METHOD FOR FUNCTIONAL DIAGNOSTICS OF A LIQUID ROCKET ENGINE DURING FIRING TESTS Russian patent published in 2022 - IPC G01M15/14 F02K9/96 

FIELD: testing.

SUBSTANCE: invention relates to the field of functional diagnostics of complex technical systems, in particular, liquid rocket engines (LRE). Method is based on using the current values of the operating parameters of LRE, measured in the course of fire testing, a mathematical model of a normally functioning engine, and the characteristics obtained autonomous testing, used to form the diagnostic features determining normal or abnormal operation, indicating the time of occurrence and localisation of the malfunction. Diagnostics is conducted as follows. A time interval is selected at the beginning of each stationary operation mode of engine, wherein the arithmetic mean values of the measured parameters are determined and taken as reference values in the controlled mode. Based on these values, the mathematical model is corrected, followed by, in the subsequent cycles of measurements, consecutively: controlling the deviations of current measured values of the parameters from the reference values; controlling the deviations of the measured values of the parameters from the calculated values thereof based on the mathematical model; controlling the characteristics of the engine obtained in the course of autonomous testing; localising the defective engine circuit containing multiple units. At each of the last two stages, if a malfunction is identified, a signal is generated to the control system to deactivate the engine.

EFFECT: invention increases the reliability of diagnostics and minimises the probability of missing a defect and triggering a false deactivation of the engine due to the introduction of stepwise multi-level control.

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