We investigate couplings between variables of attitude dynamics for a hypersonic aircraft,and present a nonlinear robust coordinated control scheme for it.First,we design three kinds of coordinated factors to restrain the strong couplings.Then,we use projection mapping to estimate the uncertain nonlinear functions of the aircraft.Combining the coordinated factors and the designed control laws,we obtain a coordinated torque and assign it to the control deflection commands by using the allocation matrix.A stability analysis demonstrates that all the signals of the closed-loop system are uniformly and fully bounded.Finally,the robust coordinated performance of the designed scheme is verified through numerical simulations.
A robust fault-tolerant control scheme is proposed for the longitudinal dynamics of an aircraft with input saturation,using the anti-windup method and the fault detection observer technology.To estimate the system fault,a detection observer is designed for the longitudinal dynamics,and a fault-tolerant control law is developed to compensate for the fault effects of the longitudinal dynamics.Then,an anti-windup compensator is augmented into the fault-tolerant control law to eliminate the effect of input saturation.Using linear matrix inequality(LMI)technology,the detection observer based fault-tolerant controller is designed to ensure the stability of the closed-loop system and the convergence of the detection observer.Finally,the developed robust fault-tolerant control scheme is applied to the longitudinal model of an aircraft and simulation results are presented to illustrate the effectiveness of the proposed control scheme.
