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Publications

Publications by Paulo Jorge Leitão

2016

Building a Robotic Cyber-Physical Production Component

Authors
Leitao, P; Barbosa, J;

Publication
SERVICE ORIENTATION IN HOLONIC AND MULTI-AGENT MANUFACTURING

Abstract
Cyber-physical systems are a network of integrated computational decisional components and physical elements. The integration of computational decisional components with the heterogeneous physical automation systems and devices is not transparent and constitutes a critical challenge for the success of this approach. The objective of the paper is to describe an approach to establish standard interfaces based on the use of the ISO 9506 Manufacturing Message Specification international standard. The proposed approach is exemplified by the construction of a robotic cyber-physical production component that is plug-in in a cyber-physical system for a small-scale production system based on Fischertechnik systems.

2015

Genetic Algorithm for Flexible Job Shop Scheduling Problem - a Case Study

Authors
Guevara, G; Pereira, AI; Ferreira, A; Barbosa, J; Leitao, P;

Publication
PROCEEDINGS OF THE INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2014 (ICNAAM-2014)

Abstract
This paper proposes the impact assessment of the workers in the optimal time of operations in a Flexible Job Shop Scheduling Problem. In this work, a real enterprise was studied. The problem consists in finding the workers operations schedule, taking into account the precedence constraints. The main objective is to minimize the finish time of the last task completed in the schedule. The genetic algorithm was used to solve the optimization problem and some numerical results are presented.

2013

Standards Compliance in Industrial Agents Applications

Authors
Seixas, I; Leitao, P;

Publication
39TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY (IECON 2013)

Abstract
Multi-agent systems are a suitable approach to address the current requirements imposed to companies demanding for more flexible, adaptive and reconfigurable systems. In spite of the promising perspective, only a reduced number of such solutions are running in industrial scenarios. Standardization is recognized as a major issue in the development of devices, systems or processes in industrial environments, constituting a real road-blocker for the wider acceptance of agent-based solutions in industry. This paper discusses the importance of standardization compliance in the development of industrial agent-based solutions and the actions to be performed to overcome this issue.

2016

A Nervousness Regulator Framework for Dynamic Hybrid Control Architectures

Authors
Jimenez, JF; Bekrar, A; Trentesaux, D; Leitao, P;

Publication
SERVICE ORIENTATION IN HOLONIC AND MULTI-AGENT MANUFACTURING

Abstract
Dynamic hybrid control architectures are a powerful paradigm that addresses the challenges of achieving both performance optimality and operations reactivity in discrete systems. This approach presents a dynamic mechanism that changes the control solution subject to continuous environment changes. However, these changes might cause nervousness behaviour and the system might fail to reach a stabilized-state. This paper proposes a framework of a nervousness regulator that handles the nervousness behaviour based on the defined nervousness-state. An example of this regulator mechanism is applied to an emulation of a flexible manufacturing system located at the University of Valenciennes. The results show the need for a nervousness mechanism in dynamic hybrid control architectures and explore the idea of setting the regulator mechanism according to the nervousness behaviour state.

2015

Self-interested Service-Oriented Agents Based on Trust and QoS for Dynamic Reconfiguration

Authors
Rodrigues, N; Leitao, P; Oliveira, E;

Publication
SERVICE ORIENTATION IN HOLONIC AND MULTI-AGENT MANUFACTURING

Abstract
Progressively increasing complexity of dynamic environments, in which services and applications are demanded by potential clients, requires a high level of reconfiguration of the offer to better match that ever changing demand. In particular, the dynamic change of the client's needs, leading to higher exigency, may require a smart and flexible automatic composition of more elementary services. By leveraging the service-oriented architectures and multi-agent system benefits, the paper proposes a method to explore the flexibility of the decision support for the services' reconfiguration based on several pillars, such as trust, reputation and QoS models, which allows the selection based on measuring the expected performance of the agents. Preliminary experimental results, extracted from a real case scenario, allow highlighting the benefits of the proposed distributed and flexible solution to balance the workload of service providers in a simple and fast manner. The proposed solution includes the agents' intelligent decision-making capability to dynamically and autonomously change services selection on the fly, towards more trustworthy services with better quality when unexpected events happen, e.g. broken machines. We then propose the use of competitive self-interested agents to provide services that best suits to the client through dynamic service composition.

2015

Integration of an Agent-based Strategic Planner in an Enterprise Service Bus Ecosystem

Authors
Ferreira, A; Pereira, A; Rodrigues, N; Barbosa, J; Leitao, P;

Publication
PROCEEDINGS 2015 IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS (INDIN)

Abstract
The continuous change in the manufacturing world is demanding more flexible, responsive and accurate planning tools, which are able to assist the decision-makers to take tactical and strategic decisions on short notice with a high level of confidence. For this purpose, these tools should dynamically explore different operative scenarios in the planning procedure and produce information about key performance indicators. This paper describes the development of an agent-based strategic planner, combining the flexibility of multi-agent systems principles with the optimization capability of a Mixed Integral Programming technique. The tool is integrated in an ecosystem of heterogeneous decision-making systems through an Enterprise Service Bus that also provides access to legacy data.

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