Dynamic flight path control coupling for energy and maneuvering integrity

Traditional autopilots suffer from inherent flight path control objective conflict problems, as arbitrary flight path and speed targets cannot be maintained with saturated energy rate control. Elementary flight envelope protections are typically introduced to protect airspeed and prevent loss of control, but rather as a "last line of defense", than as a mean of smooth and deterministic control objective resolution during normal operation. In this paper, an approach for active energy distribution prioritization and integrity protection, as integrated part of the flight path controller of a modular flight guidance and control system, is presented. The approach allows speed or flight path angle maneuvering to be prioritized in case of saturated energy control, with automatic speed priority at the edges of the envelope in order to ensure the airspeed integrity of the aircraft. The approach is analyzed and validated using high-fidelity simulations of the full closed loop system for various conditions.