Design and experimental research of a soft worm-like pipeline robot

Most of the current soft pipeline robots are capable of crawling and climbing motions but are relatively poor at steering motions and adapting to different pipe diameters. Although peristaltic soft pipeline robots can adapt to different pipe diameters, the complexity of the structure limits the minimum working pipe diameter that can be adapted by itself. Therefore, this paper proposes a worm-like soft pipeline robot. According to the motion mechanism of the worm, the idea of modular design is applied to the axial actuator and radial actuator to complete the overall structural design of the pipeline robot. The kinematic analysis of these two actuators is accomplished using the segmented constant curvature model with the D-H method. The optimization of the structural parameters through simulation resulted in better kinematic performance of the two actuators. In the experiments, the robot crawled at a speed of 4.96 mm/s in the small pipe diameter motion mode and 3.52 mm/s in the large pipe diameter motion mode. In addition, the pipe robot can accomplish 90° steering movement. The soft worm-like pipeline robot demonstrates adaptability to various pipe diameters and exhibits excellent movement performance.