Hybrid Adaptive Flight Control with Self-Improving Plant Model for Stability and Control of Damaged Aircraft

This paper presents a hybrid adaptive control method for maintaining stability and control of damaged aircraft. The hybrid method utilizes an adaptive parameter estimation scheme to improve a plant model in a flight control system. Two adaptive parameter estimation schemes are developed: 1) an indirect adaptive control law with normalization based on the Lyapunov direct method that uses tracking error for adaptation, and 2) a recursive least-squares law based on the optimal estimation method that uses plant model error for adaptation. Simulations show that the hybrid adaptive control can provide a significant improvement in the tracking performance of a flight control system.