Continuum robots can be miniaturized to just a few millimeters in diameter. Among these, notched tubular continuum robots (NTCR) show great potential in many delicate applications. Existing works in robotic modeling focus on kinematics and dynamics but still face challenges in reproducing the robot's morphology -- a significant factor that can expand the research landscape of continuum robots, especially for those with asymmetric continuum structures. This paper proposes a dual stereo vision-based method for the three-dimensional morphological reconstruction of millimeter-scale NTCRs. The method employs two oppositely located stationary binocular cameras to capture the point cloud of the NTCR, then utilizes predefined geometry as a reference for the KD tree method to relocate the capture point clouds, resulting in a morphologically correct NTCR despite the low-quality raw point cloud collection. The method has been proved feasible for an NTCR with a 3.5 mm diameter, capturing 14 out of 16 notch features, with the measurements generally centered around the standard of 1.5 mm, demonstrating the capability of revealing morphological details. Our proposed method paves the way for 3D morphological reconstruction of millimeter-scale soft robots for further self-modeling study.

翻译：连续体机器人可微型化至直径仅数毫米。其中，切口管状连续体机器人（NTCR）在众多精密应用中展现出巨大潜力。现有机器人建模研究主要集中于运动学与动力学，但在复现机器人形态方面仍面临挑战——这一关键因素能够显著拓展连续体机器人的研究领域，尤其适用于具有非对称连续体结构的机器人。本文提出一种基于双立体视觉的毫米级NTCR三维形态重建方法。该方法采用两个相对布置的固定双目相机采集NTCR点云数据，随后利用预设几何结构作为KD树方法的参考基准，对采集点云进行重定位处理，从而在原始点云质量较低的情况下仍能获得形态正确的NTCR模型。该方法已在直径3.5毫米的NTCR上验证可行性，成功捕获16个切口特征中的14个，测量值普遍集中在1.5毫米标准值附近，证明了其揭示形态细节的能力。本研究提出的方法为毫米级软体机器人的三维形态重建及后续自建模研究奠定了基础。