Percorrer por autor "Oliveira, Eugénio"
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- Adaptive services reconfiguration in manufacturing environments using a multi-agent system approachPublication . Rodrigues, Nelson; Leitão, Paulo; Oliveira, EugénioThe era of mass customization of goods forces manufacturing systems to promote agility, flexibility and responsiveness, leading to complex and unpredictable systems. Such challenges have an impact in terms of the system responsiveness and adaptation, production costs, product quality, etc. In order to improve those aspects, some flexible control manufacturing paradigms were proposed offering elasticity to change available skills and provide new services. However, the understanding of when and how to (self-) reconfigure the system aiming to perform a fast changeover, is a crucial issue. This work proposes a self-organizing multi-agent system approach for an efficient and on the fly reconfiguration of services in the manufacturing domain. Besides self-organizing techniques, other dimensions, e.g., “social-based” trust and QoS metrics, are used to ensure a constant QoS in an agile production system. The insertion of intelligent agents facilitates the improvement of strategies that perform the service reconfiguration, and in addition, permits to understand when and how self-reconfiguration takes place in order to allow a continuous improvement of the system performance. Additionally, this work addresses solutions for real industrial applications, being aligned with some characteristics of the Industrie 4.0 initiative, namely the distributed intelligence and self-* methods, e.g. self-adaptation, self-organization and self-configuration
- Agent-based approach for decentralized data analysis in industrial cyber-physical systemsPublication . Queiroz, Jonas; Leitão, Paulo; Barbosa, José; Oliveira, EugénioThe 4th industrial revolution is marked by the use of Cyber-Physical Systems (CPSs) to achieve higher levels of flexibility and adaptation in production systems that need to cope with a demanding and ever-changing market, driven by mass customization and high quality products
- An agent-based approach for the dynamic and decentralized service reconfiguration in collaborative production scenariosPublication . Rodrigues, Nelson; Leitão, Paulo; Oliveira, EugénioFuture industrial systems endorse the implementation of innovative paradigms addressing the continuous flexibility, reconfiguration, and evolution to face the volatility of dynamic markets demanding complex and customized products. Smart manufacturing relies on the capability to adapt and evolve to face changes, particularly by identifying, on-the-fly, opportunities to reconfigure its behavior and functionalities and offer new and more adapted services. This paper introduces an agent-based approach for service reconfiguration that allows the identification of the opportunities for reconfiguration in a pro-active and dynamic manner, and the implementation on-the-fly of the best strategies for the service reconfiguration that will lead to a better production efficiency. The developed prototype for a flexible manufacturing system case study allowed to verify the feasibility of greedy local service reconfiguration for competitive and collaborative industrial automation situations.
- An agent-based industrial cyber-physical system deployed in an automobile multi-stage production systemPublication . Queiroz, Jonas; Leitão, Paulo; Barbosa, José; Oliveira, Eugénio; Garcia, GiselaIndustrial Cyber-Physical Systems (CPS) are promoting the development of smart machines and products, leading to the next generation of intelligent production systems. In this context, Artificial Intelligence (AI) is posed as a key enabler for the realization of CPS requirements, supporting the data analysis and the system dynamic adaptation. However, the centralized Cloud-based AI approaches are not suitable to handle many industrial scenarios, constrained by responsiveness and data sensitivity. Edge Computing can address the new challenges, enabling the decentralization of data analysis along the cyber-physical components. In this context, distributed AI approaches such as those based on Multi-agent Systems (MAS) are essential to handle the distribution and interaction of the components. Based on that, this work uses a MAS approach to design cyber-physical agents that can embed different data analysis capabilities, supporting the decentralization of intelligence. These concepts were applied to an industrial automobile multi-stage production system, where different kinds of data analysis were performed in autonomous and cooperative agents disposed along Edge, Fog and Cloud computing layers. © 2020, Springer Nature Switzerland AG.
- An approach to inter-organizational workflow management in an electronic institutionPublication . Cardoso, Henrique; Leitão, Paulo; Oliveira, EugénioIn a virtual organization, different business partners (individual organizations) cooperate in order to achieve a common goal. The coordination of the corresponding inter-organizational workflow is an important issue. In this paper an approach towards managing the operational embodiment of a manufacturing consortium is presented. This approach is conceptualized as a service within an Electronic Institution framework providing several agent-based services related with the formation and operation of virtual organizations. The behavior of the inter-organizational workflow management service is presented, modeled as an extension to a contract monitoring service. The paper also deals with the information exchange needs between these services and with the partners involved in a virtual organization contractual relationship.
- Decentralized and on-the-fly agent-based service reconfiguration in manufacturing systemsPublication . Rodrigues, Nelson; Oliveira, Eugénio; Leitão, PauloIntelligent manufacturing systems rely on the capability to adapt and evolve to face the volatility of dynamic markets. The complexity of these systems increases with the demand of more customized and quality products, which requires more agile and flexible methods to support the dynamic and on-the-fly system reconfiguration aiming to respond quickly to product changes, by offering more efficient services. In this service-oriented manufacturing context, where process functionalities are modelled as services (e.g., quality control, welding and transportation), the dynamic reconfiguration of the services structure (e.g., in terms of quality, processing time and provided features) assumes a critical role to achieve the referred requirements. Despite the current research efforts, the service reconfiguration approaches usually use reactive event triggers, with decisions coming from a centralized decision-maker and performed manually. This means a lack of dynamic and run-time reconfiguration flexibility by discovering opportunities and needs to change, and, thus, exploring possible actions leading to new and appropriate system configurations. To overcome the mentioned issues, it is essential to provide solutions that answer to when and how to reconfigure a manufacturing system in an integrated, automatic and dynamic manner. For this purpose, this paper introduces an agent-based approach for service reconfiguration in manufacturing systems that allows the identification of opportunities in a pro-active and dynamic manner, and the on-the-fly implementation of new configuration solutions leading to a better production efficiency. The experimental results, using a flexible manufacturing system case study, allowed to verify the feasibility and benefits of the proposed agent-based service reconfiguration solution for competitive and collaborative industrial automation scenarios.
- Development of a smart electric motor testbed for Internet of things and big data technologiesPublication . Queiroz, Jonas; Barbosa, José; Dias, José João Cruz; Leitão, Paulo; Oliveira, EugénioSmart devices and Internet of Things (IoT) technologies are becoming each day more common. At the same time, besides the exponentially increasing demand to analyze the produced data, there is an evolving trend to perform the data analysis closer to the data sources, particularly at the Fog and Edge levels. In this sense, the development of testbeds that can, e.g., simulate smart devices in IoT environments, are important to explore and develop the technologies to enable the complete realization of such IoT concepts. This paper describes the digitization of an electric motor, through the incorporation of sensing and an analytical computational environment, towards the development of a testbed for IoT and Big Data technologies. The smart electric motor testbed provides real-time data streams, enabling a continuous monitoring of its operation along all the device life-cycle through advanced data analytics. Furthermore, the paper discusses how specific data analytics features fit the different IoT layers, while preliminary experiments demonstrate the testbed potentials.
- Distributing intelligence among cloud, fog and edge in industrial cyber-physical systemsPublication . Queiroz, Jonas; Leitão, Paulo; Barbosa, José; Oliveira, EugénioThe 4th industrial revolution advent promotes the reorganization of the traditional hierarchical automation systems towards decentralized Cyber-Physical Systems (CPS). In this context, Artificial Intelligence (AI) can address the new requirements through the use of data-driven and distributed problem solving approaches, such those based on Machine-Learning and Multi-agent Systems. Although their promising perspectives to enable and manage intelligent Internet of Things environments, the traditional Cloud-based AI approaches are not suitable to handle many industrial scenarios, constrained by responsiveness and data sensitive.
- Dynamic composition of service oriented multi-agent system in self-organized environmentsPublication . Rodrigues, Nelson; Leitão, Paulo; Oliveira, EugénioThe increasing relevance of complex systems in dynamic environments has received special attention from researchers during the last decade. Due to the need of a flexible and quick response to the clients' requirements, such systems become an important challenge. In this paper, self-organizing mechanisms capable to compose services in an automatic, flexible and decentralized manner are presented, mostly in which their adaptive behavior is concerned. Due to the distributed approach, we also investigate the adaptation regarding the structure of each entity. We thus propose an innovative self-learning mechanism that allows the distributed entities to learn structural relations allowing the system's evolution. This hypothesis were explored and validated by implementing a multi-agent system, in accordance with trust mechanisms to improve the interaction of agents. The achieved results show the correct agent's states in which the agents must evolve and self-organize, improving the system benefits band increasing the organization performance.
- Dynamic service reconfiguration with multi-agent systemsPublication . Rodrigues, Nelson; Leitão, Paulo; Oliveira, Eugénio; Rodrigues N.Most modern manufacturing systems rely on constantly seeking new solutions to better fulfil their manufacturing objectives. As reported in today’s manufacturing literature, dynamic service reconfiguration is one solution that permits to endorse continuous service reconfiguration, flexibility and evolvable systems. In spite of the current research efforts, real reconfiguration solutions are still lacking automated tools that support dynamic and runtime reconfigurations by discovering new adaptation needs and opportunities and, thus, explore possible actions leading to new system configurations. To overcome these issues, it is essential to provide solutions that answer to the “when” and “what” to reconfigure questions. Most of the service changes triggers rely on reactive events, where decisions come from a centralized decision-maker and are performed manually. Based on these facts a service-oriented multi-agent systems architecture is described aiming at actively promoting service reconfiguration (e.g., improvement of the service’s properties and/or update the services’ catalogue) to cope with the unexpected and unpredictable condition changes. This paper describes the processes that decide which service reconfiguration should be applied to each circumstance. The developed prototype for a flexible manufacturing system case study allowed verifying the feasibility of the proposed dynamic service reconfiguration solution in different scenarios.