Modelling, simulation and control of rotary-wing aircraft in multi-agent scenario

The topic of this thesis is the design and the implementation of mathematical models and control system algorithms for rotary-wing unmanned aerial vehicles to be used in cooperative scenarios. The use of rotorcrafts has many attractive advantages, since these vehicles have the capability to take-off and land vertically, to hover and to move backward and laterally. Rotary-wing aircraft missions require precise control characteristics due to their unstable and heavy coupling aspects. As a matter of fact, flight test is the most accurate way to evaluate flying qualities and to test control systems. However, it may be very expensive and/or not feasible in case of early stage design and prototyping. A good compromise is made by a preliminary assessment performed by means of simulations and a reduced flight testing campaign. Consequently, having an analytical framework represents an important stage for simulations and control algorithm design. In this work mathematical models for various helicopter configurations are implemented. Different flight control techniques for helicopters are presented with theoretical background and tested via simulations and experimental flight tests on a small-scale unmanned helicopter. The same platform is used also in a cooperative scenario with a rover. Control strategies, algorithms and their implementation to perform missions are presented for two main scenarios. One of the main contributions of this thesis is to propose a suitable control system made by a classical PID baseline controller augmented with L1 adaptive contribution. In addition a complete analytical framework and the study of the dynamics and the stability of a synch-rotor are provided. At last, the implementation of cooperative control strategies for two main scenarios that include a small-scale unmanned helicopter and a rover.

Design and testing of innovative, artificial intelligence-based techniques to model and control the combustion process and to reduce the Co2 emissions in modern, high-performance, gasoline direct injection engines

This work deals with the development of calibration procedures and control systems to improve the performance and efficiency of modern spark ignition turbocharged engines. The algorithms developed are used to optimize and manage the spark advance and the air-to-fuel ratio to control the knock and the exhaust gas temperature at the turbine inlet. The described work falls within the activity that the research group started in the previous years with the industrial partner Ferrari S.p.a. . The first chapter deals with the development of a control-oriented engine simulator based on a neural network approach, with which the main combustion indexes can be simulated. The second chapter deals with the development of a procedure to calibrate offline the spark advance and the air-to-fuel ratio to run the engine under knock-limited conditions and with the maximum admissible exhaust gas temperature at the turbine inlet. This procedure is then converted into a model-based control system and validated with a Software in the Loop approach using the engine simulator developed in the first chapter. Finally, it is implemented in a rapid control prototyping hardware to manage the combustion in steady-state and transient operating conditions at the test bench. The third chapter deals with the study of an innovative and cheap sensor for the in-cylinder pressure measurement, which is a piezoelectric washer that can be installed between the spark plug and the engine head. The signal generated by this kind of sensor is studied, developing a specific algorithm to adjust the value of the knock index in real-time. Finally, with the engine simulator developed in the first chapter, it is demonstrated that the innovative sensor can be coupled with the control system described in the second chapter and that the performance obtained could be the same reachable with the standard in-cylinder pressure sensors.

New knowledge, diagnostic and control tools to limit the impact of viral nervous necrosis (VNN) in the Mediterranean aquaculture sector

The role of aquaculture in satisfying the global seafood demand is essential. The expansion of the aquaculture sector and the intensification of its activities have enhanced the circulation of infectious agents. Among these, the nervous necrosis virus (NNV) represents the most widespread in the Mediterranean basin. The NNV is responsible for a severe neuropathological condition named viral nervous necrosis (VNN), impacting hugely on fish farms due to the serious disease-associated losses. Therefore, it is fundamental to develop new strategies to limit the impact of VNN in this area, interconnecting several aspects of disease management, diagnosis and prevention. This PhD thesis project, focusing on aquatic animals’ health, deals with these topics. The first two chapters expand the knowledge on VNN epidemiology and distribution, showing the possibility of interspecies transmission, persistent infections and a potential carrier role for invertebrates. The third study expands the horizon of VNN diagnosis, by developing a quick and affordable multiplex RT-PCR able to detect and simultaneously discriminate between NNV variants, reducing considerably the time and costs of genotyping. The fourth study, with the development of a fluorescent in situ hybridization technique and its application to aquatic vertebrates and invertebrates’ tissues, contributes to expand the knowledge on NNV distribution at cellular level, localizing also the replication site of the virus. Finally, the last study dealing with an in vitro evaluation of the NNV susceptibility to a commercial biocide, stress the importance to implement proper disinfectant procedures in fish farms to prevent virus spread and disease outbreaks.

Fractional Order Modeling and Control of a Flexible Satellite

Researchers have engrossed fractional-order modeling because of its ability to capture phenomena that are nearly impossible to describe owing to its long-term memory and inherited properties. Motivated by the research in fractional modeling, a fractional-order prototype for a flexible satellite whose dynamics are governed by fractional differential equations is proposed for the first time. These relations are derived using fractional attitude dynamic description of rigid body simultaneously coupled with the fractional Lagrange equation that governs the vibration of the appendages. Two attitude controls are designed in the presence of the faults and uncertainties of the system. The first is the fractional-order feedback linearization controller, in which the stability of the internal dynamics of the system is proved. The second is the fractional-order sliding mode control, whose asymptotic stability is demonstrated using the quadratic Lyapunov function. Several nonlinear simulations are implemented to analyze the performance of the proposed controllers.

Modeling, simulation, and control of a formation of multirotor aircraft for cooperative transportation of suspended loads

The work presented in this thesis aims to contribute to innovation in the Urban Air Mobility and Delivery sector and represents a solid starting point for air logistics and its future scenarios. The dissertation focuses on modeling, simulation, and control of a formation of multirotor aircraft for cooperative load transportation, with particular attention to environmental sustainability. First, a simulation and test environment is developed to assess technologies for suspended load stabilization. Starting from the mathematical model of two identical multirotors, formation-flight-keeping and collision-avoidance algorithms are analyzed. This approach guarantees both the safety of the vehicles within the formation and that of the payload, which may be made of people in the very near future. Afterwards, a mathematical model for the suspended load is implemented, as well as an active controller for its stabilization. The key focus of this part is represented by both analysis and control of payload oscillatory motion, by thoroughly investigating load kinetic energy decay. At this point, several test cases were introduced, in order to understand which strategy is the most effective and safe in terms of future applications in the field of air logistics.

Abordagem crítica sob a ótica da ação comunicativa de Habermas : gestão participativa no campus Serra do Ifes

O estudo teve como objetivo compreender de forma crítica como se caracteriza a gestão participativa no campus Serra do Ifes, a partir do entendimento e do processo interativo dos servidores Técnico-administrativos (TAEs) das classes C, D e E, e das chefias imediatas. Para tanto, a Teoria da Ação Comunicativa (TAC) de Jürgen Habermas, bem como sua proposta de democracia deliberativa foram empreendidas como marco teórico para compreensão desse processo e os conceitos norteadores da TAC (atos de fala, mundo da vida, sistema, colonização do mundo da vida, esfera pública, ação comunicativa e instrumental ou estratégica) foram empregados como elementos de análise das estruturas relevantes identificadas na pesquisa. Esse trabalho caracteriza-se como uma pesquisa de abordagem qualitativa e possui um enfoque crítico com visão dialética da realidade social. A análise foi realizada considerando o duplo efeito que a prática da gestão participativa pode significar: como comprometimento com o desempenho e reforço do sistema capitalista; e como resistência dos trabalhadores organizados às formas de dominação e controle. Os dados empíricos foram produzidos por meio de pesquisa documental, observação participante e entrevista semiestruturada. Foram entrevistados oito TAEs subordinados e 13 chefias imediatas, selecionados conforme o critério da bola de neve. Utilizou-se a análise de conteúdo para o tratamento das informações obtidas nas entrevistas. Os resultados apontam para a construção de ações participativas de cunho instrumental, estabelecidas a partir dos interesses da gestão, de grupos específicos e individuais. Sendo assim, a prática da gestão participativa caracteriza-se como um espaço estratégico para alcance do êxito e não do entendimento, onde os TAEs são corresponsáveis no processo de manutenção e construção dos fenômenos que emperram o desenvolvimento de uma participação democrática.

La letra con sangre entra La emancipada (1863) de Miguel Riofrío, primera novela ecuatoriana (Estudios)

Este ensayo revisa elementos presentes en La emancipada (1863), texto que funda la novela ecuatoriana, y que representa por primera vez el territorio de esta nación. Revisa las relaciones de esta novela con otros discursos, como el refrán tradicional que afirma «La letra con sangre entra», en referencia a la dominación y el control ejercido por las élites sobre sujetos subalternos (en este caso los indios y las mujeres). Resalta el hecho de que la protagonista da validez a un texto ajeno, al poner su firma en una carta redactada por su padre, aunque escribe en el reverso del papel su propio mensaje, éste no llega con claridad a su destino. El motivo con el que se inicia la literatura ecuatoriana es revelador de otros elementos que contribuyeron a la formación de las naciones hispanoamericanos americanas en el siglo XIX.

Capitalismo tardio e ideologia: transformação qualitativa das formas de controle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Imperialismo e educação do campo: uma análise das políticas educacionais no estado de Rondônia a partir de 1990

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Las tierras, los ganados, los trabajadores... Una posible reconstrucción de las estancias reduccionales de la experiencia jesuítica bonaerense, 1740-1752

El presente trabajo propone reconstruir el sistema productivo organizado por los misioneros de la Compañía de Jesús al sur de la jurisdicción colonial de Buenos Aires, entre 1740 y 1752. Si bien los hombres de la Compañía desarrollaron durante el siglo XVIII establecimientos productivos en todas las regiones rioplatenses, la característica de este caso se refiere a que la estancias y chacras que son descriptas tienen una vida activa de 12 años en la frontera, es decir, en territorio indígena ocupado por la reducciones pero con un dominio colonial no consolidado. Los espacios fronterizos no son habitados permanentemente por los españoles y la dominación y control del Estado suelen ser esporádicos. Por tanto, la experiencia misional se transforma en un mecanismo que pretende vigilar y controlar, pero que para existir en un territorio cuyo dominio es detentado por otras sociedades debe negociar con las mismas sus condiciones de existencia. ¿Cómo afectó esta situación a la constitución de ┤chacras' y ┤estancias' productivas? ¿En qué medida estos establecimientos se integraron a la red de establecimientos que la Compañía posee en tierras ┤españolas'? ¿La organización es similar en el ámbito fronterizo y en el ámbito ┤efectivamente' colonizado?

Las tierras, los ganados, los trabajadores... Una posible reconstrucción de las estancias reduccionales de la experiencia jesuítica bonaerense, 1740-1752

El presente trabajo propone reconstruir el sistema productivo organizado por los misioneros de la Compañía de Jesús al sur de la jurisdicción colonial de Buenos Aires, entre 1740 y 1752. Si bien los hombres de la Compañía desarrollaron durante el siglo XVIII establecimientos productivos en todas las regiones rioplatenses, la característica de este caso se refiere a que la estancias y chacras que son descriptas tienen una vida activa de 12 años en la frontera, es decir, en territorio indígena ocupado por la reducciones pero con un dominio colonial no consolidado. Los espacios fronterizos no son habitados permanentemente por los españoles y la dominación y control del Estado suelen ser esporádicos. Por tanto, la experiencia misional se transforma en un mecanismo que pretende vigilar y controlar, pero que para existir en un territorio cuyo dominio es detentado por otras sociedades debe negociar con las mismas sus condiciones de existencia. ¿Cómo afectó esta situación a la constitución de ┤chacras' y ┤estancias' productivas? ¿En qué medida estos establecimientos se integraron a la red de establecimientos que la Compañía posee en tierras ┤españolas'? ¿La organización es similar en el ámbito fronterizo y en el ámbito ┤efectivamente' colonizado?

Las tierras, los ganados, los trabajadores... Una posible reconstrucción de las estancias reduccionales de la experiencia jesuítica bonaerense, 1740-1752

El presente trabajo propone reconstruir el sistema productivo organizado por los misioneros de la Compañía de Jesús al sur de la jurisdicción colonial de Buenos Aires, entre 1740 y 1752. Si bien los hombres de la Compañía desarrollaron durante el siglo XVIII establecimientos productivos en todas las regiones rioplatenses, la característica de este caso se refiere a que la estancias y chacras que son descriptas tienen una vida activa de 12 años en la frontera, es decir, en territorio indígena ocupado por la reducciones pero con un dominio colonial no consolidado. Los espacios fronterizos no son habitados permanentemente por los españoles y la dominación y control del Estado suelen ser esporádicos. Por tanto, la experiencia misional se transforma en un mecanismo que pretende vigilar y controlar, pero que para existir en un territorio cuyo dominio es detentado por otras sociedades debe negociar con las mismas sus condiciones de existencia. ¿Cómo afectó esta situación a la constitución de ┤chacras' y ┤estancias' productivas? ¿En qué medida estos establecimientos se integraron a la red de establecimientos que la Compañía posee en tierras ┤españolas'? ¿La organización es similar en el ámbito fronterizo y en el ámbito ┤efectivamente' colonizado?

Influence of food components on lipid metabolism: scenarios and perspective on the control and prevention of dyslipidemias

Cardiovascular diseases (CVD) are the main causes of death in the Western world. Among the risk factors that are modifiable by diet, for reducing cardiovascular disease risks, the total plasma concentrations of cholesterol, triglycerides, LDL-C, and HDL-C are the most important. Dietary measures can balance these components of the lipid profile thus reducing the risk of cardiovascular diseases. The main food components that affect the lipid profile and can be modified by diet are the saturated and trans fats, unsaturated fats, cholesterol, phytosterols, plant protein, and soluble fiber. A wealth of evidence suggests that saturated and trans fats and cholesterol in the diet raise the total plasma cholesterol and LDL-C. Trans fats also reduce HDL-C, an important lipoprotein for mediating the reverse cholesterol transport. On the other hand, phytosterols, plant proteins, isoflavones, and soluble fiber are protective diet factors against cardiovascular diseases by modulating plasma lipoprotein levels. These food components at certain concentrations are able to reduce the total cholesterol, TG, and LDL-C and raise the plasma levels of HDL-C. Therefore, diet is an important tool for the prevention and control of cardiovascular diseases, and should be taken into account as a whole, i.e., not only the food components that modulate plasma concentrations of lipoproteins, but also the diet content of macro nutrients and micronutrients should be considered.

Evaluation of biologic occupational risk control practices: Quality indicators development and validation

Background: There is growing demand for the adoption of qualification systems for health care practices. This study is aimed at describing the development and validation of indicators for evaluation of biologic occupational risk control programs. Methods: The study involved 3 stages: (1) setting up a research team, (2) development of indicators, and (3) validation of the indicators by a team of specialists recruited to validate each attribute of the developed indicators. The content validation method was used for the validation, and a psychometric scale was developed for the specialists` assessment. A consensus technique was used, and every attribute that obtained a Content Validity Index of at least 0.75 was approved. Results: Eight indicators were developed for the evaluation of the biologic occupational risk prevention program, with emphasis on accidents caused by sharp instruments and occupational tuberculosis prevention. The indicators included evaluation of the structure, process, and results at the prevention and biologic risk control levels. The majority of indicators achieved a favorable consensus regarding all validated attributes. Conclusion: The developed indicators were considered validated, and the method used for construction and validation proved to be effective.

Experimental analysis of active-passive vibration control using viscoelastic materials and extension and shear piezoelectric actuators

Hybrid active-passive damping treatments combine the reliability, low cost and robustness of viscoelastic damping treatments and the high-performance, modal selective and adaptive piezoelectric active control. Numerous hybrid damping treatments have been reported in the literature. They differ mainly by the relative positions of viscoelastic treatments, sensors and piezoelectric actuators. In this work we present an experimental analysis of three active-passive damping design configurations applied to a cantilever beam. In particular, two design configurations based on the extension mode of piezoelectric actuators combined with viscoelastic constrained layer damping treatments and one design configuration with shear piezoelectric actuators embedded in a sandwich beam with viscoelastic core are analyzed. For comparison purposes, a purely active design configuration with an extension piezoelectric actuator bonded to an elastic beam is also analyzed. The active-passive damping performance of the four design configurations is compared. Results show that active-passive design configurations provide more reliable and wider-range damping performance than the purely active configuration.