The purpose of this research is to design, fabricate and test a tendon driven a continuum soft robot with three modular segments, each of which has a tunable stiffness enabled by layer jamming technology. Compared with previous studies, the robotic arm design of this project has a modular structure, which means the length of the robotic arm can be adjusted by addition of extra arm modules/segments to the existing robotic prototype. Furthermore, the new arm prototype supports motion within a 3-dimensional space. To achieve the goals, the design and fabrication for the variable stiffness robotic arm with compliant main structure and layer jamming mechanism has already been finished. Design and fabrication of the connector has also been finished to integrate several link modules into one robotic arm with multiple segments. The actuator located at the base of the arm has already been designed and tested. Finally, a stiffness test of one arm segment was conducted to verifying the load carrying capacity of the variable stiffness robotic arm, then the stiffness ratio of the layer jammed structure was calculated to analyze the stiffness improvement compared with unstiffened soft robot.
An Experimental Characterization of Mechanical Layer Jamming Systems
Centre for Robotics（机器人中心）；School of Electrical Engineering and Robotics（电气工程与机器人学学院）；Queensland University of Technology（昆士兰理工大学）；CSIRO Robotics（CSIRO机器人部）；Commonwealth Scientific and Industrial Research Organisation (CSIRO)（澳大利亚联邦科学工业研究组织（CSIRO））
In this paper, a novel tactile sensing mechanism for soft robotic fingers is proposed. Inspired by the proprioception mechanism found in mammals, the proposed approach infers tactile information from a strain sensor attached on the finger's tendon. We perform experiments to test the tactile sensing capabilities of the proposed structures, and our results indicate this method is capable of palpating texture and stiffness in both abduction and flexion contact. Under systematic cross validation, the proposed system achieved 100% and 99.7% accuracy in texture and stiffness discrimination respectiv…
A Novel Modular Cable-Driven Soft Robotic Arm with Multi-Segment Reconfigurability
Department of Agricultural and Biological Engineering, Mississippi State University（农业与生物工程系，密苏里州立大学）；Department of Electrical and Computer Engineering, Michigan State University（电气与计算机工程系，密苏里州立大学）；Texas A&M AgriLife Research and Extension Center in Dallas, Texas A&M University（德克萨斯A&M大学达拉斯分校农业与生命科学研究中心）
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 stiffness modulation mechanism for soft robotics has gained considerable attention to improve deformability, controllability, and stability. However, for the existing stiffness soft actuator, high lateral stiffness and a wide range of bending stiffness are hard to be provided at the same time. This paper presents a bioinspired bidirectional stiffening soft actuator (BISA) combining the air-tendon hybrid actuation (ATA) and a bone-like structure (BLS). The ATA is the main actuation of the BISA, and the bending stiffness can be modulated with a maximum stiffness of about 0.7 N/mm and a maxim…
We present an approach to overcoming challenges in dynamical dexterity for robots through tunable origami structures. Our work leverages a one-parameter family of flat sheet crease patterns that folds into origami bellows, whose axial compliance can be tuned to select desired stiffness. Concentrically arranged cylinder pairs reliably manifest additive stiffness, extending the tunable range by nearly an order of magnitude and achieving bulk axial stiffness spanning 200-1500 N/m using 8 mil thick polyester-coated paper. Accordingly, we design origami energy-storing springs with a stiffness of 10…
Beihang University（北京航空航天大学）；National Research Center for Rehabilitation Technical Aids（国家康复辅具研究中心）
Stiffness variation and real-time position feedback are critical for any robotic system but most importantly for active and wearable devices to interact with the user and environment. Currently, for compact sizes, there is a lack of solutions bringing high-fidelity feedback and maintaining design and functional integrity. In this work, we propose a novel minimal clutch with integrated stiffness variation and real-time position feedback whose performance surpasses conventional jamming solutions. We introduce integrated design, modeling, and verification of the clutch in detail. Preliminary expe…
Design and Validation of an Under-actuated Robotic Finger with Synchronous Tendon Routing
ShanghaiTech University（上海科技大学）；School of Information Science and Technology（信息科学与技术学院）；ShanghaiTech Automation and Robotics (STAR) Center（上海科技大学自动化与机器人中心）；King’s College London（伦敦大学国王学院）
A Modular, Tendon Driven Variable Stiffness Manipulator with Internal Routing for Improved Stability and Increased Payload Capacity
National Robotarium（国家机器人研究院）；Heriot Watt University（赫瑞瓦特大学）；Institute for Integrated Micro and Nano Systems（集成微纳系统研究所）；University of Edinburgh（爱丁堡大学）；Tough Cyberphysical AI Research Center (TCPAI)（硬核赛博物理人工智能研究中心）；Tohoku University（东北大学）；Senai Cimatec（塞奈西马泰克）
A Novel Robotic Variable Stiffness Mechanism Based on Helically Wound Structured Electrostatic Layer Jamming
ShanghaiTech University（上海科技大学）；School of Information Science and Technology（信息科学与技术学院）；ShanghaiTech Automation and Robotics (STAR) Center（上海科技大学自动化与机器人中心）
This study examines a biology-inspired approach of using reconfigurable articulation to reduce the control requirement for soft robotic arms. We construct a robotic arm by assembling Kresling origami modules that exhibit predictable bistability. Via switching between their two stable states, these origami modules can behave either like a flexible joint with low bending stiffness or like a stiff link with high stiffness, without requiring any continuous power supply. In this way, the robotic arm can exhibit pseudo-linkage kinematics with lower control requirements and improved motion accuracy. …
University of Southern California（南加利福尼亚大学）；Google Brain（谷歌大脑）
Passive elastic elements can contribute to stability, energetic efficiency, and impact absorption in both biological and robotic systems. They also add dynamical complexity which makes them more challenging to model and control. The impact of this added complexity to autonomous learning has not been thoroughly explored. This is especially relevant to tendon-driven limbs whose cables and tendons are inevitably elastic. Here, we explored the efficacy of autonomous learning and control on a simulated bio-plausible tendon-driven leg across different tendon stiffness values. We demonstrate that inc…
Graduate school of Information Sciences, Tohoku University（东北大学信息科学研究生院）
Grippers can be attached to objects in a rigid mode, and they are therefore used in various applications, for example granular jamming gripper. This paper introduces a cutting-edge radial layer jamming mechanism with is tunable stiffness, which is critical for the development of grippers. The layer jamming mechanism generates friction between the layers of multi cylindrical walls by pulling wire. This paper describes the principles of three types of proposed tendon-driven jamming mechanism, in addition to their prototypes of string configuration and the experiments conducted on the holding tor…
ATDM:An Anthropomorphic Aerial Tendon-driven Manipulator with Low-Inertia and High-Stiffness
Research Institute of Intelligent Control and Systems, Harbin Institute of Technology（哈尔滨工业大学智能控制与系统研究所）；Peng Cheng Laboratory（鹏城实验室）；Ningbo Institute of Intelligent Equipment Technology Co., Ltd.（宁波智能装备技术研究院有限公司）
We present the design, implementation, and experimental evaluation of a low-cost, customizable, easy-to-use transradial hand prosthesis capable of adapting its compliance. Variable stiffness actuation (VSA) of the prosthesis is based on antagonistically arranged tendons coupled to nonlinear springs driven through a Bowden cable-based power transmission. Bowden cable-based antagonistic VSA can, not only regulate the stiffness and the position of the prosthetic hand, but also enables a light-weight and low-cost design, by opportunistic placement of motors, batteries and controllers on any conven…
Toward Dynamic Control of Tendon-driven Continuum Robots using Clarke Transform
Continuum Robotics Laboratory, Department of Mathematical and Computational Sciences, University of Toronto（连续机器人实验室，数学与计算科学系，多伦多大学）；Institute of Mechatronic Systems, Faculty of Mechanical Engineering, Leibniz University Hannover（机电系统研究所，机械工程学院，汉诺威莱布尼茨大学）；University of Toronto Robotics Institute（多伦多大学机器人研究所）
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 …
VSTaI: Design and Characterization of Variable-Stiffness Tactile Interfaces Based on 3D-Printed Structured Fabrics
Duke-NUS Medical School（杜克-新加坡国立大学医学院）；College of Design and Engineering, National University of Singapore（新加坡国立大学设计与工程学院）；Mechanobiology Institute, National University of Singapore（新加坡国立大学力学生物学研究所）；Imperial College（帝国理工学院）
In this study, we present the Differential Spiral Joint (DSJ) mechanism for variable stiffness actuation in tendon-driven robots. The DSJ mechanism semi-decouples the modulation of position and mechanical stiffness, allowing independent trajectory tracking in different parameter space. Past studies show that increasing the mechanical stiffness achieves the wider range of renderable stiffness, whereas decreasing the mechanical stiffness improves the quality of actuator decoupling and shock absorbance. Therefore, it is often useful to modulate the mechanical stiffness to balance the required lev…
Inflated continuum robots are promising for a variety of navigation tasks, but controlling their motion with a small number of actuators is challenging. These inflated beam robots tend to buckle under compressive loads, producing extremely tight local curvature at difficult-to-control buckle point locations. In this paper, we present an inflated beam robot that uses distributed stiffness changing sections enabled by positive pressure layer jamming to control or prevent buckling. Passive valves are actuated by an electromagnet carried by an electromechanical device that travels inside the main …
Modeling, control, and stiffness regulation of layer jamming-based continuum robots
Department of Electrical Engineering, Polytechnique Montréal and GERAD（电气工程系，蒙特利尔理工学院及GERAD）；Robotics Institute, Faculty of Engineering and Information Technology, University of Technology Sydney（机器人研究所，工程与信息技术学院，技术学院悉尼大学）
Underactuated Robotic Hand with Grasp State Estimation Using Tendon-Based Proprioception
BioRobotics Laboratory (BRL), Soft Robotics Research Center (SRRC), Institute of Advanced Machines and Design (IAMD), Department of Mechanical Engineering, Institute of Engineering, Seoul National University (SNU)（生物机器人实验室（BRL）、软机器人研究中心（SRRC）、先进机械与设计研究所（IAMD）、机械工程系、工程学院、首尔国立大学（SNU））
Tendon-Actuated Robots with a Tapered, Flexible Polymer Backbone: Design, Fabrication, and Modeling
Mechatronics, Robotics and Operation Section, European Organization for Nuclear Research (CERN)（欧洲核子研究组织（CERN）机电学、机器人学与操作部门）；Department of Aeronautics and Astronautics, University of Washington（华盛顿大学航空与航天系）；Department of Engineering Cybernetics, Norwegian University of Science and Technology (NTNU)（挪威科学技术大学（NTNU）工程 cybernetics 部门）
Hong Kong University of Science and Technology（香港科技大学）；Nanjing University of Information Science and Technology（南京信息工程大学）
Soft modular robots enable more flexibility and safer interaction with the changing environment than traditional robots. However, it has remained challenging to create deformable connectors that can be integrated into soft machines. In this work, we propose a flexible connector for soft modular robots based on micropatterned intersurface jamming. The connector is composed of micropatterned dry adhesives made by silicone rubber and a flexible main body with inflatable chambers for active engagement and disengagement. Through connection force tests, we evaluate the characteristics of the connect…
Robotics and Autonomous System Group, Data61, CSIRO（澳大利亚联邦科学与工业研究组织Data61机器人自主系统组）；School of Mechanical and Mining, University of Queensland（昆士兰大学机械与采矿学院）；Computational Modelling Group, Data61, CSIRO（澳大利亚联邦科学与工业研究组织Data61计算建模组）
Granular jamming is a popular soft actuation mechanism that provides high stiffness variability with minimum volume variation. Jamming 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, grain shape has been largely ignored. Here, we focus on the use of 3D printing to expose design variables related to grain shape and size. Grains are represented by parameterised superquadrics (superellipsoids); four diverse shapes are investigated along with three size variations. Grains…
The Quadruped Soft Tail: Compliant Grasping and Swabbing for Contamination Surveys in Harsh Environments
Mechatronics, Robotics and Operation Section, European Organization for Nuclear Research (CERN)（欧洲核子研究中心（CERN）机电一体化、机器人与操作部门）；Department of Engineering Cybernetics, Norwegian University of Science and Technology (NTNU)（挪威科技大学（NTNU）工程控制论系）
