Autonomous exploration and 3-D mapping of underwater caves with the human-portable SUNFISH® AUV

The SUNFISH® AUV is a compact, light-weight, hover-capable AUV, fully controllable in all six degrees of freedom. This unique maneuverability allows SUNFISH to acquire data, sense the environment, and build fully 3-D maps in ways previously unattainable. It contains a basic sensor suite to perform a variety of missions: survey operations, precision inspection, underwater intervention, and exploration and mapping of complex 3-D geometries. It has the capability to integrate additional payloads for more specific tasks such as water sampling or biogeochemical profiling. The goal of SUNFISH development is to enable new exploration behaviors and decision making beyond that of scripted missions to the point where the vehicle accepts high-level goals and makes its own local decisions on how to achieve those objectives. We have developed autonomous exploration and auto-return capabilities for SUNFISH operating in unstructured 3-D environments. SUNFISH high-level reasoning combines online simultaneous localization and mapping (SLAM) capabilities with obstacle avoidance and real-time path planning, producing a vehicle which can perform exploration tasks in complex, extreme environments and find its way home autonomously. The result is a vehicle which can operate safely in complex, restricted spaces, and bring back detailed imagery, chemical profiles, and sonar maps of the area it has explored. This paper briefly reviews the SUNFISH vehicle capabilities and describes the deployment of the SUNFISH vehicle in several complex 3-D environments.