Predefined-Time Spacecraft Attitude Tracking with Tunable Anti-Fragile Performance Boundaries

This paper proposes a predefined-time attitude tracking control strategy for a single spacecraft by integrating tunable anti-fragile performance boundaries. To ensure attitude tracking errors remain within predefined limits, an anti-fragile transformation method is developed to dynamically adjust performance boundaries, effectively preventing singularity issues under abrupt disturbances. Furthermore, a novel non-singular predefined-time sliding mode surface is designed to eliminate chattering and ensure tracking errors converge to a neighborhood of the origin within a predefined time. The practical predefined-time stability is rigorously proven via Lyapunov theory. Numerical simulations demonstrate the effectiveness, rapid convergence, and superior anti-fragility of the proposed approach.