• CN:11-2187/TH
  • ISSN:0577-6686

›› 2014, Vol. 50 ›› Issue (16): 13-20.

• 论文 • 上一篇    下一篇

故障强度为边界浴盆形状的数控机床可靠性分析

任丽娜;芮执元;李建华   

  1. 兰州理工大学数字制造技术与应用省部共建教育部重点实验室;兰州理工大学机电工程学院
  • 发布日期:2014-08-20

Reliability Analysis of Numerical Control Machine Tools with Bounded and Bathtub Shaped Failure Intensity

REN Lina;RUI Zhiyuan;LI Jianhua   

  1. Key Laboratory of Digital Manufacturing Technology and Application of Ministry of Education, Lanzhou University of Technology; School of Mechanical and Electrical Engineering, Lanzhou University of Science and Technology
  • Published:2014-08-20

摘要: 最小维修情况下,为描述经历早期故障和耗损故障且故障强度随工作时间增加而趋近于某一常数的数控机床故障过程,提出一种新的4参数非齐次泊松过程模型。讨论模型的特性,给出模型中各参数的物理意义,推导计算模型参数及诸如最小故障强度、最小故障强度对应的故障时刻等重要可靠性指标点估计的计算公式,基于似然比检验理论,给出两台数控机床可靠性评估的模型选择方法,并基于拟合优度检验指标R,给出模型评价准则。对两台数控机床故障数据进行分析,结果表明,该模型可定量评估机床的早期故障期,适合于描述具有边界浴盆形状故障趋势的数控机床故障过程。为在机床出厂前尽可能排除早期故障提供了一定的理论依据。

关键词: 4参数非齐次泊松过程;最小维修;浴盆形状故障强度;数控机床;可靠性分析

Abstract: In minimal repair, in order to describe the failure process of numerical control(NC) machine tools experiencing both early failures and deterioration phenomena, and operating so long that the intensity function approaches a finite asymptote as the system operating time grows, a new four-parameter non-homogeneous Poisson process model is proposed. The characteristics of the model are discussed, and the physical meaning of its parameters is given, calculating formula of point estimation for model parameters and reliability indices such as the minimum intensity value and the time of minimum intensity are all derived, then a method of model selection for reliability assessment of two NC machine tools is provided based on the likelihood ratio statistic, and the model evaluation criterion is given based on the index of goodness-of-fit test. The real failure data of two NC machine tools are analyzed by using the proposed method, the results show that this method can quantitatively evaluate the machine tools’ lasting time of early failure period, it is suitable for describing the failure process of NC machine tools with bounded and bathtub shaped failure trend, and can provide a theoretical basis for eliminating as much early failures as possible before the NC machine tools leave the factory.

Key words: four-parameter non-homogeneous poisson process(4-NHPP);minimal repair;bathtub shaped failure intensity;numerical control machine tools;reliability analysis

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