Research on improved integrated FDD/FTC with effectiveness factors

This paper investigates the integrated fault detection and diagnosis (FDD) with fault tolerant control (FTC) method of the control system with recoverable faults. Firstly, a quasi-linear parameter-varying (QLPV) model is set up, in which effectiveness factors are modeled as time-varying parameters to quantify actuators and sensors faults. Based on the certainty equivalency principle, replacing the real time states in the nonlinear term of the QLPV model with the estimated states, the parameters and states can be estimated by a two-stage Kalman filtering algorithm. Then, a polynomial eigenstructure assignment (PEA) controller with time-varying parameters and states is designed to guarantee the performance of the system with recoverable faults. Finally, mathematical simulation is performed to validate the solution in a satellite closed-loop attitude control system, and simulation results show that the solution is fast and effective for on-orbit real-time computation.