Matrix-based intelligent discrete event control for flexible manufacturing systems

This dissertation is composed of three major sections: simulation and implementation of supervisory controllers of Discrete Event (DE) manufacturing systems (DEMS), analysis and design of supervisory controllers for DEMS, and analysis and design of DEMS with routing decisions, including failures and preventive maintenance dynamics.; In the first section of this work, a general description of a rule-based matrix formulation for the design of DE supervisors for manufacturing workcells is provided. The development of this matrix formulation was provided in previous works. This work uses the tools provided by this matrix formulation, and combines them with other tools such as Petri Nets and digraph theory tools to provide computationally efficient constructions and methods useful for the simulation and actual implementation of supervisors for DEMS. A supervisor is developed using LabVIEW. The same test-bed/workcell is simulated in MATLAB™ using the same matrix-formulated controller. Commensurate results were obtained while comparing simulation and implementation of the supervisory controller.; In the second section of this work, a rigorous analysis of DE manufacturing systems is presented. This section studies the structure of a general class of workcells that handle Multiple-parts in Reentrant Flow-lines (MRF). A matrix test formulation is provided as a design tool for workcells that guarantees a ‘good structure’ of MRF systems that does not lead to additional complications in the design of supervisory controllers. Incorporation of supervisory network structures in the system is suggested to directly assign shared resources, and diminish computational effort of supervisors that avoid deadlock.; In the later section of this work, analysis and design of DEC supervisors is extended to more complex systems than the MRF systems. The extended systems are denominated as Free-choice Multipart Reentrant Flow-line (FMRF) systems. FMRF systems contain free routing decisions for part paths (as in communication routing systems.) As a design tool, we provide a computationally efficient matrix test to determine ‘good structures’ among FMRF systems to facilitate their supervision and control. We also provide novel proofs needed for the development of deadlock avoidance supervision in FMRF systems. Finally, we provide the development of deadlock-free dispatching rules for DEMSs containing failures and Preventive Maintenance Schedules.