Proxy Platform for Underwater Inspection, Maintenance, and Repair

We describe the development of a custom ROV/AUV platform that is designed to facilitate cost-effective experimental research and development in the domains of underwater navigation, perception, and autonomy. Key aspects of the vehicle are that it is lightweight (i.e. man-portable), easily reconfigurable, and instrumented with a suite of navigation and perception sensors to proxy the configuration of a state-of-the-art hovering AUV. Fully equipped, the vehicle weighs 25 kg. A 3D mapping functionality based on the use of a multibeam imaging sonar is described. Results from testing in an indoor pool as well an outdoor river setting are presented. Finally, limitations of the proxy platform are reviewed with an emphasis on the impact of navigation sensor drift and lever arm displacement error. A preliminary implementation of sonar-based simultaneous localization and mapping (SLAM) is described, representing an approach to overcome these limitations.