某型加速度计是影响火箭弹控制舱贮存寿命的薄弱环节, 针对历年统计的加速度计的成败型不完全故障数据, 将“保序回归”和“变样本Pearson χ2拟合优度检验与极小卡方估计”相结合, 解决了加速度计失效频率的“倒挂”问题, 给出了分布参数并对分布函数进行了Pearson拟合优度检验。结果显示, I型极大值和威布尔分布适用于加速度计的寿命分布, 但I型极大值不具有可加速性, 因而选择威布尔分布作为寿命分布。得到了置信度0. 90、可靠度0. 95时加速度计自然贮存寿命。加速度计在90 ℃下的加速系数K=7. 2695, 预估了部分批次加速度计加速寿命试验时间, 对加速寿命试验时间规划、经费预算具有工程实际意义。

A certain type of missile-borne accelerometer is the vulnerable spot that affects the storage life of the rocket control cabin. Considering that the statistical data of accelerometer is binomial and incomplete, we used isotonic regression, variable sample Pearson χ2 test of goodness of fit together with minimum χ2 estimation, to solve the “reversal” problem of failure frequency. The distribution parameters were given, and Pearson test of goodness of fit was made to the distribution function. The result showed that: both I maximum distribution and Weibull distribution were sui, and Weibull distribution was selected as the life distribution because the former one had no accelerating ability. In the end, the natural storage life under confidence level of 0. 90 and reliability of 0. 95 was obtained. The acceleration factor under 90 ℃ is 7. 2695. Thus the Accelerated Life Time (ALT) of certain batches of accelerometer was obtained. The study is of engineering significance for ALT plan of and budget.