Many products in engineering are highly reliable with large mean lifetimes to failure. Performing lifetests under normal operations conditions would thus require long experimentation times and high experimentation costs. Alternatively, accelerated lifetests shorten the experimentation time by running the tests at higher than normal stress conditions, thus inducing more failures. Additionally, a log-linear regression model can be used to relate the lifetime distribution of the product to the level of stress it experiences. After estimating the parameters of this relationship, results can be extrapolated to normal operating conditions. On the other hand, censored data is common in reliability analysis. Interval-censored data arise when continuous inspection is difficult or infeasible due to technical or budgetary constraints. In this paper, we develop robust restricted estimators based on the density power divergence for step-stress accelerated life-tests under Weibull distributions with interval-censored data. We present theoretical asymptotic properties of the estimators and develop robust Rao-type test statistics based on the proposed robust estimators for testing composite null hypothesis on the model parameters.

翻译：工程中许多产品具有高可靠性及较长的平均失效寿命。在正常运行条件下进行寿命试验需要较长的试验时间和高昂的试验成本。加速寿命试验通过在高于正常应力水平的条件下运行试验，从而诱发更多失效，缩短了试验时间。此外，可采用对数线性回归模型将产品寿命分布与所承受的应力水平相关联。在估计出该关系的参数后，可将结果外推至正常运行条件。另一方面，删失数据在可靠性分析中常见。当由于技术或预算限制导致连续监测困难或不可行时，会产生区间删失数据。本文针对区间删失数据下的威布尔分布步进应力加速寿命试验，基于密度幂散度开发了稳健的有约束估计量。我们给出了估计量的理论渐近性质，并基于所提出的稳健估计量构建了稳健的Rao型检验统计量，用于检验模型参数的复合零假设。