Damaged Airplane Trajectory Planning Based on Flight Envelope and Motion Primitives

Abstract

This paper presents an efficient approach for safe landing trajectory generation of an airplane with structural damage to its wing flying in proximity to local terrain. A damaged airplane maneuvering flight envelope is estimated by analyzing the local stability and flying quality at each trim condition. Trim state distance to a flight envelope boundary provides a novel criterion defined as the safety value index to prioritize choice of trim conditions for postdamage flight. A library of trajectory segments including trim states and transition maneuvers between trim conditions in the local neighborhood are generated using a linear quadratic regulator controller. A potential field strategy is used to rapidly define emergency landing trajectories composed as trim state sequences based on criteria including terrain avoidance, safety value index, and safe landing requirements such as touchdown heading and position, airspeed, glide slope, and bank angle. Cost criteria are balanced by adjusting weights. Landing scenarios are presented to demonstrate the capability of the proposed approach to autonomously plan safe landing trajectories.