Fault detection method based on HHT for spacecraft mono-propellant propulsion system

Most of faults in mono-propellant propulsion system for spacecraft often occur in thrusters´ startup or shutdown process. How to design the fault diagnosis method to overcome the large overshoot interference by thruster startup/shutdown is still open. Since there are far from sufficient data for fault model prediction especially during the on-orbit flight, so we just chose pressure sensor and applied Hilbert-Huang transform (HHT) to analyze its non-stationary and nonlinear signal. Simulations are carried out on mono-propellant propulsion system model based on the finite element method, and the results show that the proposed method is effective both in steady condition and startup condition.