Robust adaptive saturation-tolerance control for USVs formation via a novel L1-VS guidance.

This paper proposes a saturation-tolerance control algorithm for the limited behavioral capability of actuators, particularly when facing external disturbances in the formation control of underactuated surface vehicles (USVs). An auxiliary subsystem that takes into account saturation-tolerant behavioral boundaries is included, which performs comprehensive compensatory control in the presence of input signals exceeding the real-time behavioral boundaries of the actuators' capability. For purpose of enhancing the precision of the guidance algorithm, a higher accuracy L1 virtual ship (L1-VS) guidance law is proposed for considering an effect of time on the dynamic virtual ship guidance principle. The computational dependence on time in the generation of the target path is lessened in the guidance design, thus indirectly realizing the reduction of the degree of the deviation of the execution route and the improvement of the stability of the system. Moreover, a robust neural damping technique and a dynamic surface control (DSC) approach are utilized in the control design for improving the system stability and reducing the danger of "explosion of complexity". One has done tremendous work to ensure semi-global uniform ultimate bounded (SGUUB) stability. The final three numerical examples are provided to evaluate the effectiveness of the proposed algorithm. • In this paper, a novel L1-VS guidance principle is proposed under the premise of higher guidance accuracy. • The L1-VS guidance eliminates the need for time-based computations on straight and turning paths. • A saturation compensation strategy is developed, thus mitigating the risk of faults stemming from behavioral overshoots. • By setting the saturation-tolerance behavior boundary, the effect of the auxiliary subsystem can be more clearly displayed. [ABSTRACT FROM AUTHOR]