Performance-Constraint Improved Formation Control for Underactuated Unmanned Surface Vehicles with Hybrid Dynamic Event-Triggered Mechanism

This paper investigates the performance-constrained formation control issues for multiple underactuated unmanned surface vehicles (USVs) under uncertain dynamics and the limited communication bandwidth. Firstly, an auxiliary input–output transformation is introduced to achieve the relative degrees where the transverse tracking errors can be compensated directly. A mapped-domain asymmetric prescribed-performance formulation is developed to regulate the admissible error boundaries independently. Under this approach, the transient and steady-state formation tracking errors can be guaranteed within the predesigned region. To reduce unnecessary information transmission, a dual-error-regulated dynamic event-triggered communication mechanism is constructed where both the formation-tracking error and the communication error jointly regulate the internal dynamic variable and triggering threshold. Furthermore, the neural network function is introduced to compensate for the system uncertainties and external disturbances. Moreover, the Lyapunov-function stability analysis illustrates that the closed-loop system formation tracking and estimation errors can converge within the equilibrium region without Zeno behavior. Finally, the numerical comparisons and hardware-in-the-loop experiments show the effectiveness of the proposed method in complex ocean environments.