Entry Guidance with Asymmetric Output Constraints on Drag Acceleration and Predefined-Time Convergence

The asymmetric output constraints on drag acceleration and the terminal flight path angle constraint in the entry guidance are investigated. The terminal flight path angle constraint is innovatively tackled by the guidance parameter in the proposed drag acceleration-energy profile. The logarithm barrier Lyapunov function with a novel switch condition is designed to handle the drag acceleration tracking problem with asymmetric output constraints. A novel tracking controller with explicitly specified convergence time is proposed to ensure the predefined-time convergence of the drag acceleration. The advantages of the algorithm are verified by the high-lift Common Aero Vehicle (CAV-H).