基于外部导向软体生长机器人的管道与洞穴三维转向与定位
Navigation and inspection in confined environments, such as tunnels and pipes, pose significant challenges for existing robots due to limitations in maneuverability and adaptability to varying geometries. Vine robots, which are soft growing continuum robots that extend their length through soft material eversion at their tip, offer unique advantages due to their ability to navigate tight spaces, adapt to complex paths, and minimize friction. However, existing vine robot designs struggle with navigation in manmade and natural passageways, with branches and sharp 3D turns. In this letter, we introduce a steerable vine robot specifically designed for pipe and burrow environments. The robot features a simple tubular body and an external tip mount that steers the vine robot in three degrees of freedom by changing the growth direction and, when necessary, bracing against the wall of the pipe or burrow. Our external tip steering approach enables: (1) active branch selection in 3D space with a maximum steerable angle of 51.7°, (2) navigation of pipe networks with radii as small as 2.5 cm, (3) a compliant tip enabling navigation of sharp turns, and (4) real-time 3D localization in GPS-denied environments using tip-mounted sensors and continuum body odometry. We describe the forward kinematics, characterize steerability, and demonstrate the system in a 3D pipe system as well as a natural animal burrow.
在隧道和管道等受限环境中进行导航与检测，由于现有机器人在机动性以及对多变几何形状的适应性方面存在局限，面临着巨大的挑战。藤蔓机器人（Vine robots）是一种通过尖端软体材料外翻实现长度延伸的柔性连续体机器人；凭借其在狭窄空间中穿行、适应复杂路径以及最大程度减小摩擦的能力，这类机器人展现出了独特的优势。然而，现有的藤蔓机器人设计在应对包含分支结构和急剧三维转弯的人造或自然通道时，往往显得力不从心。在本文中，我们介绍了一种专为管道及洞穴环境设计的可转向藤蔓机器人。该机器人采用简洁的管状本体设计，并配备了一个外部尖端转向装置；该装置通过改变生长方向，并在必要时借力抵靠管道或洞穴内壁，从而赋予藤蔓机器人三自由度的转向能力。我们所提出的这种外部尖端转向方案实现了以下功能：(1) 在三维空间中进行主动分支选择，最大转向角度可达 51.7°；(2) 在半径小至 2.5 cm 的管道网络中进行导航；(3) 凭借柔顺的尖端结构，能够顺利通过急转弯；(4) 利用尖端搭载的传感器与连续体本体里程计数据，在 GPS 信号缺失的环境中实现实时三维定位。本文详细阐述了该机器人的正运动学模型，对其转向性能进行了特性分析，并通过在三维管道系统及自然动物洞穴中的实地演示，验证了该系统的有效性。