Design of a Pneumatically Driven Inchworm-Like Gas Pipe Inspection Robot with Autonomous Control

Periodic inspection of aging gas pipes is important. However, the conventional inspection approach of excavation is unfriendly to the environment. From the perspective of Sustainable Development Goals (SDGs), in this study, we introduced a pneumatically driven robot system called WATER7 to observe the inner environment of aging pipes, in particular water inside these pipes, without excavation. The robot can locomote similar to an inchworm with a thrust module operating in a periodical pattern, select direction with an active bending module, and acquire images using a camera. The robot is designed and assembled within a diameter of 12[mm] to enable insertion into a gas meter valve as well as transition and retrieval from a 7[m] service pipe consisting of 8 pipe bends. To improve the driving performance, we also shortened the transit time by increasing air flow and improved the robustness of each module of the robot. Furthermore, an autonomous control system for autonomous burr avoidance based on image processing was developed. According to experiments, the robot average transit time and retrieval without damage count for the assumed scenario were 81[min] and 9 times, respectively. In addition, the autonomous burr avoidance was confirmed to be effective.