Дисертації з теми "Invariance to external perturbations"

Диссертация на соискание ученой степени кандидата технических наук по специальности 05.13.03 – системы и процессы управления. – Национальный технический университет "Харьковский политехнический институт", Харьков – 2016. Диссертация посвящена разработке аналоговых и цифровых инвариантных систем наведения и стабилизации основного вооружения танков на основе создания математических моделей возмущенного движения танковой пушки относительно оси цапф и танковой башни с пушкой относительно оси поворота, а также имитационных моделей внешних возмущений, действующих на основное вооружение в каналах вертикального и горизонтального наведения. Показано, что повышение степени инвариантности замкнутой системы стабилизации к действию внешних возмущений, за счет объединения в стабилизаторе двух основных принципов управления – принципа управления по отклонению и принципа управления по возмущению, приводит к снижению запаса устойчивости замкнутой системы. Для сохранения требуемого запаса устойчивости предложено введение в систему дополнительного контура обратной связи по угловому ускорению объекта стабилизации. С использованием метода гармонической линеаризации нелинейностей решена задача отыскания амплитуд и частот автоколебаний рамок гироскопической платформы, используемой в качестве гироскопического датчика углов отклонения оси канала ствола танковой пушки от линии прицеливания, а также автоколебаний давления рабочей жидкости в гидросистеме стабилизатора канала вертикального наведения. Показано, что причиной возмущения автоколебаний в первом случае является нелинейная характеристика системы разгрузки гироплатформы и "сухое" трение в осях кардановых подвесов, а во втором случае – нелинейные характеристики предохранителей гидроклапанов. Сделан вывод о том, что такие автоколебания являются высокочастотной помехой, приводящей к снижению помехозащищенности замкнутой системы наведения и стабилизации. Рассмотрены особенности цифровой инвариантной системы стабилизации наведения и стабилизации танковой пушки, в частности, необходимость использование цифровых низкочастотных фильтров Баттеруорта и Ланцоша для фильтрации высокочастотных помех выходных сигналов датчиков. Доказано, что при построении цифрового стабилизатора танковой пушки целесообразно последовательно-параллельное использование цифровых фильтров Баттеруорта и Ланцоша. Разработана структура и осуществлен выбор варьируемых констант алгоритмов стабилизации, обеспечивающих инвариантность замкнутой системы наведения и стабилизации без существенного снижения её запаса устойчивости. Моделирование процессов наведения и стабилизации в замкнутой системе с последующим анализом этих процессов позволяет сделать вывод о значительном повышении точности отработки внешнего возмущения (в 1.8 – 1.9 раз) по сравнению со штатной.
The thesis for the degree of candidate of technical sciences, specialty 05.13.03 – Systems and management processes. – National Technical University "Kharkov Polytechnic Institute", Kharkov – 2016. The thesis is dedicated to development analog and digital invariant guidance systems and stabilize the main armament of tanks through the creation of mathematical models perturbed motion tank gun relative to the axis of the pins and the tank tur ret gun relative to the axis of rotation, as well as simulation models of external disturbances acting on the main armament channels vertical and horizontal guidance. It is shown that increasing the degree of invariance closed stabilization system to external perturbations lead to lower stability margin closed system. To maintain the desired stability margin suggested the introduction of the system of additional feedback path for the angular acceleration of the object of stabilization. The features invariant digital stabilization system tank gun, including the need to use a digital low-pass filter Batteruorta and Lanczos filtering high frequency noise output signals of sensors. It is proved that the construction of a digital stabilizer tank cannon appropriate series-parallel use of digital filters Batteruorta and Lanczos. The structure created and the choice of variable constants stabilization algorithms was made that provide an invariance closed system of guidance and stabilization without significantly reducing its stability margin. Modeling of guidance and stabilization in a closed system with subsequent analysis of these processes suggests a significant increase in accuracy working off of external perturbation (at 1.8 – 1.9 times) compared with the standard.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.13.03 – системи і процеси керування. – Національний технічний університет "Харківський політехнічний інститут", Харків, – 2016. Дисертація присвячена розробці аналогових і цифрових інваріантних систем наведення і стабілізації основного озброєння танків на основі створення математичних моделей збуреного руху танкової гармати відносно вісі цапф і танкової башти з гарматою відносно вісі повороту, а також імітаційних моделей зовнішніх збурень, що діють на основне озброєння в каналах вертикального і горизонтального наведення. Показано, що підвищення ступеня інваріантності замкненої системи стабілізації до дії зовнішніх збурень приводить до зниження запасу стійкості замкненої системи. Для збереження потрібного запасу стійкості запропоновано введення до системи додаткового контуру зворотнього зв'язку за кутовим прискоренням об'єкту стабілізації. Розглянуті особливості цифрової інваріантної системи стабілізації танкової гармати, зокрема необхідність використання цифрових низькочастотних фільтрів Баттеруорта і Ланцоша для фільтрації високочастотних завад вихідних сигналів датчиків. Доведено, що при побудові цифрового стабілізатора танкової гармати доцільне послідовно-паралельне використання цифрових фільтрів Баттеруорта і Ланцоша. Розроблена структура і здійснений вибір варійованих констант алгоритмів стабілізації, які забезпечують інваріантність замкненої системи наведення і стабілізації без суттєвого зниження її запасу стійкості. Моделювання процесів наведення і стабілізації в замкненій системі з подальшим аналізом цих процесів дозволяє зробити висновок про значне підвищення точності відробки зовнішнього збурення (в 1.8 – 1.9 рази) у порівнянні зі штатною.
The thesis for the degree of candidate of technical sciences, specialty 05.13.03 – Systems and management processes. – National Technical University "Kharkov Polytechnic Institute", Kharkov – 2016. The thesis is dedicated to development analog and digital invariant guidance systems and stabilize the main armament of tanks through the creation of mathematical models perturbed motion tank gun relative to the axis of the pins and the tank tur ret gun relative to the axis of rotation, as well as simulation models of external disturbances acting on the main armament channels vertical and horizontal guidance. It is shown that increasing the degree of invariance closed stabilization system to external perturbations lead to lower stability margin closed system. To maintain the desired stability margin suggested the introduction of the system of additional feedback path for the angular acceleration of the object of stabilization. The features invariant digital stabilization system tank gun, including the need to use a digital low-pass filter Batteruorta and Lanczos filtering high frequency noise output signals of sensors. It is proved that the construction of a digital stabilizer tank cannon appropriate series-parallel use of digital filters Batteruorta and Lanczos. The structure created and the choice of variable constants stabilization algorithms was made that provide an invariance closed system of guidance and stabilization without significantly reducing its stability margin. Modeling of guidance and stabilization in a closed system with subsequent analysis of these processes suggests a significant increase in accuracy working off of external perturbation (at 1.8 – 1.9 times) compared with the standard.

Mechanisms underpinning motor control of standing balance post-stroke remain unclear. Following stroke, ankle plantarflexor muscles demonstrate impairment associated with asymmetrical postural control and decreased balance. Stroke also results in increased attentional demands during challenges to standing balance. This thesis examined motor control impairment post-stroke from medial gastrocnemius motor units to the tri-muscle plantarflexor complex. Investigation of motor, kinematic and kinetic parameters of postural control during external perturbations in standing and associated levels of physiological arousal have furthered understanding of balance impairment post-stroke. Methods: Medial gastrocnemius motor units were recorded in controls (Chapter 2) and people post-stroke (Chapter 3) in standing as perturbations were sequentially applied at the pelvis under conditions of increased anteriorly-directed challenge. In both studies, motor unit firing rate was calculated during dynamic response to perturbation, and maintenance of steady state between perturbations. Joint kinematics, surface electromyography and movements of the centre of pressure were assessed. In Chapter 4, this methodology was expanded to cross-correlation analysis of electromyography activity of the three plantarflexor muscles with anterior-posterior centre of pressure during steady state. In Chapter 5, attentional demands surrounding timing of external perturbation were manipulated to investigate effects of stroke on physiological arousal and postural reactions. Results: In healthy subjects, medial gastrocnemius utilized primarily motor unit recruitment to maintain standing with a modest increase in motor unit firing rate only during the dynamic response to external perturbations. The paretic medial gastrocnemius also primarily used motor unit recruitment; however, lacked firing rate modulation during the dynamic response, albeit firing rate was related to kinematic variables of postural control. In people post-stroke, the three plantarflexors demonstrated asymmetrical motor control of postural sway between-legs but symmetry was improved under conditions of increased challenge to standing balance. Finally, knowledge of timing of perturbations did not decrease the heightened anticipatory postural strategy and level of physiological arousal exhibited post-stroke. Conclusions: This dissertation provides new understanding of motor control of standing balance post-stroke and reveals anticipatory postural strategies adopted post-stroke under conditions challenging balance. These findings implicate the importance of introducing challenge to standing balance post-stroke in the assessment and rehabilitation of postural control post-stroke.
Medicine, Faculty of
Graduate

In this project we have used Fourier transform infrared spectroscopy to study the photoresponse of two different types of quantum dot-in-a-well infrared photodetectors (DWELL QDIPs). The basic task was to compare the photoresponse of these two detectors, and to study the influence of external resonant laser pumping on the photoresponse. Series of measurements were done at 77K. In the first measurements we investigated the photoresponse for different applied voltages at 77K.

In a second run of experiments, we used a 1064 nm infrared semiconductor laser to resonantly

pump the fundamental transition of the quantum dots. The results show that by using this

additional illumination the photoresponse was dramatically increased by creating additional

charge carriers in the quantum dots. This could be used to increase the sensitivity of infrared

detectors based on QDs.

Let X be a real reflexive locally uniformly convex Banach space with locally uniformly convex dual space X* . Let G be a bounded open subset of X. Let T:X⊃ D(T)⇒ 2X* be maximal monotone and S: X ⇒ 2X* be bounded pseudomonotone and such that 0 notin cl((T+S)(D(T)∩partG)). Chapter 1 gives general introduction and mathematical prerequisites. In Chapter 2 we develop a homotopy invariance and uniqueness results for the degree theory constructed by Zhang and Chen for multivalued (S+) perturbations of maximal monotone operators. Chapter 3 is devoted to the construction of a new topological degree theory for the sum T+S with the degree mapping d(T+S,G,0) defined by d(T+S,G,0)=limepsilondarr 0+ dS+(T+S+ J,G,0), where dS+ is the degree for bounded (S+)-perturbations of maximal monotone operators. The uniqueness and homotopy invariance result of this degree mapping are also included herein. As applications of the theory, we give associated mapping theorems as well as degree theoretic proofs of known results by Figueiredo, Kenmochi and Le. In chapter 4, we consider T:X D(T)⇒ 2X* to be maximal monotone and S:D(S)=K⇒ 2X* at least pseudomonotone, where K is a nonempty, closed and convex subset of X with 0isinKordm. Let Phi:X⇒ ( infin, infin] be a proper, convex and lower-semicontinuous function. Let f* isin X* be fixed. New results are given concerning the solvability of perturbed variational inequalities for operators of the type T+S associated with the function f. The associated range results for nonlinear operators are also given, as well as extensions and/or improvements of known results by Kenmochi, Le, Browder, Browder and Hess, Figueiredo, Zhou, and others.

On considère l'évolution adiabatique des états vitreux sous perturbations extérieures. Bien que le formalisme que nous utilisons soit très général, nous nous concentrons ici sur les sphères dures en dimension infinie où une analyse exacte est possible. Nous considérons perturbations de la frontière, notamment compression ou cisaillement simple et nous calculons la réponse des états vitreux à ces perturbations : pression et contrainte de cisaillement. Nous constatons un dépassement des deux quantités avant que l'état vitreux ne devienne instable à un point spinodal, où il fond dans le liquide (ou cède). Nous estimons également la limite d'élasticité du verre. Enfin, nous étudions la stabilité des bassins vitreux vers la rupture en sous-bassins, correspondant à une transition de Gardner. Nous constatons que près de la transition dynamique, les verres subissent une transition de Gardner après une perturbation infinitésimale. Nous étudions ensuite le régime de haute pression et haut cisaillement au-delà de la transition de Gardner
We consider the adiabatic evolution of glassy states under external perturbations. Although the formalism we use is very general, we focus here on infinite-dimensional hard spheres where an exact analysis is possible. We consider perturbations of the boundary, i. e. compression or (volume preserving) shear-strain, and we compute the response of glassy states to such perturbations: pressure and shear-stress. We find that both quantities over shoot before the glass state becomes unstable at a spinodal point where it melts into a liquid (or yields). We also estimate the yield stress of the glass. Finally, we study the stability of the glass basins towards breaking into sub-basins, corresponding to a Gardner transition. We find that close to the dynamical transition, glasses undergo a Gardner transition after an infinitesimal perturbation. We then study the high-pressure and high-strain regime beyond the Gardner transition

Ce travail porte sur l'étude de la propriété d'(A,B)-invariance de polyèdres convexes et son application à la commande sous contraintes et au problème l 1. D'abord, nous proposons une caractérisation explicite de l'(A,B)-invariance de polyèdres convexes pour des systèmes en temps discret. Cette caractérisation se traduit par des conditions nécessaires et suffisantes sous la forme de relations matricielles linéaires, et présente deux avantages majeurs vis-à-vis de celles rencontrées dans la littérature : elle s'applique à tous les polyèdres convexes et elle ne nécessite pas le calcul de sommets. Ces avantages se font sentir notamment dans le calcul du domaine (A,B)-invariant suprémal inclus dans un polyèdre donné, pour lequel nous proposons une méthode numérique. Le problème de calculer une loi de commande rendant positivement invariant en boucle fermée un polyèdre (A,B)-invariant est également traité. Les relations d'(A,B)-invariance sont alors généralisées à des systèmes soumis à des contraintes linéaires sur la commande et à des systèmes soumis à des perturbations additives bornées. Puis, les résultats obtenus en temps discret sont étendus aux systèmes en temps continu. Ensuite, le problème d'atténuation de perturbations additives persistantes, connu dans la littérature comme problème l 1, est étudié. Les domaines (A,B)-invariants intérieurement stabilisables sont d'abord caractérisés. Puis, nous proposons une approche décomposée pour le calcul du domaine intérieurement stabilisable suprémal inclus dans le polyèdre défini par les contraintes de performance l 1. Un niveau de performance donné est atteignable si et seulement si ce domaine suprémal n'est pas vide. Cette approche géométrique permet notamment de déterminer directement la solution du problème l 1 pour une classe importante de systèmes. Enfin, nous étendons l'étude de l'(A,B)-invariance de polyèdres à des systèmes dont le modèle est soumis à des incertitudes d u type structuré.

Il progressivo invecchiamento della popolazione sta sempre più sottolineando la necessità di un’accurata comprensione del tema delle cadute. Ancora oggi per gli anziani esse rappresentano una delle maggior cause di comorbidità e morte. Il traporto pubblico è un’importante risorsa di inclusione sociale e autonomia personale per la popolazione anziana, tuttavia esso comporta anche una maggiore esposizione al rischio di caduta. Le donne, notoriamente più esposte al rischio di caduta rispetto la controparte maschile, risultano maggiormente colpite da questi incidenti. Il contributo delle nuove tipologie di allenamento “pertubation-based” potrebbero essere una valida soluzione per il miglioramento dei tempi e modalità di risposta del soggetto a perturbazioni esterne che possono comportare una perdita di equilibrio. Il presente studio ha incluso 36 donne suddivise in giovani e anziane con lo scopo di descriverne differenze e caratteristiche nella risposta reattiva quando esposte a perturbazioni esterne, come quelle che possono riscontrarsi sui mezzi pubblici. I risultati hanno evidenziato le potenzialità e i limiti dei protocolli di allenamento che fanno uso di “treadmill perturbativi”, e costituiscono un vero e proprio studio di fattibilità di questi nuovi metodi per la prevenzione delle cadute.

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With advancing age, the human body suffers morphological and functional changes, which lead the postural instability in elderly people. And an important factor in this, are linked to the inappropriate uses of postural adjustments strategies: anticipatory postural adjustment (APA) and compensatory postural adjustments (CPA). Such strategies deal with an ability to respond effectively to a possible loss of balance and minimize the negative consequences of it. Although the difficulties in maintaining balance in the elderly to be known, strategies of postural adjustment, in the face of external perturbations are still scarce. Therefore, the aim of this study was to investigate the APAs and CPAs and their inter-relationships in groups of elderly with and without falls. For this purpose, two groups of 20 elderly participants (with and without history of falls) and 20 young subjects received external perturbations of posture in the frontal plane, through the impact of a pendulum on the right shoulder of the individuals in the standing position, under two conditions: unpredictable and predictetable. The electromyography activity (EMG) of lateral ventral and dorsal postural muscles by recording and integrated (∫EMG) in the typical windows for these strategies, and displacement of body center of pressure (COP). The postural disturbance occurred in the medial-lateral direction, through the impact of a pendulum on the right shoulder of individuals under two conditions: unpredictable and predictable. The results showed the elderly groups (with and without falls) had, in general, smaller amplitude activation (∫EMG) of the CPAs to the dorsal and lateral studied in the unpredictable conditions. The elderly showed changes in the pattern of synergistic lateral muscles compared to the group of young individuals. There was a greater COP displacement in the predictable condition provided for groups of elderly patients with falls compared to the young. The results of this study indicate that the decrease in muscle activity in the elderly groups against disturbances of posture, especially the lateral muscles, may leave these individuals susceptible to falls. Therefore, research and training programs/training or treatment designed to restoring balance in the elderly by improving the activation of the lateral muscles must be developed.
Com o avançar da idade, o corpo humano sofre alterações morfológicas e funcionais, que acarretam grande instabilidade postural em idosos. E um fator importante desta, esta vinculada ao uso inadequado das estratégias de ajustes posturais: o ajuste postural antecipatório (APA) e compensatório (APC). Essas estratégias tratam da capacidade de um indivíduo em responder efetivamente a uma possível perda de equilíbrio. Embora, a dificuldade na manutenção do equilíbrio em idosos seja conhecida, estudos sobre as estratégias de ajuste postural frente a perturbações externas da postura nessa população ainda são escassos. Portanto, o objetivo desse estudo foi investigar os APAs e CPAs e suas inter-relações em idosos com e sem quedas. Para tanto, dois grupos de 20 idosos cada (sem e com histórico de quedas) e 20 indivíduos jovens receberam perturbações externas da postura no plano frontal, através do impacto de um pêndulo no ombro direito dos indivíduos na posição em pé, sob condições não prevista e prevista. As atividades eletromiográficas dos músculos posturais laterais, ventrais e dorsais foram registradas e integradas (∫EMG) nas janelas de tempo típicas para as estratégias de ajuste postural assim como o deslocamento do centro de pressão corporal (COP). De forma geral, os dois grupos de idosos apresentaram, menor amplitude de ativação (∫EMG) muscular nas janelas dos APCs para os músculos laterais e dorsais na condição não prevista. Idosos também apresentaram alteração no padrão sinérgico dos músculos laterais quando comparados ao grupo de indivíduos jovens. Houve um maior deslocamento do COP na condição prevista para os grupos de idosos com quedas quando comparados aos jovens. Os resultados desse estudo indicam que a diminuição da atividade muscular nos grupos de idosos frente a perturbações da postura, especialmente dos músculos laterais, podem deixar esses indivíduos suscetíveis a quedas. Portanto, investigações e programas de treinamento/tratamento que visam treinar ou restabelecer o equilíbrio em idosos melhorando a ativação dos músculos laterais devem ser desenvolvidos.

Over the last decade the focus has shifted to ensure a holistic view of employee well-being in organisations by focusing on both physical and psychological well-being. Previous research suggests that work characteristics and psychological work-related well-being influence both the individual (i.e. health) and organisational outcomes (i.e. commitment, safety, productivity, etc.). Moreover, the increasing importance of focusing on work-related psychological well-being of employees is evident in legislation from around the world. In South Africa the Occupational Health and Safety legislation, spesifically the Construction Regulations, also recognises the importance of the psychological well-being of employees and refers to it as ?psychological fitness?. However, no clear definition or instrument for psychological fitness exists. Similarly, no instrument exist to measure work characteristics of blue-collar workers. The objectives of this research were 1) to propose a defintion for psychological fitness of blue-collar employees 2) to propose a theoretical framework to better our understanding of psychological fitness 3) to develop a psychological fitness instrument for blue-collar employees that is suitable for the South African context 4) to test the psychometric properties of the newly developed psychological fitness instrument 5) to develop a work characteristics questionnaire for blue-collar mine workers to gain insight into their work experiences, and 6) to evaluate the psychometric properties of the newly developed job demands-resources scale for blue-collar mine workers. The empirical study consisted of two phases. During the first phase, following an extensive literature review, a definition and theoretical framework for psychological fitness was proposed. Thereafter, a new instrument for measuring psychological fitness was developed and tested. An instrument for measuring the work characteristics of blue-collar mine workers has also been developed to further the understanding of their work experiences. During the second phase, the psychometric properties of the newly developed psychological fitness instrument were tested (i.e. factorial validity, factorial invariance, reliability and external validity; N = 2769). Furthermore, the psychometric properties of the newly developed job demands-resources scale for blue collar workers were also investigated (i.e. factorial validity, reliability and the relationship with theoretically relevant external variables; N = 361). During the conceptualisation process, the definition of psychological fitness has been proposed based on previous work-related well-being literature. The work-related well-being concepts, distress and eustress were proposed as indicators of psychological fitness. Therefore, psychological fitness was defined as a state in which an employee display high levels of emotional and mental energy and high levels of psychological motivation to be able to work and act safely. The dimensions of burnout and engagement were proposed as possible indicators of psychological fitness and included exhaustion, mental distance, cognitive weariness, vitality and work devotion. Furthermore, the underlying work-related well-being theories and models were identified as the theoretic framework to enable the development of a questionnaire for psychological fitness. In order to ensure that the low literacy employees understand the meaning of each questionnaire close attention has been paid during the development of items. Firstly, the psychological fitness instrument (SAPFI) for blue-collar employees has been translated into all the official languages of South Africa following a multistage translation process. Secondly, the job demands-resources scale for blue collar mine workers (JDRSM) has been translated into the three most commonly spoken languages (Sesotho, isiXhosa and Setswana) by employees working in this specific mine. During this phase various problematic items were identified and eliminated from both questionnaires using the Rasch measurement model. The final phase included the validation study where the psychometric properties of both the new instruments were investigated. The SAPFI results provided evidence for factorial validity, factorial invariance, reliability and significant relations with external variables of the distress scale. Although evidence was provided for the factorial validity, reliability and external validity of the eustress scale, factorial invariance could not be confirmed. Furthermore, the JDRSM results provided evidence for the factorial validity, reliability (except for the workload scale) and external validity. Recommendations for future research were made.
Thesis (Ph.D. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2011.

Робота виконана на кафедрі аерокосмічних систем управління Національного авіаційного університету Міністерства освіти і науки України та у Публічному акціонерному товаристві «Науково-виробниче об’єднання «Київський завод автоматики».
Дисертаційна робота присвячена науковому обґрунтуванню та розробці алгоритмів компенсації внутрішніх похибок та зовнішніх збурень у Коріолісовому вібраційному гіроскопі, а також удосконаленню його складових частин (резонатора, чутливого елементу). Автором розроблено методику та обладнання для робочого місця безелектродного вимірювання динамічних параметрів металевого резонатора після його виготовлення, розроблено конструкцію приладдя для приклеювання п’єзоелектродів до резонатора нової конструкції, методику та обладнання робочого місця для балансування мас. Розроблено та відпрацьовано на експериментальному зразку КВГ методики температурної корекції фаз сигналів квадратури та кутової швидкості, багатопараметричної корекції дрейфу нуля і масштабного коефіцієнту, що призводить до збільшення точності виміру кутової швидкості в умовах дії температурних градієнтів.
In the thesis the following new scientific results are obtained: 1. For the first time, a multi-parameter method of CVG scale factor correction is developed and implemented, which can be used during the CVG operation in the rate and in the differential modes. Ukraine patent have been obtained for this method. 2. Scientifically grounded analysis of a new design of a cylindrical resonator with holes on the walls of a cylinder having higher vibration resistance was first developed and carried out. 3. The multiparameter bias correction algorithm has been developed and implemented, which has advantages over the existing ones by accuracy. 4. For the first time experimental researches were carried out on a manufactured experimental sample of CVG with developed metal cylindrical resonator made of elenvar elloy, which showed high accuracy scale factor and bias drift correction under the action of temperature gradient, as well as high shockvibration resistance of the sample. The practical significance of thesis results are: − comparison of two designs of metallic cylindrical resonators with holes on the bottom and on the wall of the cylinder and by calculations and computer simulation the advantages of the second design over the first one in the part of shock resistance have been substantiated; − аn analysis of the different geometries of the holes has been made. Their influence on the resonant oscillation frequencies of a cylindrical resonator is revealed. Recommendations for the geometry of the resonator and its elements have been developed; − improved design of the base on which the newly designed resonator with holes on the wall of the cylinder is installed; − the choice of electrodes used for oscillation excitation and measurement of the signals is experimentally substantiated; − the technique and equipment for workplace electrodeless measurement of metallic resonator dynamic parameters after its manufacture have been developed; − the influence of frequency mismatch, wave angle and positioning errors of the electrodes on the CVG bias and scale coefficient have been evaluated; − a new accessory design has been developed to attach the electrodes to the new resonator design; − the technique and equipment of the workplace for balancing the mass of the resonator on the fourth harmonic of the unbalance to reduce its frequency mismatch have been developed. The technique was tested in the manufactured ample of CVG; − the technique of measuring the angles of non-orthogonality of the sensitive axis to its mounting surface has been developed and implemented in the experimental sample of CVG; − the use of CVG to improve the accuracy of armament stabilization was analyzed; − improved CVG standing wave control algorithm block diagram, which provides a fast start of the gyroscope when it is turned on at any temperature in the range of operating temperatures; − the techniques for temperature correction of quadrature and angular rate phases, multiparameter correction of CVG bias and scale factor have been developed and tested on experimental sample of CVG, which leads to an increase in the accuracy of measuring angular rate under temperature gradients; − the experimental results showed that the CVG with a metallic resonator is resistant to multiple shocks with amplitude 100 g and its bias is slightly dependent on the shock amplitude and does not exceed 5×10−3 deg/s. The bias sensitivity to vibration perturbations is 2.5×10−3 deg/s/g.
Диссертация посвящена научному обоснованию и разработке алгоритмов компенсации внутренних погрешностей и внешних возмущений в Кориолисового вибрационном гироскопе, а также совершенствованию его составных частей (резонатора, чувствительного элемента). Автором разработана методика и оборудование для рабочего места безэлектродного измерения динамических параметров металлического резонатора после его изготовления, разработана конструкция приспособления для приклеивания пьезоэлектродов к резонатору новой конструкции, методику и оборудование рабочего места для балансировки масс резонатора. Разработано и отработано на экспериментальном образце КВГ методики температурной коррекции фаз сигналов квадратуры и угловой скорости, многопараметрической коррекции дрейфа нуля и масштабного коэффициента, что приводит к увеличению точности измерения угловой скорости в условиях действия температурных градиентов.

Cette thèse traite de l'identification des paramètres du point de vue de l'optimisation et du contrôle de suivi distribué des systèmes multi-agents d'ordre fractionnaire (FOMASs) en tenant compte des retards, des perturbations externes, de la non-linéarité inhérente, des incertitudes des paramètres et de l'hétérogénéité dans le cadre d'une topologie de communication fixe non dirigée / dirigée. Plusieurs contrôleurs efficaces sont conçus pour réaliser avec succès le contrôle de suivi distribué des FOMASs dans différentes conditions. Plusieurs types d'algorithmes d'optimisation de l'intelligence artificielle et leurs versions modifiées sont appliquées pour identifier les paramètres inconnus des FOMASs avec une grande précision, une convergence rapide et une grande robustesse. Il est à noter que cette thèse fournit un lien prometteur entre la technique d'intelligence artificielle et le contrôle distribué
This thesis deals with the parameter identification from the viewpoint of optimization and distributed tracking control of fractional-order multi-agent systems (FOMASs) considering time delays, external disturbances, inherent nonlinearity, parameters uncertainties, and heterogeneity under fixed undirected/directed communication topology. Several efficient controllers are designed to achieve the distributed tracking control of FOMASs successfully under different conditions. Several kinds of artificial intelligence optimization algorithms andtheir modified versions are applied to identify the unknown parameters of the FOMASs with high accuracy, fast convergence and strong robustness. It should be noted that this thesis provides a promising link between the artificial intelligence technique and distributed control

Le but de ce travail est de proposer des mécanismes pour les drones multirotors qui permettent d'une part de tolérer des fautes sur le drone, et d'autre part de prendre en compte les effets du vent en extérieur. Les fautes visées comportent des fautes d'actionneurs, de capteurs, mais également des fautes logicielles sur les algorithmes de fusion de données. Dans nos travaux, nous avons développé un contrôleur robuste et un observateur des perturbations extérieures capables de coopérer avec la méthode de reconfiguration des commandes, pour tolérer de façon simultanée les défaillances de moteurs et les perturbations extérieures du vent par des techniques de tolérance aux fautes active. Egalement, nous avons proposé une nouvelle technique de tolérance aux fautes des actionneurs pour un drone octorotor coaxial. Cette technique est basée sur une loi de commande robuste avec des gains reconfigurables "self tuning sliding mode control (STSMC)", où les gains de contrôle sont réajustés en fonction de l'erreur détectée afin de maintenir la stabilité du système. Des expériences à l'intérieur ont été menées pour montrer et comparer notre solution avec deux autres techniques de tolérances aux fautes. L'efficacité et le comportement de chaque méthode ont été étudiés après des injections de fautes successives dans les actionneurs. Les principaux avantages et inconvénients de chaque méthode sont déduits en analysant les résultats obtenus. En outre, nous proposons une approche pour la tolérance aux fautes des capteurs et mécanismes logiciels de fusion de données du drone. Cette approche est basée sur la redondance des capteurs et la diversification des composants logiciels
The aim of this work is to propose mechanisms for multirotor drones that allow, on the one hand, to tolerate faults on the drone, and on the other hand to take into account the effects of the wind outdoors. The faults targeted include fault in actuators, sensors, but also software faults on the data fusion algorithms. ln our work, we have developed a robust controller and an exterior disturbance observer capable of cooperating with th, contrai reconfiguration method, to simultaneously tolerate motor failures and exterior wind disturbances through active fault tolerance techniques… We have also proposed a new technique for tolerating actuator faults for a coaxial octorotor drone. This technique is based on a robust command law with reconfigurable "self tuning sliding mode control (STSMC)" gains, where the control gains are readjusted according to the detected error in order to maintain the stability of the system. lndoor experiments are conducted to show and compare our solution with two other fault tolerance techniques. The efficiency and behavior of each method are studied after successive fault injections into the actuators. The main advantages and disadvantages of each method are deduced by analyzing the results obtained. Additionally, we provide an approach for fault tolerance of drone data fusion sensors and software mechanisms. This approach is based on the redundancy of sensors and the diversification of software components

碩士
淡江大學
資訊工程研究所
83
There are two kinds of grasping analyses in robotics researches: find the grasping force distribution among the fingers when given the contact points as well as find the points of contact when given the shape of the object. Each kind of problems is associated with optimality and stability analysis. In this paper, we start from analyzing the stability and optimality aspects of the grasping analysis under external perturbations and find a guantitative measurement that could evaluate the performance of different grasping configurations when grasping a given object. This property actually determines which grasping configuration is better hence give a solution to the two kinds of grasping analysis problems. We proof some rotation and displacement geometry model to derive a formula that describes the change of equilibrium grasping forces under the influence of external forces. Using this formula, we present a new concept, called the force mapping closure, that plays the central role of stability analysis. A minimum finger grasping force required for a non-slip contact under given external perturbation can be determined using the force mapping closure curve. Hence a method against any external perturbations is developed to construct a stable grasp. An optimal grasp can be guaranteed using the method we discussed if the external perturbations is not exceed some threshold value. In the paper, the planar cases and spatial cases is discussed, respectively, and a example of three-fingered planar grasp is provided.

Balance is critical for human posture control when standing upright and during cyclic locomotor tasks such as walking or running, as well as for acyclic tasks such as gait initiation or complex sport movements. In the course of evolution, Homo sapiens developed an upright posture for bipedalism, thus freeing the upper limbs (arms) to interact with objects. Human upright stance is characterized by two straight legs and the center of mass (COM) is located above the hip, thus maximizing potential energy (due to high COM position) enabling great maneuverability for fast re-orientation of the body axis and re-direction of movement direction in space. Nevertheless, bipedalism is mechanically much more challenging (e.g. regarding stability) compared to other body morphologies in legged animals such as a quadrupedal leg configuration. This evolutionary innovation does not only provide benefits (such as those mentioned above), but also makes control functions difficult, which might involve instability of the whole mechanical system with segments arranged like an upside-down chain. To achieve the stable upright human stance and to prevent collapse, it is fundamental to continuously balance all segments above the feet by introducing appropriate joint torques and continuously adjusting the orientation of the ground reaction forces (GRF). Nevertheless, human motor control during tasks such as standing and walking provides stability in the case of external perturbations. Thus, humans are able to respond to external perturbations, such as changing ground level, different ground properties as well as pushes and pulls at different body regions, in order to keep their balance and maintain an upright posture. Given the current biomechanical understanding of human balance and posture control, it is still not well understood which neuro-muscular control mechanisms contribute to maintaining balance in response to external perturbations. In particular, it is not clear, how the contributions to recover from perturbations are organized at different levels, e.g. muscle mechanical response, spinal reflexes, and higher control contributions (e.g. from cortical areas in the brain). The present work focuses on improving this understanding by investigating human movement and posture control in response to different external perturbations. This thesis describes how healthy humans respond to unexpected external perturbations and identifies underlying neuro-muscular mechanisms enabling the motor system to cope with such challenges during locomotion and upright standing through passive and active strategies (e.g. tendon and muscles response, changed muscle activation). The first part of the thesis presents previous research results in a systematic review thus providing insights into how leg function responds to external perturbations in selected motion tasks. It is shown that humans adjust their movements not only to the environmental context (e.g. when walking on even ground vs. slopes or climbing stairs) but also dependent on the state of their motion (i.e. current phase of gait, COM position) and in relation to the type of perturbation like changes in ground or external forces. In the following part of the thesis, human standing experiments were designed to address the ability to cope with external perturbations with respect to axial and rotational leg function. Axial leg function described forces and displacements along the leg axis, pointing from the contact point of the foot to the COM. In contrast, rotational leg function described corresponding forces and displacements perpendicular to leg axis in sagittal plane. As predicted by biomechanical leg models, the results show that biarticular muscles strongly contribute to the redirection of the GRF in order to maintain an upright posture. In a second experimental study on human hopping, the ability to adapt leg stiffness (representing the axial leg function) in order to maintain cyclic movements in response to vertical ground level perturbations was investigated. The findings demonstrate a robust leg function, reflecting the ability of the human neuro-muscular system to cope with unexpected perturbations such as moving ground during hopping. An increase in leg stiffness was found in response to an upward surface acceleration. This thesis describes and analyses the ability of the human body to respond to external perturbations leading to robust movement patterns. By translating the observed coping strategies into biomechanical and motor control models, new approaches for the design and control of legged systems (e.g. for assistive and rehabilitation devices) can be derived.

博士
國立清華大學
光電工程研究所
102
In the dissertation, stability analysis and four-wave mixing (FWM) analysis are applied to investigate the characteristics of the relaxation oscillation of the quantum dot (QD) and the quantum well (QW) semiconductor lasers and their responses to the weak external perturbation, respectively. The FWM analysis can also be utilized to extract the intrinsic parameters of the semiconductor lasers, which apparently influence the dynamical behaviors. Through the modifications of strong external perturbations on the intrinsic parameters, the dynamical behaviors of the lasers can be investigated thoroughly. The linear stability analysis has been applied on the solitary and injection-locked lasers of QD and QW structures. By deriving the characteristic equations from the small internal fluctuations, the relaxation frequencies and the damping rate can be obtained. From the damping rates of the lasers with different bias currents, linewidth enhancement factors, injection strengths, and detuning frequencies, the QD lasers show better stability than the QW lasers. Moreover, the stability and excitability of the QD laser subject to optical feedback are also numerically discussed. To investigate the responses on small external perturbations in the FWM analysis, the rate equations of the solitary and injection-locked lasers of QD and QW structures are derived for the analytical solutions. Moreover, the FWM mixing analysis on the QD lasers subject to optical feedback is also derived. All the analytical models are carefully verified with the numerical simulations. FWM analysis has been applied on a QD laser to simultaneously obtain the linewidth enhancement factor and other intrinsic laser parameters. By fitting the experimentally obtained regenerative and amplitude modulation spectra at different detuning frequencies with the respective curves analytically calculated from the rate equations, parameters including the linewidth enhancement factor, the carrier decay rate in the dots, the differential gain, and the photon decay rate can be determined simultaneously under the same operating conditions. The sensitivity and accuracy of the parameter extracted by the FWM analysis are presented. Moreover, how each parameter alters the shapes of the regenerative and amplitude modulation spectra is also discussed. Moreover, a simplified rate equation model is utilized for the FWM analysis on QD lasers subject to optical injection. The regenerative and amplitude modulation spectra of the QD laser with different intrinsic laser parameters and external injection conditions are investigated. By curve fitting the regenerative and amplitude modulation spectra experimentally, the intrinsic laser parameters of a commercial single-mode QD laser under different injection conditions are extracted. The linewidth enhancement factor at different injection levels and detuning frequencies are shown, where a reduction of about 40% from its free-running value is demonstrated. By increasing the injection strength, the linewidth enhancement factor can be further reduced to minimize the chirp in optical communications. To comprehensively investigate the characteristics of QD laser subject to external perturbations, the model for the FWM analysis on the QD laser subject to optical feedback is also developed analytically. The modifications with different feedback conditions on the regenerative and amplitude modulation spectra are discussed. Also, how the regenerative and amplitude modulation spectra vary with each intrinsic parameter is discussed. Based on the theoretical prediction, we successfully extract the intrinsic parameters of the QD laser subject to optical feedback experimentally and the linewidth enhancement factor is found to increase with optical feedback.