Competitors or cousins? Studying the parallels between distributed programming languages systemJ and IEC61499

We face a glut of languages for programming distributed software today. However, only a few languages have proven their potential with wider practical use in different domains of computing. We picked two such languages, meant for different domains, to see if they could cross-pollinate and enrich one another. Specifically, we chose SystemJ, a language to program distributed embedded systems, and IEC61499, the next generation standard for distributed industrial automation control software. Unsurprisingly, we found similar structures and artifacts between the two. We also found significant differences mainly due to differing domain-specific requirements. This comparison leads to observations and guidelines for improving both languages, and we discuss directions towards an “ideal” distributed software programming language

The DS-Pnet modeling formalism for cyber-physical system development

This work presents the DS-Pnet modeling formalism (Dataflow, Signals and Petri nets), designed for the development of cyber-physical systems, combining the characteristics of Petri nets and dataflows to support the modeling of mixed systems containing both reactive parts and data processing operations. Inheriting the features of the parent IOPT Petri net class, including an external interface composed of input and output signals and events, the addition of dataflow operations brings enhanced modeling capabilities to specify mathematical data transformations and graphically express the dependencies between signals. Data-centric systems, that do not require reactive controllers, are designed using pure dataflow models. Component based model composition enables reusing existing components, create libraries of previously tested components and hierarchically decompose complex systems into smaller sub-systems. A precise execution semantics was defined, considering the relationship between dataflow and Petri net nodes, providing an abstraction to define the interface between reactive controllers and input and output signals, including analog sensors and actuators. The new formalism is supported by the IOPT-Flow Web based tool framework, offering tools to design and edit models, simulate model execution on the Web browser, plus model-checking and software/hardware automatic code generation tools to implement controllers running on embedded devices (C,VHDL and JavaScript). A new communication protocol was created to permit the automatic implementation of distributed cyber-physical systems composed of networks of remote components communicating over the Internet. The editor tool connects directly to remote embedded devices running DS-Pnet models and may import remote components into new models, contributing to simplify the creation of distributed cyber-physical applications, where the communication between distributed components is specified just by drawing arcs. Several application examples were designed to validate the proposed formalism and the associated framework, ranging from hardware solutions, industrial applications to distributed software applications

Service-oriented architecture for device lifecycle support in industrial automation

Dissertação para obtenção do Grau de Doutor em Engenharia Electrotécnica e de Computadores Especialidade: Robótica e Manufactura IntegradaThis thesis addresses the device lifecycle support thematic in the scope of service oriented industrial automation domain. This domain is known for its plethora of heterogeneous equipment encompassing distinct functions, form factors, network interfaces, or I/O specifications supported by dissimilar software and hardware platforms. There is then an evident and crescent need to take every device into account and improve the agility performance during setup, control, management, monitoring and diagnosis phases. Service-oriented Architecture (SOA) paradigm is currently a widely endorsed approach for both business and enterprise systems integration. SOA concepts and technology are continuously spreading along the layers of the enterprise organization envisioning a unified interoperability solution. SOA promotes discoverability, loose coupling, abstraction, autonomy and composition of services relying on open web standards – features that can provide an important contribution to the industrial automation domain. The present work seized industrial automation device level requirements, constraints and needs to determine how and where can SOA be employed to solve some of the existent difficulties. Supported by these outcomes, a reference architecture shaped by distributed, adaptive and composable modules is proposed. This architecture will assist and ease the role of systems integrators during reengineering-related interventions throughout system lifecycle. In a converging direction, the present work also proposes a serviceoriented device model to support previous architecture vision and goals by including embedded added-value in terms of service-oriented peer-to-peer discovery and identification, configuration, management, as well as agile customization of device resources. In this context, the implementation and validation work proved not simply the feasibility and fitness of the proposed solution to two distinct test-benches but also its relevance to the expanding domain of SOA applications to support device lifecycle in the industrial automation domain

Communication technology selection method for smart energy metering based on analytic hierarchy process

As new communication technologies continue to emerge and the integration of these technologies into the modernization of the electricity grid becomes increasingly necessary, a variety of communication protocols and combinations are being explored for their potential use in the smart grid domain. However, given the multitude of technological possibilities available, choosing the optimal technology capable of adequately addressing the communication requirements of the intelligent grid remains a challenge for utilities. This is due, on the one hand, to the fact that different intelligent grid applications have different qualitative and quantitative communication requirements. Moreover, on the other hand, each technology has advantages and disadvantages concerning its performance characteristics in such requirements. This work uses the AHP (Analytic Hierarchy Process) methodology to select the wireless technology that presents the best performance characteristics concerning determined requirements. For this, a computational algorithm was developed in the Matlab programming environment, through which criteria such as data rate, latency, range, security, reliability, and interoperability were compared to select the best technological alternative among Wi-Fi, ZigBee, Z-Wave, and Bluetooth. Data collected from the literature review, with the performance characteristics of these technologies, were applied in a single case study simulating the practical implementation of this work. Among the analyzed criteria, simulations demonstrated that Wi-Fi was the winning technology alternative with 32.353%, followed by Z-Wave with 29.865% in second place, and ZigBee and Bluetooth were ranked third and fourth with 25.255% and 12.527%, respectively. In addition, sensitivity analysis shows how the AHP methodology can be a feasible alternative to assist decision-making in the smart grid domain.À medida que novas tecnologias de comunicação continuam a surgir e a integração destas tecnologias na modernização da rede elétrica se torna cada vez mais necessária, uma variedade de protocolos e combinações de tecnologias de comunicação vem sendo explorados para a sua potencial utilização no domínio da rede inteligente. No entanto, dada a multiplicidade de possibilidades tecnológicas disponíveis, a escolha da melhor tecnologia capaz de responder, adequadamente, aos requisitos de comunicação da rede elétrica inteligente continua sendo um desafio para diferentes atores interessados. Isto se deve, por um lado, ao fato de diferentes aplicações de rede inteligente terem diferentes requisitos de comunicação, quer sejam quantitativos ou qualitativos. Além disso, por outro lado, cada tecnologia tem vantagens e desvantagens relacionadas com as suas características de desempenho em tais requisitos. Este trabalho, portanto, utiliza a metodologia AHP (Analytic Hierarchy Process) para selecionar a tecnologia sem fios que apresenta as melhores características de desempenho relativamente a determinados requisitos. Para tal, foi desenvolvido um algoritmo computacional no ambiente de programação Matlab, através do qual critérios tais como taxa de dados, latência, alcance, segurança, confiabilidade e interoperabilidade foram comparados para selecionar a melhor alternativa tecnológica entre Wi-Fi, ZigBee, Z-Wave e Bluetooth. Os dados coletados na revisão de literatura, com as características de desempenho destas tecnologias, foram aplicados num único estudo de caso simulando a implementação prática deste método em ambiente residencial. Dentre os critérios analisados, as simulações demonstraram que o Wi-Fi foi a alternativa tecnológica vencedora com 32,353%, seguido pelo Z-Wave com 29,865% em segundo lugar, e ZigBee e Bluetooth ficaram em terceiro e quarto lugar com 25,255% e 12,527%, respectivamente. Além disso, a análise de sensibilidade, dos resultados, mostra como a metodologia AHP pode ser uma alternativa viável para auxiliar na tomada de decisões no domínio da rede inteligente

Emerging Trends in Mechatronics

Mechatronics is a multidisciplinary branch of engineering combining mechanical, electrical and electronics, control and automation, and computer engineering fields. The main research task of mechatronics is design, control, and optimization of advanced devices, products, and hybrid systems utilizing the concepts found in all these fields. The purpose of this special issue is to help better understand how mechatronics will impact on the practice and research of developing advanced techniques to model, control, and optimize complex systems. The special issue presents recent advances in mechatronics and related technologies. The selected topics give an overview of the state of the art and present new research results and prospects for the future development of the interdisciplinary field of mechatronic systems