Analysis of flexible manufacturing cells (FMCs) shows their requirement for flexible, correct, reliable, safe and distributed control. A comparison of the state of the art in software engineering for parallel systems, and an examination of safety related systems, reveal a need for formal and rigorous techniques at all stages in the software life cycle. However, parallel software, safety related software and formal techniques are complex. It is better to avoid faults rather than eliminate or tolerate them, and although less flexible, avoidance is often simpler to implement. There is a need for a tool which overcomes many of these complexities, and this thesis discusses and defines such a tool in the form of a methodology. The novelty of the work is in the combination of the core goals to manage these issues, and how the strategies guide the user to a solution which will not deadlock and which is comprehensible. Place-transition Petri nets are an ideal representation for designing and modelling the interaction of concurrent (and distributed) processes. Occam is a high level real time parallel language designed to execute on one or a network of transputers. Transputers are processing, memory and communication building blocks, and, together with occam, are shown to be suitable for controlling and communicating the control as the DCS in FMCs. The methodology developed in this thesis adopts the mathematically based tools of Petri nets, occam and transputers, and, by exploiting their structural similarities, incorporates them in a steps and tasks to improve the development of correct, reliable and hence safe occam code. The four steps: identify concurrent and sequential operations, produce Petri net graphs for all controllers, combine controller Petri net graphs and translate Petri net graphs into occam; are structured around three core goals: Petri net/occam equivalence, comprehensibility and pro-activity; which are manifest in four strategies: output-work-backwards, concurrent and sequential actions, structuralise and modularise, and deadlock avoidance. The methodology assists in all stages of the software development life cycle, and is applicable to small DCSs such as an FMC. The methodology begins by assisting in the creation of DCS requirements from the manufacturing requirements of the FMC, and guides the user to the production of dependable occam code. Petri nets allow the requirements to be specified as they are created, and the methodology's imposed restrictions enable the final Petri net design to be translated directly into occam. Thus the mathematics behind the formal tools is hidden from the user, which should be attractive to industry. The methodology is successfully applied to the example FMC, and occam code to simulate the FMC is produced. Due to the novelty of the research, many suggestions for further work are given.

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

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.

Neste trabalho foram utilizados os conceitos de célula flexível de manufatura e de automação utilizando a robótica para desenvolver uma célula robotizada de acabamento de instrumentos cirúrgicos forjados, com o objetivo de obter aumento de produção e flexibilizar o sistema de manufatura. Na produção manual de acabamento dos instrumentos cirúrgicos incluídos no estudo são realizados processos de lixamento, eletropolimento, polimento vibratório, jateamento e polimento com manta sintética e escova. Foi identificado que o sistema utilizando trabalho manual restringe a produtividade a um número de pinças insuficiente para atender à demanda do mercado. Desse modo, foi desenvolvida uma célula robotizada de acabamento, com a intenção de suprir a necessidade do aumento de produção dos instrumentos cirúrgicos. Em paralelo ao desenvolvimento da célula flexível de manufatura, estudaram-se os processos de acabamento utilizados, resultando na eliminação de etapas de acabamento no processo automatizado. Com a célula flexível de manufatura desenvolvida se obteve um aumento de produção de 96,87 % e uma redução nos custos de 50,53 % em relação à linha manual. Os produtos cuja manufatura se deseja automatizar são pinças hemostáticas, de apreensão e de campo que foram selecionadas através da análise da demanda produtiva. A matéria-prima utilizada nestes instrumentos é aço inoxidável martensítico, de denominação AISI 420D. O processo de fabricação utilizado nos componentes é o forjamento, que permite a melhora das propriedades mecânicas, modificando a disposição dos constituintes do material deformado. No entanto, foi avaliada de forma experimental a viabilidade de substituição do forjamento pelo corte laser, visando a eliminação do processo de lixamento dos componentes, com consequente aumento na taxa de produção, o que não foi possível devido à menor resistência obtida pelos componentes assim produzidos. / In this study, were used the concepts of flexible cell manufacturing and automation using robotics to develop a finishing in forged surgical instruments robot cell, in order to get increased production and a more flexible manufacturing system. On completion of the manual production of surgical instruments included in the study of processes are performed grinding, electropolishing, vibratory polishing, sandblasting and polishing synthetic blanket and brush. Was identified that the system using manual labor productivity to a limited number of tweezers insufficient to meet market demand. Thus, was developed a robotic finishing cell, with the intention of meeting the need for increasing production of surgical instruments. In parallel to the development of flexible manufacturing cell, were studied the finishing processes used, resulting in the elimination of finishing steps in the automated process. With the flexible manufacturing cell development was obtained an increase of 96.87% and production cost savings of 50.53% compared to the online manual. The products whose manufacture is desirable to automate hemostat, apprehension and field tweezers that were selected by analyzing the production demand. The raw material used in these instruments is martensitic stainless steel, designations AISI 420D. The manufacturing process used in the components is forginig, which allows the improvement of mechanical properties by modifying the arrangement of the constituents of the deformed material. However, it was experimentally evaluated the feasibility of replacing the forging by laser cutting, in order to eliminate the process of grinding the components, with consequent increase in production rate, which was not possible due to a lower resistance obtained by the components thus produced.

Neste trabalho foram utilizados os conceitos de célula flexível de manufatura e de automação utilizando a robótica para desenvolver uma célula robotizada de acabamento de instrumentos cirúrgicos forjados, com o objetivo de obter aumento de produção e flexibilizar o sistema de manufatura. Na produção manual de acabamento dos instrumentos cirúrgicos incluídos no estudo são realizados processos de lixamento, eletropolimento, polimento vibratório, jateamento e polimento com manta sintética e escova. Foi identificado que o sistema utilizando trabalho manual restringe a produtividade a um número de pinças insuficiente para atender à demanda do mercado. Desse modo, foi desenvolvida uma célula robotizada de acabamento, com a intenção de suprir a necessidade do aumento de produção dos instrumentos cirúrgicos. Em paralelo ao desenvolvimento da célula flexível de manufatura, estudaram-se os processos de acabamento utilizados, resultando na eliminação de etapas de acabamento no processo automatizado. Com a célula flexível de manufatura desenvolvida se obteve um aumento de produção de 96,87 % e uma redução nos custos de 50,53 % em relação à linha manual. Os produtos cuja manufatura se deseja automatizar são pinças hemostáticas, de apreensão e de campo que foram selecionadas através da análise da demanda produtiva. A matéria-prima utilizada nestes instrumentos é aço inoxidável martensítico, de denominação AISI 420D. O processo de fabricação utilizado nos componentes é o forjamento, que permite a melhora das propriedades mecânicas, modificando a disposição dos constituintes do material deformado. No entanto, foi avaliada de forma experimental a viabilidade de substituição do forjamento pelo corte laser, visando a eliminação do processo de lixamento dos componentes, com consequente aumento na taxa de produção, o que não foi possível devido à menor resistência obtida pelos componentes assim produzidos. / In this study, were used the concepts of flexible cell manufacturing and automation using robotics to develop a finishing in forged surgical instruments robot cell, in order to get increased production and a more flexible manufacturing system. On completion of the manual production of surgical instruments included in the study of processes are performed grinding, electropolishing, vibratory polishing, sandblasting and polishing synthetic blanket and brush. Was identified that the system using manual labor productivity to a limited number of tweezers insufficient to meet market demand. Thus, was developed a robotic finishing cell, with the intention of meeting the need for increasing production of surgical instruments. In parallel to the development of flexible manufacturing cell, were studied the finishing processes used, resulting in the elimination of finishing steps in the automated process. With the flexible manufacturing cell development was obtained an increase of 96.87% and production cost savings of 50.53% compared to the online manual. The products whose manufacture is desirable to automate hemostat, apprehension and field tweezers that were selected by analyzing the production demand. The raw material used in these instruments is martensitic stainless steel, designations AISI 420D. The manufacturing process used in the components is forginig, which allows the improvement of mechanical properties by modifying the arrangement of the constituents of the deformed material. However, it was experimentally evaluated the feasibility of replacing the forging by laser cutting, in order to eliminate the process of grinding the components, with consequent increase in production rate, which was not possible due to a lower resistance obtained by the components thus produced.

Neste trabalho foram utilizados os conceitos de célula flexível de manufatura e de automação utilizando a robótica para desenvolver uma célula robotizada de acabamento de instrumentos cirúrgicos forjados, com o objetivo de obter aumento de produção e flexibilizar o sistema de manufatura. Na produção manual de acabamento dos instrumentos cirúrgicos incluídos no estudo são realizados processos de lixamento, eletropolimento, polimento vibratório, jateamento e polimento com manta sintética e escova. Foi identificado que o sistema utilizando trabalho manual restringe a produtividade a um número de pinças insuficiente para atender à demanda do mercado. Desse modo, foi desenvolvida uma célula robotizada de acabamento, com a intenção de suprir a necessidade do aumento de produção dos instrumentos cirúrgicos. Em paralelo ao desenvolvimento da célula flexível de manufatura, estudaram-se os processos de acabamento utilizados, resultando na eliminação de etapas de acabamento no processo automatizado. Com a célula flexível de manufatura desenvolvida se obteve um aumento de produção de 96,87 % e uma redução nos custos de 50,53 % em relação à linha manual. Os produtos cuja manufatura se deseja automatizar são pinças hemostáticas, de apreensão e de campo que foram selecionadas através da análise da demanda produtiva. A matéria-prima utilizada nestes instrumentos é aço inoxidável martensítico, de denominação AISI 420D. O processo de fabricação utilizado nos componentes é o forjamento, que permite a melhora das propriedades mecânicas, modificando a disposição dos constituintes do material deformado. No entanto, foi avaliada de forma experimental a viabilidade de substituição do forjamento pelo corte laser, visando a eliminação do processo de lixamento dos componentes, com consequente aumento na taxa de produção, o que não foi possível devido à menor resistência obtida pelos componentes assim produzidos. / In this study, were used the concepts of flexible cell manufacturing and automation using robotics to develop a finishing in forged surgical instruments robot cell, in order to get increased production and a more flexible manufacturing system. On completion of the manual production of surgical instruments included in the study of processes are performed grinding, electropolishing, vibratory polishing, sandblasting and polishing synthetic blanket and brush. Was identified that the system using manual labor productivity to a limited number of tweezers insufficient to meet market demand. Thus, was developed a robotic finishing cell, with the intention of meeting the need for increasing production of surgical instruments. In parallel to the development of flexible manufacturing cell, were studied the finishing processes used, resulting in the elimination of finishing steps in the automated process. With the flexible manufacturing cell development was obtained an increase of 96.87% and production cost savings of 50.53% compared to the online manual. The products whose manufacture is desirable to automate hemostat, apprehension and field tweezers that were selected by analyzing the production demand. The raw material used in these instruments is martensitic stainless steel, designations AISI 420D. The manufacturing process used in the components is forginig, which allows the improvement of mechanical properties by modifying the arrangement of the constituents of the deformed material. However, it was experimentally evaluated the feasibility of replacing the forging by laser cutting, in order to eliminate the process of grinding the components, with consequent increase in production rate, which was not possible due to a lower resistance obtained by the components thus produced.