基于Bootstrap法的小样本数控刀架可靠性评估  

Reliability assessment of small sample CNC tool rest based on Bootstrap method

作　　者：王晓燕 王鸿凯[2] 陈彦海 王品 郎贺 WANG Xiaoyan;WANG Hongkai;CHEN Yanhai;WANG Pin;LANG He(Economic and Management School,Shenyang Aerospace University,Shenyang 110136,CHN;College of Mechanical and Electrical Engineering,Shenyang Aerospace University,Shenyang 110136,CHN;Liaoning Key Laboratory of Aircraft Safety and Airworthiness,Shenyang Aerospace University,Shenyang 110136,CHN)

机构地区：[1]沈阳航空航天大学经济与管理学院,辽宁沈阳110136 [2]沈阳航空航天大学机电工程学院,辽宁沈阳110136 [3]沈阳航空航天大学辽宁省飞机火爆防控及可靠性适航重点实验室,辽宁沈阳110136

出　　处：《制造技术与机床》2020年第11期121-124,129,共5页Manufacturing Technology & Machine Tool

基　　金：辽宁省自然科学基金资助项目(20180550752)。

摘　　要：数据扩容是目前小样本可靠性研究的重要内容之一,Bootstrap法由于只需要实际观测数据不需要先验信息,在工程实际中被广泛应用。传统Bootstrap法在扩充样本时,新生样本取值区间只限于原始小样本数据区间,这在样本充满随机性的数控刀架可靠性评估中是影响最终结果精度的弊端。针对这一弊端,改进传统Bootstrap法,对定位样本进行双向扩容,并在计算新数据时新抽取一个有可能大于1的随机数。为验证改进效果,以一份大样本数控刀架失效数据为基础,抽样得到若干组小样本数据,运用改进前后方法分别对小样本数据进行可靠性评估,结果表明改进方法在适应性与精确性上优于传统方法。因此,改进Bootstrap法在可靠性评估中其数据扩容的结果能够与本体更为接近。Data expansion is one of the important contents of small sample reliability research at present.Bootstrap method is widely used in engineering practice because it only needs actual observation data and does not need prior information.When the traditional bootstrap method is used to expand the samples,the value range of the new samples is only limited to the original small sample data range,which has become a disadvantage in the reliability assessment of the NC turret.In order to solve this problem,the traditional bootstrap method is improved to expand the sample range in two directions,and a random number that may be greater than 1 is randomly selected when calculating new data.In order to verify the improvement effect,based on a large sample of NC tool holder failure data,several groups of small sample data are obtained by sampling.The reliability assessment of small sample data is carried out by using the method before and after the improvement.The results show that the improved method is better than the traditional method in adaptability and accuracy.Therefore,the results of data expansion of the improved bootstrap method in reliability assessment can be closer to the ontology.

关 键 词：机床 数据扩容 小样本可靠性评估 BOOTSTRAP法 数控刀架可靠性 

分 类 号：TG659[金属学及工艺—金属切削加工及机床]