Degradation data-based product reliability assessment method and a parameter estimation method

Abstract

The invention belongs to the technical field of engineering design and data modeling, and discloses a degradation data-based product reliability assessment method and a parameter estimation method. The method comprises the following steps of stablishing a Wiener accelerated degradation model based on a random effect, wherein the drift parameter is a random variable obeying normal distribution; Constructing a residual life prediction model according to the accelerated degradation model, and deducing residual life distribution and a reliability function of the residual life; And according to theperformance degradation data in the stress state, through a two-step maximum likelihood estimation method, obtaining an unknown parameter estimation value of the model. According to the method, a newaccelerated degradation model and a new residual life prediction model are constructed through a classic Wiener model, and an estimated value of the residual life is obtained; According to the method, a two-step maximum likelihood estimation method is adopted, unknown parameters in the degradation model are estimated, restrictions of a traditional maximum likelihood estimation method are made up,optimal values of the unknown parameters can be obtained more accurately, the model can predict the remaining life of a product more accurately, and the application range is wide.

Description

technical field [0001] The invention belongs to the technical field of engineering design and data modeling, and in particular relates to a product reliability evaluation method and a model parameter estimation method based on degradation data. Background technique [0002] At present, the existing technologies commonly used in the industry are as follows: With the continuous advancement of science and technology and the continuous improvement of product processing techniques, more and more products have the characteristics of high reliability and long life. However, it is almost impossible for products with high and long lifespan to fail in a relatively short period of time, and even "zero failures" may occur. Therefore, it is difficult to evaluate product reliability based on failure data, and it is also more difficult to predict its remaining life. Accelerated Degradation Testing (ADT) is to accelerate the degradation of product performance by increasing the test stress l...

AI Technical Summary

Problems solved by technology

[0004](1) In the degradation model based on the Wiener process, the assumptions of two important parameters in the model are somewhat idealized, which do not match the actual data situation

[0005](2) In the accelerated degradation model based on the Wiener process, the description of the relationship between performance degradation and stress is relatively simple, and how to model the relationship between stress and model parameters is still a technical problem

Images