312 research outputs found
Anthropomorphic Twisted String-Actuated Soft Robotic Gripper with Tendon-Based Stiffening
Realizing high-performance soft robotic grippers is challenging because of
the inherent limitations of the soft actuators and artificial muscles that
drive them, including low force output, small actuation range, and poor
compactness. Despite advances in this area, realizing compact soft grippers
with high dexterity and force output is still challenging. This paper explores
twisted string actuators (TSAs) to drive a soft robotic gripper. TSAs have been
used in numerous robotic applications, but their inclusion in soft robots has
been limited. The proposed design of the gripper was inspired by the human
hand. Tunable stiffness was implemented in the fingers with antagonistic TSAs.
The fingers' bending angles, actuation speed, blocked force output, and
stiffness tuning were experimentally characterized. The gripper achieved a
score of 6 on the Kapandji test and recreated 31 of the 33 grasps of the Feix
GRASP taxonomy. It exhibited a maximum grasping force of 72 N, which was almost
13 times its own weight. A comparison study revealed that the proposed gripper
exhibited equivalent or superior performance compared to other similar soft
grippers.Comment: 19 pages, 15 figure
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
Force Control of Musculoskeletal Manipulator Driven By Spiral Motors
This paper presents force control of musculoskeletal manipulator driven by spiral motors. The kinematic and
dynamic properties are shown to address the presence of ennvironmental contact with the manipulator. From
this contact, the force control schemes were explored, by comparing between monoarticular-only structure and
biarticular structure manipulator. Force control schemes were divided into independent muscle control, end effector
step force command, and muscular viscoelasticity control. The results show advantages of biarticular actuation
compared to monoarticular-only actuation in the feasibility of magnetic levitation (gap) control alongside force
control
3D printed pneumatic soft actuators and sensors: their modeling, performance quantification, control and applications in soft robotic systems
Continued technological progress in robotic systems has led to more applications where robots and humans operate in close proximity and even physical contact in some cases. Soft robots, which are primarily made of highly compliant and deformable materials, provide inherently safe features, unlike conventional robots that are made of stiff and rigid components. These robots are ideal for interacting safely with humans and operating in highly dynamic environments. Soft robotics is a rapidly developing field exploiting biomimetic design principles, novel sensor and actuation concepts, and advanced manufacturing techniques.
This work presents novel soft pneumatic actuators and sensors that are directly 3D printed in one manufacturing step without requiring postprocessing and support materials using low-cost and open-source fused deposition modeling (FDM) 3D printers that employ an off-the-shelf commercially available soft thermoplastic poly(urethane) (TPU). The performance of the soft actuators and sensors developed is optimized and predicted using finite element modeling (FEM) analytical models in some cases. A hyperelastic material model is developed for the TPU based on its experimental stress-strain data for use in FEM analysis. The novel soft vacuum bending (SOVA) and linear (LSOVA) actuators reported can be used in diverse robotic applications including locomotion robots, adaptive grippers, parallel manipulators, artificial muscles, modular robots, prosthetic hands, and prosthetic fingers. Also, the novel soft pneumatic sensing chambers (SPSC) developed can be used in diverse interactive human-machine interfaces including wearable gloves for virtual reality applications and controllers for soft adaptive grippers, soft push buttons for science, technology, engineering, and mathematics (STEM) education platforms, haptic feedback devices for rehabilitation, game controllers and throttle controllers for gaming and bending sensors for soft prosthetic hands. These SPSCs are directly 3D printed and embedded in a monolithic soft robotic finger as position and touch sensors for real-time position and force control. One of the aims of soft robotics is to design and fabricate robotic systems with a monolithic topology embedded with its actuators and sensors such that they can safely interact with their immediate physical environment. The results and conclusions of this thesis have significantly contributed to the realization of this aim
Upravljanje silom mišićno-koštanog manipulatora pogonjenog spiralnim motorom
This paper presents force control of musculoskeletal manipulator driven by spiral motors. The kinematic and dynamic properties are shown to address the presence of ennvironmental contact with the manipulator. From this contact, the force control schemes were explored, by comparing between monoarticular-only structure and biarticular structure manipulator. Force control schemes were divided into independent muscle control, end effector step force command, and muscular viscoelasticity control. The results show advantages of biarticular actuation compared to monoarticular-only actuation in the feasibility of magnetic levitation (gap) control alongside force control.U ovome radu predstavljeno je upravljanje silom mišićno-koštanog manipulatora pogonjenog spiralnim motorom. Kinematička i dinamička svojstva prikazuju prisutnost kontakta manipulatora s okolinom. Na temelju kontakta istraženo je upravljanje silom usporedbom jednozglobne i dvozglobne strukture manipulatora. Upravljanje silom podijeljeno je u neovisno upravljanje mišićima, upravljanje alatom manipulatora (eng. end effector) i upravljanje mišićnom viskoelastičnosti. Rezultati pokazuju prednost dvozglobne strukture u odnosu na jednozglobnu u smislu izvedivosti upravljanja magnetskom levitacijom pored upravljanja silom
- …