| Deadlocks must be considered an resolved in control system design of automated manufacturing system. Iterative control algorithm is the one focuses on deadlock prevention in Petri nets. This paper analyzes a iterative control algorithm based on the improved method of mixed integer programming (RMIP algorithm) seeking for the strict minimal siphons. RMIP algorithm can avoid full strict minimal siphon enumeration in a Petri net. It can reduce the complexity in seeking for the strict minimal siphons. After this algorithms, a new one is proposed, in which a method for control of an ordinary Petri net is used for a generalized one, with a transformation from a generalized Petri net to an ordinary one and back-transformation from a controlled one to an ordinary net.In the algorithms above, many promblems are involved, such as minimal siphon enumeration, transformation from a generalized Petri net to an ordinary one and back-transformation from a controlled one to a generalized, deadlock generation problem, removing redundant control places, etc. |
