Using parallel program specifications for reactive control of underwater vehicles

摘要

This paper describes a situated reasoning architecture and a programming implementation for controlling robots in naturally changing environments. The reactive portion of the architecture produces reaction plans that exploit low-level competences as operators. The low-level competences include both obstacle avoidance heuristics and control-theoretic algorithms for generating and following a velocity/acceleration trajectory. Implemented in the GAPPS/REX situated automata programming language, robot goals can be specified logically and can be compiled into runtime virtual circuits that map sensor information into actuator commands in a fashion that allows for parallel execution. Detailed programs are described for controlling underwater vehicles being developed at the Woods Hole Oceanographic Institution, specifically the Remotely Piloted Vehicle (RPV), its successor, the Hylas, and eventually the Autonomous Benthic Explorer (ABE). Experiments with the RPV in a test tank are described in detail and will be duplicated with the Hylas. The experiments show that the robot performed both pilotaided and autonomous exploration tasks while accommodating normal changes in the task environment. ABE programs are described to illustrate how the reaction plans can be used in tasks more complex than those in the RPV experiments. The ABE is required to gather scientific data from deep ocean phenomena (e.g., thermal vents) which occur sporadically over long periods of time. A test tank simulation is described wherein the architecture is shown to easily generate robust vehicle control schemes which gather the required thermal vent data for a variety of vents of varying positions, velocities and extents.