A pesquisa na área de robótica espacial lida com problemas exclusivos, acarretados pela natureza e características dinâmicas dos sistemas. Isso torna a modelagem uma área de extrema importância para garantir um desempenho satisfatório. A maior característica dos braços robóticos espaciais é que seu movimento perturba a espaçonave na qual está acoplado. Essa propriedade deve ser levada em consideração, especialmente no caso de robôs de base livre flutuante que não possuem controle de posição ou atitude na base. A maior destreza e flexibilidade de manipuladores de múltiplos braços faz com que sua pesquisa seja colocada em foco. Eles possuem maior possibilidade de lidar com cargas maiores e fornecer maior acurácia em tarefas como montagens, reparos, abastecimento, etc. Nesse contexto, o presente trabalho tem como objetivo o desenvolvimento do modelo de um manipulador espacial de base livre flutuante de dois braços. Esse modelo, então, foi aplicado no desenvolvimento de um sistema de controle. A metodologia sugerida facilita, não só a obtenção do modelo, como também a especificação de controladores. Dois esquemas de controle foram desenvolvidos: um no espaço da tarefa e outro no espaço das juntas, com diferentes especificações de trajetórias. A simulação do sistema foi realizada no ambiente Simulink (MATLAB) e os resultados são discutidos, indicando as situações de falha dos controladores especificados. / Space robotics research faces unique problems, which are mainly related to the intrinsic nature and dynamic characteristics of its systems. As a consequence, modelling becomes essential to guarantee the best system result. A important characteristic of space robotic arms is that their movements affect their bases position and attitude. This property must be taken into account, specially in the case of free floating space manipulators which have no control system for the base. High dexterity and flexibility of multi-arm manipulators cause their research to be a focus for the community. With higher loads and accuracy demands, they are more likely to suceed in tasks such as maintenance, assembly, refueling, among others. In that context, this thesis aims to develop a model for a dual-arm free-floating space manipulator. The model, then, is used in the design of a control system. The suggested methodology makes the process easier not only the modelling, but also the controller design. Two control schemes were developed: one in joint and the other in task space, with different trajectories. System simulations were run on Simulink (MATLAB) and the obtained results were discussed, with comments regarding fault situations for the specified control systems.

Nas linhas de montagens industriais, a fim de atender os requisitos de mercado e de ciclo de vida dos produtos, os requisitos de manufatura e as novas tecnologias presentes nos equipamentos indicam a necessidade de reconfiguração e reprogramação do fluxo de processos de forma cada vez mais frequente. Atualmente, uma das opções para implantar um sistema de manufatura flexível, capaz de reagir às mudanças que ocorrem no processo de fabricação, consiste na utilização de tecnologias que forneçam maior flexibilidade, capacidade de reutilização e menor custo. Neste contexto, os robôs baseados em módulos mecatrônicos podem ser uma alternativa em relação aos manipuladores convencionais, pois apresentam uma estrutura cinemática flexível, podendo se adaptar às mudanças das linhas de produção, nas indústrias de manufatura. O presente trabalho apresenta uma proposta para o desenvolvimento de módulos mecatrônicos para a montagem de robôs manipuladores modulares, baseada em um procedimento sequencial composto das seguintes etapas: (a) elaboração do projeto mecânico modular; (b) projeto dos sistemas eletrônicos e de atuação para cada módulo; (c) definição dos agentes mecatrônicos; e (d) descrição dos modelos matemáticos e os algoritmos de comunicação entre módulos mecatrônicos. Nesta pesquisa apresenta-se um estudo no qual os módulos mecatrônicos utilizam energia de origem pneumática e são constituídos por unidades independentes utilizadas na formação de estruturas robotizadas as quais permitem a montagem de diferentes arquiteturas. Um estudo de caso é apresentado para ilustrar a construção de um robô modular cartesiano. Este robô é construído por meio de acoplamentos de módulos mecatrônicos e gerenciado pela associação dos agentes mecatrônicos presentes no sistema, os quais equacionam a cinemática da estrutura formada, planejam a trajetória a ser executada e disponibilizam informações que podem ser utilizadas para o controle, supervisão e proteção do sistema por exemplo. A arquitetura proposta permite a reconfiguração dos recursos de hardware e software, de forma que todos os módulos do robô podem ser reorganizados e/ou substituídos, dependendo da função, aplicação para as quais se destinam. / In industrial manufacturing lines, in order to meet the market requirements and life cycle of manufactured products, the manufacturing requirements and the present of new technologies in equipment, indicate the need for reconfiguration and reprogramming processes, which are becoming more frequent. Currently, one of the options to deploy a flexible manufacturing system that is capable of reacting to changes in the manufacturing process is the use of technologies that provide greater flexibility, reusability and lower cost. In this context, the robots based on mechatronic modules can be an alternative to conventional manipulators, since they have a flexible kinematic structure, which can adapt to the changes in production lines in manufacturing industries. This paper presents a proposal for the development of mechatronic modules for assembly robots modular manipulators, based on a sequential procedure consists of the following steps: (a) Develop a modular mechanical design; (b) design electronic systems and operations for each module; (c) definition of mechatronic agents; and (d) a description of mathematical models and algorithms of the communication between mechatronic modules. This research presents a study where the mechatronic modules use pneumatic energy and consist of independents units used in the formation of robotic structures, thus allowing the assembly of different architectures. In a case study, the construction of a modular Cartesian robot is presented. This robot is built by mounting the mechatronic modules and is managed by mechatronic agents present in the system (Multi-Agent System). This system obtains the kinematic equations of the formed structure, realize the path planning, and provide information that can be used for the control, like supervision and protection system for example. The proposed architecture allows reconfiguration of hardware and software resources, so that all robot modules can be rearranged and/or replaced, depending on the function or, the final application.

Propõe-se, com este trabalho, estudar numericamente se a redundância cinemática e a redundância de atuação podem ser boas alternativas para que manipuladores planares de cinemática paralela atinjam altas acelerações. Sabe-se que estes tipos de redundância promovem uma redução de singularidades do sistema robótico entre outros benefícios. No entanto, a avaliação comparativa do desempenho dinâmico de manipuladores redundantes ainda é pouco estudada. Este estudo não é trivial pois a redundância significa não somente o aumento do torque disponível, mas também que a inércia do sistema foi aumentada. A avaliação numérica deste trabalho se dará por meio do desenvolvimento de modelos cinemáticos e dinâmicos das possíveis configurações de manipuladores paralelos planares com redundância cinemática e redundância de atuação. Esta avaliação pode ser feita pela comparação entre os manipuladores redundantes e o não-redundante para desenvolver uma mesma trajetória do end-effector. Entretanto, esta avaliação é dependente da trajetória, logo esse trabalho também propõe uma avaliação através de um índice dinâmico em toda a área de trabalho dos manipuladores. / The aim of this work is to study numerically if the kinematic redundancy and the actuation redundancy can be good alternatives for parallel planar manipulators to achieve high accelerations. It is known that types of redundancy promote, among other benefits, a significant reduction in the singularities. However, the evaluation of the redundancy as a good solution to increase the dynamic performance was not studied. This study is not trivial because the redundancy means not only that there is more torque available, but also that the inertia of the system has been considerably increased. Different configurations of the redundant manipulator will be evaluated numerically through kinematic and dynamic models. This evaluation can be performed by the comparison among the non redundant manipulator and the redundant manipulators to execute the same task. This evaluation is task dependent, so this work proposes a dynamic index to desing dynamic maps over the workspace.

A pesquisa na área de robótica espacial lida com problemas exclusivos, acarretados pela natureza e características dinâmicas dos sistemas. Isso torna a modelagem uma área de extrema importância para garantir um desempenho satisfatório. A maior característica dos braços robóticos espaciais é que seu movimento perturba a espaçonave na qual está acoplado. Essa propriedade deve ser levada em consideração, especialmente no caso de robôs de base livre flutuante que não possuem controle de posição ou atitude na base. A maior destreza e flexibilidade de manipuladores de múltiplos braços faz com que sua pesquisa seja colocada em foco. Eles possuem maior possibilidade de lidar com cargas maiores e fornecer maior acurácia em tarefas como montagens, reparos, abastecimento, etc. Nesse contexto, o presente trabalho tem como objetivo o desenvolvimento do modelo de um manipulador espacial de base livre flutuante de dois braços. Esse modelo, então, foi aplicado no desenvolvimento de um sistema de controle. A metodologia sugerida facilita, não só a obtenção do modelo, como também a especificação de controladores. Dois esquemas de controle foram desenvolvidos: um no espaço da tarefa e outro no espaço das juntas, com diferentes especificações de trajetórias. A simulação do sistema foi realizada no ambiente Simulink (MATLAB) e os resultados são discutidos, indicando as situações de falha dos controladores especificados. / Space robotics research faces unique problems, which are mainly related to the intrinsic nature and dynamic characteristics of its systems. As a consequence, modelling becomes essential to guarantee the best system result. A important characteristic of space robotic arms is that their movements affect their bases position and attitude. This property must be taken into account, specially in the case of free floating space manipulators which have no control system for the base. High dexterity and flexibility of multi-arm manipulators cause their research to be a focus for the community. With higher loads and accuracy demands, they are more likely to suceed in tasks such as maintenance, assembly, refueling, among others. In that context, this thesis aims to develop a model for a dual-arm free-floating space manipulator. The model, then, is used in the design of a control system. The suggested methodology makes the process easier not only the modelling, but also the controller design. Two control schemes were developed: one in joint and the other in task space, with different trajectories. System simulations were run on Simulink (MATLAB) and the obtained results were discussed, with comments regarding fault situations for the specified control systems.

Individuals with disabilities yearn for an increased level of independence, seeking to supplement their missing function(s) and to carry on with their lives with minimal or no assistance from another person. A review of the existing assistive-care products has revealed that many of the defects in these devices, particularly in wheelchair-mounted robots, can be alleviated. Surveys have also identified tasks that users would like to perform by themselves, but are constrained from doing so by using currently available devices. An attempt has been made here to try to resolve these issues by developing a prototype of a marsupial robot that can dock into the powered wheelchair that is used for manipulation purposes. The primary function of this system is to assist the user in his/her daily tasks such as pick-up small objects and place them as per the user's commands, push to open/close doors and remove obstacles from the wheelchair path. It is with the objective of providing an enhanced quality of life to a person with impairment(s) that a proposal for a simple, safe and inexpensive approach to assist him/her in performing an activity is made here.

One of the main advantages of the Gantry-Tau machine is a large accessible workspace\footprint ratio compared to many other parallel machines. The Gantry-Tau improves this ratio further by allowing a change of assembly mode without internal link collisions or collisions between the links and the moving TCP platform. In this Thesis some of the features of the Gantry-Tau structure are described and results are presented from the analysis of the kinematic, elastostatic and elastodynamic properties of the PKM. However, the optimal kinematic, elastostatic and elastodynamic design parameters of the machine are still difficult to calculate and this thesis introduces a multi-objective optimisation scheme based on the geometric approach for the workspace area, unreachable area, joint angle limitations and link collisions as well as the functional dependencies of the elements of the static matrix and the Laplace transform to define the first resonance frequency and Cartesian and torsional stiffness. The method to calculate the first resonance frequency assumes that each link and universal joint can be described by a mass-springdamper model and calculates the transfer function from a Cartesian (TCP) force or torque to Cartesian position or orientation. The geometric methods involve the simple geometric shapes (spheres, circles, segments, etc) and vectors. The functional dependencies are based on the properties between the kinematic parameters. These approaches are significantly faster than analytical methods based on the inverse kinematics or the general Finite Elements Method (FEM). The reconfigurable Gantry-Tau kinematic design obtained by multi-objective optimisation gives the following features: • Workspace/footprint ratio more than 3.19. • First resonance frequency greater than 48 Hz. • Lowest Cartesian stiffness in the workspace 5N/μm. • The unreachable space in the middle of the workspace is not detected. • No link collisions. The results show that by careful design of the PKM, a collision free workspace without the unreachable area in the middle can be achieved. High stiffness and high first resonance frequency are important parameters for the the Gantry-Tau when used in industrial applications, such as cutting, milling and drilling of steel or aluminium and pick-and-place operations. These applications require high static and dynamic accuracy in combination with high speed and acceleration. The optimisation parameters are the support frame lengths, actuator positions,endeffector kinematics and the robot’s arm lengths. Because of the fast computational speed of the geometric approaches and computational time saving of the methods based on the functional dependency, they are ideal for inclusion in a design optimisation framework, normally a nonlinear optimisation routine. In this Thesis the evolutionary algorithm based on the complex search method is used to optimise the 3-DOF Gantry-Tau. The existing lab prototype of this machine was assembled and completed at the University of Agder

<p>In this thesis a novel method for controlling a manipulator with arbitrary number of Degrees of freedom is proposed, the proposed method has the main advantages of two common controllers, the simplicity of PID controller and the robustness and accuracy of adaptive controller. The controller architecture is based on an Artificial Neural Network (ANN) and a PID controller.</p><p>The controller has the ability of solving inverse dynamics and inverse kinematics of robot with two separate Artificial Neural Networks. Since the ANN is learning the system parameters by itself the structure of controller can easily be changed to</p><p>improve the performance of robot.</p><p>The proposed controller can be implemented on a FPGA board to control the robot in real-time or the response of the ANN can be calculated offline and be reconstructed by controller using a lookup table. Error between the desired trajectory path and the path of the robot converges to zero rapidly and as the robot performs its tasks the controller learns the robot parameters and generates better control signal. The performance of controller is tested in simulation and on a real manipulator with satisfactory results.</p>

Industrial robot manipulators are general-purpose machines used for industrial automation in order to increase productivity, flexibility, and product quality. Other reasons for using industrial robots are cost saving, and elimination of hazardous and unpleasant work. Robot motion control is a key competence for robot manufacturers, and the current development is focused on increasing the robot performance, reducing the robot cost, improving safety, and introducing new functionalities.  Therefore, there is a need to continuously improve the mathematical models and control methods in order to fulfil conflicting requirements, such as increased performance of a weight-reduced robot, with lower mechanical stiffness and more complicated vibration modes. One reason for this development of the robot mechanical structure is of course cost-reduction, but other benefits are also obtained, such as lower environmental impact, lower power consumption, improved dexterity, and higher safety. This thesis deals with different aspects of modeling and control of flexible, i.e., elastic, manipulators. For an accurate description of a modern industrial manipulator, this thesis shows that the traditional flexible joint model, described in literature, is not sufficient. An improved model where the elasticity is described by a number of localized multidimensional spring-damper pairs is therefore proposed. This model is called the extended flexible joint model. The main contributions of this work are the design and analysis of identification methods, and of inverse dynamics control methods, for the extended flexible joint model. The proposed identification method is a frequency-domain non-linear gray-box method, which is evaluated by the identification of a modern six-axes robot manipulator. The identified model gives a good description of the global behavior of this robot. The inverse dynamics problem is discussed, and a solution methodology is proposed. This methodology is based on the solution of a differential algebraic equation (DAE). The inverse dynamics solution is then used for feedforward control of both a simulated manipulator and of a real robot manipulator. The last part of this work concerns feedback control. First, a model-based nonlinear feedback control (feedback linearization) is evaluated and compared to a model-based feedforward control algorithm. Finally, two benchmark problems for robust feedback control of a flexible manipulator are presented and some proposed solutions are analyzed.

In this thesis a novel method for controlling a manipulator with arbitrary number of Degrees of freedom is proposed, the proposed method has the main advantages of two common controllers, the simplicity of PID controller and the robustness and accuracy of adaptive controller. The controller architecture is based on an Artificial Neural Network (ANN) and a PID controller. The controller has the ability of solving inverse dynamics and inverse kinematics of robot with two separate Artificial Neural Networks. Since the ANN is learning the system parameters by itself the structure of controller can easily be changed to improve the performance of robot. The proposed controller can be implemented on a FPGA board to control the robot in real-time or the response of the ANN can be calculated offline and be reconstructed by controller using a lookup table. Error between the desired trajectory path and the path of the robot converges to zero rapidly and as the robot performs its tasks the controller learns the robot parameters and generates better control signal. The performance of controller is tested in simulation and on a real manipulator with satisfactory results.

Parallel manipulators have been the subject of study of much robotic research during the past three decades. A parallel manipulator typically consists of a moving platform that is connected to a fixed base by at least two kinematic chains in parallel. Parallel manipulators can provide several attractive advantages over their serial counterpart in terms of high stiffness, high accuracy, and low inertia, which enable them to become viable alternatives for wide applications. But parallel manipulators also have some disadvantages, such as complex forward kinematics, small workspace, complicated structures, and a high cost. To overcome the above shortcomings, progress on the development of parallel manipulators with less than 6-DOF has been accelerated. However, most of presented parallel manipulators have coupled motion between the position and orientation of the end-effector. Therefore, the kinematic model is complex and the manipulator is difficult to control. Only recently, research on parallel manipulators with less than six degrees of freedom has been leaning toward the decoupling of the position and orientation of the end-effector, and this has really interested scientists in the area of parallel robotics. Kinematic decoupling for a parallel manipulator is that one motion of the up-platform only corresponds to input of one leg or one group of legs. And the input cannot produce other motions. Nevertheless, to date, the number of real applications of decoupled motion actuated parallel manipulators is still quite limited. This is partially because effective development strategies of such types of closed-loop structures are not so obvious. In addition, it is very difficult to design mechanisms with complete decoupling, but it is possible for fewer DOF parallel manipulators. To realize kinematic decoupling, the parallel manipulators are needed to possess special structures; therefore, investigating a parallel manipulator with decoupling motion remains a challenging task. This thesis deals with lower mobility parallel manipulator with decoupled motions. A novel parallel manipulator is proposed in this thesis. The manipulator consists of a moving platform that is connecting to a fixed base by three legs. Each leg is made of one C (cylinder), one R (revolute) and one U (universal) joints. The mobility of the manipulator and structure of the inactive joint are analyzed. Kinematics of the manipulator including inverse and forward kinematics, velocity equation, kinematic singularities, and stiffness are studied. The workspace of the parallel manipulator is examined. A design optimization is conducted with the prescribed workspace. It has been found that due to the special arrangement of the legs and joints, this parallel manipulator performs three translational degrees of freedom with decoupled motions, and is fully isotropic. This advantage has great potential for machine tools and Coordinate Measuring Machine (CMM). / UOIT