基于随机有色网的柔性制造系统可用性评价方法

摘要

An availability evaluation method for flexible manufaeturing system (FMS) is proposed. Aiming at the difficulty of the former evaluation methods for availability such as fault tree analysis method and dependability graph method can not represent the dynamic property and the interconnection of system, a method for modeling the process of FMS based on stochastic Petri nets and colored Petri nets - SCPN is defined, then the Markov chain for the SCPN model of the manufacturing cell is constructed, a new method for the availability evaluation of FMS is introduced by adding the coverage rate and the precise repair rate to the availability model. The experiment shows the proposed method can model the FMS and obtain the availability of the manufacturing cell and FMS, and it is better than the former evaluation methods.%提出了一种柔性制造系统(FMS)的可用性评价新方法.针对传统可用性评价方法如故障树分析法、可靠图法等难以表达复杂系统的动态特性和系统内部的关联性的缺点,定义了一种基于随机Petri网和有色网对FMS生产过程进行表示的方法——SCPN(stochastic colored Petri nets).通过构造制造单元的SCPN模型获得同构的马尔科夫链转移矩阵,将覆盖率和修复率加入可用性分析模型中,从而得到一种对FMS可用性进行评价的新方法.实验结果表明,所提方法可以对FMS进行建模,并能得到制造单元以及FMS的可用性,较以往的可用性评价方法更准确和全面.