Design and analysis of wheel-clamping external pipeline inspection robot

Abstract To address the limitations of existing external pipeline inspection robots, including a narrow range of adaptable pipe diameters and difficulty traversing obstacles like cross-pipelines, a novel wheel-clamping robot capable of circumferential rotation was designed. The composite drive mechanism of the robot adopts a dual-slider multi-link mechanism to realize the rapid switching of the two motion modes of the robot axis: forward and circumferential rotation. Following clarification of the robotic mechanism and component dimensions, a geometric model of key points was established, determining an adaptable pipeline diameter range of 74–203 mm. The force analysis was carried out to analyze the working state of the robot axis forward and circumferential rotation, and the minimum driving torque required to complete the above two motions is 0.84 and 1.23 N·m, respectively. Finally, the robot prototype was made, and the experiments of the prototype running on the pipeline were carried out. The experimental results show that the average speed of the robot is 0.195 m/s when it is moving along the axis on the pipeline, and it stably navigates obstacles through circumferential rotation, smoothly crossing T-shaped pipelines of different diameters, which is adaptable to the complex pipeline working conditions.