A magneto-elastic model for soft magnetic concentric tube robots.

IF 5.7 2区工程技术 Q1 ENGINEERING, MECHANICAL

Nonlinear Dynamics Pub Date : 2026-01-01 Epub Date: 2026-07-30 DOI:10.1007/s11071-026-12856-3

Peter Lloyd, Joshua Davy, Yael L May, Jurgen E Schneider, Pietro Valdastri

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引用次数: 0

Abstract

This paper presents a numerical solution to a reduced-order analytical energy formulation of a soft, magnetically actuated concentric tube continuum robot. Unlike conventional concentric tube robots, which rely on pre-curved elastic energy storage and suffer from material stiffness constraints and snap through instability, our design uses softly magnetic rings adhered to braided sleeves to generate deformation directly from a strong, stationary background field. While high-field MRI systems provide a convenient actuation environment, the proposed design principle is broadly applicable to any application featuring a sufficiently strong background magnetic field (B $≳$ 1T). We derive a complete magneto-elastic formulation that couples easy-plane magnetic torque with sleeve curvature to determine stable catheter configurations. The model captures mechanical hysteresis, bistability, and the nonlinear relationship between base rotation and tip pose. Experimental validation in the background field of a 7T pre-clinical MRI scanner demonstrates strong agreement with simulated deformation, with an overall RMS error of $4 . 4^{\circ}$ . This framework provides a foundation for closed-loop control, systematic design optimization, and self-sensing capabilities in magnetically actuated soft continuum robots, enabling new classes of highly compliant robotic systems for constrained and sensitive environments.

Supplementary information: The online version contains supplementary material available at 10.1007/s11071-026-12856-3.

查看原文本刊更多论文

软磁同心管机器人的磁弹性模型。

本文给出了软磁驱动同心管连续体机器人的降阶解析能量公式的数值解。与传统的同心管机器人不同，同心管机器人依赖于预弯曲的弹性能量存储，并且受到材料刚度限制和不稳定性的影响，我们的设计使用软磁环附着在编织袖上，直接从强大的静止背景场中产生变形。虽然高场MRI系统提供了一个方便的驱动环境，但所提出的设计原则广泛适用于具有足够强背景磁场（B≥1T）的任何应用。我们推导了一个完整的磁弹性公式，将易平面磁转矩与套筒曲率耦合在一起，以确定稳定的导管结构。该模型捕获了机械滞回、双稳性以及基座旋转和尖端位姿之间的非线性关系。在7T临床前MRI扫描仪的背景场中进行的实验验证与模拟变形非常吻合，总体均方根误差为4。4°。该框架为磁驱动软连续体机器人的闭环控制、系统设计优化和自感知能力提供了基础，为约束和敏感环境提供了新型高度柔性机器人系统。补充资料：在线版本包含补充资料，下载地址：10.1007/s11071-026-12856-3。

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来源期刊

Nonlinear Dynamics 工程技术-工程：机械

CiteScore

9.00

自引率

17.90%

发文量

966

审稿时长

5.9 months

期刊介绍： Nonlinear Dynamics provides a forum for the rapid publication of original research in the field. The journal’s scope encompasses all nonlinear dynamic phenomena associated with mechanical, structural, civil, aeronautical, ocean, electrical, and control systems. Review articles and original contributions are based on analytical, computational, and experimental methods. The journal examines such topics as perturbation and computational methods, symbolic manipulation, dynamic stability, local and global methods, bifurcations, chaos, and deterministic and random vibrations. The journal also investigates Lie groups, multibody dynamics, robotics, fluid-solid interactions, system modeling and identification, friction and damping models, signal analysis, and measurement techniques.