Near-optimal and minimal PN supervisors of FMS with uncontrollability and unobservability
Near-optimal and minimal PN supervisors of FMS with uncontrollability and unobservability
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DOI：
10.1109/smc.2017.8123211
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发表时间：
2017-10
期刊：
影响因子：
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通讯作者：
B. Huang;YanDong Pei;Yuwang Yang;Mengchu Zhou;Jianqiang Li
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文献类型：
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作者：
B. Huang;YanDong Pei;Yuwang Yang;Mengchu Zhou;Jianqiang Li
针对柔性制造系统，本文提出了一种基于Petri网的死锁预防方法，以在不可控和不可观测的变迁存在的情况下获得高度许可和结构最小的监督者。首先，我们定义容许标记，形成一个最大强连通分量（SCC）包含初始标记，而不是导致不受控制的SCC外。然后，一个整数线性规划问题被制定为构造一个监督者，允许所有的容许标记，并禁止所有的第一个不容许状态的容许区。它还确保没有不可控的转换被控制，也没有不可观察的转换被监控程序观察到。该方法可以应用于关键过渡不可控和/或不可观测的植物网络。此外，所得到的监督是无死锁的，高度宽容的，结构最小的可控性和可观性的存在。
For flexible manufacturing systems, this paper presents a Petri net based deadlock prevention method to obtain highly permissive and structurally minimal supervisors in the presence of uncontrollable and unobservable transitions. First, we define admissible markings which form a maximal strongly connected component (SCC) containing the initial marking and not leading outside the SCC uncontrollably. Then, an integer linear programming problem is formulated to construct a supervisor which permits all admissible markings and forbids all the very first inadmissible states from the admissible zone. It also ensures that no uncontrollable transitions are controlled and no unobservable ones are observed by the supervisor. The method can be applied to the plant nets whose crucial transitions are uncontrollable and/or unobservable. In addition, the obtained supervisors are deadlock-free, highly permissive, and structurally minimal in the presence of controllability and observability.