Fixed-time Trajectory Tracking Control of Unmanned Underwater Vehicle with Prescribed Performance

This paper investigates the fixed-time trajectory tracking problem for horizontal maneuvering of an unmanned underwater vehicle (UUV) with prescribed performance. Under the proposed prescribed-performance fixed-time sliding mode control (PPFTSMC) method, the trajectory tracking errors fast converge to a specified range that rounds towards zero in fixed time. In the controller design, with the aid of performance function and transformation, the posture tracking errors are prescribed to constrained errors, which satisfy the desired transient and steady-state performance. Then, by virtue of fixed-time and sliding mode control, the manifold is designed by the transformation errors, which likes the nonsingular fast terminal sliding mode control framework. Finally, rigorously theoretical analysis of the closed-loop system is given, and comparisons of numerical simulations demonstrate the effectiveness of the proposed PPFTSMC method.