具有一阶自回归测量误差的步进加速退化可靠性分析

针对传统方法在步进应力加速退化建模时常常忽略测量误差间自相关性的问题,提出一种具有一阶自回归(AR(1))测量误差的步进应力加速退化可靠性分析方法.利用Wiener过程描述产品的性能退化过程,同时引入一阶自回归AR(1)模型表征具有自相关性的测量误差项.然后,建立漂移系数与加速应力之间的加速关系模型,并对漂移系数进行随机化处理以表征产品个体差异性.在首达时概念下,给出失效时间分布函数和概率密度函数的解析表达式.然后,提出一种加速退化模型参数极大似然估计方法.最后,通过激光器算例分析验证了本文方法的适用性和有效性,结果表明:与传统方法相比,本文方法建模合理性更优,且能有效提高产品退化可靠性分析精度,进而为产品合理维修决策的制定提供有力支撑.

Reliability analysis for step-stress accelerated degradation test subject to AR(1) measurement errors

The autocorrelation among measurement errors has been usually ignored in the traditional accelerated degradation modeling procedure. For this problem, a step-stress accelerated degradation model is proposed by simultaneously considering a first-order autoregressive (AR(1)) measurement error series for reliability analysis. The Wiener process is utilized to describe the performance degradation procedure, and an AR(1) model is adopted for modeling the measurement error term. In addition, the relation function between the drift parameter and the accelerated stress is also constructed. Meanwhile, a parameter in the accelerated relation function is randomized to characteristic the individual variation. Then, under the concept of the first hitting time, closed-forms of the probability density function and the distribution function are derived. Moreover, the maximum likelihood estimation method is used for estimating unknown parameters in the proposed model. Finally, a real application involving the GaAs laser is conducted to illustrate the validity and efficiency of the proposed model. Results show that compared with the reference methods, the proposed model shows a better fitting goodness and an enhanced accuracy, and so that it can provide a strong support for further maintenance decision making.