Fault-Tolerant Control Laws against Sensors Failures for Hypersonic Flight

Abstract

In this paper a Fault-Tolerant Control strategy against sensors failures for Hypersonic flight has been proposed. The novel approach is based on the robustness capabilities of Direct Model Following (DAMF) method and at the same time it uses sensors accuracy information to improve the adaptivity to sensors failures. DAMF is a Model Reference Control Strategy that asymptotically guarantees a null error between the output of the reference model and the one of the real plant, through a direct adaptation of control loop gains. The proposed algorithm modifies the Direct Adaptive Model Following method by adding a module, that varies the controller parameters having a direct influence on the updating rules of controller gains (i.e. on the adaptive capability of the controller) to obtain Fault Tolerance capabilities. A numerical analysis, carried out by using the flight dynamics model of FTB X vehicle, a flying test bed designed in the framework of Unmanned Space Vehicle programme of Italian Aerospace Research Centre, has demonstrated that the proposed fault-tolerant algorithm has good tracking performances and global closed loop stability in case of both single and multiple failures. Nomenclature x = plant system state vector y = plant system output vector y m = reference system output vector A m = reference system parameters B m = reference system parameters r = reference system input vector u = control law G 0 = adaptation gain matrix C 0 = adaptation gain matrix ν = adaptation gain matrix K 0 = feed-forward gain matrix P = matrix solution of the Lyapunov equation Q = positive definite weighting matrix A e = error matrix γ 1 = adaptation speed parameter γ 2 = adaptation speed parameter γ 3 = adaptation speed parameter R = matrix of the states feedback variables uncertainties R 0 = nominal value matrix of the states feedback variables uncertainties k = a scale factor α = angle of attack q = pitch rate σ = standard deviation of the sensor noise

Adaptive anti-saturation fault-tolerant control of hypersonic vehicle with actuator faults

“…x ð Þ, and f h x ð Þ are known, b x ð Þ is nonsingular known from Mu et al 14 Combining equations (5) and (10), the hypersonic vehicle second-order system can be described as…”

“…Thus, the investigation of the fault-tolerant control method for the hypersonic vehicle bears a profound significance for improving the reliability and safety of vehicle control system. [3][4][5] In recent years, domestic and foreign experts and scholars have conducted a considerable amount of researches and explorations on the hypersonic vehicle control. So far, they have achieved some remarkable results in the study of fault-tolerant control for the longitudinal model of the hypersonic vehicle.…”

Equations of Disturbed Motion of the Moving Part of the Gyroscope Suspension

“…Moreover, it appropriately alerts the fact that a liquid and static gimbal is a perfect conductor of sound waves and in no way serves for the energy dispersion of the transmitted field. As a result, the very idea of the float gimbal under these conditions goes to the shaky ground of unreliability of the air-borne equipment under the operational use of hypersonic flying vehicles [ 18 , 19 ].…”

L 1 adaptive control of a generic hypersonic vehicle model with a blended pneumatic and thrust vectoring control strategy

“…Adaptive control has been investigated in the research field of flight control since the mid 1950s. It requires less modelling information than classical robust controllers, and it is able to improve the performance in case of system uncertainties, parametric variations, and failures, thus making it a potential solution to the problem of hypersonic control [26]. A number of adaptive controllers have been designed for hypersonic flight [2,4,9,10,15,18,26].…”