Dissertations / Theses: 'Robust passivity'

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Abroug, Neil. "Commande robuste multi-variable des systèmes de comanipulation." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAD027/document.

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À l'aube de la quatrième révolution industrielle, la comanipulation robotique est une technologie clé tant elle allie la dextérité de l'opérateur humain à la puissance de la machine. Ce partage de tache entre humain et la machine, en sus dans un environnement incertain et inconnu à l'avance, apporte un lot de difficultés intrinsèques à la nature de cette interaction. Cette problématique a été intensivement étudiée durant les vingt dernières années, par diverses équipes de recherches, le plus souvent sur des dispositifs à un seul degré de liberté et avec des hypothèses fortes sur la nature du contrôleur. Dans la présente thèse, nous traitons la problématique de la comanipulation robotique à travers la commande Hoo structurée, cadre de travail particulièrement adapté aux systèmes multivariables et pouvant être étendu à une certaine classe de systèmes non linéaires – les robots manipulateurs en font partie – à travers une modélisation linéaire à paramètres variants (LPV). Les exigences de performance et de stabilité propres aux systèmes de comanipulation sont exprimées en termes de contraintes Hoo et de conditions de secteurs à respecter. Les objectifs de commande ainsi formalisés, sont résolus par optimisation non lisse afin de tirer profit des structures particulières des contrôleurs de robots de comanipulation. La validation de la méthodologie est réalisée par des simulations intensives et des expérimentations sur des dispositifs réels
At the dawn of the fourth industrial revolution, robotic comanipulation is a key technology as it combines the dexterity of the human operator with the power of the machine. This task sharing between human and machine, in an uncertain and previously unknown environment, brings a lot of intrinsic difficulties to the nature of this interaction. This problem has been intensively studied over the last two decades by various research teams, mostly on devices with a single degree of freedom and with strong hypotheses about the controller structure. In this thesis, we deal with the problem of robotic comanipulation through the scope of the structured Hoo control, a framework particularly adapted to multivariable systems and which can be extended to a certain class of non-linear systems – manipulating robots are part of it – through linear parameter varying (LPV) models. The performance and stability requirements specific to comanipulation systems are expressed in terms of Hoo constraints and sector bounds. The control objectives thus formalised are solved by non-smooth optimization in order to take advantage of the particular structures of the comanipulation robot controllers. The validity of the methodology is carried out by intensive simulations and experiments on real devices

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Ryalat, Mutaz. "Design and implementation of nonlinear and robust control for Hamiltonian systems : the passivity-based control approach." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/398131/.

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Recently, control techniques that adopt the geometrical structure and physical properties of dynamical systems have gained a lot of interest. In this thesis, we address nonlinear and robust control problems for systems represented by port-controlled Hamiltonian (PCH) models using the interconnection and damping assignment passivity-based control(IDA-PBC) methodology, which is the most notable technique facilitating the PCH framework. In this thesis, a novel constructive framework to simplify and solve the partial differential equations (PDEs) associated with IDA-PBC for a class of underactuated mechanical systems is presented. Our approach focuses on simplifying the potential energy PDEs to shape the potential energy function which is the most important procedure in the stabilization of mechanical systems. The simplification is achieved by parametrizing thedesired inertia matrix that shapes the kinetic energy function, thus achieving total energy shaping. The simplification removes some constraints (conditions and assumptions) that have been imposed in recently developed methods in literature, thus expanding the class of systems for which the methods can be applied including the separable PCH systems(systems with constant inertia matrix) and non-separable PCH systems (systems with non-constant inertia matrix). The results are illustrated through software simulations and hardware experiments on real engineering applications. We also propose an integral control and adaptive control schemes to improve the robustness of the IDA-PBC method in presence of uncertainty. We first provide some results for the case of fully-actuated mechanical systems, and then extend those results to underactuated systems which are more complex. Integral action control on both the passive and non-passive outputs in the IDA-PBC construction, a strategy to ensure the robustness of the systems by preserving its stability in face of external disturbances, is introduced, establishing the input-to-state stability (ISS) property. The results are applied to both the separable and non-separable PCH systems and illustrated via several simulations. The extension to the non-separable case exhibits more complicated design as we need to take into account the derivative of the inertia matrix. Finally, the IDA-PBC method is employed to solve an important nonlinear phenomenon called ‘pull-in’ instability associated with the electrostatically actuated microelectromechanical systems (MEMSs). The control construction is an output-feedback controller that ensures global asymptotic stability and avoids velocity measurement which may not be practically available. Furthermore, the integral, adaptive and ISS control schemes proposed in this thesis for mechanical systems are extended to facilitate the stabilization of electromechanical systems which exhibit strong coupling between different energy domains.

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Hui, Xin. "Cascade Control of a Hydraulic Prosthetic Knee." Cleveland State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=csu1459772543.

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Ihle, Ivar-Andre Flakstad. "Coordinated Control of Marine Craft." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-945.

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This thesis contains new results on the problem of coordinating a group of vehicles. The main motivation driving this work is the development of control laws that steer individual members of a formation, such that desired group behavior emerges. Special attention is paid to analysis of coordination issues, in particular formation control of marine craft where robustness to unknown environmental forces is important. Coordinated control applications for marine craft include: underway replenishment, maintaining a formation for increased safety during travel and instrument resolution, and cooperative transportation. A review of formation control structures is given, together with a discussion of special issues that arise in coordination of independent vehicles.

The main contributions of this thesis may be grouped into two categories:

• Path-following designs for controlling a group of vehicles

• Multi-body motivated formation modeling and control

A previously developed path following design is used to control a group of vehicles by synchronizing the individual path parameters. The path following design is advantageous since the path parameter, i.e., that parameter which determines position along a path, is scalar; hence coordination is achieved with a little amount of real-time communication. The path following design is also extended to the output-feedback case for systems where only parts of the state vector are known. The path following scheme is exploited further in a passivity-based design for coordination where the structural properties render an extended selection of functions for synchronization available. Performance and robustness properties in different operational conditions can be enhanced with a careful selection of these functions. Two designs are presented; a cascaded interconnection where a consensus system provides synchronized path parameters as input to the individual path following systems renders time-varying formations possible and increases robustness to communication problems; a feedback interconnection which is more robust to vehicle failures. Both designs are extended to sampled-data designs where plant and controller dynamics are updated in continuous-time and path parameters are exchanged over a communication network where transmission occurs at discrete intervals. Bias estimation is included to provide integral action against slowlyvarying environmental forces and model uncertainties.

A scheme for formation modeling and control, inspired by analytical mechanics of multi-body systems and Lagrangian multipliers, is proposed. In this approach to formation control, various formation behaviors are determined by imposing constraint functions on group members. Several examples illustrate these formation behaviors. The stabilization scheme presented is made more robust with respect to unknown time-varying disturbances. In addition, the scheme is extended towards adaptive estimation of unknown plant and parameters. Furthermore, it can be applied with no major modifications to the case of position control for a single vehicle.

The formation control scheme is such that it may be used in combination with a set of position control laws for a single vessel, thus enabling the designer to choose from a large class of control laws available in the literature. The input-to-state stability (ISS) framework is utilised to investigate robustness to environmental and communication disturbances. A loop-transform, together with the ISS framework, yields an upper bound on the inter-vessel time delay below which formation stability is maintained.

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Romero, Velázquez José Guadalupe. "Commande robuste par façonnement d’énergie de systèmes non-linéaires." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112019/document.

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Cette thèse porte sur la conception de commandes robustes pour les systèmes non linéaires, mettant l'accent sur les systèmes mécaniques. Des résultats concluants sont présentés pour résoudre deux situations très abordées dans la théorie du contrôle : 1) La stabilité des systèmes non linéaires perturbés ; 2) Le suivi global de trajectoire dans les systèmes mécaniques en ayant seulement connaissance de la position. Nous avons commencé par donner une méthode de conception des commandes robustes pour assurer une régulation de sortie non passive. En outre, si le système est perturbé (pas appariés), des preuves rigoureuses pour les rejeter sont fournies. Ce résultat est principalement inspiré d'un changement de coordonnées et de l'action intégrale dynamique. Si le scénario à traiter concerne des systèmes mécaniques avec des perturbations variant dans le temps, nous dotons le système de propriétés comme IISS (Integral Input- State Stable) et ISS (Input-State Stable). Ce résultat est obtenu en modifiant la procédure de conception de manière à rejeter les perturbations constantes (pas appariés). Cependant, en raison de la non-linéarité du système, les commandes qui en résultent ont une grande complexité. Pour le même problème, un deuxième et élégant résultat est donné au cas où un changement préalable de variable (impulsions) est réalisé. Finalement, une réponse convaincante au problème de suivi de trajectoire pour les systèmes mécaniques est donnée en tenant compte uniquement des informations de position. Nous résolvons ce problème en deux étapes. Premièrement, quelques modifications sont apportées à la preuve de stabilité d'un observateur de vitesse basée sur la théorie de l'invariance et l’Immersion récemment publié. Notez que ceci est un observateur satisfaisant la convergence exponentielle de vitesse dans les systèmes mécaniques. Deuxièmement et sur la base du changement de coordonnées (impulsions), un contrôleur de suivi avec stabilité exponentielle, tenant compte de la position et de la vitesse, est proposé. De telle sorte qu'avec la combinaison des deux résultats, le suivi de trajectoire exponentielle avec retour de position est donné
This thesis focuses on the design of robust control for nonlinear systems, mainly on mechanical systems. The results presented are to two situations widely discussed in control theory: 1) The stability of nonlinear systems disturbed; 2) The global tracking trajectory in mechanical systems having only knowledge of the position. We started giving a design method of robust controls to ensure regulation on non-passive output. In addition, if the system is perturbed (constant unmatched), rigorous proof to its rejection is provided. This result is based mainly on change of coordinates and integral dynamic control. When the scenario to deal are mechanical systems with time-varying matched and unmatched, disturbance, the system is endowed with strong properties as IISS (Integral Input-State Stable) and ISS (Input-State Stable). This is achieved based on the design method to rejection of constant disturbances (unmatched). However, due to the nonlinearity of the system, the controllers have a high complexity. For the same problem, a second and elegant result is given making a initial change of coordinate on the momenta variable, such that the controller significantly simplifies, preserving the aforementioned robustness properties. Finally, a convincing answer to the problem of global exponential tracking of mechanical systems is given taking into account only the position information. We solve this problem in two steps. First, some slight variation is presented to the proof of stability of a speed observer based on Immersion and Invariance theory recently published. Note that this is a speed observer satisfying the exponential convergence speed in mechanical systems. Secondly, and based on the change of coordinates (momenta), a globally exponentially stable tracking controller with position and velocity known is proposed. The combination of both results give the first global exponential tracking controller of mechanical systems without velocity measurements

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Maya, Gonzalez Martin. "Frequency domain analysis of feedback interconnections of stable systems." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/frequency-domain-analysis-of-feedback-interconnections-of-stable-systems(c6415a11-3417-48ba-9961-ecef80b08e0e).html.

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The study of non-linear input-output maps can be summarized by three concepts: Gain, Positivity and Dissipativity. However, in order to make efficient use of these theorems it is necessary to use loop transformations and weightings, or so called ”multipliers”.The first problem this thesis studies is the feedback interconnection of a Linear Time Invariant system with a memoryless bounded and monotone non-linearity, or so called Absolute Stability problem, for which the test for stability is equivalent to show the existence of a Zames-Falb multiplier. The main advantage of this approach is that Zames–Falb multipliers can be specialized to recover important tools such as Circle criterion and the Popov criterion. Albeit Zames-Falb multipliers are an efficient way of describing non-linearities in frequency domain, the Fourier transform of the multiplier does not preserve the L1 norm. This problem has been addressed by two paradigms: mathematically complex multipliers with exact L1 norm and multipliers with mathematically tractable frequency domain properties but approximate L1 norm. However, this thesis exposes a third factor that leads to conservative results: causality of Zames-Falb multipliers. This thesis exposes the consequences of narrowing the search Zames-Falb multipliers to causal multipliers, and motivated by this argument, introduces an anticausal complementary method for the causal multiplier synthesis in [1].The second subject of this thesis is the feedback interconnection of two bounded systems. The interconnection of two arbitrary systems has been a well understood problem from the point of view of Dissipativity and Passivity. Nonetheless, frequency domain analysis is largely restricted for passive systems by the need of canonically factorizable multipliers, while Dissipativity mostly exploits constant multipliers. This thesis uses IQC to show the stability of the feedback interconnection of two non-linear systems by introducing an equivalent representation of the IQC Theorem, and then studies formally the conditions that the IQC multipliers need. The result of this analysis is then compared with Passivity and Dissipativity by a series of corollaries.

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Kasal, Roshan Nivas. "Analysis of Passivity for Compliantly Controlled Robots." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1599138459663234.

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Jaballah, Belgacem. "Observateurs robustes pour le diagnostic et la dynamique des véhicules." Phd thesis, Université Paul Cézanne - Aix-Marseille III, 2011. http://tel.archives-ouvertes.fr/tel-00734379.

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Le cadre général du travail de recherche est l'amélioration de la sécurité routi ère pour les véhicules automobiles et les conducteurs en utilisant les outils automatique. Dans le cadre de la dynamique du véhicule, les e orts d'interaction entre le pneumatique et la chaussée sont des données indispensables d'où la nécessité d'estimer en temps réel les variables qui caractérisent ces e orts. Cette estimation est réalisée à l'aide des observateurs non linéaires tel que les observateurs à mode glissant d'ordre 1 et d'ordre supérieure. Une proposition de découpage de modèle dynamique complet de véhicule en trois sous-systèmes (caisse, suspensions et roues) en se basant sur la théorie de passivité. Tous ces théories sont validées à l'aide de deux simulateur de véhicule SCANeRstudio et SIMK106N.

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9

Welge-Lüssen, Tobias Carsten Lutz. "Design of a passively actuated robot manipulator /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17701.

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Mohammed, Ali. "PASSIVITY-BASED TRACKING CONTROL OF A ROBOT MANIPULATOR USING AN EXTENDED STATE OBSERVER." Cleveland State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=csu1590253786792864.

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11

Pantel, Erica. "Design and control of a passively stabilized multimodal hopping robot." Diss., [La Jolla] : University of California, San Diego, 2010. http://wwwlib.umi.com/cr/ucsd/fullcit?p1476561.

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Thesis (M.S.)--University of California, San Diego, 2010.
Title from first page of PDF file (viewed June 10, 2010). Available via ProQuest Digital Dissertations. Includes bibliographical references (leaf 68).

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Boxerbaum, Alexander Steele. "A Whegs Robot Featuring a Passively Compliant, Actively Controlled Body Joint." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1270238370.

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Lamy, Xavier. "Conception d'une Interface de Pilotage d'un Cobot." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://tel.archives-ouvertes.fr/tel-00748986.

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Dans le contexte industriel actuel, il existe encore un grand nombre de tâches pénibles qui ne peuvent pas être automatisées, et où le geste humain reste indispensable. L'introduction d'une assistance robotique peut alors être envisagée pour réduire les efforts que l'opérateur doit fournir, et ainsi éviter l'occurrence de troubles musculosquelettiques. En permettant à l'opérateur de manipuler conjointement un outil (ou objet) porté par le robot, il est possible envisager une collaboration sous forme de compensation de gravité, d'augmentation d'effort ou de réalisation de guides virtuels. Les robots industriels peuvent être des candidats pertinents pour ce type de collaboration, car leurs qualités mécaniques sont particulièrement complémentaires à celles de l'homme : ils sont notamment optimisés pour avoir une grande force, rigidité et précision absolue. Cependant les frottements dans les articulations et l'inertie importante de ces robots s'opposent à une interaction physique avec l'opérateur fluide et légère. L'utilisation d'un capteur d'effort au niveau de l'effecteur et d'une boucle d'effort est donc incontournable. On montre que la stabilité d'un système ainsi asservi dépend alors fortement de l'impédance mécanique qu'oppose la main de l'opérateur lorsqu'il manipule l'effecteur du robot. Nous appuierons notre étude sur une modélisation du robot capable de prendre en compte une flexibilité structurelle entre l'actionneur et la mesure d'effort, qui est à l'origine des limites de stabilité. Afin de résoudre le compromis performance/stabilité très contraignant qui en découle, nous proposons une loi de commande en impédance prenant en compte les caractéristiques de la prise de main sur une poignée d'interaction spécialement conçue. Pour caractériser la prise de main, il nous a été nécessaire de développer un capteur capable de cartographier la pression appliquée sur la surface arrondie de la poignée. Nous détaillons l'architecture et le fonctionnement d'un tel capteur, et montrons qu'il peut aussi être employé pour recouvrir le corps du robot. Nous proposons ainsi une solution pour assurer la sécurité de l'utilisateur vis-à-vis des autres parties mobiles du robot, peu sensibles aux interactions physiques avec l'opérateur ou avec son environnement. Nous complétons notre étude en considérant une interaction tripartite où le robot amplifie les efforts que l'opérateur applique sur l'outil. En adaptant les outils théoriques communément employés dans le domaine de la téléopération, nous menons une étude approfondie sur les limites de stabilité et de performances de ce dispositif. L'ensemble de ces travaux reposent sur des développements théoriques appuyés par des expérimentations sur un robot industriel réel.

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14

Tomlinson, Charles M. "Design and construction of a three degree-of-freedom lightweigh passively-damped robot arm." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/17094.

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Romero, Velázquez José Guadalupe. "Commande robuste par façonnement d'énergie de systèmes non-linéaires." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00797371.

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Cette thèse porte sur la conception de commandes robustes pour les systèmes non linéaires, mettant l'accent sur les systèmes mécaniques. Des résultats concluants sont présentés pour résoudre deux situations très abordées dans la théorie du contrôle : 1) La stabilité des systèmes non linéaires perturbés ; 2) Le suivi global de trajectoire dans les systèmes mécaniques en ayant seulement connaissance de la position. Nous avons commencé par donner une méthode de conception des commandes robustes pour assurer une régulation de sortie non passive. En outre, si le système est perturbé (pas appariés), des preuves rigoureuses pour les rejeter sont fournies. Ce résultat est principalement inspiré d'un changement de coordonnées et de l'action intégrale dynamique. Si le scénario à traiter concerne des systèmes mécaniques avec des perturbations variant dans le temps, nous dotons le système de propriétés comme IISS (Integral Input- State Stable) et ISS (Input-State Stable). Ce résultat est obtenu en modifiant la procédure de conception de manière à rejeter les perturbations constantes (pas appariés). Cependant, en raison de la non-linéarité du système, les commandes qui en résultent ont une grande complexité. Pour le même problème, un deuxième et élégant résultat est donné au cas où un changement préalable de variable (impulsions) est réalisé. Finalement, une réponse convaincante au problème de suivi de trajectoire pour les systèmes mécaniques est donnée en tenant compte uniquement des informations de position. Nous résolvons ce problème en deux étapes. Premièrement, quelques modifications sont apportées à la preuve de stabilité d'un observateur de vitesse basée sur la théorie de l'invariance et l'Immersion récemment publié. Notez que ceci est un observateur satisfaisant la convergence exponentielle de vitesse dans les systèmes mécaniques. Deuxièmement et sur la base du changement de coordonnées (impulsions), un contrôleur de suivi avec stabilité exponentielle, tenant compte de la position et de la vitesse, est proposé. De telle sorte qu'avec la combinaison des deux résultats, le suivi de trajectoire exponentielle avec retour de position est donné.

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16

Ingvast, Johan. "Quadruped robot control and variable leg transmissions." Doctoral thesis, Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-600.

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Fantoni-Coichot, Isabelle. "Commande non linéaire des systèmes mécaniques sous-motorisés." Compiègne, 2000. http://www.theses.fr/2000COMP1301.

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Mes travaux présentent l'application d'algorithmes théoriques modernes non linéaires pour commander quelques classes importantes de systèmes mécaniques sous-actionnés, qui sont les systèmes ayant plus de degrés de liberté que d'actionneurs. L'obtention des modèles et le développement des différentes lois de commande sont décrits pour les systèmes suivants : le pendule inversé, le système du transport d'une grue, le système du pendubot, le pendule rotationnel de Furuta, le pendule actionné par une roue inertielle, le système constitué de plusieurs bras reliés par des ressorts sur un plan horizontal, le robot manipulateur planaire possédant deux joints prismatiques et un joint de révolution. Pour chaque système, le modèle est obtenu en utilisant le formalisme d'Euler-Lagrange. Puisque l'utilisation des techniques standard de commande non linéaire ne sont pas toujours applicables pour de tels systèmes, il a été montré qu'une approche basée sur l'énergie et sur les propriétés de passivité de chaque système pouvait être appliquée pour établir l'algorithme de commande et ainsi résoudre le problème de stabilisation. L'approche a été basée sur la théorie de Lyapunov et l'analyse de la stabilité a été étudiée pour chaque système pour prouver la convergence de l'algorithme vers un ensemble invariant désiré. Des simulations et des applications réelles ont illustré la performance des algorithmes sur plusieurs plates-formes expérimentales. Des algorithmes de contrôle ont également été établis pour deux véhicules sous-motorisés : l'aéroglisseur et l'avion à décollage et atterrissage vertical. Différentes stratégies de commande basées sur la théorie de Lyapunov ont été proposées pour arrêter simplement le système de l'aéroglisseur ou bien le stabiliser à un endroit précis. Pour le PVTOL, la construction d'une fonction de Lyapunov a été établie et a donné lieu à une nouvelle loi de commande basée sur la technique du forwarding.

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Splendori, Roberta. "Development of control algorithm for adjusting the needle insertion path during robot assisted breast biopsy procedure." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.

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The MURAB project, created and developed by the RAM group at the university of Twente in the Netherlands, aims to improve the precision and the efficiency of the breast biopsy procedure, reducing as much as possible the intervention time and the discomfort for the patient. In this framework, a lot of studies have been conducted concerning efficient control methods capable of positioning the end effector of a KUKA LBR Med robotic arm at the location where the hypothetical lesion has been individualized. Starting from these methods, the main goal of this Thesis is to develop a control algorithm able to modify the robot trajectory such that it can find and reach the lesion position, even in presence of variations of this target location; caused for example by small patient’s motions. After a brief literature review about the already existing robot assisted breast biopsy procedures, an elaborated study relative to the control strategies adopted in the collaboration and interaction between humans and robotic systems has been presented. This leads to the characterization and implementation of the final controller, defined as an impedance controller with energy and power limitations to increase the safety of the patient and energy tanks to ensure passivity. The validity and the stability of this control approach have been analyzed and tested firstly with a 20 sim simulation and then with experiments in laboratory. The results will show how it is possible to compensate rotational and / or translational errors in the robot end effector’s positioning through a suitable tuning of some parameters, while keeping a good image quality of the determined target and without loosing contact between the probe and the breast phantom / skin. Meanwhile, a proper characterization of the controller’s parameters allows to guarantee the compliance of the manipulator, fundamental to ensure the safety of the patient and of the interaction of the robot with the surrounding environment.

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Forbes, James Richard. "Design of Optimal Strictly Positive Real Controllers Using Numerical Optimization for the Control of Large Flexible Space Structures." Thesis, 2008. http://hdl.handle.net/1807/11142.

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The design of optimal strictly positive real (SPR) compensators using numerical optimization is considered. The plants to be controlled are linear and nonlinear flexible manipulators. For the design of SISO and MIMO linear SPR controllers, the optimization objective function is defined by reformulating the H2-optimal control problem subject to the constraint that the controllers must be SPR. Various controller parameterizations using transfer functions/matrices and state-space equations are considered. Depending on the controller form, constraints are enforced (i) using simple inequalities guaranteeing SPRness, (ii) in the frequency domain, or (iii) by implementing the Kalman-Yakubovich- Popov lemma. The design of a gain-scheduled SPR controller using numerical optimization is also considered. Using a family of linear SPR controllers, the time dependent scheduling signals are parameterized, and the objective function of the optimizer seeks to find the form of the scheduling signals which minimizes the manipulator tip tracking error while minimizing the control effort.

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Teo, Yik Ren. "Passivity-Based Control of a class of Underactuated Robotic System." Thesis, 2013. http://hdl.handle.net/1959.13/1039266.

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Masters Research - Master of Philosophy (MPhil)
The control problem investigated in this thesis is motivated by the desire to use standard off-the-shelf robotics combined with advanced motion control for aerospace automated manufacturing. Aerospace manufacturing is characterised by a low production rate, tight tolerances, and production of large components. These unique characteristics have led to the use of custom made robotic manipulators for automated manufacturing. Such robots are expensive and hard to maintain. Hence, the combination of standard off-the-shelf robots with advanced control is an attractive alternative for some applications. The use of the lighter robots brings the problem of undesired vibrations, which can affect the required tolerances. These vibrations appear in components of the robotic system, which are not actuated; and thus, the control problem result in that of an underactuated mechanical system. Since robot motion follows the physical laws of mechanics, motion control designs based on energy-related properties like passivity and dissipativity have been very successful. Passive systems are a class of dynamic systems in which a magnitude akin to energy is exchanged between the system and its environment, and the rate at which this magnitude is exchanged is not less than the increase of its storage in the system. When the systems under study are physical, passivity relates to the exchange of energy; thus, physical passive systems can never store more energy than that supplied by the environment, and under certain conditions passivity ensures stability. The analogy to magnitudes akin to energy allows one to use a powerful set of mathematical tools related to physical phenomena for designing control systems in different areas of science and technology. We consider an idealised physical system representative of a class of robotic systems that has a robotic manipulator mounted on a base that can vibrate due to the motion of the robotic manipulator. The base is assumed to be unactuated. We derive a Port- Hamiltonian System (PHS) model. The important property of PHS models is that of passivity, which leads to stability. This characteristic of PHS models has been exploited to develop different energy-based control techniques. In this project, we explore the use of a control design technique called Interconnection and Damping Assignment Passivity Based Control (IDA-PBC). This strategy seeks to design a controller that shapes the energy of the system through its interconnection and injects damping so that the closedloop system results in a PHS. With such closed-loop system, the closed-loop Hamiltonian can be used as natural Lyapunov function to demonstrate stability. We addressed the problem in different stages. We first consider the problem of set point regulation for the end effector of the robot. Then we extend the problem to incorporate integral action to increase robustness to slowly-varying disturbances using dynamic extension. Finally, we consider the problem of trajectory tracking with and without integral action. This thesis is the result of research collaboration between Boeing Research & Technology Australia and the University of Newcastle. The idealised physical system considered in the thesis is motivated by a SCARA-Tau parallel kinematic robot manipulator. The particular task envisaged for this robot requires the robot to be mounted such that the axis of rotation is horizontal. Such configuration results in a non-axial gravity field, and as the robot moves, a heavy tool it is expected to excite some of the resonant modes of both the robot and base on which the robot is mounted. The results obtained for the idealised physical model in terms of accuracy of tool motion show a significant performance improvement with respect to other techniques proposed in the literature. Furthermore, through the addition of integral action the system is able to deal with constant external disturbances and provide robustness to modelling uncertainty. The addition of integral action and the design of tracking controllers for underactuated mechanical system in the Port-Hamiltonian framework has not been developed in the literature. Hence, this is a significant contribution to the field.

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21

Huang, Chin-I., and 黃勤鎰. "Controlling Constrained and Coordinated Robots by Using Adaptive, Sliding-Mode, and Passivity-Based Methods." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/11283845987027035825.

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Abstract:

碩士
中原大學
電機工程學系
88
In this thesis, the motion and force control for asymptotic tracking of constrained robots and coordinated manipulators using adaptive, sliding mode and passivity-based methods is pro-posed. For constrained robots with joint flexibility, two strategies are employed. One method is to use a composite adaptive control plus backstepping method to obtain achieve zero mo-tion /force tracking errors. Another method is to use smooth sliding mode control plus back-stepping method to obtain good performance for flexible joint constrained manipulators under influence of disturbance. In robot control, the velocity measurement is often needed. Never-theless, under boundwidth consideration the velocity feedback has some disadvantages. Therefore, to avoid this a passivity-based observer and controller is designed. These strategies use the property of conceptual duality, i.e., the structure of controller and observer is similar can be switched with one another. The advantages of the proposed controller include its sim-ple structure and the design strategies are more easy and general. The simulation results show that the motion and force tracking errors converge to zero for both constrained and coordinat-ed robots.

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Alghamdi, Norah K. "Modeling Human Learning in Games." Thesis, 2020. http://hdl.handle.net/10754/666444.

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Abstract:

Human-robot interaction is an important and broad area of study. To achieve success- ful interaction, we have to study human decision making rules. This work investigates human learning rules in games with the presence of intelligent decision makers. Par- ticularly, we analyze human behavior in a congestion game. The game models traffic in a simple scenario where multiple vehicles share two roads. Ten vehicles are con- trolled by the human player, where they decide on how to distribute their vehicles on the two roads. There are hundred simulated players each controlling one vehicle. The game is repeated for many rounds, allowing the players to adapt and formulate a strategy, and after each round, the cost of the roads and visual assistance is shown to the human player. The goal of all players is to minimize the total congestion experienced by the vehicles they control. In order to demonstrate our results, we first built a human player simulator using Fictitious play and Regret Matching algorithms. Then, we showed the passivity property of these algorithms after adjusting the passivity condition to suit discrete time formulation. Next, we conducted the experiment online to allow players to participate. A similar analysis was done on the data collected, to study the passivity of the human decision making rule. We observe different performances with different types of virtual players. However, in all cases, the human decision rule satisfied the passivity condition. This result implies that human behavior can be modeled as passive, and systems can be designed to use these results to influence human behavior and reach desirable outcomes.

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Yu-Cheng, Lin, and 林育正. "A Study on Application of Passively Compliant End Effectors for Robot Manipulators." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/88093183343457410786.

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Abstract:

碩士
大同工學院
機械工程研究所
86
Three application systems for real time modification of robot trajectory are studied in the thesis. The first system is the simulating system of automatic welding of robot.The second system, which can be applied in reverse engineering, is the measurement system of object's profile.The third system is for automatic surface polishing for unknown three-dimensional surface.The systems use passive end-effectors, which can be mounted on the wrist of industrial robots.As work proceeds, the end-effectors use position sensors to measure the deviation of the robot's programmed trajectories from the real workpiece profiles.A personal computer is used to acquire sensory data, and compute the desired adjustment of the robot motion.The adjustment is then sent to the robot controller and is executed in a point-to-point manner.Low bandwidth point-to-point control is possible because of the passive compliant movement of the end-effectors.The systems are tested experimentally.Experimental results show that real time robot trajectory compensation can be satisfactorily achieved in a point to point manner if a passive end-effector system is designed and installed as proposed in this thesis.

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Dissertations / Theses on the topic 'Robust passivity'

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