Development of a peristaltic crawling robot for long-distance inspection of sewer pipes

We have developed a robot that can inspect long distances in thin sewer pipes. Inspections of sewer pipes are necessary to prevent accidents such as road caving accidents. However, thin sewer pipes cannot be easily inspected by existing methods. To solve this problem, we developed a peristaltic crawling robot that mimics earthworm locomotion. This robot comprises six units: five joint parts and a head part with a camera that inspects inside the sewer pipes. As the actuator in the unit is a pneumatic artificial muscle, the robot is driven by air pressure. Air is supplied to each unit through an electric valve mounted directly on the unit, thereby preventing delay in air transfer. We confirmed that the robot can stably drive through horizontal and vertical sewer pipes. In driving tests through a bending pipe, we identified materials for the joint parts that enable the robot to smoothly travel through the pipe. During these tests, we further evaluated the robot's traveling performance by measuring its driving speed through the pipe.