Abstract: This article investigates the integrated fault detection and diagnosis (FDD) and faulttolerant control (FTC) method of the on-orbit satellite attitude control system (ACS) with recovered faults. First, considering the faults of actuators and/or sensors, we introduce the control and/or measurement effectiveness factor(s) into the attitude dynamics and/or the kinematical equation. A twostage Kalman filtering algorithm is developed to estimate the value of the effectiveness factor(s), which is used to quantify the effectiveness of control and measurement. Then, the reconfiguration faulttolerant controller is introduced to compensate the former controller by using online statistical hypothesis tests based on the information from the twostage Kalman filtering. Finally, mathematical simulation is performed to validate the solution in a satellite closedloop ACS, and simulation results show that the solution is fast and effective and the proposed solution is suitable in on-orbit real-time computation.

Key words: fault detection and diagnosis, fault-tolerant control, Kalman filtering, satellites, attitude control