PLC Implementation of a DES Supervisor for a Manufacturing Testbed: An Implementation Perspective.

M.A.Sc Thesis by Ryan J. Leduc, 1996


The goal of this work is to investigate issues involved in modeling and designing supervisors for large, real systems, and issues involved in implementing DES supervisors on programmable logic controllers (PLC). A PLC based manufacturing testbed has been created to help investigate these issues.

A detailed plant model for the testbed was created (size on the order of 10^16 states) and 29 modular supervisors were designed to implement the control specifications. Several model reduction theorems were created to handle a plant this large.

A generic implementation method was created, translating supervisors into clocked Moore synchronous state machines (CMSSM). The CMSSM were then implemented as relay ladder logic programs on the PLC. The testbed supervisors were implemented using the algorithm, and the testbed is now operational. This demonstrates that the algorithm works.


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