Guidance and control of airplanes under actuator failures and severe structural damage

This paper presents control algorithms for guidance and control of airplanes under actuator failures and severe structural damage. The presented control and guidance algorithms are validated through experimentation on the Georgia Institute of Technology Twinstar twin engine, fixed-wing, unmanned aerial system. Damage scenarios executed include sudden loss of all aerodynamic actuators resulting in propulsion-only flight, 25% of the left wing missing, suddenlossof50%of the right wing and aileron in-flight, and injected actuator time delay. Astate-dependent guidance logic is described that ensures the aircraft tracks feasible commands in the presence of faults. The commands are used by an outer-loop linear controller to generate feasible attitude commands. The inner-loop attitude control can be achieved by using either a linear attitude controller or a neural network-based model reference adaptive controller. The results indicate the possibility of using control methods to ensure safe autonomous flight of transport aircraft through validation on a scaled model that has characteristics of a typical transport category aircraft.