Measures of reconfigurability and its key characteristics in intelligent manufacturing systems

\In recent years, the fields of reconfigurable manufacturing systems, holonic manufacturing systems, and multi-agent systems have made technological advances to support the ready reconfiguration of automated manufacturing systems. While these technological advances have demonstrated robust operation and been qualitatively successful in achieving reconfigurability, limited effort has been devoted to the measurement of reconfigurability in the resultant systems. Hence, it is not clear (1) to which degree these designs have achieved their intended level of reconfigurability, (2) which systems are indeed quantitatively more reconfigurable and (3) how these designs may overcome their design limitations to achieve greater reconfigurability in subsequent design iterations. Recently, a reconfigurability measurement process based upon axiomatic design knowledge base and the design structure matrix has been developed. Together, they provide quantitative measures of reconfiguration potential and ease. This paper now builds upon these works to provide a set of composite reconfigurability measures. Among these are measures for the key characteristics of reconfigurability: integrability, convertibility, and customization, which have driven the qualitative and intuitive design of these technological advances. These measures are then demonstrated on an illustrative example followed by a discussion of how they adhere to requirements for reconfigurability measurement in automated and intelligent manufacturing systems

Hydrogen fuel cell pick and place assembly systems : heuristic evaluation of reconfigurability and suitability

Proton Exchange Membrane Fuel Cells (PEMFCs) offer numerous advantages over combustion technology but they remain economically uncompetitive except for in niche applications. A portion of this cost is attributed to a lack of assembly expertise and the associated risks. To solve this problem, this research investigates the assembly systems that do exist for this product and systematically decomposes them into their constituent components to evaluate reconfigurability and suitability to product. A novel method and set of criteria are used for evaluation taking inspiration from heuristic approaches for evaluating manufacturing system complexity. It is proposed that this can be used as a support tool at the design stage to meet the needs of the product while having the capability to accept potential design changes and variants for products beyond the case study presented in this work. It is hoped this work develops a new means to support in the design of reconfigurable systems and form the foundation for fuel cell assembly best practice, allowing this technology to reduce in cost and find its way into a commercial space

Integrated Assessment of Assembly fixtures Re-configurability

The needs of consumers are changing over time. As a result, the manufacturers are looking for new methods to adapt effectively and efficiently to market changes. These involve supplying customers with a variety of products in a reasonable time with decreasing the cost. Reconfigurable fixtures are an important means for dealing with increased product variety and shorter life cycles, as they help change between the product variants effectively and decrease the time and resources required to introduce new product variants. In this thesis, an integrated method to assess the reconfigurability of assembly fixtures is developed. This assessment is based on four core reconfigurability characteristics: scalability, modularity, convertibility, and customized flexibility. A clear definition of the scalability of the reconfigurable assembly fixtures was developed. A mathematical model for each characteristic of reconfigurable assembly fixtures was developed. Their indices were determined then combined using a radar plot to assess the reconfigurability of the reconfigurable assembly fixture. Welding tack fixture is chosen as a case study in this thesis. Two redesign recommendations were proposed. The results showed the most appropriate design with highest reconfigurability index because it was designed to produce the same number of product variants with less reconfiguration time, cost, effort, and complexity. The significance of research in this thesis is to help in the design stage of the assembly fixture by comparing different configurations for the assembly fixture to choose the best one and suggesting some changes for the assembly fixture design and configuration. This is essential to minimize the number of fixtures to be produced when the new part component/ variant is introduced

Reconfigurability level assessment in Portuguese companies

O conceito de sistemas de produção reconfiguráveis (SPRs) surgiu como uma estratégia para alcançar sistemas de produção mais ágeis, capazes de ajustar a funcionalidade e capacidade quando necessário. Este tópico é um problema atual para empresas porque a viabilidade de SPRs foi alcançada recentemente devido às novas tecnologias promovidas pela Indústria 4.0. Em SPRs, a reconfigurabilidade é a capacidade que permite a mudança de um produto para outro, a adição ou remoção de recursos, com mínimo esforço e sem demora. Por esta razão, a avaliação do nível de reconfigurabilidade é de extrema importância para as indústrias. O objetivo desta pesquisa é descrever o desenvolvimento de um índice de reconfigu rabilidade (RI) que pode ser utilizado por empresas para definir o quão reconfiguráveis são seus sistemas de manufatura. Especificamente, este estudo pretende determinar em que medida cada característica fundamental contribui para a composição da reconfi gurabilidade e o nível atual de reconfigurabilidade presente nas empresas portuguesas. Adicionalmente, este trabalho tenta estabelecer uma relação entre as características es senciais e o desempenho operacional dos sistemas de manufatura, e a extensão em que cada característica básica é implementada em diferentes setores industriais. Para construir o IR, uma pesquisa por questionário foi usada para selecionar as va riáveis e uma análise de componentes principais (ACP) foi aplicada aos resultados da pesquisa para determinar as contribuições das características centrais. O IR foi usado para estabelecer um ranking dos setores industriais das empresas respondentes e para discutir o nível de implementação das características centrais de reconfigurabilidade. Os resultados mostram que cada característica central contribui com uma quantidade diferente para a composição da reconfigurabilidade. A adaptabilidade e a diagnostica bilidade são as que mais contribuem, com 25% cada. As empresas portuguesas têm um nível moderado de reconfigurabilidade implementado. Em relação ao desempenho ope racional, a modularidade parece contribuir para a qualidade e entrega; integrabilidade para entrega e flexibilidade; adaptabilidade para custo e qualidade e capacidade de di agnóstico para qualidade e entrega. Entre os setores industriais, a reconfigurabilidade varia de níveis baixos a moderados. A implementação das características centrais variam significativamente, mas o RI parece estar relacionado aos níveis de flutuações do mercado

Hydrogen Fuel Cell Pick and Place Assembly Systems: Heuristic Evaluation of Reconfigurability and Suitability

Proton Exchange Membrane Fuel Cells (PEMFCs) offer numerous advantages over combustion technology but they remain economically uncompetitive except for in niche applications. A portion of this cost is attributed to a lack of assembly expertise and the associated risks. To solve this problem, this research investigates the assembly systems that do exist for this product and systematically decomposes them into their constituent components to evaluate reconfigurability and suitability to product. A novel method and set of criteria are used for evaluation taking inspiration from heuristic approaches for evaluating manufacturing system complexity. It is proposed that this can be used as a support tool at the design stage to meet the needs of the product while having the capability to accept potential design changes and variants for products beyond the case study presented in this work. It is hoped this work develops a new means to support in the design of reconfigurable systems and form the foundation for fuel cell assembly best practice, allowing this technology to reduce in cost and find its way into a commercial space

Convertibility Evaluation of Automated Assembly System Designs for High Variety Production

© 2017 The Authors. The recent advancements in technology and the high volatility in automotive market compel industries to design their production systems to offer the required product variety. Although, paradigms such as reconfigurable modular designs, changeable manufacturing, holonic and agent based systems are widely discussed to satisfy the need for product variety management, it is essential to practically assess the initial design at a finer level of granularity, so that those designs deemed to lack necessary features can be flagged and optimised. In this research, convertibility expresses the ability of a system to change to accommodate product variety. The objective of this research is to evaluate the system design and quantify its responsiveness to change for product variety. To achieve this, automated assembly systems are decomposed into their constituent components followed by an evaluation of their contribution to the system's ability to change. In a similar manner, the system layout is analysed and the measures are expressed as a function of the layout and equipment convertibility. The results emphasize the issues with the considered layout configuration and system equipment. The proposed approach is demonstrated through the conceptual design of battery module assembly system, and the benefits of the model are elucidated

Convertibility Evaluation of Automated Assembly System Designs for High Variety Production

The recent advancements in technology and the high volatility in automotive market compel industries to design their production systems to offer the required product variety. Although, paradigms such as reconfigurable modular designs, changeable manufacturing, holonic and agent based systems are widely discussed to satisfy the need for product variety management, it is essential to practically assess the initial design at a finer level of granularity, so that those designs deemed to lack necessary features can be flagged and optimised. In this research, convertibility expresses the ability of a system to change to accommodate product variety. The objective of this research is to evaluate the system design and quantify its responsiveness to change for product variety. To achieve this, automated assembly systems are decomposed into their constituent components followed by an evaluation of their contribution to the system's ability to change. In a similar manner, the system layout is analysed and the measures are expressed as a function of the layout and equipment convertibility. The results emphasize the issues with the considered layout configuration and system equipment. The proposed approach is demonstrated through the conceptual design of battery module assembly system, and the benefits of the model are elucidated

Skill-based reconfiguration of industrial mobile robots

Caused by a rising mass customisation and the high variety of equipment versions, the exibility of manufacturing systems in car productions has to be increased. In addition to a exible handling of production load changes or hardware breakdowns that are established research areas in literature, this thesis presents a skill-based recon guration mechanism for industrial mobile robots to enhance functional recon gurability. The proposed holonic multi-agent system is able to react to functional process changes while missing functionalities are created by self-organisation. Applied to a mobile commissioning system that is provided by AUDI AG, the suggested mechanism is validated in a real-world environment including the on-line veri cation of the recon gured robot functionality in a Validity Check. The present thesis includes an original contribution in three aspects: First, a recon - guration mechanism is presented that reacts in a self-organised way to functional process changes. The application layer of a hardware system converts a semantic description into functional requirements for a new robot skill. The result of this mechanism is the on-line integration of a new functionality into the running process. Second, the proposed system allows maintaining the productivity of the running process and exibly changing the robot hardware through provision of a hardware-abstraction layer. An encapsulated Recon guration Holon dynamically includes the actual con guration each time a recon guration is started. This allows reacting to changed environment settings. As the resulting agent that contains the new functionality, is identical in shape and behaviour to the existing skills, its integration into the running process is conducted without a considerable loss of productivity. Third, the suggested mechanism is composed of a novel agent design that allows implementing self-organisation during the encapsulated recon guration and dependability for standard process executions. The selective assignment of behaviour-based and cognitive agents is the basis for the exibility and e ectiveness of the proposed recon guration mechanism