An In-pipe Inspection Module with an Omnidirectional Bent-pipe Self-adaptation Mechanism using a Joint Torque Control

Abstract

This study presents an in-pipe inspection robot module, called AIRo-2.3s. This robot module can control its joint angle and torque and adapt to any directed bent pipe regardless of its orientation. Stretching the drive wheels against the inner wall of pipes is essential for adapting robots to be used in vertical pipes and slippery inner surfaces. To achieve this, a series elastic actuator (SEA) with a high reduction system and a polyurethane rubber is installed to sense the joint torque. More than 100 N constant traction force and a wide range of adaptive inner diameters (4 to 6 in.) are achieved despite the short body length, a minimum number of the drive wheels, and a simple joint of 1 degree of freedom. Experiments to verify the performance in bent pipes are conducted after the robot module configuration is described.