Soft grippers, for stable grasping of objects, with high compliance could be considered a suitable candidate for replacement of conventional rigid grippers, and in recent years, they have been emerging exponentially in industries. Not only are these highly adaptable grippers capable of static grasping of an object, but also they can be utilized for performing object manipulation tasks. Plenty of contemporary studies have been emphasizing on static grasping ability of soft grippers. However, in this thesis, planar in-hand object manipulation in a soft gripper which comprises a pair of soft finger is investigated.
Southern University of Science and Technology（南方科技大学）
Soft grippers are receiving growing attention due to their compliance-based interactive safety and dexterity. Hybrid gripper (soft actuators enhanced by rigid constraints) is a new trend in soft gripper design. With right structural components actuated by soft actuators, they could achieve excellent grasping adaptability and payload, while also being easy to model and control with conventional kinematics. However, existing works were mostly focused on achieving superior payload and perception with simple planar workspaces, resulting in far less dexterity compared with conventional grippers. In…
Georgia Institute of Technology（佐治亚理工学院）；Intel Labs（英特尔研究院）；Meta Reality Labs（Meta现实实验室）；Hello Robot Inc.（Hello Robot公司）
Soft robotic grippers facilitate contact-rich manipulation, including robust grasping of varied objects. Yet the beneficial compliance of a soft gripper also results in significant deformation that can make precision manipulation challenging. We present visual pressure estimation & control (VPEC), a method that infers pressure applied by a soft gripper using an RGB image from an external camera. We provide results for visual pressure inference when a pneumatic gripper and a tendon-actuated gripper make contact with a flat surface. We also show that VPEC enables precision manipulation via close…
DePaul University（德保罗大学）；University of Arkansas（阿肯色大学）；Clemson University（克莱姆森大学）
We propose a novel tri-fingered soft robotic gripper with decoupled stiffness and shape control capability for performing adaptive grasping with minimum system complexity. The proposed soft fingers adaptively conform to object shapes facilitating the handling of objects of different types, shapes, and sizes. Each soft gripper finger has an inextensible articulable backbone and is actuated by pneumatic muscles. We derive a kinematic model of the gripper and use an empirical approach to map input pressures to stiffness and bending deformation of fingers. We use these mappings to achieve decouple…
Source-Free Bistable Fluidic Gripper for Size-Selective and Stiffness-Adaptive Grasping
Advanced Robotics Centre, National University of Singapore（新加坡国立大学先进机器人中心）；Department of Electrical and Computer Engineering, National University of Singapore（新加坡国立大学电子与计算机工程系）
Robot arms that assist humans should be able to pick up, move, and release everyday objects. Today's assistive robot arms use rigid grippers to pinch items between fingers; while these rigid grippers are well suited for large and heavy objects, they often struggle to grasp small, numerous, or delicate items (such as foods). Soft grippers cover the opposite end of the spectrum; these grippers use adhesives or change shape to wrap around small and irregular items, but cannot exert the large forces needed to manipulate heavy objects. In this paper we introduce RIgid-SOft (RISO) grippers that comb…
Tohoku University（东北大学）；Graduate school of Information Sciences, Tohoku University（东北大学信息科学研究科）
Able to grasp objects of any shape and size, universal grippers using variable stiffness phenomenon such as granular jamming have been developed for disaster robotics application. However, as their contact interface is mainly composed of unrigid and burnable silicone rubber, conventional soft grippers are not applicable to objects with sharp sections such as broken valves and glass fragments, especially on fire. In this research, the authors proposed a new method of variable stiffness mechanism using a string of beads that can be composed of cut-resistant and incombustible metals, arrange the …
CSIRO Data61（联邦科学与工业研究组织数据61所）；Indian Institute of Technology Hyderabad（印度理工学院海得拉巴分校）；TU Delft（代尔夫特理工大学）
Soft robotic grasping has rapidly spread through the academic robotics community in recent years and pushed into industrial applications. At the same time, multimaterial 3D printing has become widely available, enabling the monolithic manufacture of devices containing rigid and elastic sections. We propose a novel design technique that leverages both technologies and can automatically design bespoke soft robotic grippers for fruit-picking and similar applications. We demonstrate the novel topology optimisation formulation that generates multi-material soft grippers, can solve internal and exte…
Hybrid Gripper with Passive Pneumatic Soft Joints for Grasping Deformable Thin Objects
School of Mechanical Engineering, Hanoi University of Science and Technology（河内科技大学机械工程学院）；Department of Computer Science, University of Liverpool（利物浦大学计算机科学系）；Graduate School of Information Science and Technology, The University of Tokyo（东京大学信息科学与技术研究生院）
A Modular Pneumatic Soft Gripper Design for Aerial Grasping and Landing
The Hong Kong Polytechnic University（香港理工大学）；Hong Kong Center for Construction Robotics（香港建造机器人中心）；Research Centre of Unmanned Autonomous Systems（无人自主系统研究中心）；Department of Aeronautical and Aviation Engineering（航空及民航工程系）；Department of Mechanical Engineering（机械工程系）
Hybrid Soft Electrostatic Metamaterial Gripper for Multi-surface, Multi-object Adaptation
Empa - Swiss Federal Laboratories for Materials Science and Technology（瑞士联邦材料科学与技术实验室（Empa））；École Polytechnique Fédérale de Lausanne（洛桑联邦理工学院）；Imperial College London（帝国理工学院）；Commonwealth Scientific and Industrial Research Organisation (CSIRO)（英联邦科学与工业研究组织（CSIRO））
Southern University of Science and Technology（南方科技大学）；University of Hong Kong（香港大学）
Over the past few decades, efforts have been made towards robust robotic grasping, and therefore dexterous manipulation. The soft gripper has shown their potential in robust grasping due to their inherent properties-low, control complexity, and high adaptability. However, the deformation of the soft gripper when interacting with objects bring inaccuracy of grasped objects, which causes instability for robust grasping and further manipulation. In this paper, we present an omni-directional adaptive soft finger that can sense deformation based on embedded optical fibers and the application of mac…
Soft grippers are gaining momentum across applications due to their flexibility and dexterity. However, the infinite-dimensionality and non-linearity associated with soft robots challenge modeling and closed-loop control of soft grippers to perform grasping tasks. To solve this problem, data-driven methods have been proposed. Most data-driven methods rely on intensive model learning in simulation or offline, and as such it may be hard to generalize across different settings not explicitly trained upon and in physical robot testing where online control is required. In this paper, we propose an …
Hybrid Rigid-Soft Robotic Gripper with Shape Adaptation, Uniform Force Distribution, and Self-Locking Capabilities
Intelligent Equipment Research Center, Beijing Academy of Agriculture and Forestry Sciences（北京市农林科学院智能装备研究中心）；College of Engineering, China Agricultural University（中国农业大学工学院）；College of Engineering, Shanxi Agricultural University（山西农业大学工学院）
BioRobotics Institute, Scuola Superiore Sant’Anna（圣安娜高等研究院生物机器人研究所）
Soft robotic grippers are shown to be high effective for grasping unstructured objects with simple sensing and control strategies. However, they are still limited by their speed, sensing capabilities and actuation mechanism. Hence, their usage have been restricted in highly dynamic grasping tasks. This paper presents a soft robotic gripper with tunable bistable properties for sensor-less dynamic grasping. The bistable mechanism allows us to store arbitrarily large strain energy in the soft system which is then released upon contact. The mechanism also provides flexibility on the type of actuat…
Global berry production and consumption have significantly increased in recent years, coinciding with increased consumer awareness of the health-promoting benefits of berries. Among them, fresh market blackberries and raspberries are primarily harvested by hand to maintain post-harvest quality. However, fresh market berry harvesting is an arduous, costly endeavor that accounts for up to 50% of the worker hours. Additionally, the inconsistent forces applied during hand-harvesting can result in an 85% loss of marketable berries due to red drupelet reversion (RDR). Herein, we present a novel, ten…
Beihang University（北京航空航天大学）；California NanoSystems Institute（加州纳米系统研究所）；University of California, Santa Barbara（加州大学圣巴巴拉分校）
A key challenge in robotics is to create efficient methods for grasping objects with diverse shapes, sizes, poses, and properties. Grasping with hand-like end effectors often requires careful selection of hand orientation and finger placement. Here, we present a soft, fingerless gripper capable of efficiently generating multiple grasping modes. It is based on a soft, cylindrical accordion structure containing coupled, parallel fluidic channels. It is controlled via pressure supplied from a single fluidic port. Inflation opens the gripper orifice for enveloping an object, while deflation allows…
While compliant grippers have become increasingly commonplace in robot manipulation, finding the right stiffness and geometry for grasping the widest variety of objects remains a key challenge. Adjusting both stiffness and gripper geometry on the fly may provide the versatility needed to manipulate the large range of objects found in domestic environments. We present a system for actively controlling the geometry (inflation level) and compliance of Soft-bubble grippers - air filled, highly compliant parallel gripper fingers incorporating visuotactile sensing. The proposed system enables large,…
In this paper, we presented a data-driven framework to optimize the out-of-plane stiffness for soft grippers to achieve mechanical properties as hard-to-twist and easy-to-bend. The effectiveness of this method is demonstrated in the design of a soft pneumatic bending actuator (SPBA). First, a new objective function is defined to quantitatively evaluate the out-of-plane stiffness as well as the bending performance. Then, sensitivity analysis is conducted on the parametric model of an SPBA design to determine the optimized design parameters with the help of Finite Element Analysis (FEA). To enab…
A Vision-Based Collision Sensing Method for Stable Circular Object Grasping with A Soft Gripper System
Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology（电子与计算机工程系，香港科学与技术大学）；Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology（土木与环境工程系，香港科学与技术大学）
CSIRO（澳大利亚联邦科学与工业研究组织）；University of Queensland（昆士兰大学）；Queensland University of Technology（昆士兰科技大学）；University of Melbourne（墨尔本大学）
The application of granular jamming in soft robotics is a recent and promising new technology offer exciting possibilities for creating higher performance robotic devices. Granular jamming is achieved via the application of a vacuum pressure inside a membrane containing particulate matter, and is particularly interesting from a design perspective, as a myriad of design parameters can potentially be exploited to induce a diverse variety of useful behaviours. To date, the effect of variables such as grain shape and size, as well as membrane material, have been studied as a means of inducing besp…
Developing Simulation Models for Soft Robotic Grippers in Webots
Faculty of Science and Engineering, University of Groningen（格罗宁根大学科学与工程学院）；School of Electrical Engineering and Informatics, Bandung Institute of Technology（班达理工大学电气工程与信息学院）
CSIRO（联邦科学与工业研究组织）；Queensland University of Technology（昆士兰科技大学）；University of Queensland（昆士兰大学）
Granular jamming has recently become popular in soft robotics with widespread applications including industrial gripping, surgical robotics and haptics. Previous work has investigated the use of various techniques that exploit the nature of granular physics to improve jamming performance, however this is generally underrepresented in the literature compared to its potential impact. We present the first research that exploits vibration-based fluidisation actively (e.g., during a grip) to elicit bespoke performance from granular jamming grippers. We augment a conventional universal gripper with …
Georgia Institute of Technology（佐治亚理工学院）；Georgia Institute of Technology/Emory（佐治亚理工学院/埃默里大学）
Growing global demand for food, coupled with continuing labor shortages, motivates the need for automated agricultural harvesting. While some specialty crops (e.g., apples, peaches, blueberries) can be harvested via existing harvesting modalities, fruits such as blackberries and raspberries require delicate handling to mitigate fruit damage that could significantly impact marketability. This motivates the development of soft robotic solutions that enable efficient, delicate harvesting. This paper presents the design, fabrication, and feasibility testing of a tendon-driven soft gripping system …
Low-Contact Grasping of Soft Tissue with Complex Geometry using a Vortex Gripper
Osaka University（大阪大学）；National Institute of Advanced Industrial Science and Technology (AIST)（日本国立先进工业科学技术研究院）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；UT Southwestern Medical Center（德克萨斯大学西南医学中心）
University of Zagreb（萨格勒布大学）；Faculty of Electrical Engineering and Computing（电气工程与计算学院）
This paper presents a serial chain hinge support, a rigid but flexible structure that improves the mechanical performance and robustness of soft-fingered grippers. Gravity can reduce the integrity of soft fingers in horizontal approach, resulting in lower maximum payload caused by a large deflection of fingers. To substantiate our claim we performed several experiments on payload and deflection of the SofIA gripper under both horizontal and vertical approach. In addition, we show that this reinforcement does not impede the original compliant behavior of the gripper, maintaining the original ki…
Manipulation in cluttered environments like homes requires stable grasps, precise placement and robustness against external contact. We present the Soft-Bubble gripper system with a highly compliant gripping surface and dense-geometry visuotactile sensing, capable of multiple kinds of tactile perception. We first present various mechanical design advances and a fabrication technique to deposit custom patterns to the internal surface of the sensor that enable tracking of shear-induced displacement of the manipuland. The depth maps output by the internal imaging sensor are used in an in-hand pro…
A Dexterous and Compliant Gripper With Soft Hydraulic Actuation for Microgravity Manipulation
Aerospace Engineering Program, University of California, Berkeley（加州大学伯克利分校航空航天工程系）；Department of Mechanical Engineering, University of California, Berkeley（加州大学伯克利分校机械工程系）；Department of Mechanical Engineering, National University of Singapore（新加坡国立大学机械工程系）
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 …
This work presents a new fiberless soft pneumatic actuator that can work multifunctional and bidirectional, and its embedded sensors give it a self-proprioception ability. This actuator works based on the idea of employing helical pressure channels. Applying the controlled input pressures into these two channels causes a variety of deformations and actuation. In particular, single pressure, imbalanced pressures, and balanced pressures applied in the channels cause bidirectional coilings, opposite bendings, and elongation, respectively, in a single unit actuator. Also, two U-shaped microchannel…
Whole-Body Proprioceptive Morphing: A Modular Soft Gripper for Robust Cross-Scale Grasping
Mechanical Engineering Department at the University of Michigan-Ann Arbor（密歇根大学安娜堡分校机械工程系）；Robotics Department at the University of Michigan-Ann Arbor（密歇根大学安娜堡分校机器人学系）
SCANS: A Soft Gripper with Curvature and Spectroscopy Sensors for In-Hand Material Differentiation
Electrical and Computer Engineering Department, Northeastern University（电气与计算机工程系，东北大学）；Lincoln Laboratory, Massachusetts Institute of Technology（林肯实验室，麻省理工学院）
