Adaptive Fixed-Time Robust $H_{\infty}$ Tracking Control of UUVs with Asymmetric State Constraints

This paper focuses on a practical fixed-time stable trajectory tracking control problem based on a prescribed performance constraint for an unmanned underwater vehicle (UUV) system. First, a barrier function (BF)-based prescribed performance control (PPC) strategy based on fixed-time convergence is proposed by combining the error transformation with an asymmetric obstacle function to achieve the global control performance requirement and realize performance with an asymmetric output constraint, followed by a novel filter based on the practical fixed-time criterion, and a robust
$H_{\infty}$
controller without the singularity problem is designed.