore for a period of one year for 2003 and January 2004 is estimated and reported in this thesis. This approach has also been applied to study the behaviour of the ionosphere over low latitude IGS station at Fortaleza, Brazil data during the great magnetic storm on the 15th July 2000 and the results were found to be consistent with the results of Basu et al. In addition, Using Constant Kalman filter, the TEC enhancement over Indian region has been estimated for the October 2003 Ionospheric storm, and the results were found to be consistent with the reported results in the literature.