关键词: 半Markov决策过程, 缓慢退化系统, 线性混合效应模型, 策略迭代算法

Abstract: To study the maintenance strategy of slow degradation system under the condition of incomplete sampling and individual differences,a linear mixed effect model was employed to model the slow degradation system with individual differences,and autoregressive method was used to adjust the correlation of time series in the model residuals,which had improved the accuracy of model.On this basis,a reasonable state space and maintenance decision space were constructed to solve the state transition probability of degradation process,and the optimal maintenance strategy was solved by using policy iteration algorithm to minimize the long-term estimated cost per unit time.The maintenance strategy based on semi-Markov decision process was demonstrated by a practical case of laser degradation.Compared with the classical maintenance strategy based on service life and periodic inspection,the results showed that the proposed method could describe the degradation process more accurately and help to formulate maintenance strategy considering both cost and reliability.

Key words: semi-Markov decision process, slow degradation system, linear mixed-effects model, policy iteration algorithm