Structural design and in-pipeline passability of a deformable tracked pipeline inspection robot

YAN Hongwei; WANG Guorui; WEI Hongmei; MA Yaohui; REN Haojie; ZHAO Pengyang

doi:10.16578/j.issn.1004.2539.2026.05.016

Abstract：[Objective]Aiming at the poor passability of existing pipeline robots at bends,inclined pipelines and step-like obstacles,a new type of deformable tracked pipeline inspection robot was designed to explore its in-pipeline passing mechanism,verify the rationality of the robot's structural design and improve its adaptability to complex pipeline environments.[Methods]Firstly,the overall structure of the robot with a central variable diameter mechanism as the core and three circumferentially uniformly distributed deformable crawler foot modules was designed to realize adaptive adaptation to pipe diameters of DN180-DN220.Secondly,the geometric constraint and speed models for the robot's elbow passing were established,and a differential speed control strategy was proposed to optimize the robot's operational stability in pipelines.Thirdly,a virtual prototype of the robot was built to carry out motion simulations of elbow and complex pipelines,so as to verify the improvement effect of the robot's in-pipeline passability.Finally,a physical prototype of the robot was developed and a test platform was built to conduct passability tests in vertical pipelines,obstructed pipelines and elbow environments,completing the cross verification of simulation and test results.[Results]The robot can pass through a 90° vertical pipeline smoothly with a maximum obstacle-crossing height of 15 mm.The proposed differential speed cornering strategy enables the robot to pass through bends stably at all posture angles from 0° to 90°,and the average cornering speed is increased by 15%-28%compared with the constant speed cornering mode without jamming or distortion during the whole cornering process.In complex pipeline environments,the contact force between the robot's crawler feet and the pipe wall never drops to zero,and its in-pipeline passability is significantly improved,which fully meets the design index requirements and provides a reference for the structural optimization and motion control of tracked pipeline inspection robots.