Abstract: This article proposes a novel adaptive fault estimation design method based on an adaptive fault diagnosis observer. The conventional adaptive fault estimation design method is faced with problems that the performance of fault estimation does not meet performance requirements and that a strict equation constraint adds to design difficulties. The adaptive fault estimation design method proposed in this article not only enhances the performance of fault estimation evidently, but also avoids the strict equation constraint by using inequality transform. Based on Lyapunov stability theory, new sufficient conditions for error dynamic systems are given to guarantee the stability of error dynamics in terms of matrix inequalities. Finally, simulation results of a certain type of flight control systems are presented to show the validity of the proposed method.

Key words: adaptive observer, fault estimation, fault diagnosis, flight dynamics, linear matrix inequalities