Super-twisting扩张状态观测器在四旋翼飞行器故障重构中的应用

针对四旋翼飞行器姿态控制系统的故障重构问题,提出一种基于super-twisting算法的扩张状态观测器,以扩张状态的形式对飞行器执行机构故障进行直接估计,同时实现了旋翼增益故障的故障隔离与精确重建。为抑制外部扰动对观测器稳定性的影响,一般需要将观测器的增益设置较大,但同时会引发噪声扩展问题。因此引入了观测器参数的自适应调整算法,在保证观测器稳定收敛的同时降低了噪声对故障重构精度的影响。此外,基于李雅普诺夫方法证明了滑模观测器的渐近收敛特性,并通过数值仿真验证了观测器对故障重构的有效性。仿真结果表明所构建的故障观测器能够迅速地对执行机构故障做出反应，并在外界扰动存在的情况下对故障程度实现准确估计。

Application of super-twisting extended state observer in fault reconfiguration of quadrotor aircraft

According to the fault reconfiguration problem of the attitude control system of quadrotor aircraft, an extended state observer based on super-twisting algorithm is proposed. The fault of aircraft actuator is estimated directly by the extended state type, and the fault isolation and accurate reconstruction of the gain fault of driving unit are realized. In order to suppress the influence of the external disturbances on observer stability, it is generally necessary to set the observer's gain to a large extent, but it often leads to noise expansion. An adaptive adjusting algorithm of observer parameters is introduced to ensure the stable convergence of the observer and reduce the influence of the noise on the accuracy of fault reconstruction. In addition, the asymptotic convergence of the sliding mode observer is proved based on the Lyapunov method, and the effectiveness of the observer for fault reconstruction is verified by the numerical simulation. The simulation result shows that the constructed fault observer responds to the actuator fault quickly. And in the presence of external disturbance, the fault degree is estimated accurately.