Disturbance Observer Based on Multipoint Feedback

An observer-based disturbance estimation method has been developed. A polynomial approximation of the disturbance is introduced, and the disturbance observer is constructed. The observer gain is optimized so that the estimation error is minimized. In this method, the estimated disturbance is adjusted by feedback of the estimated output error at several arbitrary time points. The design parameters related to the multipoint feedback determine the properties of the disturbance model. The proposed method is applied to aircraft dynamics and verified by numerical simulations and flight testing data. The simulation results show that the proposed method estimates disturbance input precisely.