A Mission Executor for an Autonomous Underwater Vehicle

Abstract

The Naval Postgraduate School has been conducting research into the design and testing of an Autonomous Underwater Vehicle (AUV). One facet of this research is to incrementally design a software architecture and implement it in an advanced testbed, the AW 11. As part of the high level architecture, a Mission Executor is being constructed using CLIPS version 5.0. The Mission Executor is an expert system designed to oversee progress from the AW launch point to a goal area and back to the origin. It is expected that the Executor will make informed decisions about the mission, taking into account the navigational path, the vehicle subsystems health and the sea environment, as well as the specific mission profile which is downloaded from an offboard mission planner. Heuristics for maneuvering, avoidance of uncharted obstacles, waypoint navigation, and reaction to emergencies (essentially the expert knowledge of a submarine captain) are required. Many of the vehicle subsystems are modeled as objects using the CLIPS Object Oriented Language (COOL) embedded in CLIPS 5.0. Additionally, truth maintenance is applied to the knowledge base to keep configurations updated.