A Low Cost Underwater Robot with Grippers for Visual Inspection of External Pipeline Surface

Abstract

Underwater robots are used in surveillance, academic and military applications because of their capability to execute risky tasks underwater without human intervention. In this study, a robot is built at low cost budget to carry out inspection at specified depth in a water body. Preliminary studies are performed to understand the buoyancy and stability of an underwater robot. Different configurations of propeller arrangements are identified and the final prototype is arrived after meeting the specific application requirements. Dual grippers are incorporated with the underwater robot, one for holding the pipe to avoid underwater currents and other for gripping/releasing the pipe. Gyroscope sensor is embodied in the underwater robot to maintain stability from its feedback signals. A high definition camera is mounted in front of the underwater robot for live video and image capturing purposes. Thus the underwater robot is able to meet all its requirements with minimal frontal drag. For validation purpose, computational fluid dynamics (CFD) studies are carried out with dynamic meshes and boundary conditions. The deviation between CFD and experimental results is found to be within the acceptable limits. The detailed cost analysis for the construction and testing of this underwater robot is also briefly tabulated.