In-Pipe Inspection Crawler Adaptable to the Pipe interior Diameter

One of the most important requirements of repairing and maintaining of pipelines is the ability to monitor and evaluate the pipe’s interior. In this paper, a novel apparatus to traverse pipes is introduced. The mechanism employs three independent rubber track units which are circumferentially spaced out 120 degree apart symmetrically. The apparatus employs an active mode to adapt to a wide range of pipeline diameters from 250 mm to 350 mm. However, this range can be easily extended by increasing the length of the robot’s linkages. It has also the capability of traversing vertical, horizontal and curved pipes. Further, it can passively pass over small obstacles of the interior surface of the pipes and navigate through various elbow joints in the piping system with the help of the special design of the springed arms. Moreover, a novel autonomous adjusting algorithm is presented to assist the operator in better regulation of the contact force without utilizing any force sensor. Finally, a prototype unit is built and tested in different situations. A pan and tilt camera is also mated on the robot. Key Words— In-pipe inspection, Robot design, Active pipe-diameter adaptability, Tractive force adjusting;