Development of half-inch pipe inspection robot using extension units

Abstract

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.