Leak Fault Detection of Liquid Rocket Engine Based on Strong Tracking Filter

Abstract

The propellant leak is one of the most common and especially dangerous faults in liquid rocket engine (LRE). By analyzing the performance of the engine, we know that the leak of hydraulic lines can be expressed as the variation of the e uid resistance coefe cients. If leaks occur in the hydraulic line, the corresponding e uid resistance coefe cients will be changed. An approach is presented to detect and diagnose the leak of hydraulic line based on a strong tracking e lter. The method uses a strong tracking e lter to estimate the e uid resistance coefe cients and to compare the estimated e uid resistance coefe cients with their normal values. Then the modie ed bias method is used to detect the leak fault. We simulate the leaks occurring in the main system or in the subsidiary system of LRE. The results show that the approach is feasible. Nomenclature Ab = area of gas generator, m 2 A f, B f, C f = coefe cients for second-order polynomial e t for fuel pump pressure head curve Ao, Bo, Co = coefe cients for second-order polynomial e t for oxidizer pump pressure head curve At = area of combustion chamber, m 2