Design and implementation of 3-RRR spherical parallel robot with three coaxial actuator

This work, entitled “Design and Implementation of 3-RRR Spherical Parallel Robot with Three Coaxial Actuators” has had the scope to analytically study the kinematics (both inverse and forward one) of a coaxial configuration of a spherical manipulator. The complete 3D design of the robot has been realised, building it thanks to a 3D printing process called FDM Technology (fused deposition modelling). Moreover, it has been modelled a Feed-Forward Position Control in order to move the three electrical motors, in Matlab environment. As for the state of the art, this thesis has distanced itself from the literature before [5, 4, 6, 3], not using a Denavith-Hartenberg’s approach or a loop equation process, in order to describe the kinematics, but investigating on new method, that could be more efficient in a computational terms, and exploiting its peculiar characteristics and functioning. For these reasons, it has been chosen a geometric method [20] to realise the analytical model of the manipulator. This approach has involved only constant and variable distances, relative to a set of fundamental points, after defining the parameters of the robot’s architecture. In the end, these choices, mentioned before, lead to obtain, as a results, a clear simulation of the robot, in order to better manage it and to focus on the core of both the kinematics and implementations, instead of the traditional process to obtain them, already investigated in literatureIncomin

Omni-joint; proof of concept & comparative Study

Robots mainly consist of links and joints, hence studying different joints and coming up with new joints will contribute in advancing robots. The methodology used in this thesis is; Proofing the concept of the Omni-Joint by theoretical analysis and manufacturing a prototype, comparing the following revolute joints; Omni-Joints, Hooke\u27s joint, and Ordinary joint. The comparison is regarding; points of singularity, range of field of motion, inverse kinematics and applying it on different paths using MATLAB, and finally studying the stresses on the Omni-Joint using FEM with CAD software AutoDesk-Inventor in different postures. The results are that unlike the Ordinary-joint and the Hooke-joint the Omni-Joint has; no singularities, continues range of field of motion, simple one to one kinematics

Kinematics and Robot Design II (KaRD2019) and III (KaRD2020)

This volume collects papers published in two Special Issues “Kinematics and Robot Design II, KaRD2019” (https://www.mdpi.com/journal/robotics/special_issues/KRD2019) and “Kinematics and Robot Design III, KaRD2020” (https://www.mdpi.com/journal/robotics/special_issues/KaRD2020), which are the second and third issues of the KaRD Special Issue series hosted by the open access journal robotics.The KaRD series is an open environment where researchers present their works and discuss all topics focused on the many aspects that involve kinematics in the design of robotic/automatic systems. It aims at being an established reference for researchers in the field as other serial international conferences/publications are. Even though the KaRD series publishes one Special Issue per year, all the received papers are peer-reviewed as soon as they are submitted and, if accepted, they are immediately published in MDPI Robotics. Kinematics is so intimately related to the design of robotic/automatic systems that the admitted topics of the KaRD series practically cover all the subjects normally present in well-established international conferences on “mechanisms and robotics”.KaRD2019 together with KaRD2020 received 22 papers and, after the peer-review process, accepted only 17 papers. The accepted papers cover problems related to theoretical/computational kinematics, to biomedical engineering and to other design/applicative aspects

Parallel Manipulators

In recent years, parallel kinematics mechanisms have attracted a lot of attention from the academic and industrial communities due to potential applications not only as robot manipulators but also as machine tools. Generally, the criteria used to compare the performance of traditional serial robots and parallel robots are the workspace, the ratio between the payload and the robot mass, accuracy, and dynamic behaviour. In addition to the reduced coupling effect between joints, parallel robots bring the benefits of much higher payload-robot mass ratios, superior accuracy and greater stiffness; qualities which lead to better dynamic performance. The main drawback with parallel robots is the relatively small workspace. A great deal of research on parallel robots has been carried out worldwide, and a large number of parallel mechanism systems have been built for various applications, such as remote handling, machine tools, medical robots, simulators, micro-robots, and humanoid robots. This book opens a window to exceptional research and development work on parallel mechanisms contributed by authors from around the world. Through this window the reader can get a good view of current parallel robot research and applications

Kinematics and Robot Design I, KaRD2018

This volume collects the papers published on the Special Issue “Kinematics and Robot Design I, KaRD2018” (https://www.mdpi.com/journal/robotics/special_issues/KARD), which is the first issue of the KaRD Special Issue series, hosted by the open access journal “MDPI Robotics”. The KaRD series aims at creating an open environment where researchers can present their works and discuss all the topics focused on the many aspects that involve kinematics in the design of robotic/automatic systems. Kinematics is so intimately related to the design of robotic/automatic systems that the admitted topics of the KaRD series practically cover all the subjects normally present in well-established international conferences on “mechanisms and robotics”. KaRD2018 received 22 papers and, after the peer-review process, accepted only 14 papers. The accepted papers cover some theoretical and many design/applicative aspects

Dynamic modeling, property investigation, and adaptive controller design of serial robotic manipulators modeled with structural compliance

Research results on general serial robotic manipulators modeled with structural compliances are presented. Two compliant manipulator modeling approaches, distributed and lumped parameter models, are used in this study. System dynamic equations for both compliant models are derived by using the first and second order influence coefficients. Also, the properties of compliant manipulator system dynamics are investigated. One of the properties, which is defined as inaccessibility of vibratory modes, is shown to display a distinct character associated with compliant manipulators. This property indicates the impact of robot geometry on the control of structural oscillations. Example studies are provided to illustrate the physical interpretation of inaccessibility of vibratory modes. Two types of controllers are designed for compliant manipulators modeled by either lumped or distributed parameter techniques. In order to maintain the generality of the results, neither linearization is introduced. Example simulations are given to demonstrate the controller performance. The second type controller is also built for general serial robot arms and is adaptive in nature which can estimate uncertain payload parameters on-line and simultaneously maintain trajectory tracking properties. The relation between manipulator motion tracking capability and convergence of parameter estimation properties is discussed through example case studies. The effect of control input update delays on adaptive controller performance is also studied

Advanced Strategies for Robot Manipulators

Amongst the robotic systems, robot manipulators have proven themselves to be of increasing importance and are widely adopted to substitute for human in repetitive and/or hazardous tasks. Modern manipulators are designed complicatedly and need to do more precise, crucial and critical tasks. So, the simple traditional control methods cannot be efficient, and advanced control strategies with considering special constraints are needed to establish. In spite of the fact that groundbreaking researches have been carried out in this realm until now, there are still many novel aspects which have to be explored

MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics

El libro de actas recoge las aportaciones de los autores a través de los correspondientes artículos a la Dinámica de Sistemas Multicuerpo y la Mecatrónica (Musme). Estas disciplinas se han convertido en una importante herramienta para diseñar máquinas, analizar prototipos virtuales y realizar análisis CAD sobre complejos sistemas mecánicos articulados multicuerpo. La dinámica de sistemas multicuerpo comprende un gran número de aspectos que incluyen la mecánica, dinámica estructural, matemáticas aplicadas, métodos de control, ciencia de los ordenadores y mecatrónica. Los artículos recogidos en el libro de actas están relacionados con alguno de los siguientes tópicos del congreso: Análisis y síntesis de mecanismos ; Diseño de algoritmos para sistemas mecatrónicos ; Procedimientos de simulación y resultados ; Prototipos y rendimiento ; Robots y micromáquinas ; Validaciones experimentales ; Teoría de simulación mecatrónica ; Sistemas mecatrónicos ; Control de sistemas mecatrónicosUniversitat Politècnica de València (2011). MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/13224Archivo delegad

Graphical modelling of modular machines

This research is aimed at advancing machine design through specifying and implementing (in "proof of concept" form) a set of tools which graphically model modular machines. The tools allow mechanical building elements (or machine modules) to be selected and configured together in a highly flexible manner so that operation of the chosen configuration can be simulated and performance properties evaluated. Implementation of the tools has involved an extension in capability of a proprietary robot simulation system. This research has resulted in a general approach to graphically modelling manufacturing machines built from modular elements. A focus of study has been on a decomposition of machine functionality leading to the establishment of a library of modular machine primitives. This provides a useful source of commonly required machine building elements for use by machine designers. Study has also focussed on the generation of machine configuration tools which facilitate the construction of a simulation model and ultimately the physical machine itself. Simulation aspects of machine control are also considered which depict methods of manipulating a machine model in the simulation phase. In addition methods of achieving machine programming have been considered which specify the machine and its operational tasks. Means of adopting common information data structures are also considered which can facilitate interfacing with other systems, including the physical machine system constructed as an issue of the simulation phase. Each of these study areas is addressed in its own context, but collectively they provide a means of creating a complete modular machine design environment which can provide significant assistance to machine designers. Part of the methodology employed in the study is based on the use of the discrete event simulation technique. To easily and effectively describe a modular machine and its activity in a simulation model, a hierarchical ring and tree data structure has been designed and implemented. The modularity and reconfigurability are accommodated by the data structure, and homogeneous transformations are adopted to determine the spatial location and orientation of each of the machine elements. A three-level machine task programming approach is used to describe the machine's activities. A common data format method is used to interface the machine design environment with the physical machine and other building blocks of manufacturing systems (such as CAD systems) where systems integration approaches can lead to enhanced product realisation. The study concludes that a modular machine design environment can be created by employing the graphical simulation approach together with a set of comprehensive configuration. tools. A generic framework has been derived which outlines the way in which machine design environments can be constructed and suggestions are made as to how the proof of concept design environment implemented in this study can be advanced

Design of Wheelchair Robot for Active Postural Support (WRAPS) for Users with Trunk Impairments

People with severe trunk impairments cannot maintain or control upright posture during sitting or reaching out with the upper body. Passive orthoses are clinically available to support the trunk and promote the use of upper extremities in this population. However, these orthoses only rigidly position the torso on a wheelchair but do not facilitate movement of the trunk. In this dissertation, we introduce a novel active-assistive torso brace system for upperbody movements by a subject while seated. We have named this system as Wheelchair Robot for Active Postural Support (WRAPS). We propose designs of two robots, one for the pelvis and the other for the trunk. Each of the two devices has a parallel chain architecture to accommodate the range of motion (ROM), respectively for the pelvic and thoracic segments. The first thoracic robot was designed for the upper trunk motion relative to the pelvis. It has a 2[RP]S-2UPS architecture which provides four degrees-of-freedom (DOFs) to the end-effector placed on the upper trunk. The second is a pelvic robot which is designed to orient the pelvic segment relative to the seat. It has a 3-DOF [RRR]U-2[RR]S architecture, coupled with translation to accommodate pelvic movements relative to the seat. These robot architectures are synthesized based on human movement data. WRAPS can modulate the displacement of both the pelvic and the thoracic segments. Additionally, the forces can be applied on the torso through the end-effectors of these robots. Each of the robot prototypes was evaluated with able-bodied subjects to assess the device wearability, kinematic performances, and control system