ISSN : 1796-203X
Volume : 4    Issue : 8    Date : August 2009

Development of a Discrete Event Controller Supervisor using a Hybrid Matrix Formulation with
Fuzzy Logic Conflict Resolution  
Jose Mireles Jr., Frank L. Lewis, Roberto C. Ambrosio, and Edgar Martínez
Page(s): 697-704
Full Text:
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Using a patented matrix formulation, a Discrete Event (DE) controller is designed for a
manufacturing cell. The DE controller can directly be implemented from standard manufacturing
tools such as the Bill of Materials or the assembly tree. The matrices also make it straightforward to
actually implement the DE controller for sequencing the jobs and assigning the resources. We use
virtual places to interact with our machine resources to control and supervise the DE system as a
transient timed place Petri Net (PN) system. This modified PN together with marking transition
equation provides a complete dynamical description of a Discrete Event System (DES). In this
paper, we include to our DE supervisor several new structures that contain all decision making
attributes for each part and resource jobs in the Manufacturing processes. The versatility of
this DE controller permits implementing different methodologies for decision making and conflict
resolution, including artificial intelligence techniques, as well as optimization of the resource
assignment and part throughput. This paper shows an example of such versatility included in the
supervisor by showing a hybrid decision making development.

Index Terms
Petri nets, Virtual Places, Timed Place Petri Net, Discrete Event Systems, Reentrant flow lines,
Flexible manufacturing systems, Fuzzy Logic