Ion thrustor minimum subsample reliability assessment method

Abstract

An ion thrustor minimum subsample reliability assessment method comprises the following steps that first, according to the failure and structure features of an ion thrustor, a service life distribution model is selected; second, according to the ground service life verification test results of the ion thrustor, a reliability analyzing method is selected, if a subsample is non-failure data, an ion thrustor non-failure data reliability analyzing method is selected, and if the subsample is minimum failure data, an ion thrustor minimum failure data reliability analyzing method is selected; third, the service life dispersibility of the ion thrustor non-failure data is determined; fourth, the parameter values of the ion thrustor minimum failure data service life distribution model are computed; and fifth, the reliability lower confidence limit of the given service life of the ion thrustor and the service life lower confidence limit of the given reliability are computed. The reliability assessment method for ion thrustor non-failure data and minimum failure data is established, reliability assessment accuracy is improved, and a foundation is provided for reliability assessment of the ion thrustor in the future.

Description

technical field [0001] The invention relates to a method for evaluating the reliability of a very small sample of an ion thruster, in particular to a reliability analysis method in which the life test data of the ion thruster has no failure and very little failure data. It belongs to the technical field of aerospace reliability analysis. Background technique [0002] The ion thruster is a kind of electric propulsion. It uses the medium xenon gas to ionize to generate charged ions, which are accelerated and ejected under the action of an electrostatic field to generate thrust, so it is also called electrostatic propulsion. Compared with traditional chemical thrusters, it has the characteristics of high specific impulse, high efficiency and low thrust. It can be used to perform space missions such as north-south position protection, orbit improvement and deep space exploration. Because the thrust of the ion thruster is relatively small, this requires that it must run for a l...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a method for evaluating the reliability of a very small sample of an ion thruster. What it needs to solve is that the amount of information contained in the ground life test data of the ion thruster is small and the technical problems of reliability analysis are difficult. A method for evaluating the reliability of extremely small samples of ion thrusters with no failure data or very little failure data. This method selects a reasonable life distribution model according to the main failure modes and structural characteristics of ion thrusters, and fully develops and utilizes its life test data information. Obtain conservative life dispersion and realize the reliability evaluation of the extremely small sample of the ion thruster. It has the characteristics of convenient calculation and high accuracy of analysis results, and can be extended to the reliability analysis of similar products with long life and high reliability.

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