I present the design, implementation and control of a novel, linkage-based, underactuated hand exoskeleton aimed to assist patients with hand disabilities during grasping tasks for robot assisted physical rehabilitation or robot assisted activities of daily living. Even though the proposed exoskeleton was designed with the purpose of assisting users during interactions with real objects around them, its use can be extended for haptic applications as well. In this thesis, I will deeply mention the exoskeletons in the literature, detail the design decisions and implement various control strategies to use this exoskeleton for different applications in the future.
This study presents the design and the kinematic optimization of a novel, underactuated, linkage-based robotic hand exoskeleton to assist users in performing grasping tasks. The device has been designed to apply only normal forces to the finger phalanges during flexion/extension of the fingers, while providing automatic adaptability for different finger sizes. Thus, the easiness of the attachment to the user's fingers and better comfort have been ensured. The analyses of the device kinematic pose, statics, and stability of grasp have been performed. These analyses have been used to optimize th…
Centre for Advanced Robotics（高级机器人中心）；School of Engineering and Materials Science（工程与材料科学学院）；Queen Mary University of London（伦敦玛丽女王大学）
Common disabilities like stroke and spinal cord injuries may cause loss of motor function in hands. They can be treated with robot assisted rehabilitation techniques, like continuously opening and closing the hand with help of a robot, in a cheaper, and less time consuming manner than traditional methods. Hand exoskeletons are developed to assist rehabilitation, but their bulky nature brings with it certain challenges. As soft robots use elastomeric and fabric elements rather than heavy links, and operate with pneumatic, hydraulic or tendon based rather than traditional rotary or linear motors…
This paper introduces the i-HY Hand, an underactuated hand driven by 5 actuators that is capable of performing a wide range of grasping and in-hand manipulation tasks. This hand was designed to address the need for a durable, inexpensive, moderately dexterous hand suitable for use on mobile robots. The primary focus of this paper will be on the novel minimalistic design of i-HY, which was developed by choosing a set of target tasks around which the design of the hand was optimized. Particular emphasis is placed on the development of underactuated fingers that are capable of both firm power gra…
Hand synergies, or joint coordination patterns, have become an effective tool for achieving versatile robotic grasping with simple hands or planning algorithms. Here we propose a method to determine the hand synergies such that they can be physically implemented in an underactuated fashion. Given a kinematic hand model and a set of desired grasps, our algorithm optimizes a Mechanically Realizable Manifold designed to be achievable by a physical underactuation mechanism, enabling the resulting hand to achieve the desired grasps with few actuators. Furthermore, in contrast to existing methods fo…
Most current hand exoskeletons have been designed specifically for rehabilitation, assistive or haptic applications to simplify the design requirements. Clinical studies on post-stroke rehabilitation have shown that adapting assistive or haptic applications into physical therapy sessions significantly improves the motor learning and treatment process. The recent technology can lead to the creation of generic hand exoskeletons that are application-agnostic. In this paper, our motivation is to create guidelines and best practices for generic exoskeletons by reviewing the literature of current de…
This manuscript presents control of a high-DOF fully actuated lower-limb exoskeleton for paraplegic individuals. The key novelty is the ability for the user to walk without the use of crutches or other external means of stabilization. We harness the power of modern optimization techniques and supervised machine learning to develop a smooth feedback control policy that provides robust velocity regulation and perturbation rejection. Preliminary evaluation of the stability and robustness of the proposed approach is demonstrated through the Gazebo simulation environment. In addition, preliminary e…
In this paper, we focus on a rarely used paradigm in the design of underactuated robot hands: the use of springs as agonists and tendons as antagonists. We formalize this approach in a design matrix also considering its interplay with the underactuation method used (one tendon for multiple joints vs. multiple tendons on one motor shaft). We then show how different cells in this design matrix can be combined in order to facilitate the implementation of desired postural synergies with a single motor. Furthermore, we show that when agonist and antagonist tendons are combined on the same motor sha…
We present the development of a cable-based passive forearm exoskeleton that is designed to assist supination for hemiparetic stroke survivors. Our device uniquely provides torque sufficient for counteracting spasticity within a below-elbow apparatus. The mechanism consists of a spiral single-tendon routing embedded in a rigid forearm brace and terminated at the hand and upper-forearm. A spool with an internal releasable-ratchet mechanism allows the user to manually retract the tendon and rotate the hand to counteract involuntary pronation synergies due to stroke. We characterize the mechanism…
University of Heidelberg（海德堡大学）；University of Genoa（热那亚大学）；University Niccolò Cusano（尼可洛·库萨诺大学）
Bimanual object manipulation involves multiple visuo-haptic sensory feedbacks arising from the interaction with the environment that are managed from the central nervous system and consequently translated in motor commands. Kinematic strategies that occur during bimanual coupled tasks are still a scientific debate despite modern advances in haptics and robotics. Current technologies may have the potential to provide realistic scenarios involving the entire upper limb extremities during multi-joint movements but are not yet exploited to their full potential. The present study explores how hands…
A low-cost 1-DOF hand exoskeleton for neuromuscular rehabilitation has been designed and assembled. It consists of a base equipped with a servo motor, an index finger part, and a thumb part, connected through three gears. The index part has a tri-axial load cell and an attached ring to measure the finger force. An admittance control scheme was designed to provide intuitive control and positive force amplification to assist the user's finger movement. To evaluate the effects of different control parameters on neuromuscular re-sponse of the fingers, we created an integrated exoskeleton-hand musc…
University of Birmingham（伯明翰大学）；Universita di Pisa（比萨大学）
Recent advances have been made in learning of grasps for fully actuated hands. A typical approach learns the target locations of finger links on the object. When a new object must be grasped, new finger locations are generated, and a collision free reach-to-grasp trajectory is planned. This assumes a collision free trajectory to the final grasp. This is not possible with underactuated hands, which cannot be guaranteed to avoid contact, and in fact exploit contacts with the object during grasping, so as to reach an equilibrium state in which the object is held securely. Unfortunately, these con…
In this paper we explore state-of-the-art underactuated, compliant robot gripper designs through looking at their performance on a generic grasping task. Starting from a state of the art open gripper design, we propose design modifications,and importantly, evaluate all designs on a grasping experiment involving a selection of objects resulting in 3600 object-gripper interactions. Interested in non-planned grasping but rather on a design's generic performance, we explore the influence of object shape, pose and orientation relative to the gripper and its finger number and configuration. Using op…
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））
Massachusetts Institute of Technology（麻省理工学院）；Tsinghua University（清华大学）
Soft robots offer significant advantages in adaptability, safety, and dexterity compared to conventional rigid-body robots. However, it is challenging to equip soft robots with accurate proprioception and tactile sensing due to their high flexibility and elasticity. In this work, we describe the development of a vision-based proprioceptive and tactile sensor for soft robots called GelFlex, which is inspired by previous GelSight sensing techniques. More specifically, we develop a novel exoskeleton-covered soft finger with embedded cameras and deep learning methods that enable high-resolution pr…
Icahn School of Medicine at Mount Sinai（西奈山伊坎医学院）；Grove School of Engineering（格罗夫工程学院）；City College of New York（纽约城市学院）；Moss Rehabilitation Research Institute（莫斯康复研究所）；University of Wisconsin-Madison（威斯康星大学麦迪逊分校）
Individuals with spinal cord injury (SCI) and stroke who is lack of manipulation capability have a particular need for robotic hand exoskeletons. Among assistive and rehabilitative medical exoskeletons, there exists a sharp trade-off between device power on the one hand and ergonomics and portability on other, devices that provide stronger grasping assistance do so at the cost of patient comfort. This paper proposes using fin-ray inspired, cable-driven finger orthoses to generate high fingertip forces without the painful compressive and shear stresses commonly associated with conventional cabl…
Institute of Industrial Technologies and Automation (ITIA), National Research Council (CNR) of Italy（意大利国家研究委员会工业技术与自动化研究所）；Department of Mechanical Engineering, Politecnico di Milano（米兰理工大学机械工程系）；Department of Mechanical and Industrial Engineering, Universitá degli Studi di Brescia（布雷西亚大学机械与工业工程系）
This paper presents a concurrent whole-body control (cWBC) for human-exoskeleton systems that are tightly coupled at a Cartesian level (e.g., feet, hands, torso). The exoskeleton generates joint torques that i) cancel the effects of gravity on the coupled system, ii) perform a primary task (e.g., maintaining the balance of the system), and iii) exploit the kinematic redundancy of the system to amplify the forces exerted by the human operator. The coupled dynamic system is demonstrated to be passive, as its overall energy always goes dissipated until a minimum is reached. The proposed method is…
Tactile SoftHand-A: 3D-Printed, Tactile, Highly-underactuated, Anthropomorphic Robot Hand with an Antagonistic Tendon Mechanism
School of Engineering Mathematics and Technology（工程数学与技术学院）；Bristol Robotics Laboratory（布里斯托尔机器人实验室）；University of Bristol（布里斯托尔大学）；School of Robotics（机器人学院）；Xi'an Jiaotong-Liverpool University（西安交通大学利物浦大学）；Department of Information Engineering（信息工程系）；Research Center "E.Piaggio"（E.Piaggio研究中心）；University of Pisa（比萨大学）；Soft Robotics for Human Cooperation and Rehabilitation（人机合作与康复软机器人）；Istituto Italiano di Tecnologia（意大利技术研究院）
From Vision to Assistance: Gaze and Vision-Enabled Adaptive Control for a Back-Support Exoskeleton
Department of Innovative Technologies (DTI), Dalle Molle Institute for Artificial Intelligence (IDSIA), University of Applied Sciences and Arts of Southern Switzerland (SUPSI)（创新技术系（DTI）、人工智能研究所（IDSIA）、瑞士应用科学与艺术大学（SUPSI））；Department of Informatics, Systems and Communication (DISCo), University of Milano-Bicocca（信息、系统与通信系（DISCo）、米兰-比科卡大学）；Department of Mechanical Engineering, Politecnico di Milano（机械工程系、米兰理工学院）
DexEXO: A Wearability-First Dexterous Exoskeleton for Operator-Agnostic Demonstration and Learning
Department of Computer Science（计算机科学系）；Department of Electrical and Computer Engineering（电气与计算机工程系）；Department of Mechanical and Aerospace Engineering（机械与航空航天工程系）
Human-Exoskeleton Kinematic Calibration to Improve Hand Tracking for Dexterous Teleoperation
Walker Department of Mechanical Engineering, The University of Texas at Austin（德克萨斯大学机械工程系）；Sony Group Corporation, Tokyo, Japan（索尼集团公司，日本东京）；Meta Reality Labs Research, Redmond, WA, USA（Meta现实实验室研究）
Grasp synergies represent a useful idea to reduce grasping complexity without compromising versatility. Synergies describe coordination patterns between joints, either in terms of position (joint angles) or effort (joint torques). In both of these cases, a grasp synergy can be represented as a low-dimensional manifold lying in the high-dimensional joint posture or torque space. In this paper, we use the term \textit{Mechanically Realizable Manifolds} to refer to the subset of such manifolds (in either posture or torque space) that can be achieved via mechanical coupling of the joints in undera…
This paper proposes an MPC-based controller to efficiently execute multiple hierarchical tasks for underactuated and constrained robotic systems. Existing task-space controllers or whole-body controllers solve instantaneous optimization problems given task trajectories and the robot plant dynamics. However, the task-space control method we propose here relies on the prediction of future state trajectories and the corresponding costs-to-go terms over a finite time-horizon for computing control commands. We employ acceleration energy error as the performance index for the optimization problem an…
The aim of this work is to utilize an adaptive decentralized control method called virtual decomposition control (VDC) to control the orientation and position of the end-effector of a 7 degrees of freedom (DoF) right-hand upper-limb exoskeleton. The prevailing adaptive VDC approach requires tuning of 13n adaptation gains along with 26n upper and lower parameter bounds, where n is the number of rigid bodies. Therefore, utilizing the VDC scheme to control high DoF robots like the 7-DoF upper-limb exoskeleton can be an arduous task. In this paper, a new adaptation function, so-called natural adap…
In this paper, we propose a single-actuator gripper that can lift thin objects lying on a flat surface, in addition to the ability as a standard parallel gripper. The key is a crawler on the fingertip, which is underactuated together with other finger joints and switched with a passive and spring-loaded mechanism. While the idea of crawling finger is not a new one, this paper contributes to realize the crawling without additional motor. The gripper can passively change the mode from the parallel approach mode to the pull-in mode, then finally to the power grasp mode, according to the grasping …
