Adaptive synchronisation control for leader follower ships with disturbances and actuator attacks

This article studies the synchronisation control for ships during underway replenishment with disturbances, actuator attacks when the velocity of leader ship is unknown. To represent the stochastic nature of disturbances caused by wind, waves, and currents, a first-order Markov process is employed, and to resist the environmental disturbances, a stochastic disturbance observer (SDO) is designed for estimation. Next, a virtual ship is used to estimate the velocity of the leader ship, thereby minimising the need for direct measurement. Meanwhile, to address time-varying actuator attacks, an additive self-correction signal is introduced. Finally, an adaptive synchronisation control scheme is proposed, combining disturbance observer-based control (DOBC), adaptive control, and dynamic surface control (DSC) techniques. This scheme has been shown to ensure that all signals within the closed-loop system are asymptotically bounded in the mean square. The effectiveness and robustness of the proposed controller is verified through simulation examples in two different cases.