Design and Fabrication of a Novel Autonomous Pipeline Scanning Robot

Energy pipelines require regular inspection and health monitoring against defects, cracks, and corrosion due to the fluid pipe interaction and external environment conditions. Accurate and efficient pipeline inspection is extremely important to the oil and gas industry. Inspection of pipelines is usually carried out either internally using smart pigs and tethered robots or externally with limited inspection options. Internal inspection has many limitations and external inspection is still primitive. However, external inspection has the advantage of being carried out without interruption of the production process. In this paper, a novel design for an autonomous robot for pipeline external inspection is presented. Although, the proposed design is developed mainly to fit a magnetic flux leakage based inspection technique, the robot modular design will fit other inspection methods and applications with minimal design modifications. The proposed robot is designed to carry multiple hall effect sensors and allow adjustment of the radial distance between the sensors and the pipe surface. Also, the robot is able to scan different size pipes and maintain constant distance from the pipe surface. A prototype is fabricated using 3D printer and standard fasteners to evaluate the workability of the proposed design. The initial testing of the developed prototype showed that the robot can be made to move at a constant speed without slipping. The design details and the prototype elements are delineated in this paper.