539 research outputs found
Design, modeling and implementation of a soft robotic neck for humanoid robots
Mención Internacional en el título de doctorSoft humanoid robotics is an emerging field that combines the flexibility and safety of soft
robotics with the form and functionality of humanoid robotics. This thesis explores the potential
for collaboration between these two fields with a focus on the development of soft joints for the
humanoid robot TEO. The aim is to improve the robot’s adaptability and movement, which are
essential for an efficient interaction with its environment.
The research described in this thesis involves the development of a simple and easily transportable
soft robotic neck for the robot, based on a 2 Degree of Freedom (DOF) Cable Driven
Parallel Mechanism (CDPM). For its final integration into TEO, the proposed design is later
refined, resulting in an efficiently scaled prototype able to face significant payloads.
The nonlinear behaviour of the joints, due mainly to the elastic nature of their soft links,
makes their modeling a challenging issue, which is addressed in this thesis from two perspectives:
first, the direct and inverse kinematic models of the soft joints are analytically studied,
based on CDPM mathematical models; second, a data-driven system identification is performed
based on machine learning techniques. Both approaches are deeply studied and compared, both
in simulation and experimentally.
In addition to the soft neck, this thesis also addresses the design and prototyping of a soft
arm capable of handling external loads. The proposed design is also tendon-driven and has a
morphology with two main bending configurations, which provides more versatility compared
to the soft neck.
In summary, this work contributes to the growing field of soft humanoid robotics through
the development of soft joints and their application to the humanoid robot TEO, showcasing the
potential of soft robotics to improve the adaptability, flexibility, and safety of humanoid robots.
The development of these soft joints is a significant achievement and the research presented in this thesis paves the way for further exploration and development in this field.La robótica humanoide blanda es un campo emergente que combina la flexibilidad y seguridad
de la robótica blanda con la forma y funcionalidad de la robótica humanoide. Esta
tesis explora el potencial de colaboración entre estos dos campos centrándose en el desarrollo
de una articulación blanda para el cuello del robot humanoide TEO. El objetivo es mejorar la
adaptabilidad y el movimiento del robot, esenciales para una interacción eficaz con su entorno.
La investigación descrita en esta tesis consiste en el desarrollo de un prototipo sencillo
y fácilmente transportable de cuello blando para el robot, basado en un mecanismo paralelo
actuado por cable de 2 grados de libertad. Para su integración final en TEO, el diseño propuesto
es posteriormente refinado, resultando en un prototipo eficientemente escalado capaz de manejar
cargas significativas.
El comportamiemto no lineal de estas articulaciones, debido fundamentalmente a la naturaleza
elástica de sus eslabones blandos, hacen de su modelado un gran reto, que en esta tesis
se aborda desde dos perspectivas diferentes: primero, los modelos cinemáticos directo e inverso
de las articulaciones blandas se estudian analíticamente, basándose en modelos matemáticos de
mecanismos paralelos actuados por cable; segundo, se aborda el problema de la identificación
del sistema mediante técnicas basadas en machine learning. Ambas propuestas se estudian y
comparan en profundidad, tanto en simulación como experimentalmente.
Además del cuello blando, esta tesis también aborda el diseño de un brazo robótico blando
capaz de manejar cargas externas. El diseño propuesto está igualmente basado en accionamiento
por tendones y tiene una morfología con dos configuraciones principales de flexión, lo que
proporciona una mayor versatilidad en comparación con el cuello robótico blando.
En resumen, este trabajo contribuye al creciente campo de la robótica humanoide blanda
mediante el desarrollo de articulaciones blandas y su aplicación al robot humanoide TEO, mostrando el potencial de la robótica blanda para mejorar la adaptabilidad, flexibilidad y seguridad
de los robots humanoides. El desarrollo de estas articulaciones es una contribución
significativa y la investigación presentada en esta tesis allana el camino hacia nuevos desarrollos
y retos en este campo.Programa de Doctorado en Ingeniería Eléctrica, Electrónica y Automática por la Universidad Carlos III de MadridPresidenta: Cecilia Elisabet García Cena.- Secretario: Dorin Sabin Copaci.- Vocal: Martin Fodstad Stole
A New Approach of Soft Joint Based on a Cable-Driven Parallel Mechanism for robotic Applications
A soft joint has been designed and modeled to perform as a robotic joint with 2 Degrees of Freedom (DOF) (inclination and orientation). The joint actuation is based on a Cable-Driven Parallel Mechanism (CDPM). To study its performance in more detail, a test platform has been developed using components that can be manufactured in a 3D printer using a flexible polymer. The mathematical model of the kinematics of the soft joint is developed, which includes a blocking mechanism and the morphology workspace. The model is validated using Finite Element Analysis (FEA) (CAD software). Experimental tests are performed to validate the inverse kinematic model and to show the potential use of the prototype in robotic platforms such as manipulators and humanoid robots.The research leading to these results has received funding from the project Desarrollo de articulaciones blandas para aplicaciones robóticas, with reference IND2020/IND-1739, funded by the Comunidad Autónoma de Madrid (CAM) (Department of Education and Research), and from RoboCity2030-DIH-CM, Madrid Robotics Digital Innovation Hub (Robótica aplicada a la mejora de la calidad de vida de los ciudadanos, FaseIV; S2018/NMT-4331), funded by Programas de Actividades I+D en la Comunidad de Madrid and cofunded by Structural Funds of the EU
Gait Training using Pneumatically Actuated Robot System
Powered exoskeleton device for gait rehabilitation has been designed and realized, together with proper control architecture. Its DOFs allow free leg motion, while the patient walks on a treadmill with its weight, completely or partially supported by the suspension system. The use of pneumatic actuators for actuation of this rehabilitation system is reasonable, because they offer high force output, good backdrivability, and good position and force control, at a relatively low cost. The effectiveness of the developed rehabilitation system and proposed control architecture was experimentally tested. During the experiments, the movement was natural and smooth while the limb moves along the target trajectory
SMA-driven soft robotic neck: design, control and validation
Replicating the behavior and movement of living organisms to develop robots which are better adapted to the human natural environment is a major area of interest today. Soft device development is one of the most promising and innovative technological fields to meet this challenge. However, soft technology lacks of suitable actuators, and therefore, development and integration of soft actuators is a priority. This article presents the development and control of a soft robotic neck which is actuated by a flexible Shape Memory Alloy (SMA)-based actuator. The proposed neck has two degrees of freedom that allow movements of inclination and orientation, thus approaching the actual movement of the human neck. The platform we have developed may be considered a real soft robotic device since, due to its flexible SMA-based actuator, it has much fewer rigid parts compared to similar platforms. Weight and motion noise have also been considerably reduced due to the lack of gear boxes, housing and bearings, which are commonly used in conventional actuators to reduce velocity and increase torque.This work was supported in part by the Spanish Ministry of Economy and Competitiveness through the Exoesqueleto para Diagnostico y Asistencia en Tareas de Manipulación Spanish Research Project under Grant DPI2016-75346-R and the HUMASOFT Project under Grant DPI2016-75330-P, in part by the Programas de Actividades I+D en la Comunidad de Madrid through the RoboCity2030-DIH-CM Madrid Robotics Digital Innovation Hub (Robótica aplicada a la mejora de la calidad de vida de los ciudadanos, fase IV) under Grant S2018/NMT-4331, and in part by the Structural Funds of the EU
Robust control strategy for improving the performance of a soft robotic link
[Abstract] The robotic neck mechanism considered in this paper has as main element a soft link that emulates a human neck with two DOF (flexion, extension and lateral bending). The mechanism is based on a Cable-Driven Parallel Mechanism (CDPM) with components easy to manufacture in a 3D printer.Due to the soft link properties and the platform mechanics, it is important to provide a robust control system. Two designs, a robust PID controller and a Fractional Order PI controller (FOPI) are proposed and compared, the fractional order control showing an enhanced performance. Both control approaches are tested in the real prototype, validating the soft neck feasibility and showing the robustness of the platform to mass changes at the neck tip.Comunidad de Madrid. Consejería de educación e Investigación; IND2020/IND-1739Comunidad de Madrid; S2018/NMT-433
非線形弾性要素による内部力補償に基づく無段階変位–力変換機構の創生 ― 微小操作力で強大な磁気力・把持力・制動力・張力を制御可能とするロボット要素 ―
Tohoku University博士(情報科学)thesi
Surrogate models for the design and control of soft mechanical systems
Soft mechanical systems constitute stretchable skins, tissue-like appendages, fibers and fluids, and utilize material deformation to transmit forces or motion to perform a mechanical task. These systems may possess infinite degrees of freedom with finite modes of actuation and sensing, and this creates challenges in modeling, design and controls. This thesis explores the use of surrogate models to approximate the complex physics between the inputs and outputs of a soft mechanical system composed of a ubiquitous soft building block known as Fiber Reinforced Elastomeric Enclosures (FREEs). Towards this the thesis is divided into two parts, with the first part investigating reduced order models for design and the other part investigating reinforcement learning (RL) framework for controls.
The reduced order models for design is motivated by the need for repeated quick and accurate evaluation of the system performance. Two mechanics-based models are investigated: (a) A Pseudo Rigid Body model (PRB) with lumped spring and link elements, and (b) a Homogenized Strain Induced (HIS) model that can be implemented in a finite element framework. The parameters of the two models are fit either directly with experiments on FREE prototypes or with a high fidelity robust finite element model. These models capture fundamental insights on design by isolating a fundamental dyad building block of contracting FREEs that can be configured to either obtain large stroke (displacement) or large force. Furthermore, the thesis proposes a novel building block-based design framework where soft FREE actuators are systematically integrated in a compliant system to yield a given motion requirement. The design process is deemed useful in shape morphing adaptive structures such as airfoils, soft skins, and wearable devices for the upper extremities.
Soft robotic systems such as manipulators are challenging to control because of their flexibility, ability to undergo large spatial deformations that are dependent on the external load. The second part of this work focuses on the control of a unique soft continuum arm known as the BR2 manipulator using reinforcement learning (RL). The BR2 manipulator has a unique parallel architecture with a combined bending mode and torsional modes, and its inherent asymmetric nature precludes well defined analytical models to capture its forward kinematics. Two RL-based frameworks are evaluated on the BR2 manipulator and their efficacy in carrying out position control using simple state feedback is reported in this work. The results highlight external load invariance of the learnt control policies which is a significant factor for deformable continuum arms for applications involving pick and place operations. The manipulator is deemed useful in berry harvesting and other agricultural applications
Advanced Mobile Robotics: Volume 3
Mobile robotics is a challenging field with great potential. It covers disciplines including electrical engineering, mechanical engineering, computer science, cognitive science, and social science. It is essential to the design of automated robots, in combination with artificial intelligence, vision, and sensor technologies. Mobile robots are widely used for surveillance, guidance, transportation and entertainment tasks, as well as medical applications. This Special Issue intends to concentrate on recent developments concerning mobile robots and the research surrounding them to enhance studies on the fundamental problems observed in the robots. Various multidisciplinary approaches and integrative contributions including navigation, learning and adaptation, networked system, biologically inspired robots and cognitive methods are welcome contributions to this Special Issue, both from a research and an application perspective
On a Jansen leg with multiple gait patterns for reconfigurable walking platforms
Legged robots are able to move across irregular terrains and those based on 1-degree-of-freedom planar linkages can be energy efficient, but are often constrained by a limited range of gaits which can limit their locomotion capabilities considerably. This article reports the design of a novel reconfigurable Theo Jansen linkage that produces a wide variety of gait cycles, opening new possibilities for innovative applications. The suggested mechanism switches from a pin-jointed Grübler kinematic chain to a 5-degree-of-freedom mechanism with slider joints during the reconfiguration process. It is shown that such reconfigurable linkage significantly extend the capabilities of the original design, while maintaining its mechanical simplicity during normal operation, to not only produce different useful gait patterns but also to realize behaviors beyond locomotion. Experiments with an implemented prototype are presented, and their results validate the proposed approach
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Operational criteria for battlefield vehicles
textModern military ground vehicles are no longer able to respond effectively to the rapidly changing mission requirements of modern military conflicts. Military vehicle architectures, which utilize passive suspension components and traditional drivetrain/steering systems, do not provide the operational flexibility to meet the demands of the operator. Advances in intelligent actuation technology allow for the development of a new vehicle architecture - the Intelligent Corner Vehicle (ICV). The ICV utilizes intelligent actuator technology to actively control the four degrees of freedom of each wheel of the vehicle - drive, camber, steering, and suspension. The utilization of intelligent actuation requires the characterization of the motions and behavior of the tire and the vehicle chassis in order to effectively apply the tire to the road surface - the development of vehicle performance criteria. A brief review of the state of wheeled military systems is presented. Many modern military vehicles were designed to improve protection at the expense of mobility - a process that has had negative effects on vehicle capability. An overview of the pneumatic tire used for wheeled vehicles is presented, highlighting the nonlinearities of tire behavior. The complexity of tire force generation drives the need for the application of intelligent actuation. Traditional actuation of wheel motion is presented along with a variety of current efforts to apply intelligent actuation to individual degrees of freedom of the tire. These efforts can be shown to improve vehicle performance, but intelligent actuation must be applied to all aspects of tire motion, requiring the use of the ICV architecture and the generation of performance criteria by which the complex motion of the vehicle may be evaluated. The Robotics Research Group has a history of developing and evaluating performance criteria for complex dynamic systems. and review of performance criteria developed for serial chain robotics is presented. These criteria address task independent actuator motion in addition to actuator ranges and limits, and their application to the ICV is discussed. A brief overview of several important concepts of classical vehicle dynamics are presented. The application of criteria derived from these concepts to the ICV architecture is discussed. This report presents the complexities of tire behavior and vehicle motion, the need for alternative architectures (the ICV), and a variety of performance criteria required to evaluate vehicle motion in real time. Criteria that are presented are summarized along with their definition and physical meaning. Future work for the development of the ICV involves the generation of a vehicle model for evaluating the application and range values of the presented criteria.Mechanical Engineerin
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