Finite-Time Unknown Observer-Based Interactive Trajectory Tracking Control of Asymmetric Underactuated Surface Vehicles

摘要

In this brief, a finite-time unknown observer-based interactive trajectory tracking control (FUO-ITTC) scheme is created for an asymmetric underactuated surface vehicle (AUSV). In lieu of a selfish trajectory which might be essentially inaccessible for an AUSV, the philosophy of an interactive trajectory, which features freely prescribed surge and yaw dynamics, and sway interactions with cross-tracking dynamics, is innovatively established for the first time, and thereby contributing to a family of uniformly trackable trajectories which completely remove persistent-excitation constraints on the desired yaw rate. By defining a composite coordinate transformation (CCT), interactive trajectory tracking error dynamics are formulated in a cascade structure with finite-time vanishing residuals. By virtue of the CCT-based cascade structure, FUO-based surge and yaw controllers are separately synthesized with an interaction law. The entire FUO-ITTC closed-loop system stability is guaranteed by combining the Lyapunov approach with cascade analysis, which in turn rigorously proves that both kinematic and dynamic tracking errors globally asymptotically converge to zero. Comprehensive experiments and comparisons are conducted on a benchmark AUSV and demonstrate the remarkable performance of the proposed FUO-ITTC scheme in terms of both transient and steady-state tracking accuracy.