A study of an in-pipe mobile robot driven by pneumatic pressures on the model of a green caterpillar - Development and basic characteristics of an in-pipe mobile robot using suction brakes

Abstract

This paper describes development of an in-pipe mobile robot driven by pneumatic pressures. Town gas is supplied to houses through polyethylene pipes laid under the road. It are necessary to inspect these pipes regularly caused by the gas leak owing to earth load and oscillation for driving cars on the road. The robot is fabricated on the model of a green caterpillar for the purpose of inspecting these pipes. The caterpillar moves forward on leaf by waving motion of somites and clinging to a leaf for using abdominal legs and anal prolegs. The robot is structured by three somites and four suction brakes. This somite which structured by four pneumatic bellows actuators plays the role of the caterpillar's somite, and suction brake plays the role of the abdminal prolegs and anal prolegs. We confirmed that the robot's moving speed is 9.2 mm/s at acrylic pipe more 110 mm in inner diameter, and maximum traction force is 28.4 N. The robot having traction force 28.4 N can move mathematically in a horizontal pipe which has two elbows and 30 m length. In addition, mechanism of traction force is clarified by using the dynamic model of the robot.