The Intelligent Control Paradigm for software architecture is the result of this work. The Viable Software Approach is developed as an instance of the paradigm. The approach uses the Viable System Model as the basis for software system architecture. The result is a model-based architecture and approach for developing software systems by piecemeal adaptation with the goal that they become adaptive systems at runtime. Software built in this manner is called Viable Software. Viable Software represents a unifying class of self-controlling software that is an “intelligent” control system. Cybernetics, Control Theory, and Complexity Theory are the background for this work, and aspects relevant to this work are presented. These results are related to software architecture and software engineering. Rationale for the selection of the Viable System Model as a basis for software systems is given. The Viable System Model is described. The model is restated as an Alexanderian “pattern language” to make it more accessible to software engineering. A Viable Software Approach is proposed and expressed in the form of a Product Line Architecture that arranges the Viable System Model, the Viable Software Architecture, a Viable Component Framework, and a Component Transfer Protocol into a system for generative programming. An important result is the formalisation of the pattern of the Viable System into the interface specifications of the Viable Component. Three case studies illustrate the approach. The first is an analysis and extension of the Groove collaboration system. This study shows how the approach is used to map an existing system into the Viable Software Architecture and add fuzzy-adaptive user interface controllers. The second study presents the design and detailed software construction of an adaptive camera controller as part of a smart environment. The final study shows how a Business-to-Business e-Commerce system can be evolved and an expert system-based controller developed to implement business contracts.

The Intelligent Control Paradigm for software architecture is the result of this work. The Viable Software Approach is developed as an instance of the paradigm. The approach uses the Viable System Model as the basis for software system architecture. The result is a model-based architecture and approach for developing software systems by piecemeal adaptation with the goal that they become adaptive systems at runtime. Software built in this manner is called Viable Software. Viable Software represents a unifying class of self-controlling software that is an “intelligent” control system. Cybernetics, Control Theory, and Complexity Theory are the background for this work, and aspects relevant to this work are presented. These results are related to software architecture and software engineering. Rationale for the selection of the Viable System Model as a basis for software systems is given. The Viable System Model is described. The model is restated as an Alexanderian “pattern language” to make it more accessible to software engineering. A Viable Software Approach is proposed and expressed in the form of a Product Line Architecture that arranges the Viable System Model, the Viable Software Architecture, a Viable Component Framework, and a Component Transfer Protocol into a system for generative programming. An important result is the formalisation of the pattern of the Viable System into the interface specifications of the Viable Component. Three case studies illustrate the approach. The first is an analysis and extension of the Groove collaboration system. This study shows how the approach is used to map an existing system into the Viable Software Architecture and add fuzzy-adaptive user interface controllers. The second study presents the design and detailed software construction of an adaptive camera controller as part of a smart environment. The final study shows how a Business-to-Business e-Commerce system can be evolved and an expert system-based controller developed to implement business contracts.

The Intelligent Control Paradigm for software architecture is the result of this work. The Viable Software Approach is developed as an instance of the paradigm. The approach uses the Viable System Model as the basis for software system architecture. The result is a model-based architecture and approach for developing software systems by piecemeal adaptation with the goal that they become adaptive systems at runtime. Software built in this manner is called Viable Software. Viable Software represents a unifying class of self-controlling software that is an “intelligent” control system. Cybernetics, Control Theory, and Complexity Theory are the background for this work, and aspects relevant to this work are presented. These results are related to software architecture and software engineering. Rationale for the selection of the Viable System Model as a basis for software systems is given. The Viable System Model is described. The model is restated as an Alexanderian “pattern language” to make it more accessible to software engineering. A Viable Software Approach is proposed and expressed in the form of a Product Line Architecture that arranges the Viable System Model, the Viable Software Architecture, a Viable Component Framework, and a Component Transfer Protocol into a system for generative programming. An important result is the formalisation of the pattern of the Viable System into the interface specifications of the Viable Component. Three case studies illustrate the approach. The first is an analysis and extension of the Groove collaboration system. This study shows how the approach is used to map an existing system into the Viable Software Architecture and add fuzzy-adaptive user interface controllers. The second study presents the design and detailed software construction of an adaptive camera controller as part of a smart environment. The final study shows how a Business-to-Business e-Commerce system can be evolved and an expert system-based controller developed to implement business contracts.

The Intelligent Control Paradigm for software architecture is the result of this work. The Viable Software Approach is developed as an instance of the paradigm. The approach uses the Viable System Model as the basis for software system architecture. The result is a model-based architecture and approach for developing software systems by piecemeal adaptation with the goal that they become adaptive systems at runtime. Software built in this manner is called Viable Software. Viable Software represents a unifying class of self-controlling software that is an “intelligent” control system. Cybernetics, Control Theory, and Complexity Theory are the background for this work, and aspects relevant to this work are presented. These results are related to software architecture and software engineering. Rationale for the selection of the Viable System Model as a basis for software systems is given. The Viable System Model is described. The model is restated as an Alexanderian “pattern language” to make it more accessible to software engineering. A Viable Software Approach is proposed and expressed in the form of a Product Line Architecture that arranges the Viable System Model, the Viable Software Architecture, a Viable Component Framework, and a Component Transfer Protocol into a system for generative programming. An important result is the formalisation of the pattern of the Viable System into the interface specifications of the Viable Component. Three case studies illustrate the approach. The first is an analysis and extension of the Groove collaboration system. This study shows how the approach is used to map an existing system into the Viable Software Architecture and add fuzzy-adaptive user interface controllers. The second study presents the design and detailed software construction of an adaptive camera controller as part of a smart environment. The final study shows how a Business-to-Business e-Commerce system can be evolved and an expert system-based controller developed to implement business contracts.

Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Johnson, Eric; Committee Co-Chair: Calise, Anthony; Committee Member: Prasad, J.V.R.; Committee Member: Tannenbaum, Allen; Committee Member: Tsiotras, Panagiotis.

Ο σκοπός αυτής της διπλωματικής είναι η ανάπτυξη ενός προσαρμοστικού ελεγκτή για έναν εύκαμπτο ρομποτικό βραχίονα. Οι μετρήσεις του συστήματος θεωρούνται πως παρεμβάλλονται από θόρυβο, του οποίου τα όρια είναι γνωστά εξ’αρχής. Ένας Set Memebership εκτιμητής υπολογίζει το δυνατό set (ορθότοπο) μέσα στο οποίο βρίσκονται οι τιμές του διανύσματος των παραμέτρων. Από τις ακμές του ορθοτόπου αυτού προκύπτουν τα όρια μέσα στα οποία βρίσκονται οι παράμετροι του συστήματος, τα οποία χρησιμοποιούνται για τον υπολογισμό της αβεβαιότητας της εκτίμησης της εξόδου του συστήματος. Ο ελεγκτής καθορίζει τα κέρδη του μέσα σε μια online βελτιστοποίηση ενός κόστους, το οποίο βάζει κάποια βάρη στην προσπάθεια του ελέγχου (control effort), στην προκλημένη αβεβαιότητα στην έξοδο του συστήματος αλλά και στο σφάλμα παρακολούθησης της εξόδου με ένα σήμα αναφοράς. Μετά την εφαρμογή του ελεγκτή, ελέγχεται η ευστάθεια των οριακών κλειστών συστημάτων που προκύπτουν από την εφαρμογή κάθε πιθανού νόμου ελέγχου. Εξετάζεται επίσης η συμπεριφορά του Set Memebership εκτιμητή σε περίπτωση σφάλματος, δηλαδή στην περίπτωση που το σύστημά μας αλλάζει καθώς δουλεύει ο έλεγχος. / The development of an adaptive controller for a flexible link manipulator is the subject of this diploma thesis. The system’s measurements are assumed to be corrupted with noise of a priori known bounds. A Set Membership Identifier computes the feasible set (orthotope) within which the parameter vector resides. The orthotope’s vertices provide the parameter-vector’s bounds, which are used to compute the predicted system-output uncertainty. The controller tunes its gains through an on-line minimization of a cost that penalizes the control effort, the induced uncertainty on the system output, and the tracking error. After the application of the controller, the stability of the ‘extreme’ closed loop systems, derived from every possible control law, is checked. The behavior of the Set Membership Identifier is checked in the case where a fault occurs, which means that there is a change in our system’s structure while the controller is functioning.

Distributed processing cluster design using commodity hardware and software has proven to be a technological breakthrough in the field of parallel and distributed computing. The research presented herein is the original investigation on distributed processing using hybrid processing clusters to improve the calculation efficiency of the compute-intensive applications. This has opened a new frontier in affordable supercomputing that can be utilised by businesses and industries at various levels. Distributed processing that uses commodity computer clusters has become extremely popular over recent years, particularly among university research groups and research organisations. The research work discussed herein addresses a bespoke-oriented design and implementation of highly specific and different types of distributed processing clusters with applied load balancing techniques that are well suited for particular business requirements. The research was performed in four phases, which are cohesively interconnected, to find a suitable solution using a new type of distributed processing approaches. The first phase is an implementation of a bespoke-type distributed processing cluster using an existing network of workstations as a calculation cluster based on a loosely coupled distributed process system design that has improved calculation efficiency of certain legacy applications. This approach has demonstrated how to design an innovative, cost-effective, and efficient way to utilise a workstation cluster for distributed processing. The second phase is to improve the calculation efficiency of the distributed processing system; a new type of load balancing system is designed to incorporate multiple processing devices. The load balancing system incorporates hardware, software and application related parameters to assigned calculation tasks to each processing devices accordingly. Three types of load balancing methods are tested, static, dynamic and hybrid, which each of them has their own advantages, and all three of them have further improved the calculation efficiency of the distributed processing system. The third phase is to facilitate the company to improve the batch processing application calculation time, and two separate dedicated calculation clusters are built using small form factor (SFF) computers and PCs as separate peer-to-peer (P2P) network based calculation clusters. Multiple batch processing applications were tested on theses clusters, and the results have shown consistent calculation time improvement across all the applications tested. In addition, dedicated clusters are built using SFF computers with reduced power consumption, small cluster size, and comparatively low cost to suit particular business needs. The fourth phase incorporates all the processing devices available in the company as a hybrid calculation cluster utilises various type of servers, workstations, and SFF computers to form a high-throughput distributed processing system that consolidates multiple calculations clusters. These clusters can be utilised as multiple mutually exclusive multiple clusters or combined as a single cluster depending on the applications used. The test results show considerable calculation time improvements by using consolidated calculation cluster in conjunction with rule-based load balancing techniques. The main design concept of the system is based on the original design that uses first principle methods and utilises existing LAN and separate P2P network infrastructures, hardware, and software. Tests and investigations conducted show promising results where the company's legacy applications can be modified and implemented with different types of distributed processing clusters to achieve calculation and processing efficiency for various applications within the company. The test results have confirmed the expected calculation time improvements in controlled environments and show that it is feasible to design and develop a bespoke-type dedicated distributed processing cluster using existing hardware, software, and low-cost SFF computers. Furthermore, a combination of bespoke distributed processing system with appropriate load balancing algorithms has shown considerable calculation time improvements for various legacy and bespoke applications. Hence, the bespoke design is better suited to provide a solution for the calculation of time improvements for critical problems currently faced by the sponsoring company.

Made available in DSpace on 2016-08-31T13:33:43Z (GMT). No. of bitstreams: 1 DaniloSP_DISSERT.pdf: 1541140 bytes, checksum: a3ab0c19a32a7eaf392690513de9a9a5 (MD5) Previous issue date: 2015-07-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study is to evaluate different strategies for adaptive control in order to contribute to better performance controllers with synchronous generators with uncertainties of the parameters or disturbances. The permanent magnet synchronous generators are growing in the market for wind power generation, this being the necessary motivation for choosing this plant. A study and analysis of subsystems of wind energy conversion are performed, and the model of the wind turbine, the mechanical transmission system and synchronous generator are described. The project strategy with conventional control is performed and will be the target of comparison for the implemented adaptive control strategies / O objetivo deste trabalho é avaliar diferentes estratégias de controle adaptativo a fim de contribuir para a melhoria do desempenho de controladores de geradores síncronos com incertezas dos parâmetros ou perturbações. Os geradores síncronos de ímã permanente estão crescendo rapidamente no mercado de geração de energia eólica, sendo a motivação necessária para a escolha desta planta. Um estudo e análise dos subsistemas de conversão de energia eólica são realizados, sendo descrito o modelo da turbina eólica, do sistema de transmissão mecânico e do gerador síncrono. O projeto com estratégia de controle convencional é abordado e será alvo de comparação para as estratégias de controle adaptativo implementadas

Les décollements autour d’un corps en mouvement sont à l’origine de détériorations des performances aérodynamiques, de fatigues structurelles ou de nuisances sonores. La compréhension de ces phénomènes reste encore aujourd’hui l’un des enjeux majeurs de la recherche en aérodynamique. Le développement de systèmes permettant de contrôler l’écoulement et d’altérer ou de réduire les décollements apparaît comme une solution prometteuse en vue d’améliorer les performances aérodynamiques. On distingue les systèmes de contrôles passifs, simples d’utilisation mais incapables de s’adapter aux modifications de l’écoulement, des systèmes actifs qui disposent d’une grande adaptabilité mais nécessitent un apport extérieur d’énergie pour fonctionner. La stratégie du contrôle auto-adaptif s’apparente à un compromis entre ces deux méthodes. En s’inspirant de mécanismes présents dans la nature, elle permet d’associer amélioration des performances aérodynamiques, adaptabilité et autonomie. Ce travail de thèse porte sur l’étude expérimentale du contrôle du sillage turbulent d’un corps épais à l’aide d’actionneurs bio-inspirés avec un double objectif : i. déterminer les paramètres optimaux du dispositif de contrôle qui prend la forme d’un couple de volets flexibles, ii. Identifier les mécanismes physiques d’interactions entre l’actionnement et l’écoulement. Pour mener à bien cet objectif, de nombreux instruments de mesure complémentaires ont été mis en oeuvre. Une étude paramétrique a permis de démontrer l’efficacité du dispositif pour différentes configurations (fixes et auto-adaptatives) et d’identifier des configurations d’intérêt. La caractérisation de l’écoulement autour et dans le sillage du cylindre carré sans et avec contrôle a révélé un allongement de la longueur de recirculation à l’arrière du cylindre et la réduction de l’expansion du sillage. L’un des résultats majeurs de l’étude est que la réduction de traînée obtenue est principalement liée à une action du système sur l’anisotropie des fluctuations de l’écoulement et plus particulièrement sur l’entrainement du fluide dans le sillage de l’obstacle. / Flow separations around moving bodies lead to detrimental effects such as aerodynamic performances loss, structural fatigue and noises production. The understanding of these phenomena remains one of the most challenging issue of modern fluid dynamics. A promising solution to improve aerodynamic performances relies on the development of flow control devices able to prevent or mitigate the effects of separation. One can distinguish the passive flow control strategy, with easy to use devices but unable to adapt to the flow changes, from the active flow control strategy which benefits from a great adaptability but requires external power supply. Self-adaptive flow control appears to be a good compromise between those two strategies. Inspired from mechanisms at play in Nature, it combines good aerodynamic performances, self-adaptability and self-sustainability. This PhD thesis is dedicated to the experimental investigation of the turbulent flow over a bluff-body controlled by means of bio-inspired devices. The objective is two-folds : i. Design the control device which consists of a couple of compliant flaps, ii. Identify the physical mechanisms governing the interactions between the flow and the devices. A great number of complementary measurement techniques have been used in order to achieve these objectives. The efficiency of the devices for different configurations – locked and self-adaptive flaps - has been demonstrated through a parametric study. It has led to the identification of the main parameters involved in the control mechanism. The flow characterization around and in the wake of both uncontrolled and controlled cylinder revealed an increase in the length of the recirculation region and the reduction of the wake width. One of the major findings of this study is that the control essentially modifies the turbulent velocity field leading to a reduction of the lateral flow entrainment in the wake of the obstacle.

Alors que de nombreux exosquelettes destinés à la rééducation neuromotrice ont été développés ces dernières années, ces dispositifs n'ont pas encore permis de vrai progrès dans la prise en charge des patients cérébrolésés. Une des clés pour améliorer les faibles résultats thérapeutiques obtenus serait de constamment adapter la thérapie robotisée en fonction de l'évolution du patient et de sa récupération, en adaptant l'assistance fournie par le robot pour maximiser l'engagement du patient. L'objectif de cette thèse est donc de comprendre les processus d'adaptations réciproques dans un contexte d'interaction physique Homme-Exosquelette. Dans un premier temps nous avons donc développé un nouveau type de contrôleur adaptatif qui assiste le sujet "au besoin", en modulant l'assistance fournie; et évalué différent signaux pour piloter cette adaptation afin de suivre au mieux la récupération du patient. Dans un deuxième temps, nous avons étudié l'adaptation de sujets sains à l'application de champs de forces distribués par un exosquelette sur leur bras durant la réalisation de mouvements dans l'espace. En effet, lors d'une interaction physique homme-robot, le sujet adapte aussi son comportement aux contraintes exercées par le robot. D'importantes différences inter-individuelles ont été observées, avec une adaptation à la contrainte imposée chez seulement 21% des sujets, mais avec des effets à-posteriori persistants mesurés chez 85% d'entre eux; ainsi qu'une généralisation dans l'espace de ces effets et un transfert à des contextes différents (hors du robot). Ces premiers résultats devraient permettre à terme d'améliorer la rééducation neuromotrice robotisée. / While many robotic exoskeletons have been developed for stroke rehabilitation in recent years, there were not yet improvements to the traditional therapy. A key to unleash the potentiality of robotics is to adapt the assistance provided by the robot in order to maximize the subject engagement and effort, by having the robotic therapy evolving with the patient recovery. For this reason, we aim at better understanding the process of reciprocal adaptation in a context of physical Human-Robot Interaction (pHRI). We first developed a new adaptive controller, which assists the subject "as-needed", by regulating its interaction to maximize the human involvement. We further compared different signals driving this adaptation, to better following the functional recovery level of the patients. While the control is performed by the robot, the subject is also adapting his movements, and this adaptation has not yet been studied when dealing with 3D movements and exoskeletons. Therefore, we exposed human motions to distributed force fields, generated by the exoskeleton at the joint level, to produce specific inter-joint coordination and to analyse the effects of this exposition. With healthy participants, we observed important inter-individual difference, with adaptation to the fields in 21% of the participants, but post-effects and persisting retention of these in time in 85% of the subjects, together with spatial generalization, and, preliminarily, transfer of the effects outside of the exoskeleton context. This work towards understanding pHRI could provide insights on innovative ways to develop new controllers for improving stroke motor recovery with exoskeletons.