Confusion Detection And Control For Flexible Manufacturing System Based On Petri Nets

It is inevitable that there are concurrency and conflict in flexible manufacturing system.When concurrency and conflict exist in flexible manufacturing system,it is not possible to observe whether there is a conflict from the same final state of the system.In flexible manufacturing system,the uncertainty of the conflict will lead to the user’s decision-making mistakes,and may cause serious economic losses.Under this background,based on the proposed confusion algorithm,this paper puts forward two different flexible manufacturing system confusion control strategy using inhibitor arcs and generalized linear constraints.The confusion subnet is the carrier of the confusion,and the confusion is the dynamic behavior of the confusion subnet under the effective marking.The dynamic behavior of the confusion subnet can be described and analyzed by the confusion subnet structure and the effective marking.How to quickly and efficiently find the structure of the confusion subnet becomes the primary task of the confusion analysis and control.In this paper,we propose two different algorithms for the detection of chaotic subnet structures,the first,disposes some places and transitions which are not as possible candidates to construct a structural confusion.Then,we look for confusion in the remaining places and transitions.This method can reduce the time complexity.The second,The Petri net system is represented by the incidence matrix,and the judgment theorem of the conflict and concurrent transition in the incidence matrix is given.Then,we propose another algorithm based on incidence matrix to detect the structure of confusion subnet.On the basis of detecting the structure of confusion subnet,this paper also proposes two different confusing control schemes,The first algorithm,changes the occurrence of changes in the rules and suppress the occurrence of confusion in the occurrence of confusion by adding inhibitor arcs to the Petri net system.When the confusion appears to be resolved.The second scheme,in accordance with the pre-defined control strategy,with the generalized mutually exclusive constraints ofthe monitor configuration method for the design of the monitor,and the design of the monitor,pre-applied to the network system in the various confused subnet structure.These monitors can ensure that the monitor is effective only when the corresponding marking of the confusion subnet structure leads to a confusion conflict.In this paper,after each proposed a confusion detection algorithm and control strategy,One application example is presented to illustrate the proposed approach.Finally,a flexible manufacturing system is used to test the proposed method and control strategy,The simulation results show that the proposed confusion detection algorithm can detect the confusion network structure,the proposed confusion control scheme makes the sequence of the transition to the same final state of the arrival sequence is unique,and then confusion disappears.