Development of Pneumatically Driven Peristaltic-Type Robot for Long Distance Inspection in Half-inch Pipes

If pipes with narrow diameters are not well inspected, preventing accidents become difficult. Therefore, we developed a pneumatically powered earthworm-type robot for Half-inch pipes (each having an inner diameter of approximately 16 mm); these pipes are extremely difficult to inspect. When the robot travels for a long distance, its speed significantly decreases. When the movement distance of one cycle is small and the inter-operation period is short, the influence of the response delay of the pneumatic actuator increases and the speed decreases. Therefore, we developed a robot whose response delay is less likely to influence the driving speed and that has a large amount of movement per cycle. To create the proposed robot, we developed an extension unit and a grip unit as pneumatic actuators and experimented on pneumatic response characteristics. Also, the driving speed was measured using running tests. This confirmed that the robot's speed increased, and the speed decay owing to the long air tube decreased. The proposed robot will help reduce accidents arising from the corrosion of pipelines.