Petri网的一类禁止状态问题的混合型监控器算法设计

针对广义互斥约束下Petri网的不可控影响子网为状态机的一类禁止状态问题,给出了观测器的设计方法,并基于观测器得到了求解最大允许控制策略的算法.利用观测器将广义互斥约束简化为单禁止库所约束,并将存在不可控变迁的问题简化为相当于变迁全部可控的问题,这有效地解决了不可控变迁带来的计算复杂性问题.最后,利用一个地铁交通调度示例验证和说明该监控器设计方法.

Combined Supervisor Synthesis for a Class of Forbidden State Problems in Petri Nets

A class of forbidden state problems in which the influence uncontrollable subnets are state machines for the given general mutual exclusion constraint(GMEC)on plant Petri nets is addressed.A method of designing the observers is proposed,and an algorithm of synthesizing the optimal supervisors is obtained based on the observers.It makes it possible to transform a GMEC with multi forbidden places into that with only one forbidden place and to reduce the control problem with uncontrolled transitions into that without any uncontrolled transition.The computational complexity of the supervisor synthesis is then efficiently reduced.A metro line supervisory example illustrates the theoretic results.