Abstract:

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.

Key words: quadrotor aircraft, fault reconfiguration, extended state observer (ESO), super-twisting algorithm