Fault Diagnosis Method of Liquid Rocket Engine Based on Mathematical Model Time-Invariant Information

Abstract

The invention provides a fault diagnosis method for a liquid rocket engine based on time-invariant information of a mathematical model. The fault diagnosis method comprises the following steps: firstly, establishing the mathematical model of each main constituent part aiming at the liquid rocket engine, and constructing a time-invariant coefficient for characterizing a working state of each part;analyzing a change principle of the time-invariant coefficient for characterizing the state of each part under the influence of a working state of the engine; defining a threshold value of each part according to the change principle; acquiring state data of each part under the working state of a liquid rocket engine to be detected; calculating the time-invariant coefficient of each part accordingto the acquired state data, and comparing the time-invariant coefficient with the determined threshold value; carrying out engine fault detection and diagnosis. According to the fault diagnosis methodprovided by the invention, the problem that the fault detection and diagnosis of the liquid rocket engine are difficult under the conditions that priori knowledge is lacked, fault samples are not enough, fault modes are not complete and the like is solved, and the fault detection and diagnosis of the liquid rocket engine under difficult conditions can be effectively realized.

Description

technical field [0001] The invention relates to the field of liquid rocket engine fault detection, in particular to a liquid rocket engine fault diagnosis method based on mathematical model time-invariant information. Background technique [0002] The liquid rocket engine is the main power device and key component of the launch vehicle propulsion system, but at the same time, the liquid rocket engine is a very complex fluid-thermal power system, which not only works in harsh environments such as high temperature, high pressure, strong vibration and strong corrosion, but also Moreover, the energy release in the working stage is very concentrated, so it is a frequent failure site. So far, the world has been studying liquid rocket engines for nearly a hundred years, and various fault detection and isolation technologies are becoming more and more mature. However, in actual launch missions, losses and disasters caused by engine failures are still unavoidable. Once a rocket engi...

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Problems solved by technology

[0005] The present invention is aimed at fault detection and detection due to the lack of prior knowledge, insufficient fault samples, and incomplete fault modes, especially for new liquid rocket engines that are still in the trial production stage, because not only the fault samples are lacking, but the normal samples are also very limited. For the problem of difficult diagnosis, a liquid rocket engine fault diagnosis method based on the time-invariant information of the mathematical model is proposed. This method is an envelope method using the time-invariant information in the mathematical model of the engine system as a statistical index

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