面向不完全维修数控机床可靠性评估.pdf

学兔兔 第49卷第23期 机 械 工 程 学 报 V_01．49 NO．23 2013年 12月 JOURNAL OF MECHANICAL ENGINEERING Dec． 2 O l 3 DoI：10．3901，JME．2013．23．136 面向不完全维修的数控机床可靠性评估水 张根保 李冬英 ，2 刘 杰 柳 剑 (1．重庆大学机械工程学院 重庆 400044： 2．邵阳学院机械与能源工程系 邵阳 422004) 摘要：为实现不完全维修条件下的数控机床可靠性评估，提出基于对数线性比例强度模型(Log-linear proportional intensity model，LPIM)的多台数控机床可靠性评估方法，建立故障时间的对数线性比例强度函数式。用极大似然估计法和Fisher信息 矩阵法给出了模型参数的点估计与区间估计，给出机床可靠性指标的点估计和基于Delta法的区间估计，采用似然比检验方 法对时间趋势和修复功效的显著性进行检验。实例分析表明，考虑维修活动影响时，LPIM优于Weibul1分布法和非齐次泊 松过程模型，能定量反映出维修对机床可靠性的作用，得出的瞬时和累积可靠性特性更符合实际。 关键词：数控机床 不完全维修 可靠性评估 似然比 中图分类号：TG659 TB114 Reliability Assessment for Multiple NC Machine Tools Oriented to General Repair ZHANG Genbao1 LI Dongying1，2 LIU Jie! LIU Jian (1．College of Mechanical Engineering，Chongqing University,Chongqing 400044； 2．Department of Mechanical and Energy Engineering，Shaoyang University,Shaoyang 422004) Abstract：An approach of assessing reliability for multiple NC machine tools with general repair based on log-linear proportional intensity model(LPIM)is proposed，and an LPIM function for failure times is built．Point and confidence bounds estimates of model parameters are given by maximum likelihood method and Fisher information marx method．Point estimates of reliability metriCS are also derived with their confidence bounds offered through Delta method．Likelihood ratio tests are adopted to check the time trend and repair effect．A real example analysis demonstrates that．LP1M approach outperform s Weibu11 distribution method and NHPP model considering the effects of repair activitie