关键词: 边界强度过程模型, 免疫克隆算法, 极大似然估计, 数控机床, 可靠性评估

Abstract: To solve the problem of zero failure intensity of Bounded Intensity Process (BIP) model at the initial time,a Modified BIP (MBIP) model was presented by introducing the location parameter into the BIP model.By taking the log-likelihood function of failure time as an optimal object,the immune clone algorithm was used to give the maximum likelihood estimators of model parameters and reliability indices.Two examples of real failure data from Numerical Control (NC) machine tools were taken to prove the proposed method,and the results of log-likelihood function and goodness-of-fit showed that the MBIP model was better than BIP model,which could provide a theoretical basis for making a reasonable maintenance strategy.

Key words: modified bounded intensity process, immune clone algorithm, maximum likelihood estimation, numerical control machine tools, reliability assessment