Reliability Data Modeling and Analysis of Aeronautic Equipment Based on Log-Logistic Distribution

Abstract

In order to promote the feasibility and practicability of reliability data analysis, this paper constructs a reliability data analysis model of aeronautic equipment components based on Log-Logistic distribution, discusses the method of determining the probability distribution type and the parameter estimation method of Log-Logistic distribution. Firstly, the mathematical model of Log-Logistic distribution was constructed, and then the parameters and curve fitting of Log-Logistic distribution model were estimated by maximum likelihood estimation method and least squares estimation method. The information matrix and asymptotic confidence intervals for maximum likelihood estimation are given. Finally, it is verified by a practical example. Specifically, the 30 sets failure data for aeronautic equipment components are verified by experiments. The maximum likelihood estimation and least squares estimation method are used to process the sample data, and their goodness of fit are compared and analyzed. The results show that the former has higher estimation accuracy. The lifetime forecast result indicates that the equipment reliability descend to 50% after 548.932h for working, which is consistent with the maintenance frequency of every 500h in the application.