The diploma thesis deals with the design of mechanism for manipulation with bars and creating a batch of square steel bars. In intoduction of this thesis is describtion of principle of curent mechanisms. In following chapters are described the most important parts of new mechanism and their design. In final sections are risk analysis and financial evaluation.

Although in many of the tasks in robotics, what is sought mainly includes accuracy, precision, flexibility, adaptivity, etc., yet in wearable robotics, there are some other aspects as well that could distinguish a reliable and promising approach. The three key elements that are addressed are as follows: control, actuation, and sensors. Where the goal for each of the previously mentioned objectives is to find a solution/design compatible with humans. A possible way to understand the human motor behaviours is to generate them on human-like robots. Biologically inspired action generation is promising in control of wearable robots as they provide more natural movements. Furthermore, wearable robotics shows exciting progress, also with its design. Soft exosuits use soft materials to build both sensors and actuators. This work investigates an adaptive representation model for actions in robotics. The concrete action model is composed of four modularities: pattern selection, spatial coordination, temporal coordination, and sensory-motor adaptation. Modularity in motor control might provide us with more insights about action learning and generalisation not only for humanoid robots but also for their biological counterparts. Successfully, we tested the model on a humanoid robot by learning to perform a variety of tasks (push recovery, walking, drawing, grasping, etc.). In the next part, we suggest several soft actuation mechanisms that overcome the problem of holding heavy loads and also the issue of on-line programming of the robot motion. The soft actuators use textile materials hosting thermoplastic polyurethane formed as inflatable tubes. Tubes were folded inside housing channels with one strain-limited side to create a flexor actuator. We proposed a new design to control the strained side of the actuator by adding four textile cords along its longitudinal axis. As a result, the actuator behaviour can be on-line programmed to bend and twist in several directions. In the last part of this thesis, we organised piezoresistive elements in a superimposition structure. The sensory structure is used on a sensory gripper to sense and distinguish between pressure and curvature stimuli. Next, we elaborated the sensing gripper by adding proximity sensing through conductive textile parts added to the gripper and work as capacitive sensors. We finally developed a versatile soft strain sensor that uses silicone tubes with an embedded solution that has an electrical resistance proportional to the strain applied on the tubes. Therefore, an entirely soft sensing glove exhibits hand gestures recognition. The proposed combinations of soft actuators, soft sensors, and biologically inspired action representation might open a new perspective to obtain smart wearable robots. / Obwohl bei vielen Aufgaben in der Robotik vor allem Genauigkeit, Präzision, Flexibilität, Anpassungsfähigkeit usw. gefragt sind, gibt es in der Wearable-Robotik auch einige andere Aspekte, die einen zuverlässigen und vielversprechenden Ansatz kennzeichnen. Die drei Schlüsselelemente, sind die folgenden: Steuerung, Aktuatoren und Sensoren. Dabei ist das Ziel für jedes der genannten Elemente, eine menschengerechte Lösung und ein menschengerechtes Design zu finden. Eine Möglichkeit, die menschliche Motorik zu verstehen, besteht darin, sie auf menschenähnlichen Robotern zu erzeugen. Biologisch inspirierte Bewegungsabläufe sind vielversprechend bei der Steuerung von tragbaren Robotern, da sie natürlichere Bewegungen ermöglichen. Darüber hinaus zeigt die tragbare Robotik spannende Fortschritte bei ihrem Design. Zum Beispiel verwenden softe Exoskelette weiche Materialien, um sowohl Sensoren als auch Aktuatoren zu erschaffen. Diese Arbeit erforscht ein adaptives Repräsentationsmodell für Bewegungen in der Robotik. Das konkrete Bewegungsmodell besteht aus vier Modularitäten: Musterauswahl, räumliche Koordination, zeitliche Koordination und sensorisch-motorische Anpassung. Diese Modularität in der Motorsteuerung könnte uns mehr Erkenntnisse über das Erlernen und Verallgemeinern von Handlungen nicht nur für humanoide Roboter, sondern auch für ihre biologischen Gegenstücke liefern. Erfolgreich testeten wir das Modell an einem humanoiden Roboter, indem dieser gelernt hat eine Vielzahl von Aufgaben auszuführen (Stoß-Ausgleichsbewegungen, Gehen, Zeichnen, Greifen, etc.). Im Folgenden schlagen wir mehrere weiche Aktuatoren vor, welche das Problem des Haltens schwerer Lasten und auch die Frage der Online- Programmierung der Roboterbewegung lösen. Diese weichen Aktuatoren verwenden textile Materialien mit thermoplastischem Polyurethan, die als aufblasbare Schläuche geformt sind. Die Schläuche wurden in Gehäusekanäle mit einer dehnungsbegrenzten Seite gefaltet, um Flexoren zu schaffen. Wir haben ein neues Design vorgeschlagen, um die angespannte Seite eines Flexors zu kontrollieren, indem wir vier textile Schnüre entlang seiner Längsachse hinzufügen. Dadurch kann das Verhalten des Flexors online programmiert werden, um ihn in mehrere Richtungen zu biegen und zu verdrehen. Im letzten Teil dieser Arbeit haben wir piezoresistive Elemente in einer Überlagerungsstruktur organisiert. Die sensorische Struktur wird auf einem sensorischen Greifer verwendet, um Druck- und Krümmungsreize zu erfassen und zu unterscheiden. Den sensorischen Greifer haben wir weiterentwickelt indem wir kapazitiv arbeitende Näherungssensoren mittels leitfähiger Textilteile hinzufügten. Schließlich entwickelten wir einen vielseitigen weichen Dehnungssensor, der Silikonschläuche mit einer eingebetteten resistiven Lösung verwendet, deren Wiederstand sich proportional zur Belastung der Schläuche verhält. Dies ermöglicht einem völlig weichen Handschuh die Erkennung von Handgesten. Die vorgeschlagenen Kombinationen aus weichen Aktuatoren, weichen Sensoren und biologisch inspirierter Bewegungsrepräsentation kann eine neue Perspektive eröffnen, um intelligente tragbare Roboter zu erschaffen.

De nos jours, les systèmes intègrent de plus en plus de fonctionnalités dans des volumes de plus en plus petits grâce aux microcomposants intégrés. L'assemblage de ces microcomposants nécessite des systèmes de manipulation précis et reproductibles. Un nombre considérable de recherches ont été menées afin de mettre au point des actionneurs et des microrobots capables d'effectuer des tâches de positionnement ou de manipulation avec des précisions microniques voire submicroniques. Les technologies piézoélectriques jouent un rôle fondamental dans les applications de positionnement à résolution nanométrique ou même inférieure. Ces matériaux permettent la conception et le développement de systèmes de positionnement avec résolution et bande passante élevées. Cependant, des effets non linéaires tels que l'hystérésis et la dérive lente affectent la précision de la position des systèmes à base piézoélectrique s'ils ne sont pas contrôlés. Souvent, des capteurs de position sont montés sur ces systèmes pour permettre un contrôle en boucle fermée et l'élimination des effets d'hystérésis et de dérive lente. Néanmoins, l'intégration de capteurs permettant un asservissement robuste et de qualité pose des problèmes spécifiques aux microrobots. Cela est particulièrement vrai lorsque le nombre de degrés de liberté augmente. En effet, les capteurs de position qui jouissent d'une bonne résolution et précision sont généralement très volumineux et coûteux. Les solutions alternatives à l’intégration de capteurs de position externes peuvent être regroupées en deux catégories: soit par contrôle en boucle ouverte, également appelé schémas de contrôle prédictifs, soit par des techniques basées sur le contrôle par auto-détection (Self-Sensing Actuation - SSA), c’est-à-dire un contrôle en boucle fermée utilisant l'actionneur piézoélectrique comme son propre capteur.Dans cette thèse, l'objectif est de concevoir et de contrôler un système de positionnement basé sur la technologie piézoélectrique avec une méthode de mesure intégrée par SSA et ayant plusieurs degrés de liberté. À cette fin, les deux classes de SSA, à savoir le SSA basé sur l’effet direct piézoélectrique et le SSA basé sur la modification des propriétés électriques de l'actionneur piézoélectrique (PEA), sont étudiées en profondeur afin de déterminer celle qui convient le mieux au contrôle de la force et de la position dans les actionneurs piézoélectriques caractérisés par le fluage et non-linéarités d'hystérésis et consacrés à des opérations précises. De plus, cette étude présente un modèle constitutif et une technique d’identification de paramètres améliorés, qui prend en compte l’effet de couplage électromécanique et les non linéarités sur les propriétés du matériau piézoélectrique (constantes élastiques et diélectriques).Une nouvelle technique d'évaluation en temps réel des propriétés électriques du PEA est développée. Cette évaluation est basée sur la mesure de l’amplitude du courant de détection résultant de l’application d’une tension d’entrée haute fréquence de faible amplitude superposée à la tension d’entrée de commande qui actionne le PEA. Ensuite, un estimateur qui utilise le courant de détection pour estimer la position du PEA est conçu. Enfin, une plate-forme microrobotique pour le positionnement planaire à haute résolution avec la mesure intégrée par SSA développée est présentée. / Currently, systems integrate more and more functionalities into smaller volumes thanks to embedded micro-components. The assembly of those components requires precise and repeatable systems of manipulation. Substantial amounts of research have been carried out for developing actuators and microrobots to perform positioning or manipulation with micron- or even submicron accuracies. Piezoelectric technologies play a fundamental role in positioning applications with nanoscale or even lower resolution. These materials make possible the design and development of positioning systems with high resolution and bandwidth. However, nonlinear effects such as hysteresis and creep affect the position accuracy of piezoelectric-based systems if not controlled. Often, position sensors are mounted to these systems to permit a feedback control and the elimination of the hysteresis and creep effects. Nonetheless, the integration of sensors to enable quality and robust servo control poses specific problems for microrobots. This is especially true when the number of degrees of freedom (DOF) increases. Precision position sensors are usually very bulky and expensive. Alternative solutions to the integration of external position sensors can be grouped into two categories: either by open-loop control, also called feedforward control schemes or by Self-Sensing Actuation (SSA) control-based techniques, that is, a feedback control that uses the piezoelectric actuator as its own sensor.In this thesis, the objective is to design and control a piezoelectric-based positioning system with an embedded measurement by SSA method and having several degrees of freedom. To this end, the two classes of SSA, namely SSA based on the piezoelectric direct effect and the SSA based on the change of electrical properties of the piezoelectric actuator (PEAs), are studied in depth to determine the more adequate for force and position control in piezoelectric actuators typified by creep and hysteresis nonlinearities and devoted to precise operations. Additionally, from this study, an improved constitutive model and parameter identification technique are presented which includes the electromechanical coupling effect on the piezoelectric material properties (elastic and dielectric constants).A novel technique for real-time evaluation of the PEA's electrical properties is developed. This evaluation is based on the measurement of the amplitude of the detection current that results from the application of high-frequency low amplitude input voltage that is superimposed to the control input voltage which actuates the PEA. Then an estimator that uses the detection current to estimate the PEA's position is designed. Finally, a microrobotics platform for planar positioning with high resolution and the developed embedded measurement by SSA is presented.

Orientador: Cláudio Kitano / Resumo: Nesta dissertação de mestrado é apresentado um vibrômetro para a medição de deslocamentos nanométricos. O vibrômetro proposto está baseado em um interferômetro de Michelson modificado, homódino e em malha fechada. A demodulação em tempo real é executada inteiramente em modo digital, utilizando uma plataforma embarcada que realiza a aquisição de dados, processamento dos sinais, controle PI (proporcional-integral) e a geração dos sinais que acionam o modulador de fase óptica (baseado em uma célula Pockels) e o atuador piezoelétrico sob estudo. Dois sinais em quadratura de fase são obtidos a partir de um único sinal interferométrico utilizando uma tensão de modulação principal e, em seguida, a conhecida técnica de multiplicação cruzada é aplicada para calcular a variação da fase óptica de interesse. A condição de quadratura é atingida pelo próprio controlador PI por meio da análise da figura de Lissajous dos sinais fora de fase. O novo vibrômetro óptico é capaz de medir deslocamentos nanométricos, e é simples, barato, exato, imune ao desvanecimento e auto-consistente. O controlador PI é robusto, uma vez que o método de demodulação é capaz de trabalhar com elevado ruído eletrônico, variações indesejáveis no ganho do amplificador e na tensão de meia-onda da célula Pockels com a temperatura e outras perturbações externas. O novo sistema foi utilizado para determinar a magnitude da resposta em frequência de dois protótipos de atuadores piezoelétricos flextensionais multiatuados. As ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: A vibrometer to measure nanometric displacements is presented in this work. The proposed vibrometer is based on a modified closed loop homodyne Michelson interferometer. Real-time phase demodulation is carried out entirely in a digital mode, using an embedded platform that performs data acquisition, signal processing, PI (proportional-integral) control and the generation of signals that drive the electrooptic Pockels cell phase shifter and the piezoelectric actuator under test. Two phase quadrature signals are generated from a single interferometric output, using the interleaving action, in alternation, of a digitally generated principal modulating signal, and then the well-known cross-multiplication technique is applied to perform the computation of the phase shift of interest. The quadrature condition is reached by the PI control itself, using the length difference between the major axis and the minor axis of the ellipse formed by the Lissajous figure associated with the out of phase signals as the controller error signal. The new optical vibrometer is capable of measuring nanometric displacements, and is simple, inexpensive, accurate, immune to fading and self-consistent. The PI controller is robust, since the demodulation method is able to work under high electronic noise, undesirable variations in Pockels cell half-wave voltage with temperature, amplifier gain and other external entrances. The new method was used to determine the displacement frequency response curves of... (Complete abstract click electronic access below) / Mestre

Soft materials have gained increasing prominence in science and technology over the last few decades. This shift from traditional rigid materials to soft, compliant materials have led to the emergence of a new class of devices which can interact with humans safely, as well as reduce the disparity in mechanical compliance at the interface of soft human tissue and rigid devices.<br><br>One of the largest application of soft materials has been in the field of flexible electronics, especially in wearable sensors. While wearable sensors for physical attributes such as strain, temperature, etc. have been popular, they lack applications and significance from a healthcare perspective. Point-of-care (POC) devices, on the other hand, provide exceptional healthcare value, bringing useful diagnostic tests to the bedside of the patient. POC devices, however, have been developed for only a limited number of health attributes. In this dissertation I propose and demonstrate wireless, wearable POC devices to measure and communicate the level of various analytes in and the properties of multiple biofluids: blood, urine, wound exudate, and sweat.<br><br>Along with sensors, another prominent area of soft materials application has been in actuators and robots which mimic biological systems not only in their action but also in their soft structure and actuation mechanisms. In this dissertation I develop design strategies to improve upon current soft robots by programming the storage of elastic strain energy. This strategy enables us to fabricate soft actuators capable of programmable and low energy consuming, yet high speed motion. Collectively, this dissertation demonstrates the use of soft compliant materials as the foundation for developing new sensors and actuators for human use and interaction.

Already since some time, Bosch Rexroth offers solutions as compact servo hydraulic actuators (SHA). Because there are lot of requests from the market, we thought about reducing the inquiry processing time and delivery time by designing a kit system for the SHA solutions. This system should be flexible enough to cover different technical solutions (e.g. cylinder), functionalities and design styles [... aus dem Text]

Two - stage servovalves, despite being widely used in aircraft and industry because of their reliability and high performance, have a few disadvantages that are still unsolved at the state of the art, such as the power consumption caused by the quiescent flow (internal leakage) in the pilot stage, and the complexity and high number of parts of the torque motor assembly of the pilot stage. The solution to these problems can help to reduce costs, weight, power consumption, and to enhance the reliability and producibility as well as the performance of these valves. This paper presents a novel configuration of servovalve, which has the potential to overcome the above-mentioned issues. The proposed servo-valve includes a novel architecture for the pilot stage by using two piezo-electric actuators (ring benders). In this paper, the performance of this novel pilot stage is assessed. To this end, a valve prototype has been constructed and tested; the experimental results are also used to validate a numerical model obtained with the software Simscape Fluids. The results show that, acting on specific parameters, the performance of the piezo-valve can be very competitive, while ensuring very low internal leakage and complexity.

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