Optimal deadlock avoidance Petri net supervisors for automated manufacturing systems

Optimal deadlock avoidance Petri net supervisors

for automated manufacturing systems

Keyi XING; Feng TIAN; Xiaojun YANG

【期刊名称】《《控制理论与应用（英文版）》》 【年(卷),期】2007(005)002

【摘要】Deadlock avoidance problems are investigated for automated manufacturing systems with flexible routings.Based on the Petri net models of the systems, this paper proposes, for the first time, the concept of perfect maximal resourcetransition circuits and their saturated states. The concept facilitates the development of system liveness characterization and deadlock avoidance Petri net supervisors. Deadlock is characterized as some perfect maximal resource-transition circuits reaching their saturated states. For a large class of manufacturing systems, which do not contain center resources, the optimal deadlock avoidance Petri net supervisors are presented. For a general manufacturing system, a method is proposed for reducing the system Petri net model so that the reduced model does not contain center resources and, hence, has optimal deadlock avoidance Petri net supervisor. The controlled reduced Petri net model can then be used as the liveness supervisor of the system. 【总页数】7页(152-158)

【关键词】Manufacturing system; Petri net; Deadlock avoidance;