The Flexible Manufacturing Cell (FMC) represents an important and widely utilized constituent of hierarchically structured automated manufacturing systems. The control of FMCs is therefore of great importance in automated manufacturing. However, there are few tools and methodologies available for specifying and developing the control logic. The few tools that do exist have proven to be impractical due to their equirements for compatibility by the constituent equipment. Therefore, this research focuses on the development of a solution to the control of FMCs through the development of a programming language that provides a methodology and capabilities for developing the supervisory control applications. Accordingly, a programming language was developed in which the control logic is specified in modules, each of which control an equipment or resource in the cell. These modules interact with each other according to well defined models of interaction to achieve the control. The language provides features to enable this modularity and the interaction between the modules. The process plan of the parts that are produced in the cell drive the control logic and are also the means of communication between the modules. Additionally, several features required for control such as the detection of deadlocks, part information and so on are also developed. In the proposed language, the communication problem is separated from the logic specification. Guidelines and requirements are developed for a language implementation system that will enable the communication with the cell devices and that works with the language structure. / Master of Engineering

published_or_final_version / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xii, 156 p. : ill., (some col.). Includes abstract and vita. Advisor: Shahrukh A. Irani, Dept. of Industrial and Systems Engineering. Includes bibliographical references (p. 147-156).

Deadlocks are critical events in Flexible Manufacturing Cells (FMC) that result from circular waits among a set of resources. Circular waits happen when a set of resources with finite capacity are in a permanent hold due to wait state to admit new jobs. Past literature examines the deadlock-free scheduling in FMCs considering many types of resources and techniques. This thesis proposes a new resource-oriented deadlock-free approach using a robot equipped with dual-grippers serving as a material handler in a FMC. The proposed methodology uses Constraint Programming (CP). The system performance is analyzed using different buffer configurations. Many test problems are generated to validate the developed models. The finding demonstrates that the proposed dual-gripper robot (DGR) can outperform the single-gripper robot (SGR) in many settings for FMCs. Likewise, the experience with the CP for the modeling and solving approach proposed in this research consolidates its application to FMC deadlock-free scheduling problems.

Deadlocks are critical events in Flexible Manufacturing Cells (FMC) that result from circular waits among a set of resources. Circular waits happen when a set of resources with finite capacity are in a permanent hold due to wait state to admit new jobs. Past literature examines the deadlock-free scheduling in FMCs considering many types of resources and techniques. This thesis proposes a new resource-oriented deadlock-free approach using a robot equipped with dual-grippers serving as a material handler in a FMC. The proposed methodology uses Constraint Programming (CP). The system performance is analyzed using different buffer configurations. Many test problems are generated to validate the developed models. The finding demonstrates that the proposed dual-gripper robot (DGR) can outperform the single-gripper robot (SGR) in many settings for FMCs. Likewise, the experience with the CP for the modeling and solving approach proposed in this research consolidates its application to FMC deadlock-free scheduling problems.

Thesis (M.S.)--Ohio University, June, 2007. / Title from PDF t.p. Includes bibliographical references.

Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 2001? / Bibliography: leaves 172-184.

This research examined the relationship between manufacturing input parameters and factory performance in a cellular manufacturing environment.

Esta tese explora características de sistemas de manufatura celular virtual, de técnicas de escalonamento e despacho em tempo de execução e de algoritmos genéticos para assegurar um alto grau de flexibilidade de rotas de processo e eficiência na programação de tarefas de sistemas de manufatura do tipo (NDDJSS – non-deterministic dynamic job shop system). Desenvolve-se assim, um método de programação baseado em duas novas técnicas, de clustering e de escalonamento e despacho, respectivamente, aplicado a sistemas de manufatura do tipo NDDJSS. Apresentam-se inicialmente os conceitos fundamentais considerados na organização de sistemas de manufatura em células de trabalho e suas implicações em termos de esforço de coordenação e controle das células e das tarefas; a abordagem por organização funcional das células de manufatura virtuais; ascaracterísticas, definições e notação usadas para problemas de escalonamento; a descrição de técnicas de escalonamento e despacho de sistemas de manufatura; aspectos relevantes de computação evolutiva, mais especificamente, de algoritmos genéticos. Em seguida, introduz-se a nova técnica de clustering e a nova técnica de escalonamento e despacho, juntamente com os requisitos e as formulações associadas. A nova técnica de clustering forma células de manufatura virtuais balanceadas quanto ao volume de trabalho, com alto grau de flexibilidade de rotas de processo. A nova técnica de escalonamento e despacho é autônoma, estável, adaptativa, flexível, contingente, monotônica e relativamente robusta, permitindo a geração de escalas em tempo de execução, ao mesmo tempo em que mantém a medida de desempenho, o makespan, dentro de uma faixa de desempenho pré-estabelecida. Exemplificam-se as aplicações das duas novas técnicas, através de exemplos extraídos da literatura técnica e simulados através de um programa de computador chamado (DEVICE – Design of virtual cells), desenvolvido especialmente para esta pesquisa. Após simulação obtêm-se os resultados de forma estruturada para análise. Os respectivos resultados da aplicação do método de programação proposto comprovam o potencial dessa abordagem. / This thesis explores characteristics of virtual cellular manufacturing systems, of scheduling and dispatching techniques for real time requirements and genetic algorithms for assures a high level of routeing flexibility and efficiency in tasks programming for (NDDJSS – non-deterministic dynamic job shop system). It introduces a programming method based in two new clustering and scheduling and dispatching techniques, respectively, applied in NDDJSS manufacturing systems. Initialy, the work presents basic concepts considered in the organization of cellular manufacturing systems and its implications for coordination and control efforts of cells and tasks, respectively; an approach of virtual mufacturing cells through the functional organization; the characteristics, definitions and notation used for scheduling problems; the description of more manufacturing systems scheduling and dispatching techniques; relevant aspects of evolutionary computation in specialty, the genetic algorithms. Subsequently, the work also introduces the new clustering and scheduling and dispatching techniques, the requirements and the formulas associated. The new clustering technique builds balanced workload with high flexibility of process routeing. Also, the new scheduling and dispatching technique is autonomous, stable, adaptative, flexible, contingent, monotonic and relatively robust, providing scales generating in running mode (real time) and mantaining the performance measures “makespan" within the stabilished range of performance. The applications of the two new techniquesare exemplified based on two examples picked from technique literature and so simulated through a new software called (DEVICE – design of virtual cells). The software DEVICE was designed specialty for this research. After run some simulations, the structured form results are obtained for analisys. The respectively results obtained for the proposed method application proves the powerful of this approach.