Browsing by Author "Restivo, Francisco"
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- ADACOR, a collaborative production automation and control architecturePublication . Leitão, Paulo; Colombo, Armando W.; Restivo, FranciscoAn analysis of the ADACOR collaborative manufacturing control architecture from the point of view of the Collaborative Manufacturing Management paradigm shows how ADACOR supports integration and extension across the manufacturing value chain.
- ADACOR: a holonic architecture for agile and adaptive manufacturing controlPublication . Leitão, Paulo; Restivo, FranciscoIn the last decades significant changes in the manufacturing environment have been noticed: moving from a local economy towards a global economy, with markets asking for products with higher quality at lower costs, highly customised and with short life cycle. In these circumstances, the challenge is to develop manufacturing control systems with intelligence capabilities, fast adaptation to the environment changes and more robustness against the occurrence of disturbances. This paper presents an agile and adaptive manufacturing control architecture that addresses the need for the fast reaction to disturbances at the shop floor level, increasing the agility and flexibility of the enterprise, when it works in volatile environments. The proposed architecture introduces an adaptive control that balances dynamically between a more centralised structure and a more decentralised one, allowing combining the global production optimisation with agile reaction to unexpected disturbances.
- Agent-based holonic production controlPublication . Leitão, Paulo; Restivo, FranciscoThe manufacturing system environment is typically a complex system, involving many variables and constraints, being in certain cases a chaotic system. The introduction of new paradigms to face globalisation, distribution of activities and customer satisfaction requirements, increases the problem complexity. The new manufacturing control approaches should support the agile adaptation to volatile technological and economical environments and should react dynamically and quickly to disturbances. This paper intends to introduce an agent-based approach to the manufacturing problem, that uses holonic concepts, is focused on distributed manufacturing shop floor control for discrete batch production, considers the optimisation of set-up and maintenance operations, and develops mechanisms for agile and fast reaction to disturbances without compromising the global production optimisation.
- An agile and cooperative architecture for distributed manufacturing systemsPublication . Leitão, Paulo; Restivo, FranciscoWorld-wide competition among enterprises leads to the need for new systems to perform the control of distributed manufacturing systems, through the integration of information systems and self-organisation features, in order to adapt quickly to the environment changes. This paper presents an agile and cooperative architecture for distributed manufacturing systems based in the multiagent technology which implements some holonic and bionic concepts and supports a new control approach, including the re-engineering phase.
- An approach to the formal specification of holonic control systemsPublication . Leitão, Paulo; Colombo, Armando W.; Restivo, FranciscoIn the manufacturing world, globalisation leads to a trend towards the reduction of batches and product life cycle, and the increase of part diversity, which are in conflict with other requirements, such as the cost reduction achieved with higher productivity. Thus, the challenge is to develop flexible, agile and intelligent management and control architectures that satisfy the referred requirements. The holonic manufacturing and the agent-based manufacturing approaches allow a new approach to the manufacturing problem, through concepts such as modularity, decentralisation, autonomy and re-use of control software components. ADACOR, one of the holonic architectures recently proposed, defines a set of autonomous and intelligent holons aiming to improve the performance of control system in industrial scenarios characterised by the frequent occurrence of unexpected disturbances. The formal modeling and validation of the specifications of the ADACOR-holons and of the interactions between these holons to implement the manufacturing control functions is of critical importance. In this paper, a formal methodology is introduced and applied to model the dynamic behaviour of the ADACOR-holon classes.
- Arquitecturas adaptativas e cooperativas para sistemas de fabrico distribuídosPublication . Leitão, Paulo; Restivo, FranciscoA pressão competitiva actual, é ditada por um mercado aberto e global, e no qual as empresas são confrontadas com exigências cada vez mais fortes. A adopção de novos conceitos e paradigmas de fabrico, combinados com a implementação de novas tecnologias é a resposta a estes requisitos e a solução para o incremento da competitividade. Arquitecturas de controlo distribuídas, cooperativas, auto-organizativas e heterogéneas são prometedoras neste contexto. A arquitectura apresentada, pretende solucionar de forma eficaz os requisitos dos sistemas de fabrico emergentes, sendo baseada na tecnologia de multiagentes, e implementando alguns conceitos associados aos sistemas de fabrico holónico e biónico, suportando uma nova abordagem ao controlo, que inclui as fases operacional e de reengenharia do ciclo de vida de uma empresa.
- Behaviour and integration of service-oriented automation and production devices at the shop-floorPublication . Mendes, João M.; Restivo, Francisco; Colombo, Armando W.; Leitão, PauloAutomation and manufacturing systems are changing in the direction of cooperative ecosystems with heterogeneous entities. An important feature that should be considered is the vertical integration from the business needs down to the shop-floor where the real action takes place. This paper analyses the integration of shop-floor devices into the IT-enterprise but maintaining also a certain degree of independence in terms of behaviour. Service-oriented paradigm is used as the main backbone due its proven merits in the business levels and recently also in automation and production systems. In the provided example, high-level Petri nets (HLPN) demonstrate a set of useful features, namely the partial behaviour description and analysis and some parameters in the integration. The resulting application leads to an easy integration of autonomous devices in the IT-enterprise, taking especially in account the requirements of the shop-floor level.
- A collaborative automation approach to distributed production systemsPublication . Colombo, Armando W.; Schoop, Ronald; Leitão, Paulo; Restivo, FranciscoThe new enterprise organizations, such as virtual enterprise and smart enterprise, require the usage of collaborative automation approaches, addressing the flexibility and dynamic re-configurability. Collaborative automation is a result of the integration of emerging technologies and paradigms like smart agent-based control technology, mechatronics, communication and information. This paper reviews the paradigms evolution from CIM to the collaborative manufacturing management and discusses how and why the holonic control architecture ADACOR is a typical architecture that exhibits the real meaning of the collaborative manufacturing management concept.
- Composition of Petri nets models in service-oriented industrial automationPublication . Mendes, João M.; Leitão, Paulo; Restivo, Francisco; Colombo, Armando W.In service-oriented systems, composition of services is required to build new, distributed and more complex services, based on the logic behavior of individual ones. This paper discusses the formal composition of Petri nets models used for the process description and control in service-oriented automation systems. The proposed approach considers two forms for the composition of services, notably the offline composition, applied during the design phase, and the online composition, related to the synchronization of Petri nets models on the fly. An experimental case study is used to illustrate the proposed composition approach.
- Customizable service-oriented Petri net controllersPublication . Mendes, João M.; Restivo, Francisco; Leitão, Paulo; Colombo, Armando W.In industrial automation, service-orientation is a relatively new and ascending concept and thus, concrete integrated methodologies are missing to accomplish the required development tasks. A suitable approach is to use the powerful set of features that Petri nets formalism provides for such dynamic systems. This paper presents a token game template that is part of the open methodology for the development of customized Petri nets controllers, targeting the engineering of service-oriented industrial automation. This template is based on a state machine specification for the life-cycle of transitions that leaves several options open for extending it with features depending on the application. The practical use and implementation should bring, among others, featured-full and integrated modeling, analysis and control capabilities, which is required by service-oriented ecosystems. This core structure was used and validated in the development of control applications for an industrial automation system.