基于变迁覆盖的制造系统死锁控制策略

Transition cover-based deadlock control policies for manufacturing systems

中文关键词  柔性制造系统  Petri网  死锁控制

英文关键词  flexible manufacturing systems  Petri nets  deadlock control

中文摘要

      基于系统Petri网模型, 研究柔性制造系统的死锁控制问题. 论文利用变迁覆盖为系统设计活性控制器. 变迁覆盖是由一组极大完备资源变迁回路组成的集合, 其变迁集覆盖了Petri网中所有极大完备资源变迁回路的变迁集. 验证变迁覆盖的有效性, 然后仅对有效变迁覆盖中的极大完备资源变迁回路添加控制位置, 就得到系统的活性受控Petri网. 这种受控Petri网包含的控制位置个数少, 从而结构相对简单. 最后通过一个例子说明了所提出的死锁控制策略的构成与特点.

英文摘要

      Based on Petri net models of flexible manufacturing systems, the deadlock control problem is addressed. The concept of transition-cover is employed to design a live controller for flexible manufacturing systems. A transition cover is a subset of maximal perfect resource transition circuits whose transition set covers transitions of all maximal perfect resource transition circuits in Petri nets. After validating the effectiveness of a transition cover, we can build a live controlled Petri net by only adding a control place to each maximal perfect resource transition circuit in the effective transition cover. The number of control places in such a controlled Petri net is small and the structure of the controlled Petri net is simple. The proposed deadlock control policy is illustrated by an example.