Flight Evaluation of Reactionary Envelope Protection System for UAVs

Reactionary envelope protection is an automatic envelope protection method proposed for limit protection in Uninhabited Aerial Vehicles. The approach uses adaptive estimate of limit parameter dynamics and finite-time horizon predictions for detecting impending limit boundary violations. Limit violations are prevented by treating the limit boundary as an obstacle and by correcting nominal control/command inputs to track a limit parameter safe-response profile near the limit boundary. Previously, reactionary envelope protection method has been used to implement an automatic load factor limit protection system within the GTMax simulation architecture. This paper presents the recent results from Software-in-the-Loop and flight evaluations of the reactionary load factor limit protection system. A detailed description of the GTMax integrated simulation and flight test architecture is presented. The flight test results show that the reactionary load factor limit protection system is successful in maintaining the vehicle load factor response within prescribed upper limit while executing an aggressive e-turn maneuver.