J. Marco Mendes

Service-Oriented Agents for Collaborative Industrial Automation and Production Systems

Service-oriented Multi-Agent Systems (SoMAS) is an approach to combine the fundamental characteristics of service-oriented and multi-agent methods into a new platform for industrial automation. Several research works already targeted the connection of these technologies, presenting different perspectives in how and why to join them. This research focuses on available efforts and solutions in the area of SoMAS and explains the idea behind the service-oriented agents in industrial automation. A SoMAS system is mainly composed by shared resources in form of services and their providing/requesting agents. The paper also discusses the required engineering aspects of these systems, from the internal anatomy to the interaction patterns. Parameters of flexibility, reconfiguration, autonomy and reduced development efforts were considered and they should be the trademark of SoMAS. Aiming to illustrate the proposed approach, an example of service-oriented automation agents is given.

High-level Petri nets for the process description and control in service-oriented manufacturing systems

The use of service-orientation principles in manufacturing systems is a promising solution to achieve modularity, flexibility, re-configurability and interoperability. Crucial issues in these service-oriented systems are the description and co-ordination of the execution of the services offered by the distributed entities. This paper introduces an integrated approach for the design, analysis, validation, simulation and process execution of service-oriented manufacturing systems, using the High-level Petri net formalism as the formal language to describe the system behaviour. The use of the proposed approach contributes to achieving an easier and faster development of these solutions and provides the basis to support modularity and re-configurability.

Integration of virtual and real environments for engineering service-oriented manufacturing systems

Engineering frameworks are currently required to support the easy, low-cost, modular and integrated development of manufacturing systems addressing the emergent requirements of re-configurability, responsiveness and robustness. This paper discusses the integration of 2D/3D digital software tools with Petri net based service-oriented frameworks to allow the design, configuration, analysis, validation, simulation, monitoring and control of manufacturing systems in a virtual environment and its posterior smooth migration into the real “physical” environment. An experimental case study was implemented to validate the proposed concepts, using the Continuum platform to design, compose, analyze, validate and simulate the Petri nets based service-oriented manufacturing control system, and the Delmia AutomationTM software suite to support the rapid prototyping and the easy simulation of the designed control solution. The experimental results prove several aspects of the proposed approach, notably the smooth migration between the design and the operation phases, one of the main objectives of the work.

High-Level Petri Nets control modules for service-oriented devices: A case study

This paper describes a solution for the control of service-oriented devices based on modular and special adapted high-level Petri nets process description of intra- and inter-control activities. The procedure is applied on a case study scenario, corresponding to a real transfer system made of several control devices represented as service-oriented components able to share information between them. The high-level Petri Nets are adapted to associable models applicable to describe control processes and sufficient elastic for different control strategies. Valuable and flexible control features are obtained from its application, such as an integrated methodology for the modular control with decision support and validation.

Composition of Petri nets models in service-oriented industrial automation

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.

Energy aware knowledge extraction from Petri nets supporting decision-making in service-oriented automation

This paper introduces an approach to decision support systems in service-oriented automation control systems, which considers the knowledge extracted from the Petri nets models used to describe and execute the process behavior. Such solution optimizes the decision-making taking into account multi-criteria, namely productive parameters and also energy parameters. In fact, being manufacturing processes typically energy-intensive, this allows contributing for a clean and saving environment (i.e. a better and efficient use of energy). The preliminary experimental results, using a real laboratorial case study, demonstrate the applicability of the knowledge extracted from the Petri nets models to support real-time decision-making systems in service-oriented automation systems, considering some energy efficiency criteria.

Process optimization of service-oriented automation devices based on Petri nets

This paper introduces a novel method for the specification and selection of criteria-weighted operation modes for the orchestration of services in industrial automation using Petri nets. The objective is to provide to the internal decision support system of a service-oriented automation device or of another applicable computational system the capability to select the best path in a Petri net orchestration model considering different criteria to evaluate the quality of services, such as the time, energy efficiency and reliability. The transition-invariants obtained from the Petri net represent the set of possible modi operandi and these are then weighted with decision criteria. The result will be afterwards evaluated in order to select the optimal modus operandi to be executed by the device. Based on the experiments, this method permits the dynamic optimization of processes in real-time, considering available parameters from devices and other resources.

Customizable service-oriented Petri net controllers

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.

Service-oriented computing in manufacturing automation: A SWOT analysis

Service-oriented Computing (SOC) is being applied in industrial manufacturing automation to face the current demand for modular, flexible and reconfigurable solutions. Highlighted from the other existing methodologies, SOC may carry an alternative but natural solution to design and engineer manufacturing automation systems and consequently the ability to seamless integrate into the modern IT-enterprise. However, SOC still has a long way to be adopted by industrial solutions, mainly fulfilling the particularities of the manufacturing domain. This paper discusses the applicability of the SOC in industrial manufacturing automation by using a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis. The discussed aspects show the great potential of SOC to solve industrial manufacturing automation problems, but also the need to smooth some sharp edges.

Next Generation of Engineering Methods and Tools for SOA-Based Large-Scale and Distributed Process Applications

Engineering methods and tools are seen as key for designing, testing, deploying and operating future infrastructures. They accompany critical processes from ‘cradle-to-grave’. Here we provide an overview of the user and business requirements for engineering tools, including system development, modelling, visualisation, commissioning and change in an SOA engineering environment. An appraisal of existing engineering tools appropriate to IMC-AESOP, both commercial and development prototypes are presented, culminating in the presentation of tool cartography graphically, defining the impact of these tools within the enterprise and system lifecycle.