A Belief Rule Based Model for Life Prediction via the Accelerated Degradation Test

Abstract

AbstractIn engineering practice, to ensure the safety of complex engineering systems, the life prediction has attracted an increasing attention. In previous studies, few effective methods can be used to establish the life prediction model of a type of systems that have the following features: (1) the storage lives are much longer than the working lives, (2) lots of quantitative testing data are not available, (3) some expert knowledge can be used, and (4) the system’s performance degradation cannot be observed directly. As such, a life prediction method is constructed on the basis of belief rule base (BRB) and the accelerated degradation test, where two BRBs are involved, expressed by BRB_1 and BRB_2 respectively. Moreover, BRB_1 is employed to describe the relevance between the external stress and the hidden working state. BRB_2 is applied to establish the forecasting model of hidden working states. Once the predicted hidden working state achieves the boundary line, the corresponding working time is the life of the equipment and some measures need to be taken to maintain or change the equipment. Some uncertain parameters exist in the prediction model which can be determined by experts and it can lead to the inaccuracy of the model. Thus, an algorithm is proposed for updating parameters based on the maximum likelihood (ML). An experiment of the life prediction for aerospace relay is used to prove the reasonability of the life prediction model.KeywordsBelief rule base (BRB)Life predictionAccelerated degradation test