Compound Faults Parameter Estimation and Fault-tolerant Control in F-16 Fighter Flight Control System

Aims at the compound faults of the flight control system of F-16 fighter, which is composed of pitch rate sensor and aileron fault, this paper proposes a dual-channel state estimation scheme to estimate multiple fault parameters based on the observer principle at the same time. According to the fault estimation results, the flight control system can be fault-toleranted. The three-channel state coupling characteristic of pitch and yaw roll makes the control system introduce other fault information when detecting and diagnosing a single fault, which seriously reduces the accuracy of fault diagnosis. In this paper, by constructing two observers in different channels and designing the estimated parameter change rate in the observer based on Lyapunov stability theory, the residual error of the two observers can converge synchronously. Then the fault parameters can be estimated in the observer system. Based on the nonlinear dynamic inverse control scheme and the compensated state quantity, the flight control performance of the fighter can be improved.