西安电子科技大学学报 ›› 2022, Vol. 49 ›› Issue (3): 199-205.doi: 10.19665/j.issn1001-2400.2022.03.022

• 计算机科学与技术&人工智能 • 上一篇    下一篇

一种Petri网最优控制序列的高效设计方法

邹岷强(),马子玥()   

  1. 西安电子科技大学 机电工程学院,陕西 西安 710071
  • 收稿日期:2021-01-12 修回日期:2021-11-24 出版日期:2022-06-20 发布日期:2022-07-04
  • 作者简介:邹岷强(2000—),女,西安电子科技大学本科生,E-mail: qmzou@stu.xidian.edu.cn|马子玥(1984—),男,副教授,E-mail: maziyue@xidian.edu.cn
  • 基金资助:
    国家自然科学基金(61703321);国家自然科学基金(61873342);陕西省科学基金(2019JQ-022)

Efficient method for designing optimal control sequences in Petri nets

ZOU Minqiang(),MA Ziyue()   

  1. School of Electro-Mechanical Engineering,Xidian University,Xi’an 710071,China
  • Received:2021-01-12 Revised:2021-11-24 Online:2022-06-20 Published:2022-07-04

摘要:

提出了一种基于基本标识分析的Petri网最优控制序列设计算法,根据给定的源标识和目标标识集合,生成一个成本最低的控制序列,使得源标识在执行该控制序列后到达指定的目标标识集合。该算法在Petri网的基本标识空间进行Dijkstra搜索,在减少无望分支的同时将搜索范围缩小为可达集的一个较小子集,从而很大程度上缓解了状态爆炸问题。由于搜索过程中全图未知,结点将随着计算动态增加。笔者给出了该算法的最优性证明,证明该算法每次迭代所选取的松弛结点与全局Dijkstra搜索保持一致,故最终得到的最优序列相同。进一步地提出了一种变迁选取规则,通过选择符合特定要求的显式变迁集合,将目标集合隐式可达性的判定问题转换为一个简单代数不等式的逻辑判定,使得无须求解整数规划即可快速确定目标集合的隐式可达性。实验结果表明,与基于整数规划的方法相比,该方法具有在线计算量小、求解速度快的优点,适用于受控系统需要对控制需求作出快速响应的场合。

关键词: Petri网, Dijkstra搜索算法, 基本标识, 控制序列, 调度, 最优控制

Abstract:

An algorithm for designing optimal control sequences in Petri nets based on basic marking analysis is proposed,which drives a plant net from a given source marking to a given target marking set with a least-cost control sequence.The algorithm performs Dijkstra search in the basic marking space of the Petri net so that only a small subset of the reachability set is explored with the unpromising branches discarded,which can alleviate the state explosion problem to a great extent.The entire basic reachability graph is initially unknown and revealed stepwise during the search process.It is proved that the proposed algorithm is optimal,since the nodes relaxed in each iteration is identical to that in the standard Dijkstra search,which guarantees the optimality of the outputted control sequence.Moreover,a rule for selecting the set of explicit transitions is developed so that the verification of implicit reachability can be done by checking the validity of a simple inequality.By doing so,it is now possible to quickly determine the implicit reachability of the target set without solving exhaustive integer linear programming problems.Experimental results show that,compared with the method based on integer linear programming in the literature,the method proposed in this paper has a high computational efficiency and can be used in cases where a plant must respond promptly to a request of reconfiguration.

Key words: Petri nets, Dijkstra search algorithm, basis marking, control sequence, scheduling, optimal

中图分类号: 

  • TP2718
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