Reliability Modeling and Evaluation of Inertial Actuators Based on Inverse Gaussian Process of Individual Differences

Satellite momentum wheels are characterized by small sample size, high cost, and complex failure mechanism. The degradation process of such products is affected by many factors such as lubricant margin, current, temperature, etc., them affect each other, and the degradation process of a performance index extracted separately as a model to assess the life and reliability of momentum wheels are not comprehensive. In order to evaluate the reliability of satellite momentum wheels more accurately, a multi-degradation indicator momentum wheel reliability assessment model based on Copula function is established. At first, through historical degradation data establish the Wiener process-based model of individual degradation indicators; secondly, the parameters in the Wiener process model are estimated based on Bayes method and Gibbs sampling using OpenBUGS software, and using maximum likelihood estimation method to estimate the unknown parameters of Copula function; finally, Copula function is selected through the AIC/BIC criterion, to finish the momentum wheel's reliability modeling and evaluation of the multi-degradation index based on the Copula function. For the life prediction and reliability assessment of satellite momentum wheels the work provides a theoretical basis and technical support.