Research On Designing And Application Of Deds Controller Based On Petri Net

Petri net can easily express the views of special relativity. In modeling and systems analysis, it can not only express through graphical representation, but also analyze its nature with a number of mathematical methods. Because of these advantages, it is widely used in discrete event systems.However, Petri net have some problems in large-scale discrete event systems, such as its oversize state matrix in dimension, computational complexity, lacking of unified theoretical system and so on. Those problems limit its application in discrete event system. In this paper, we are mainly discussing about discrete event system controller design based on Petri net, the main research work are summarized as follows:(1) In this paper we presented the design of controllers with Petri net in discrete event systems:This paper improves the controller design of discrete event systems based on the concept of simplification technology and local design technology. Using simplified techniques and local design principles Petri nets can effectively reduce system design complexity. Further, this method is also used in the place, and changes the identified constraints among a mixed excitation, as compared with the conventional method, the system and constraints involved is more general. We can not implement with a giving constraints because of deadlock. The effectiveness and feasibility of the method is applied on the theory and verification.(2) For linear inequality constraints, we first considering the case without uncontrollable transitions and constructed a structure-based controller, which is maximum permitted and does not require to considering about the entire Petri net incidence matrix like place invariant. It just consider about the transitions associated with constraint places and constraint transitions. In some system states, deadlock may not exist, but it occurs after we added a controller, we discussed this problem and did deadlock prevention approach.(3)For the decentralized control, there may have a conflict in decentralized monitors and the original system which will cause a blockage of the closed loop system. This paper introduces the concept of a coordinator to solve this problem. In order to detect the system confliction we used the CFN structured to design the coordinator. This approach is visual, and has a relatively high computational efficiency. Moreover, the resulting closed-loop system acquired through this method is non-blocking and maximum permitted. Finally, we display and interpretation the entire algorithm steps and procedures with an example.