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Petri Net Synthesis for Discrete Event Control of Manufacturing Systems develops two essential resource-sharing concepts: parallel and sequential mutual exclusions and theoretical results in Petri synthesis. A parallel mutual exclusion (PME) is defined to model a resource shared by independent distributed processes, and a sequential mutual exclusion is a sequential composition of PMEs, modeling a resource shared by sequentially-related processes. A hybrid synthesis methodology for Petri net models and controllers is proposed using top-down, modular, and bottom-up design ideas and the mutual exclusion theory. An aggregate Petri net model is refined by replacing places and /or transitions with basic design modules which are mathematically and graphically described. Petri net design methods are presented for such buffers as automatic storage and retrieval systems. Using the proposed method synthesizes both Petri net structure and feasible initial markings, guaranteeing that resulting Petri nets have desirable system properties such as freedom from deadlock and cyclic behavior. A Petri net controller is extended to error recovery for automated manufacturing systems. The theory can guarantee that the desired system properties achieved by the original design will be preserved when the controller is augmented to deal with an error in the prescribed methods. Control code has been directly generated from Petri net definitions. The algorithm and implementation details are given for a flexible manufacturing system. Using the approach presented in Petri Net Synthesis for Discrete Event Control of Manufacturing Systems, engineers and research workers can develop their own discrete event control applications and experiments.

Over the past two decades, research in the theory of Petri nets and the development of graphical tools has yielded a powerful methodology. The contributions in Petri Nets in Flexible and Agile Automation present theoretical development of Petri nets as well as in industrial applications to areas such as discrete- event control design, scheduling, performance evaluation and deadlock avoidance. These contributions also include comparative studies of Petri nets and other approaches. A primary theme of this book is to provide a unified approach to the applications of Petri nets in flexible and agile automation and, in that regard, a common notation and terminology is used. The book also allows readers to evaluate the benefits and applicability of state-of-the-art Petri net methods and apply CAD tools to problems of interest. Petri Nets in Flexible and Agile Automation is not only an essential reference for researchers, it is also a very useful tool for engineers, analysts and managers who are responsible for the design, implementation and operation of the next generation of manufacturing systems.

Deadlock problems in flexible manufacturing systems (FMS) have received more and more attention in the last two decades. Petri nets are one of the more promising mathematical tools for tackling deadlocks in various resource allocation systems. In a system modeled with Petri nets, siphons are tied to the occurrence of deadlock states as a structural object. The book systematically introduces the novel theory of siphons, traps, and elementary siphons of Petri nets as well as the deadlock control strategies for FMS developed from it. Deadlock prevention methods are examined comparatively. The many FMS examples presented to demonstrate the concepts and results of this book range from the simple to the complex. Importantly, to inspire and motive the reader's interest in further research, a number of interesting and open problems in this area are proposed at the end of each chapter.

Discrete-event dynamic systems (DEDs) permeate our world, being of great importance in modern manufacturing processes, transportation and various forms of computer and communications networking. “Modeling and Control of Discrete-event Dynamic Systems” begins with the mathematical basics required for the study of DEDs and moves on to present various tools used in their modeling and control. Among the instruments explained are many forms of Petri net, the sequential function chart, state charts, formal languages and max-plus algebra. Industrial examples illustrate the concepts and methods discussed. Using them, readers will be able to understand DEDs quickly and to master the control methods to analyze and improve the performance of their systems. Final-year undergraduates and graduates embarking on further courses in control, manufacturing and process engineering, computer studies or operations research will find this text an invaluable aid in learning about the control of this important class of systems.