一种利用基本信标的柔性制造系统死锁控制器设计方法

对于一类网系统ES³PR提出了一种有效的死锁控制策略．严格极小信标分为基本信标和从属信标，对每个基本信标通过添加控制库所，保证其能够被标识，同时不产生新的可被清空的信标．从属信标的控制通过调整基本信标的控制深度变量来实现．通过对添加的控制库所冗余性的分析，去除了冗余的控制库所，得到了许可状态更多、结构更为简单的Petri网控制器．

A deadlock prevention policy for FMS using elementary siphons

We develop an effective control policy to prevent deadlocks from occurring in a class of Petri nets, ES^3PR, where deadlocks are related to unmarked siphons. Strict minimal siphons are divided into elementary and dependent ones. For each elementary siphon, a monitor is added to ensure that it is sufficiently marked without gnerating emptiable control-induced siphons. The controllability of a dependent siphon is guaranteed by changing the control depth variables of its related elementary siphons, which leads to a liveness-enforcing supervisor for a plant model. Furthermore, by checking the redundancy of the additional monitors, some control-redundant monitors can be removed, which leads to a more permissive and structurally simple net supervisor.