考虑性能依赖的元动作单元多态可靠性分析

Reliability analysis method of meta-action unit in multi-state system considering performance dependence

摘要:

为研究单元之间相互作用所引起的性能依赖给多态系统可靠性造成的影响.利用功能-运动-动作(FMA)分解理论将多态系统分解成多个元动作,以元动作单元为研究对象,运用非齐次马尔科夫模型描述元动作单元的多状态演变过程;通过设定状态转移系数将状态转移率与依赖特性相关联,构建新的状态转移矩阵,再运用Kolmogorov微分方程求得多态单元处于各状态的概率,并利用向量通用发生函数建立考虑单元性能依赖特性的多态系统可靠性分析模型,讨论了不同依赖情形下的模型特点;以国内某卧式加工中心的分度转台系统为例验证了单元依赖特性对系统可靠性的影响.结果表明:具有依赖特性单元的状态转移率会随着对应自立单元的性能退化而改变;与单元相互独立的多态系统相比,在单元处于高性能状态时,具有单元依赖特性的多态系统可靠度更高;在单元处于低性能状态时,具有单元依赖特性的多态系统可靠度更低.研究结果可为机械系统可靠性设计和产品维修周期设计提供相应的理论依据.

Abstract:

To analyze the effect of performance dependence caused by interaction among units on the reliability of multi-state system, the function-motion-action (FMA) theory is used to decompose a multi-state system into meta-actions. By using the non-homogeneous Markov model, the multi-state evolution process of the meta-action unit is described. By setting the state transition coefficient to associate the state transition rate with the dependency property, a new state transition matrix is constructed. The Kolmogorov differential equation is used to obtain the probability. The model considering the performance-dependent characteristics of the units is established by the vector universal generation function. The index turntable system is used as an example to verify the influence of the unit dependence characteristics on the system. The results show that the state transfer rate will change with the performance degradation of the free cells. Compared with the multi-state system with independent units, when the unit is in a high performance state, the multi-state system with unit-dependent characteristics is more reliable. On the contrary, the system is more vulnerable. The results provide theoretical basis for the reliability design and the product maintenance cycle setting.