Development of an In-Pipe Robot With Differential Screw Angles for Curved Pipes and Vertical Straight Pipes

The in-pipe robots based on screw drive mechanism are very promising in the aspects of pipe inspecting and maintaining. The novel design of an in-pipe robot with differential screw angles is presented for the curved pipes and vertical straight pipes. The robot is mainly composed of the screw drive mechanism, adaptive linkage mechanism, and the elastic arm mechanism. The alternative adjusting abilities of the mobile velocity and traction, and the adaptive steering ability in curved pipes, are achieved by the special designs. A parameter design approach in consideration of the climbing and steering abilities is proposed in detail for the springs and length of the elastic arms. The results are applied to the prototype design of the robot. In several groups of experiments, the proposed robot is competent to pass through curved pipes and vertical straight pipes. The results prove that the proposed mechanism and parameter design approach are both valid.