Prescribed‐Time Disturbance‐Observing Chainlike Filtering Approach to Double‐Sided Event‐Driven Formation Tracking of Underactuated Underwater Vehicles With Kinematic and Kinetic Disturbances

ABSTRACT This paper investigates the distributed prescribed‐time formation tracking problem for uncertain multiple six‐degree‐of‐freedom underactuated underwater vehicles operating in dynamic state and input‐triggered environments. A critical challenge lies in addressing the nondifferentiability of event‐triggered state variables during recursive control design while estimating both kinematic and kinetic disturbances within a predefined time frame. To overcome these challenges, we propose a novel prescribed‐time disturbance‐observing chainlike filter (PDCF) capable of estimating intermittently triggered state signals and external disturbances in three‐dimensional operational spaces. Based on the PDCF, a distributed prescribed‐time formation tracking strategy is developed, featuring double‐sided event‐triggered mechanisms that dynamically update thresholds based on formation tracking errors. This approach ensures efficient control input and state update processes. Auxiliary signals are introduced into the control design to address the underactuated dynamics and input saturation problems further. A rigorous theoretical analysis guarantees the practical prescribed‐time stability of the closed‐loop system while preventing Zeno behavior. Finally, the comparative simulation results demonstrate the effectiveness and robustness of the proposed method, highlighting its capacity to achieve the desired formation tracking with enhanced resource efficiency.