微制造数控系统的实时有限状态机建模研究

为提高传统有限状态机（FSM）分析微制造数控系统（NCS）实时性特征的能力，提出了一种实时有限状态机（RTFSM）模型.该模型对传统FSM概念进行扩展，通过增加时间属性来描述状态行为的执行时间以及状态间切换所需的时间耗费.考虑到对复杂NCS控制流程进行设计、分析计算量较大，引入图论中的时间约束网络理论，采用经过修正的Floyd算法对模型中各个状态行为开始和结束时间的取值范围进行分析计算，从而实现控制流程的可调度性判定.实例研究表明，实时有限状态机可有效地建立微制造NCS控制流程模型，并降低对控制流程进行可调度性分析的复杂度，适用于NCS实时性研究.

Research on real-time FSM modeling for microfabrication NC system

To enhance the capability of traditional finite state machine(FSM) in analyzing real-time performance of microfabrication numerical control system(NCS),a real-time finite state machine(RTFSM) model was proposed.The concept of traditional FSM was extended in the model,and the execution time of states action and the time cost of states transition were described by setting several additional time attributes.Considering the large amount of calculation in analysis and design of complex NCS 's control flows,temporal constraint network of graph theory was introduced.The value range of the start time and end time of every state in RTFSM model was calculated by modified Floyd algorithm,and the schedulability of a control flow was examined.A case study indicates that RTFSM can effectively model control flows of microfabrication NCS and reduce complexity in schedulability examination,and can be applied to research real-time characteristics of NCS.