Design and Dynamics of a Tendon-Actuated Flexible Crawling Robot
Abstract Flexible crawling robots have extensive applications in various fields, including on-orbit modular assembly, space transportation, and spacecraft surface maintenance. This article designs a tendon-actuated flexible crawling robot with the advantages of light weight, compact form factor, simple drive, versatile maneuverability, all-round movement, and capabilities of accomplishing intricate crawling tasks for detection, searching, and on-orbit […]
A Joint Optimization Framework for Workspace Analysis of an Underactuated Hybrid Pose Adjustment Robot
Abstract Cable-driven parallel robots (CDPRs) are promising for construction automation owing to their large workspaces and high payload capacity. However, underactuated CDPRs (UACDPRs), which possess fewer cables than end-effector degrees-of-freedom, are generally underconstrained and suffer from issues such as pose ambiguity, discontinuous attitude transitions, and nonuniform cable force distributions. This article proposes a joint optimization […]
Adaptive Impact Response of Coupled Tendon Constrained Inflatables for Occupant Safety in Future Mobility
Abstract The transition to autonomous vehicles poses a challenge for occupant safety devices during a collision due to the large variation in the direction and location of passenger impacts. A new technological approach is presented that offers adaptive impact response (i.e., trajectory control, energy absorption, and peak acceleration reduction) for diverse impact scenarios through a […]
Closed-Form Solutions to the Direct Kinematics of a Family of 3- X PS Parallel Mechanisms
Abstract We derive closed-form solutions to the direct-kinematics problem of a family of three and six degrees-of-freedom 3-X_PS parallel manipulators. In this class, the direct kinematics reduces to the classical “three-points-on-three-lines” problem, where the three lines have direction vectors that are mutually separated by 120 deg and are all horizontal. In some earlier works, the […]
Joint Stiffness-Based Assisted-as-Needed Control Strategy for Wrist Rehabilitation
Abstract This article introduces a novel stiffness-based assist-as-needed (AAN) control strategy aimed at optimizing the balance between robotic assistance and patient engagement in wrist rehabilitation. Central to the proposed approach is a joint stiffness estimation technique that enables precise, direction-specific assessment of the patient’s motor condition. The derived stiffness profile is utilized to adaptively modulate […]
Constrained Lagrangian-Based, Nonholonomic Modeling and Validation of a Pneumatically Actuated Wheeled Soft Robot
Abstract This article presents three configurations of a pneumatically actuated, symmetric, wheeled soft robot that is able to locomote forwards, backwards, and in a circular trajectory on a planar surface. The robot can achieve 22 cm/s (1.38 body lengths/s) in straight-line speed. We also extend a modeling framework from previous work to express the dynamics […]
Straight-Line Metamaterial Approximating an Ideal Shear Cell 1
Abstract Mechanical metamaterials are architected structures designed to exhibit unconventional mechanical responses. Their engineered properties make them especially valuable for realizing precise motion and load-bearing functions, with broad applications in machines, robotics, and related technologies. Straight-line mechanisms, typically based on compliant or rigid designs, offer compactness and accuracy but are often limited by parasitic motion, […]
Evaluation Method of Motion/Force Transmission Performance for Parallel Mechanisms With Sub-Moving Platforms
Abstract A class of parallel mechanisms with sub-moving platforms (PMs-SMPs) has significant advantages in stiffness and loading capacity over traditional parallel mechanisms (PMs). A detailed classification of both the PMs-SMPs and their sub-PMs is given. One of the essential roles for PMs is to transmit motion/force between the input and output ends. An evaluation method […]
Kinematic Analysis for a Planar Continuum Parallel Manipulator With Large-Deflection Links Based on Transfer Learning
Abstract This article presents a transfer learning method to address the kinematics problem of a planar continuum parallel manipulator with large-deflection links. This method is motivated by the need for lightweight, space-efficient mechanisms in small spaces or human–machine collaborative environments. The manipulator has two independent branch chains with highly flexible panels as links, and the […]
Workspace-Intersection-Based Inverse Kinematics Solution for a Two-Segment Variable-Length Continuum Manipulator
Abstract This article proposes an improved inverse kinematics solution for a two-segment continuum manipulator actuated by pneumatic artificial muscles (PAMs). A contraction model of PAMs is incorporated to construct a dynamic workspace volume, thereby overcoming the limitations of conventional geometric approaches that rely on the constant-length assumption. A K-dimensional tree algorithm is employed to accelerate […]