Implementation of 2-DOF Grabber Arm and Computer Vision on Remotely Operated Underwater Vehicle

Abstract The development and applications of remotely operated and autonomous underwater vehicles have significantly increased in recent years. As these vehicles operate in the harsh underwater environment, demanding requirements for their design usually reflect in a high cost of underwater systems. However, with more readily available inexpensive electronics and powering systems, lower cost developments have been initiated. In the present work, several modifications of a low-cost remotely operated underwater platform are described. One is a construction of a two-degree-of-freedom arm for manipulating underwater objects. The second is an improvement of the propulsion control on the vehicle to allow for gradual variation of thrust forces instead of the original on/off mode. The third enhancement is a computer vision system for identifying underwater objects of interest that is applied for automated steering of the vehicle. Initial tests with these elements in a laboratory tank are presented and discussed. They include (1) autonomous detection of a target and maneuvering towards it, (2) grabbing and moving an object with manual remote control, and (3) the combined test with autonomous identification, grabbing, and moving of a target. The reported developments and test results can help other researchers pursuing low-cost developments of underwater vehicles.