Design and Control of Modular Soft-Rigid Hybrid Manipulators with Self-Contact
Computer Science and Artificial Intelligence Laboratory, MIT（麻省理工学院计算机科学与人工智能实验室）；Delft University of Technology（代尔夫特理工大学）；German Aerospace Center (DLR)（德国航空航天中心）
Zach J. Patterson, Emily Sologuren, Cosimo Della Santina, Daniela Rus
Soft robotics focuses on designing robots with highly deformable materials, allowing them to adapt and operate safely and reliably in unstructured and variable environments. While soft robots offer increased compliance over rigid body robots, their payloads are limited, and they consume significant energy when operating against gravity in terrestrial environments. To address the carrying capacity limitation, we introduce a novel class of soft-rigid hybrid robot manipulators (SRH) that incorporates both soft continuum modules and rigid joints in a serial configuration. The SRH manipulators can seamlessly transition between being compliant and delicate to rigid and strong, achieving this through dynamic shape modulation and employing self-contact among rigid components to effectively form solid structures. We discuss the design and fabrication of SRH robots, and present a class of novel control algorithms for SRH systems. We propose a configuration space PD+ shape controller and a Cartesian impedance controller, both of which are provably stable, endowing the soft robot with the necessary low-level capabilities. We validate the controllers on SRH hardware and demonstrate the robot performing several tasks. Our results highlight the potential for the soft-rigid hybrid paradigm to produce robots that are both physically safe and effective at task performance.
SkinGrip: An Adaptive Soft Robotic Manipulator with Capacitive Sensing for Whole-Limb Bed Bathing Assistance
Institute for Robotics and Intelligent Machines, Georgia Institute of Technology（佐治亚理工学院机器人与智能机器研究所）；Robotics Institute, Carnegie Mellon University（卡内基梅隆大学机器人学院）
Shahid Beheshti University（沙希德·贝赫什提大学）；Technical University of Denmark（丹麦技术大学）
Compliance is a strong requirement for human-robot interactions. Soft-robots provide an opportunity to cover the lack of compliance in conventional actuation mechanisms, however, the control of them is very challenging given their intrinsic complex motions. Therefore, soft-robots require new approaches to e.g., modeling, control, dynamics, and planning. One of the control strategies that ensures compliance is the impedance control. During the task execution in the presence of coupling force and position constraints, a dynamic behavior increases the flexibility of the impedance control. This im…
There is a surge of research interest in the field of tensegrity robotics. Robots developed under this paradigm provide many advantages and have distinguishing features in terms of structural compliance, dexterity, safety, and weight reduction. This paper proposes a new robotic mechanism based on tensegrity ('tension-integrity') robots and reconfigurable modular robots. The specific actuation schemes for this tensegrity robot with multiple degrees of freedom are presented. This article describes an easy-to-assemble 350 mm tensegrity based robot prototype by stacking a series of rigid struts li…
Massachusetts Institute of Technology（麻省理工学院）；Lightspeed & Quantum Studios, Tencent America（腾讯美国光速量子工作室）
Traditional robotic manipulator design methods require extensive, time-consuming, and manual trial and error to produce a viable design. During this process, engineers often spend their time redesigning or reshaping components as they discover better topologies for the robotic manipulator. Tactile sensors, while useful, often complicate the design due to their bulky form factor. We propose an integrated design pipeline to streamline the design and manufacturing of robotic manipulators with knitted, glove-like tactile sensors. The proposed pipeline allows a designer to assemble a collection of …
The Chinese University of Hong Kong（香港中文大学）；Hong Kong Center for Logistics Robotics（香港物流机器人中心）
In this paper, we propose a novel variable-length estimation approach for shape sensing of extensible soft robots utilizing fiber Bragg gratings (FBGs). Shape reconstruction from FBG sensors has been increasingly developed for soft robots, while the narrow stretching range of FBG fiber makes it difficult to acquire accurate sensing results for extensible robots. Towards this limitation, we newly introduce an FBG-based length sensor by leveraging a rigid curved channel, through which FBGs are allowed to slide within the robot following its body extension/compression, hence we can search and mat…
Swiss Federal Institute of Technology in Zürich (ETH Zürich)（苏黎世联邦理工学院）
Flying manipulators are aerial drones with attached rigid-bodied robotic arms and belong to the latest and most actively developed research areas in robotics. The rigid nature of these arms often lack compliance, flexibility, and smoothness in movement. This work proposes to use a soft-bodied robotic arm attached to an omnidirectional micro aerial vehicle (OMAV) to leverage the compliant and flexible behavior of the arm, while remaining maneuverable and dynamic thanks to the omnidirectional drone as the floating base. The unification of the arm with the drone poses challenges in the modeling a…
Most aerial manipulators use serial rigid-link designs, which results in large forces when initiating contacts during manipulation and could cause flight stability difficulty. This limitation could potentially be improved by the compliance of continuum manipulators. To achieve this goal, we present the novel design of a compact, lightweight, and modular cable-driven continuum manipulator for aerial drones. We then derive a complete modeling framework for its kinematics, statics, and stiffness (compliance). The framework is essential for integrating the manipulator to aerial drones. Finally, we…
Most aerial manipulators use serial rigid-link designs, which results in large forces when initiating contacts during manipulation and could cause flight stability difficulty. This limitation could potentially be improved by the compliance of continuum manipulators. To achieve this goal, we present the novel design of a compact, lightweight, and modular cable-driven continuum manipulator for aerial drones. We then derive a complete modeling framework for its kinematics, statics, and stiffness (compliance). The modeling framework can guide the control and design problems to integrate the manipu…
In the modern days, manipulators are found in the automated assembly lines of industries that produce products in masses. These manipulators can be used only in one configuration, that is either serial or parallel. In this paper, a new module which has two degrees of freedom is introduced. By connecting the two and three modules in series, 4 and 6 DoF hybrid manipulators can be formed respectively. By erecting 3 modules in parallel and with some minor modifications, a 6 DoF parallel manipulator can be formed. Hence the manipulator is reconfigurable and can be used as hybrid or parallel manipul…
Indian Institute of Technology Ropar（印度理工学院鲁尔基分校（罗帕尔分校））
Modular and reconfigurable robotic systems have been designed to provide a customized solution for the non-repetitive tasks to be performed in a constrained environment. Customized solutions are normally extracted from task-based optimization of the possible manipulator configurations but the solution are not integrated, for providing the modular compositions directly. In this work, in the first phase, a strategy of finding unconventional optimal configurations with minimal number of degrees-of-freedom are discussed based upon the prescribed working locations and the cluttered environment. The…
Modular robots can be tailored to achieve specific tasks and rearranged to achieve previously infeasible ones. The challenge is choosing an appropriate design from a large search space. In this work, we describe a framework that automatically synthesizes the design and controls for a serial chain modular manipulator given a task description. The task includes points to be reached in the 3D space, time constraints, a load to be sustained at the end-effector, and obstacles to be avoided in the environment. These specifications are encoded as a constrained optimization in the robot's kinematics a…
Prismatic-Bending Transformable (PBT) Joint for a Modular, Foldable Manipulator with Enhanced Reachability and Dexterity
Department of Mechanical Engineering, University of California, Berkeley（加州大学伯克利分校机械工程系）；The Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong（香港中文大学机械与自动化工程系）；FANUC Advanced Research Laboratory, FANUC America Corporation, USA（FANUC美国公司先进研究实验室）
AeRSoM: An Aerial Rigid-Soft Integrated Manipulator for Contact-Rich Manipulation
Hunan University（湖南大学）；National Engineering Research Center for Robot Visual Perception and Control Technology（国家机器人视觉感知与控制技术工程研究中心）；Beihang University（北京航空航天大学）
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）
Soft robotic manipulators provide numerous advantages over conventional rigid manipulators in fragile environments such as the marine environment. However, developing analytic inverse models necessary for shape, motion, and force control of such robots remains a challenging problem. As an alternative to analytic models, numerical models can be learned using powerful machine learned methods. In this paper, the Kinematics Transformer is proposed for developing accurate and precise inverse kinematic models of soft robotic limbs. The proposed method re-casts the inverse kinematics problem as a seq…
Arizona State University（亚利桑那州立大学）；Fulton Schools of Engineering（富尔顿工程学院）；The Polytechnic School（理工学院）
This paper evaluates how laminated techniques may be used to replicate the performance of more traditionally manufactured robotic manipulators. In this case study, we introduce a laminated 2-DOF spherical, parallel manipulator. Taking advantage of laminating techniques in the construction of the robot can result in considerable saving in construction costs and time, but, the challenges caused by this technique have to be addressed. By using stiffer materials in rigid links, the rigidity of the robot is increased to an acceptable level. We discuss one method for compensating position uncertaint…
Innopolis University（因诺波利斯大学）；Centre National de la Recherche Scientifique (CNRS)（法国国家科学研究中心）；Le Laboratoire des Sciences du Numérique de Nantes (LS2N)（南特数字科学实验室）；IMT Atlantique（大西洋国立高等工业技术与矿业学校）
The paper presents advancement of the matrix structural analysis technique (MSA) for stiffness modeling of robotic manipulators. In contrast to the classical MSA, it can be applied to both parallel and serial manipulators composed of flexible and rigid links connected by rigid, passive or elastic joints with multiple external loadings. The manipulator stiffness model is presented as a set of basic equations describing the link elasticities that are supplemented by a set of constraints describing connections between links. These equations are aggregated straightforwardly in a common linear syst…
Unified Hierarchical MPC in Task Executing for Modular Manipulators across Diverse Morphologies
Humanoids and Human Centered Mechatronics Research Line, Istituto Italiano Di Tecnologia (IIT)（意大利理工学院人机一体化机电一体化研究组）；Tencent Robotics X Lab（腾讯机器人实验室）；The University of Hong Kong（香港大学）
ETH Zurich（苏黎世联邦理工学院）；The Sapienza University of Rome（罗马第一大学）；The University of Tokyo（东京大学）
Soft robots are made of compliant materials and perform tasks that are challenging for rigid robots. However, their continuum nature makes it difficult to develop model-based control strategies. This work presents a robust model-based control scheme for soft continuum robots. Our dynamic model is based on the Euler-Lagrange approach, but it uses a more accurate description of the robot's inertia and does not include oversimplified assumptions. Based on this model, we introduce an adaptive sliding mode control scheme, which is robust against model parameter uncertainties and unknown input distu…
Customization of manipulator configurations using modularity and reconfigurability aspects is receiving much attention. Modules presented so far in literature deals with the conventional and standard configurations. This paper presents the 3D printable, light-weight and unconventional modules: MOIRs' Mark-2, to develop any custom `n'-Degrees-of-Freedom (DoF) serial manipulator even with the non-parallel and non-perpendicular jointed configuration. These unconventional designs of modular configurations seek an easy adaptable solution for both modular assembly and software interfaces for automat…
Dynamic motions are a key feature of robotic arms, enabling them to perform tasks quickly and efficiently. Soft continuum manipulators do not currently consider dynamic parameters when operating in task space. This shortcoming makes existing soft robots slow and limits their ability to deal with external forces, especially during object manipulation. We address this issue by using dynamic operational space control. Our control approach takes into account the dynamic parameters of the 3D continuum arm and introduces new models that enable multi-segment soft manipulators to operate smoothly in t…
A Task-Driven, Planner-in-the-Loop Computational Design Framework for Modular Manipulators
Humanoids and Human Centered Mechatronics Research Line, Italian Institute of Technology (IIT) Genoa, Italy（意大利理工学院（IIT）热那亚人类与以人为中心的机电研究组）；Department of Industrial Engineering, University of Trento, Trento, Italy（特伦托大学工业工程系）
Modular Adaptive Aerial Manipulation under Unknown Dynamic Coupling Forces
The University of Manchester（曼彻斯特大学）；Czech Technical University in Prague（布拉格捷克技术大学）；International Institute of Information Technology Hyderabad（海德拉巴国际信息技术学院）；Southeast University（东南大学）
Örebro University（厄勒布鲁大学）；Center for Applied Autonomous Sensor Systems (AASS)（应用自主传感器系统中心）
Integrating the heterogeneous controllers of a complex mechanical system, such as a mobile manipulator, within the same structure and in a modular way is still challenging. In this work we extend our framework based on Behavior Trees for the control of a redundant mechanical system to the problem of commanding more complex systems that involve multiple low-level controllers. This allows the integrated systems to achieve non-trivial goals that require coordination among the sub-systems.
Queensland University of Technology（昆士兰科技大学）；Australian Centre for Robotic Vision（澳大利亚机器人视觉中心）；University of New South Wales（新南威尔士大学）
Tendon-driven snake-like arms have been used to create highly dexterous continuum robots so that they can bend around anatomical obstacles to access clinical targets. In this paper, we propose a design algorithm for developing patient-specific surgical continuum manipulators optimized for oriental dexterity constrained by task-space obstacles. The algorithm uses a sampling-based approach to finding the dexterity distribution in the workspace discretized by voxels. The oriental dexterity measured in the region of interest in the task-space formed a fitness function to be optimized through diffe…
University of Toronto Institute for Aerospace Studies（多伦多大学航空航天研究所）；University of Zagreb（萨格勒布大学）
We present a novel approach for mobile manipulator self-calibration using contact information. Our method, based on point cloud registration, is applied to estimate the extrinsic transform between a fixed vision sensor mounted on a mobile base and an end effector. Beyond sensor calibration, we demonstrate that the method can be extended to include manipulator kinematic model parameters, which involves a non-rigid registration process. Our procedure uses on-board sensing exclusively and does not rely on any external measurement devices, fiducial markers, or calibration rigs. Further, it is full…
Plug, Play and Comply: Plugin-Based Compliant Control in ROS 2
College of Information Science and Technology, Eastern Institute of Technology（信息科学与技术学院，东方理工学院）；Zhejiang Key Laboratory of Industrial Intelligence and Digital Twin, Eastern Institute of Technology（浙江省工业智能与数字孪生重点实验室，东方理工学院）
