SPiralRoll: A Novel Adjustable-Stiffness Underactuated 3-DoF Joint with Torsion Springs for Rolling Robots

• URL: http://arxiv.org/abs/2606.22443v1
• Date: Sun, 21 Jun 2026 11:27:50 GMT
• Title: SPiralRoll: A Novel Adjustable-Stiffness Underactuated 3-DoF Joint with Torsion Springs for Rolling Robots
• Abstract summary: SPiralRoll is a novel torsion-spring-based underactuated compliant mechanism for rolling robots and compliant robotic actuation.<n>The mechanism uses arc-distributed elastic members and two motor inputs to realize three physically observable output motions.<n>The full-arc design provides better structural support and smoother deformation, whereas the single-arc design yields larger deformation and stronger inertial excitation.
• Score: 1.0604607292133101
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Compliant mechanisms are important in robotics because they can improve adaptability, safety, and energy efficiency while reducing hardware complexity. This paper presents SPiralRoll, a novel torsion-spring-based underactuated compliant mechanism for rolling robots and compliant robotic actuation. The mechanism uses arc-distributed elastic members and two motor inputs to realize three physically observable output motions: rotational motion, radial expansion/contraction, and axial spin induced by nonlinear compliant deformation. Two configurations, namely full-arc and single-arc designs, are developed and experimentally evaluated. Beyond benchtop validation, the mechanism is integrated into a spherical rolling robot, where proof-of-concept experiments demonstrate forward rolling and turning. The results show that the full-arc design provides better structural support and smoother deformation, whereas the single-arc design yields larger deformation and stronger inertial excitation, making it more suitable for pendulum-driven rolling locomotion. Overall, SPiralRoll provides a low-cost, compact, and fully 3D-printable solution for underactuated compliant rolling robots and adaptive robotic joints.

Related papers

• Design and stability analysis of an underactuated hand with passively rotating fingers [1.3649494534428745]
  This paper presents an innovative design and stability analysis of an underactuated robotic finger with spatial mobility.<n>The finger architecture incorporates a revolute joint at its base, enabling passive spatial rotation that facilitates both cylindrical and spherical grasping.<n>The integration of underactuation-both within individual fingers and among multiple fingers-reduces mechanical complexity, cost, and control demands while preserving functional adaptability.
  arXiv  Detail & Related papers  (2026-07-21T10:37:18Z)
• PenduMorph: Development and Motion Analysis of Pendulum-Actuated Rolling Reconfigurable Spherical Robot with Magnetic-Coupling [9.674037525896503]
  "PenduMorph" is a wireless reconfigurable rolling spherical robot designed as a modular platform for enclosed locomotion and inter- module interaction.<n>The proposed robot extends our previous pendulum-actuated rolling disk concept to a fully enclosed spherical architecture integrating a 2-DoF internal pendulum, onboard control, battery-powered operation, and magnetic docking.
  arXiv  Detail & Related papers  (2026-06-21T13:24:52Z)
• Friction Characterization of a Cable-Driven Differential Actuation System for Lower-Limb Exoskeletons [42.628421392139]
  Lower-limb exoskeletons require actuation systems that can provide accurate joint torque control.<n> Conventional architectures often rely on independently actuated joints and joint-level torque sensors.<n>This paper presents a novel differential actuation architecture for hip-knee flexion/extension.
  arXiv  Detail & Related papers  (2026-06-14T19:47:32Z)
• ZipFold: Modular Actuators for Scaleable Adaptive Robots [52.52738470247707]
  This paper introduces a compact, easy-to-fabricate deployable actuator that achieves reversible scale and stiffness transformations.<n>The simple actuation method allows for smooth, continuous transitions between compact (flexible) and expanded (quasi-rigid) states.
  arXiv  Detail & Related papers  (2026-04-06T23:50:03Z)
• Design of an In-Pipe Robot with Contact-Angle-Guided Kinematic Decoupling for Crosstalk-Suppressed Locomotion [20.379309593600414]
  In-pipe inspection robots must traverse confined pipeline networks with elbows and three-dimensional fittings.<n>In compact V-shaped platforms, these functions often rely on shared contacts or indirect actuation.<n>This paper presents a V-shaped in-pipe robot with a joint-axis-and-wheel-separation layout that provides two physically independent actuation channels.
  arXiv  Detail & Related papers  (2026-03-28T11:40:36Z)
• A Pin-Array Structured Climbing Robot for Stable Locomotion on Steep Rocky Terrain [2.9126697571352556]
  We present a novel mobile climbing robot equipped with compliant pin-array structured grippers.<n>Each pin features a vertically split design, combining an elastic element with a metal spine to enable mechanical interlocking with microscale surface features.<n>The robot demonstrated robust and stable locomotion in indoor tests on inclined walls (10-30 degrees) and in outdoor tests on natural rocky terrain.
  arXiv  Detail & Related papers  (2026-03-17T14:05:42Z)
• When Rolling Gets Weird: A Curved-Link Tensegrity Robot for Non-Intuitive Behavior [0.6372261626436676]
  This research presents a solution with a semi-circular, curved-link tensegrity robot.<n>The robot strikes a balance between efficient rolling locomotion and controlled stability, enabled by discontinuities at the arc endpoints.<n>A preliminary impact test highlights the tensegrity structure's inherent shock absorption capabilities and conformability.
  arXiv  Detail & Related papers  (2026-03-17T13:30:33Z)
• Shape Control of a Planar Hyper-Redundant Robot via Hybrid Kinematics-Informed and Learning-based Approach [42.55947704321053]
  Hyper-redundant robots offer high dexterity, making them good at operating in confined and unstructured environments.<n>To extend the reachable workspace, we built a multi-segment flexible rack actuated planar robot.<n>We propose a hybrid kinematics-informed and learning-based shape control method, named SpatioCoupledNet.
  arXiv  Detail & Related papers  (2026-03-11T04:35:06Z)
• Physical Human-Robot Interaction for Grasping in Augmented Reality via Rigid-Soft Robot Synergy [43.680646123465316]
  Hybrid rigid-soft robots combine the precision of rigid manipulators with the compliance and adaptability of soft arms.<n>We present a novel augmented reality (AR)-based physical human-robot interaction framework that enables direct teleoperation of a hybrid rigid-soft robot.
  arXiv  Detail & Related papers  (2026-02-19T06:56:47Z)
• Robo3R: Enhancing Robotic Manipulation with Accurate Feed-Forward 3D Reconstruction [70.06600045165905]
  3D spatial perception is fundamental to general robotic manipulation, yet obtaining reliable, high-quality 3D geometry remains challenging.<n>We introduce Robo3R, a manipulation-ready 3D reconstruction model that predicts accurate, metric-scale scene geometry directly from RGB images and robot states in real time.<n>We observe consistent gains in performance, suggesting the promise of this alternative 3D sensing module for robotic manipulation.
  arXiv  Detail & Related papers  (2026-02-10T18:58:15Z)
• Preliminary Analysis and Simulation of a Compact Variable Stiffness Wrist [9.674808390941672]
  This paper introduces a novel 3 Degrees of Freedom (DoFs) parallel wrist that achieves variable stiffness through redundant elastic actuation.<n>The device employs only four motors, rendering it compact and lightweight.
  arXiv  Detail & Related papers  (2025-12-04T16:43:57Z)
• Efficient Design of Compliant Mechanisms Using Multi-Objective Optimization [50.24983453990065]
  We address the synthesis of a compliant cross-hinge mechanism capable of large angular strokes.<n>We formulate a multi-objective optimization problem based on kinetostatic performance measures.
  arXiv  Detail & Related papers  (2025-04-23T06:29:10Z)
• Humanoid Whole-Body Locomotion on Narrow Terrain via Dynamic Balance and Reinforcement Learning [54.26816599309778]
  We propose a novel whole-body locomotion algorithm based on dynamic balance and Reinforcement Learning (RL)<n> Specifically, we introduce a dynamic balance mechanism by leveraging an extended measure of Zero-Moment Point (ZMP)-driven rewards and task-driven rewards in a whole-body actor-critic framework.<n> Experiments conducted on a full-sized Unitree H1-2 robot verify the ability of our method to maintain balance on extremely narrow terrains.
  arXiv  Detail & Related papers  (2025-02-24T14:53:45Z)
• VAE-Loco: Versatile Quadruped Locomotion by Learning a Disentangled Gait Representation [78.92147339883137]
  We show that it is pivotal in increasing controller robustness by learning a latent space capturing the key stance phases constituting a particular gait. We demonstrate that specific properties of the drive signal map directly to gait parameters such as cadence, footstep height and full stance duration. The use of a generative model facilitates the detection and mitigation of disturbances to provide a versatile and robust planning framework.
  arXiv  Detail & Related papers  (2022-05-02T19:49:53Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.