185 research outputs found
Dynamic modelling and visco-elastic parameter identification of a fibre-reinforced soft fluidic elastomer manipulator
A dynamic model of a soft fibre-reinforced fluidic elastomer is presented and experimentally verified, which
can be used for model-based controller design. Due to the
inherent visco-(hyper)elastic characteristics and nonlinear timedependent behaviour of soft fluidic elastomer robots, analytic
dynamic modelling is challenging. The fibre reinforced noninflatable soft fluidic elastomer robot used in this paper can produce both planar and spatial movements. Dynamic equations
are developed for both cases. Parameters, related to the viscoelastic behaviour of the robot during elongation and bending
motion, are identified experimentally and incorporated into
our model. The modified dynamic model is then validated in
experiments comparing the time responses of the physical robot
with the corresponding outputs of the simulation model. The
results validate the accuracy of the proposed dynamic model
Design, fabrication and control of soft robots
Conventionally, engineers have employed rigid materials to fabricate precise, predictable robotic systems, which are easily modelled as rigid members connected at discrete joints. Natural systems, however, often match or exceed the performance of robotic systems with deformable bodies. Cephalopods, for example, achieve amazing feats of manipulation and locomotion without a skeleton; even vertebrates such as humans achieve dynamic gaits by storing elastic energy in their compliant bones and soft tissues. Inspired by nature, engineers have begun to explore the design and control of soft-bodied robots composed of compliant materials. This Review discusses recent developments in the emerging field of soft robotics.National Science Foundation (U.S.) (Grant IIS-1226883
Autonomous Soft Robotic Fish Capable of Escape Maneuvers Using Fluidic Elastomer Actuators
In this work we describe an autonomous soft-bodied robot that is both self-contained and capable of rapid, continuum-body motion. We detail the design, modeling, fabrication, and control of the soft fish, focusing on enabling the robot to perform rapid escape responses. The robot employs a compliant body with embedded actuators emulating the slender anatomical form of a fish. In addition, the robot has a novel fluidic actuation system that drives body motion and has all the subsystems of a traditional robot onboard: power, actuation, processing, and control. At the core of the fish's soft body is an array of fluidic elastomer actuators. We design the fish to emulate escape responses in addition to forward swimming because such maneuvers require rapid body accelerations and continuum-body motion. These maneuvers showcase the performance capabilities of this self-contained robot. The kinematics and controllability of the robot during simulated escape response maneuvers are analyzed and compared with studies on biological fish. We show that during escape responses, the soft-bodied robot has similar input–output relationships to those observed in biological fish. The major implication of this work is that we show soft robots can be both self-contained and capable of rapid body motion.National Science Foundation (U.S.) (NSF IIS1226883)National Science Foundation (U.S.) (NSF CCF1138967)National Science Foundation (U.S.) (1122374
Soft manipulators and grippers: A review
Soft robotics is a growing area of research which utilizes the compliance and adaptability of soft structures to develop highly adaptive robotics for soft interactions. One area in which soft robotics has the ability to make significant impact is in the development of soft grippers and manipulators. With an increased requirement for automation, robotics systems are required to perform task in unstructured and not well defined environments; conditions which conventional rigid robotics are not best suited. This requires a paradigm shift in the methods and materials used to develop robots such that they can adapt to and work safely in human environments. One solution to this is soft robotics, which enables soft interactions with the surroundings while maintaining the ability to apply significant force. This review paper assesses the current materials and methods, actuation methods and sensors which are used in the development of soft manipulators. The achievements and shortcomings of recent technology in these key areas are evaluated, and this paper concludes with a discussion on the potential impacts of soft manipulators on industry and society
OpenPneu: Compact platform for pneumatic actuation with multi-channels
This paper presents a compact system, OpenPneu, to support the pneumatic
actuation for multi-chambers on soft robots. Micro-pumps are employed in the
system to generate airflow and therefore no extra input as compressed air is
needed. Our system conducts modular design to provide good scalability, which
has been demonstrated on a prototype with ten air channels. Each air channel of
OpenPneu is equipped with both the inflation and the deflation functions to
provide a full range pressure supply from positive to negative with a maximal
flow rate at 1.7 L/min. High precision closed-loop control of pressures has
been built into our system to achieve stable and efficient dynamic performance
in actuation. An open-source control interface and API in Python are provided.
We also demonstrate the functionality of OpenPneu on three soft robotic systems
with up to 10 chambers
Computational Modeling and Experimental Characterization of Pneumatically Driven Actuators for the Development of a Soft Robotic Arm
abstract: Soft Poly-Limb (SPL) is a pneumatically driven, wearable, soft continuum robotic arm designed to aid humans with medical conditions, such as cerebral palsy, paraplegia, cervical spondylotic myelopathy, perform activities of daily living. To support user's tasks, the SPL acts as an additional limb extending from the human body which can be controlled to perform safe and compliant mobile manipulation in three-dimensional space. The SPL is inspired by invertebrate limbs, such as the elephant trunk and the arms of the octopus. In this work, various geometrical and physical parameters of the SPL are identified, and behavior of the actuators that comprise it are studied by varying their parameters through novel quasi-static computational models. As a result, this study provides a set of engineering design rules to create soft actuators for continuum soft robotic arms by understanding how varying parameters affect the actuator's motion as a function of the input pressure. A prototype of the SPL is fabricated to analyze the accuracy of these computational models by performing linear expansion, bending and arbitrary pose tests. Furthermore, combinations of the parameters based on the application of the SPL are determined to affect the weight, payload capacity, and stiffness of the arm. Experimental results demonstrate the accuracy of the proposed computational models and help in understanding the behavior of soft compliant actuators. Finally, based on the set functional requirements for the assistance of impaired users, results show the effectiveness of the SPL in performing tasks for activities of daily living.Dissertation/ThesisMasters Thesis Mechanical Engineering 201
- …