Active Control Objective Prioritization for High-Bandwidth Automatic Flight Path Control

Inherent flight path control objective conflicts arise when energy rate or path curvature controls are saturated, precluding arbitrary flight path and speed target tracking, and arbitrary, concurrent vertical and lateral plane maneuvering. Flight envelope protection to protect airspeed and prevent loss of control are usually a last line of defense, and not an integrated strategy for smooth and deterministic control objective resolution during normal operation. In this paper, active energy rate and force distribution prioritizations, as integrated parts of the flight path controller of a modular flight guidance and control system, are presented. The prioritizations allow 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 energy integrity of the aircraft, and lateral or vertical plane maneuvering in case of saturated transverse force control. The approach is validated using high-fidelity simulations and initial flight testing.