A Coverage Motion Planning Approach for UVMS-Based Propeller Cleaning in Obstacle-Occluded Environments

Abstract

This work addresses the problem of underwater propeller cleaning in environments containing obstacles using an Underwater Vehicle Manipulator System (UVMS). Prior propeller-cleaning approaches plan coverage tool paths without explicitly considering the connectivity of the associated Surface-Constrained Configuration Space (SCCS), leading to unnecessary lift-offs in obstacle-occluded settings. In contrast, we formulate the coverage problem in the disconnected SCCS as a Generalized Traveling Salesman Problem (GTSP) within a hierarchical framework, accounting for obstacles and attempting to minimize the number of tool lift-offs. We consider explicitly the tool lift-off paths in the GTSP cost formulation, utilizing the hierarchical framework to guide the search without exhaustively evaluating all possible paths. To achieve smoother tool paths with fewer turns, we introduce a cost that promotes alignment with desired coverage curves. Finally, we time-parameterize the coverage path into a whole-body UVMS trajectory by minimizing the duration of the cleaning task, while respecting the robot hardware limitations. The effectiveness of the proposed method is demonstrated in a realistic simulation scenario.