Formation Path Following Control of Underactuated USVs -- With Proofs

TL;DR

This paper introduces a formation control strategy for two underactuated USVs to follow curved paths amidst ocean currents, combining LOS guidance and NSB control, with theoretical proofs and experimental validation.

Contribution

The paper presents a novel formation control method for underactuated USVs that ensures curved path following and formation maintenance using a combined LOS and NSB framework.

Findings

The control system guarantees USGES and UGAS stability.

Simulations and experiments confirm effective path following and formation control.

Underactuated sway dynamics remain bounded under the proposed control.

Abstract

This paper proposes a formation control method for two underactuated unmanned surface vessels (USVs) to follow curved paths in the presence of ocean currents. By uniting a line-of-sight (LOS) guidance law and the null-spacebased behavioral control (NSB) framework, we achieve curved path following of the barycenter, while maintaining the desired vessel formation. The closed-loop dynamics are investigated using cascaded systems theory, and it is shown that the closed-loop system is USGES and UGAS, while the underactuated sway dynamics remains bounded. Both simulation and experimental results are presented to verify the theoretical results.