Online Coverage Path Generation for Aquatic Environmental Monitoring with Multiple USVs through Constraint-based Control

In this paper, we address aquatic environmental monitoring with multiple Unmanned Surface Vehicles (USVs). In order to deal with the unignorable dynamic properties of the USVs and disturbances from the environment, we present a hierarchical control architecture such that the high-level control generates ideal paths in the sense of the monitoring performance and the low-level control is responsible for following the path while rejecting the disturbances. We then formulate a novel online path generation problem based on the formulation of so-called persistent coverage control. After transforming the cost minimization to a constraint-based specification, we design an online path generation mechanism based on the concept of the constraint-based control. The present system is demonstrated through simulation with both an idealized mathematical model and an identified USV model.