高超声速飞行器间歇故障改进自适应容错控制

Improved adaptive fault-tolerant control of intermittent faults in hypersonic flight vehicle

提出一种外部扰动/内部白噪声复合干扰和间歇性故障下的再入段变结构高超声速飞行器故障诊断和容错控制方法.首先给出再入姿态系统模型以及间歇故障模型.然后基于所研究的随机固定幅值故障模式对角速率系统中的周期性外部扰动进行预处理,根据处理结果,通过引入滑动时间窗设计一种残差信号.由于系统中存在白噪声,根据噪声分布特性并基于改进的残差信号提出两个假设检验,进而设计检测故障的两个阈值区间以检测间歇故障的发生和消失时间.与传统残差设计方法相比,改进的残差信号对于故障发生和消失时间的检测更准确.基于扩张系统设计一个自适应估计律用于估计故障,并使得估计误差满足L2-增益干扰抑制.最后提出一个自适应容错控制算法使得系统的姿态角输出能够跟踪给定的参考信号.利用Lyapunov函数证明了系统的稳定性,Matlab仿真结果验证了所提出方法的有效性.

This paper proposes the fault diagnosis and fault-tolerant control(FTC)for reentry hypersonic vehicles with external disturbance/interior white noise composite interference and intermittent faults.First,the reentry attitude system model and the intermittent failure model are given.Then,based on the random fixed-amplitude failure mode,the periodic external disturbance in the angular rate system is pre-processed.Due to the existence of white noise in the system,two hypothesis tests are proposed based on the noise distribution characteristics and the improved residual signal,and then two threshold intervals for detecting faults are designed to detect the occurrence and disappearance time of intermittent faults.Compared with the traditional residual design method,the improved residual detection is more accurate.Based on the expanded system,an adaptive estimation law is designed to estimate the faults and make the estimation error satisfy L2-gain interference suppression.Finally,an adaptive FTC algorithm is proposed to make the system’s angle output track a given reference signal.Lyapunov functions prove the stability of the proposed method,and Matlab simulation verifies its effectiveness.