scholarly journals Soft Robotics: Biological Inspiration, State of the Art, and Future Research

2008 ◽  
Vol 5 (3) ◽  
pp. 99-117 ◽  
Author(s):  
Deepak Trivedi ◽  
Christopher D. Rahn ◽  
William M. Kier ◽  
Ian D. Walker

Traditional robots have rigid underlying structures that limit their ability to interact with their environment. For example, conventional robot manipulators have rigid links and can manipulate objects using only their specialised end effectors. These robots often encounter difficulties operating in unstructured and highly congested environments. A variety of animals and plants exhibit complex movement with soft structures devoid of rigid components. Muscular hydrostats (e.g. octopus arms and elephant trunks) are almost entirely composed of muscle and connective tissue and plant cells can change shape when pressurised by osmosis. Researchers have been inspired by biology to design and build soft robots. With a soft structure and redundant degrees of freedom, these robots can be used for delicate tasks in cluttered and/or unstructured environments. This paper discusses the novel capabilities of soft robots, describes examples from nature that provide biological inspiration, surveys the state of the art and outlines existing challenges in soft robot design, modelling, fabrication and control.

Author(s):  
Lee-Huang Chen ◽  
Kyunam Kim ◽  
Ellande Tang ◽  
Kevin Li ◽  
Richard House ◽  
...  

This paper presents the design, analysis and testing of a fully actuated modular spherical tensegrity robot for co-robotic and space exploration applications. Robots built from tensegrity structures (composed of pure tensile and compression elements) have many potential benefits including high robustness through redundancy, many degrees of freedom in movement and flexible design. However to fully take advantage of these properties a significant fraction of the tensile elements should be active, leading to a potential increase in complexity, messy cable and power routing systems and increased design difficulty. Here we describe an elegant solution to a fully actuated tensegrity robot: The TT-3 (version 3) tensegrity robot, developed at UC Berkeley, in collaboration with NASA Ames, is a lightweight, low cost, modular, and rapidly prototyped spherical tensegrity robot. This robot is based on a ball-shaped six-bar tensegrity structure and features a unique modular rod-centered distributed actuation and control architecture. This paper presents the novel mechanism design, architecture and simulations of TT-3, the first untethered, fully actuated cable-driven six-bar tensegrity spherical robot ever built and tested for mobility. Furthermore, this paper discusses the controls and preliminary testing performed to observe the system’s behavior and performance.


2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Lee-Huang Chen ◽  
Kyunam Kim ◽  
Ellande Tang ◽  
Kevin Li ◽  
Richard House ◽  
...  

This paper presents the design, analysis, and testing of a fully actuated modular spherical tensegrity robot for co-robotic and space exploration applications. Robots built from tensegrity structures (composed of pure tensile and compression elements) have many potential benefits including high robustness through redundancy, many degrees-of-freedom in movement and flexible design. However, to take full advantage of these properties, a significant fraction of the tensile elements should be active, leading to a potential increase in complexity, messy cable, and power routing systems and increased design difficulty. Here, we describe an elegant solution to a fully actuated tensegrity robot: The TT-3 (version 3) tensegrity robot, developed at UC Berkeley, in collaboration with NASA Ames, is a lightweight, low cost, modular, and rapidly prototyped spherical tensegrity robot. This robot is based on a ball-shaped six-bar tensegrity structure and features a unique modular rod-centered distributed actuation and control architecture. This paper presents the novel mechanism design, architecture, and simulations of TT-3, an untethered, fully actuated cable-driven six-bar spherical tensegrity robot. Furthermore, this paper discusses the controls and preliminary testing performed to observe the system's behavior and performance and is evaluated against previous models of tensegrity robots developed at UC Berkeley and elsewhere.


MRS Bulletin ◽  
2010 ◽  
Vol 35 (6) ◽  
pp. 417-421 ◽  
Author(s):  
Leeor Kronik ◽  
Norbert Koch

AbstractOrganic-based interfaces can possess a range of surprising electronic properties that are of intense interest from both the basic science and the applied research points of view. In this issue of MRS Bulletin, we provide state-of-the-art overviews of selected topics involving three complementary aspects of the electronic properties of organic-based interfaces: the nascent electronics technologies that would gain from improved understanding and control of such interfaces; the novel properties that organic-based interfaces may possess; and the experimental and theoretical challenges afforded by such studies.


2017 ◽  
Vol 9 (2) ◽  
pp. 168781401668885 ◽  
Author(s):  
Xin Li ◽  
Qiang Huang ◽  
Xuechao Chen ◽  
Zhangguo Yu ◽  
Jinying Zhu ◽  
...  

This article presents a novel under-actuated robot hand, which has a thumb and two cooperative fingers. The thumb has two joints with 2 degrees of freedom driven by one motor. Each of the other two fingers has the same mechanism structure with the thumb and forms a cooperative mechanism, which is driven by only one motor with 4 degrees of freedom in total. All the under-actuated fingers are designed with the transmission mechanisms based on a kind of mechanism combined with the linkage mechanism and the passive elements. In this article, it is shown that under-actuated hand is able to reproduce most of the grasping behaviors of the human hand anthropomorphically and self-adaptively, without increasing the complexity of mechanism and control. The grasping stability analysis is given to help to understand the size range and load range of a stable grasp. Finally, the experiment results verify the high efficiency and stability of the novel mechanism.


2019 ◽  
Vol 3 (1) ◽  
pp. 24
Author(s):  
Steffen Ihlenfeldt ◽  
Jens Müller ◽  
Marcel Merx ◽  
Christoph Peukert

Typically, the feed dynamics of machine tools are limited to reduce excitations of machine structure oscillations. Consequently, the potential increase in productivity provided by electrical direct drives cannot be exploited. The novel approach of the Kinematically Coupled Force Compensation (KCFC) combines the principles of redundant axes and force compensation to achieve an increase in the machine’s feed dynamics. Because the drive reaction forces are directly applied to the machine frame, they cancel out each other perfectly if the relative motion at the Tool Centre Point (TCP) is split according to the mass ratio of the slides. In this paper, the principle of KCFC is introduced briefly and possible improvements in the design of machine structures and control are presented. The results of experimental investigations obtained by means of a 1D-KCFC Test Bed illustrate the effectiveness of the principle. Moreover, a further increase of the compensation quality can be achieved by decoupling the force flow from the machine frame, by means of elastic elements. Finally, an outlook on future research with reference to the 1D-implementation as well as possible applications of the KCFC in highly productive processes is given.


2021 ◽  
Vol 15 ◽  
Author(s):  
Geng Gao ◽  
Mojtaba Shahmohammadi ◽  
Lucas Gerez ◽  
George Kontoudis ◽  
Minas Liarokapis

Over the last decade underactuated, adaptive robot grippers and hands have received an increased interest from the robotics research community. This class of robotic end-effectors can be used in many different fields and scenarios with a very promising application being the development of prosthetic devices. Their suitability for the development of such devices is attributed to the utilization of underactuation that provides increased functionality and dexterity with reduced weight, cost, and control complexity. The most critical components of underactuated, adaptive hands that allow them to perform a broad set of grasp poses are appropriate differential mechanisms that facilitate the actuation of multiple degrees of freedom using a single motor. In this work, we focus on the design, analysis, and experimental validation of a four output geared differential, a series elastic differential, and a whiffletree differential that can incorporate a series of manual and automated locking mechanisms. The locking mechanisms have been developed so as to enhance the control of the differential outputs, allowing for efficient grasp selection with a minimal set of actuators. The differential mechanisms are applied to prosthetic hands, comparing them and describing the benefits and the disadvantages of each.


2021 ◽  
Vol 8 ◽  
Author(s):  
Kevin McDonald ◽  
Tommaso Ranzani

Soft robots provide significant advantages over their rigid counterparts. These compliant, dexterous devices can navigate delicate environments with ease without damage to themselves or their surroundings. With many degrees of freedom, a single soft robotic actuator can achieve configurations that would be very challenging to obtain when using a rigid linkage. Because of these qualities, soft robots are well suited for human interaction. While there are many types of soft robot actuation, the most common type is fluidic actuation, where a pressurized fluid is used to inflate the device, causing bending or some other deformation. This affords advantages with regards to size, ease of manufacturing, and power delivery, but can pose issues when it comes to controlling the robot. Any device capable of complex tasks such as navigation requires multiple actuators working together. Traditionally, these have each required their own mechanism outside of the robot to control the pressure within. Beyond the limitations on autonomy that such a benchtop controller induces, the tether of tubing connecting the robot to its controller can increase stiffness, reduce reaction speed, and hinder miniaturization. Recently, a variety of techniques have been used to integrate control hardware into soft fluidic robots. These methods are varied and draw from disciplines including microfluidics, digital logic, and material science. In this review paper, we discuss the state of the art of onboard control hardware for soft fluidic robots with an emphasis on novel valve designs, including an overview of the prevailing techniques, how they differ, and how they compare to each other. We also define metrics to guide our comparison and discussion. Since the uses for soft robots can be so varied, the control system for one robot may very likely be inappropriate for use in another. We therefore wish to give an appreciation for the breadth of options available to soft roboticists today.


Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Soukaina Krafes ◽  
Zakaria Chalh ◽  
Abdelmjid Saka

This paper describes some important classes of two degrees of freedom of underactuated mechanical system and also surveys review of the recent state-of-the-art concerning the mathematical modeling of these systems, their classification, and all the control strategies (linear, nonlinear, and intelligent) that have been made so far (i.e., from the year 2000 to date) to control these systems. Future research and challenges concerning the improvement, the effectiveness, and robustness of the proposed controllers for underactuated mechanical systems are presented.


2019 ◽  
Vol 9 (3) ◽  
pp. 229 ◽  
Author(s):  
Jiang ◽  
Vauras ◽  
Volet ◽  
Salo ◽  
Kajamies

This study explored teachers’ autonomy-supportive and controlling behaviors through video-taped observation in the classroom. Four lessons by two teachers from a secondary school in Finland were videotaped and analyzed using a rigorous coding protocol. It was found that teachers employed both autonomy-supportive and controlling teaching during the same lesson, and even combined them in the same instructional sequence. This finding suggests the complexity of the use of autonomy support and control in the classroom, as well as their context-dependent aspects. The novel finding from this study was that teachers showed error tolerance and creativity to support students’ autonomy. Showing error tolerance and teaching creatively have not been investigated from the perspective of autonomy support in previous research. Furthermore, this study suggested that indirect control and its negative effects on students’ learning and well-being should arouse more concern in future research. Implications for teaching practice concerning supporting students’ autonomy have been provided.


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