Dynamic Observer-Based Multi-AUV Enclosing Control for Target Without Velocity Measurement

This paper focuses on the problem of enclosing control for moving targets using multiple underactuated autonomous underwater vehicles (AUVs). For the target with unknown velocity measurement, a dynamic observer is designed to provide estimated positions and velocities of the target to AUVs, and possess the capability to adapt to dynamic changes in interaction topology and interruptions in link connectivity. Leveraging a self-organized scheme, a kinematic controller based on the dynamic observer is developed, enabling the AUVs to rearrange their positions within the formation, thereby increasing the flexibility of their collaboration. To compensate for the impacts of external interference, an extended state observer (ESO) is employed to estimate the aggregated disturbances, which encompass uncertain dynamics and perturbations. Then, an ESO-based dynamic controller is derived using the backstepping method to ensure that actual velocities of AUVs align with the commanded velocities generated by the kinematic controller. Sufficient conditions for stability and numerical examples are finally provided to demonstrate the effectiveness and advantages of the theoretical results.