Abstract
To make the inspection robot pass in small pipes or vertical pipes, it is hard to equip several motors and mechanisms. Screw drive mechanisms have been focused because a minimum number of motor is only one. It can achieve downsizing, lightweight and energy-saving. Some existing robots can pass in the curved pipes with large curvature radius. However, it can not pass in the pipes with small curvature radius and mobility analysis and verification have not been conducted. In this paper, we consider the cross-sectional shape of a curved pipe that the in-pipe robot attaches. Necessary spring stiffness of elastic driving arms and motor torques are derived for the robot to pass in the curved pipe and the vertical pipe where the friction force changes.
