arXiv:2611.07320v1 Announce Type: new Abstract: Within the multiple-model framework, active fault diagnosis applies auxiliary control input signals to ex?cite the system such that fault modes are distinguishable. For aircraft systems, it has been pointed out by some rele?vant works that certain faults cannot be effectively detected and isolated in time without actively exciting the aircraft dynamics. However, existing works have not simultane?ously addressed the optimal auxiliary control design with theoretical guarantees and the FDI method with an effective mechanism for triggering the active fault diagnosis. Hence, we are motivated to propose a framework of active FDI for aircraft systems to explicitly address the aforementioned issue. Specifically, we first formulate a receding-horizon FDI scheme for estimating the likelihood of candidate fault modes with proved effectiveness, and then we propose a method for estimating mode probabilities, based on which a mechanism is designed for triggering auxiliary control for active fault diagnosis. The auxiliary control signal design is formulated such that the effectiveness for FDI is theoret?ically guaranteed and the disruption to nominal flight oper?ation is minimized. Numerical test results are presented to demonstrate the effectiveness of the proposed framework.