Multi-target tracking and surrounding control for multi-USV system under unknown disturbances based on distributed NMPC

As an important research area of unmanned vehicles, multi-unmanned surface vehicle (multi-USV) systems have demonstrated high efficiency, flexibility, and robustness in marine missions. In the context of collaborative control design for multi-USV systems, this paper investigates the multi-target tracking and surrounding control problem for multi-USV systems under unknown disturbances. During the multi-target tracking phase, a circular domain is constructed to enclose all targets, and the center of this circular domain is set as a virtual target, thereby transforming the tracking of moving targets into the tracking of a single virtual target. In the surrounding phase, an event-triggered mechanism is designed to address the escape behaviors of the multi-target. When an escape behavior occurs, the original multi-USV system allocates a portion of the USVs to form a subsystem to track and surround the escaping target, while the remaining USVs continue to surround the other targets. Therefore, to address the multi-target tracking and surrounding control problem for the multi-USV system, a distributed nonlinear model predictive(NMPC) control method is designed in this paper. Additionally, to obtain the precise state variables of multi-target, a Distributed Adaptive Unscented Kalman Filter (DAUKF) is designed to estimate the states of the targets. Finally, a numerical simulation is presented to demonstrate the feasibility and effectiveness of the control method designed in this paper.