Refining IOPT Petri Nets Class for Embedded System Controller Modeling

Since its inception, the Input-Output Place-Transition (IOPT) class of Petri nets have changed in response to the gained experience in the use of its associated tools freely available as a cloud based toolset. Here, we informally present the current state of the IOPT net class as supported by the IOPT-Tools, publicly available at http://gres.uninova.pt/IOPT-Tools/. The corresponding formal syntax and semantics are presented, followed by an illustrative example. Finally, we give a brief presentation of the respective XML-based interchange format and conclude

Towards an integrated tool support for the analysis of IOPT Nets using the Spin Model Checker

This paper presents a model translation to allow automatic simulation and verification of controller models for cyber-physical systems. The models are constructed using IOPT nets, a non-autonomous Petri nets class. Those models are then translated into Promela models to be executed by the Spin model checker, a widely used open-source software verification tool. Three illustrative examples are presented: one autonomous model and two non-autonomous models. As future work, it is foreseen the integration with the freely available IOPT-Tools framework

From non-autonomous Petri net models to executable state machines

Petri nets have long been known as a readable and powerful graphical modelling language. In particular, Petri nets also allow the creation of high-level models of embedded controllers. These models can be translated to executable code. This possibility is already available in some tools including the IOPT Tools. Another possibility is to translate the Petri net model into a state machine, which can then be easily executed by an even larger number of platforms for cyber-physical systems. In that sense, this paper presents a tool that is able to generate a state machine from a non-autonomous class of Petri supported by the IOPT Tools framework (which is publicly available). These state machines would be too large to be manually generated, but can now be automatically created, simulated, and verified using an higher-level modelling language. The state machines can then be used for execution or even as input for additional verification tools. This paper presents the translation algorithm and an illustrative example.This work was partially financed by Portuguese Agency FCT Fundação para a Ciência e Tecnologia, in the framework of project UID/EEA/00066/2019

Developing Globally-Asynchronous Locally- Synchronous Systems through the IOPT-Flow Framework

Throughout the years, synchronous circuits have increased in size and com-plexity, consequently, distributing a global clock signal has become a laborious task. Globally-Asynchronous Locally-Synchronous (GALS) systems emerge as a possible solution; however, these new systems require new tools. The DS-Pnet language formalism and the IOPT-Flow framework aim to support and accelerate the development of cyber-physical systems. To do so it offers a tool chain that comprises a graphical editor, a simulator and code gener-ation tools capable of generating C, JavaScript and VHDL code. However, DS-Pnets and IOPT-Flow are not yet tuned to handle GALS systems, allowing for partial specification, but not a complete one. This dissertation proposes extensions to the DS-Pnet language and the IOPT-Flow framework in order to allow development of GALS systems. Addi-tionally, some asynchronous components were created, these form interfaces that allow synchronous blocks within a GALS system to communicate with each other

Support for Technical Phases and Conceptual Model

Worldwide, many wheelchair users find it difficult to use or acquire a wheelchair that is appropriate for them, either because they do not have the necessary financial support or because they do not have access to trained healthcare professionals (HCPs), but they are essential for the correct provision of assistive products and user training. Consequently, although wheelchairs are designed to promote the well-being of many users, in many cases, they end up being abandoned or do not provide any benefit, with the chance of causing harm and potentially putting people in danger. This article proposes the creation and use of a Digital Twin (DT) of a Power Wheelchair (PWC) to promote the health of wheelchair users, by facilitating and improving the delivery of remote services by HCPs, as well as to include monitoring services to support timely maintenance. Specifically, a DT is a virtual counterpart that is seamlessly linked to a physical asset, both relying on data and information exchange for mirroring each other. Currently, DT is emerging and being applied to different areas as a promising approach to gather insightful data, which are shared between the physical and virtual worlds and facilitate the means to design, monitor, analyze, optimize, predict, and control physical entities. This article gives an overview of the Digital Twin concept, namely its definition, types, and properties, and seeks to synthesize the technologies and tools frequently used to enable Digital Twins; we also explain how a DT can be used in the technical phases of the PWC provision process and propose a conceptual model highlighting the use of an MDD approach benefiting from a Petri net formalism, which is presented to systematize the development of a PWC Dpublishersversionpublishe

Arquitetura de suporte ao desenvolvimento de sistemas auto-configuráveis para redes de sensores sem fios

A agricultura em geral e os espac¸os verdes em particular permanecem como atividades em que a quantidade de ´agua desperdic¸ada persiste em n´ıveis muito altos. Apesar de toda a tecnologia dispon´ıvel atualmente, ainda ´e comum encontrar parques e espac¸os verdes onde os sistemas de irrigac¸˜ao aplicados s˜ao frequentemente acionados com uma necessidade duvidosa. Atualmente, a maioria dos sistemas de irrigac¸˜ao s˜ao operados manualmente ou baseados em sistemas equipados com controladores hor´arios. A Internet das coisas, pode ajudar na recolha de informac¸˜oes, na tomada de decis˜oes, na obtenc¸˜ao de dados atrav´es de sensores e no seu feedback. Este trabalho apresenta uma abordagem para desenvolver sistemas IoT reconfigur´aveis usando tecnologias sem fios como, por exemplo, um sistema de irrigac¸˜ao autom´atico. Trˆes principais contribuic¸˜oes s˜ao propostas: (1) Uma abordagem de automatizac¸˜ao de projeto de sistemas IoT suportada no uso de um formalismo de modelac¸˜ao gr´afica para a definic¸˜ao de regras que especificam o comportamento do sistema, permitindo a gerac¸˜ao autom´atica de c´odigo para microcontroladores, bem como a comunicac¸˜ao atrav´es de protocolo sem fios. (2) Uma ferramenta de automatizac¸˜ao de projeto para o desenvolvimento de redes de sensores sem fios em LoRa modeladas com redes de Petri IOPT; (3) o desenvolvimento de um prot´otipo de um sistema de irrigac¸˜ao autom´atico sem fios, suportando a verificac¸˜ao e selec¸˜ao autom´atico de dispositivos sensores, com base no tipo de sensor requerido e o respetivo indicador de intensidade de sinal recebido

Modelo gráfico para simulação e controlo do chão de fábrica no contexto da indústria 5.0

Os valores da indústria 5.0 alteram o paradigma do atual modelo de produção. Com repercussões em toda a cadeia de valor. Desafios como a mass customization, abrem oportunidades para novas abordagens em que se contempla a redução do desperdício de forma a otimizar a utilização dos recursos do planeta. O objetivo deste trabalho é propor um modelo funcional que apresenta o chão de fábrica como um prestador de serviços para o produto a ser construído. Desta forma o processo de fabrico adapta-se dinamicamente a eventuais alterações. São apresentadas simulações e análises dos resultados de forma a validar o modelo. Assim, pretende-se contribuir com um modelo capaz de realizar simulações. E que a integração do modelo com os atuais dispositivos físicos, através de tecnologias da Internet das Coisas, permita a reutilização dos mesmos além de controlar o chão de fábrica

A complex systems approach to education in Switzerland

The insights gained from the study of complex systems in biological, social, and engineered systems enables us not only to observe and understand, but also to actively design systems which will be capable of successfully coping with complex and dynamically changing situations. The methods and mindset required for this approach have been applied to educational systems with their diverse levels of scale and complexity. Based on the general case made by Yaneer Bar-Yam, this paper applies the complex systems approach to the educational system in Switzerland. It confirms that the complex systems approach is valid. Indeed, many recommendations made for the general case have already been implemented in the Swiss education system. To address existing problems and difficulties, further steps are recommended. This paper contributes to the further establishment complex systems approach by shedding light on an area which concerns us all, which is a frequent topic of discussion and dispute among politicians and the public, where billions of dollars have been spent without achieving the desired results, and where it is difficult to directly derive consequences from actions taken. The analysis of the education system's different levels, their complexity and scale will clarify how such a dynamic system should be approached, and how it can be guided towards the desired performance

An integration framework for managing rich organisational process knowledge

The problem we have addressed in this dissertation is that of designing a pragmatic framework for integrating the synthesis and management of organisational process knowledge which is based on domain-independent AI planning and plan representations. Our solution has focused on a set of framework components which provide methods, tools and representations to accomplish this task.In the framework we address a lifecycle of this knowledge which begins with a methodological approach to acquiring information about the process domain. We show that this initial domain specification can be translated into a common constraint-based model of activity (based on the work of Tate, 1996c and 1996d) which can then be operationalised for use in an AI planner. This model of activity is ontologically underpinned and may be expressed with a flexible and extensible language based on a sorted first-order logic. The model combines perspectives covering both the space of behaviour as well as the space of decisions. Synthesised or modified processes/plans can be translated to and from the common representation in order to support knowledge sharing, visualisation and mixed-initiative interaction.This work united past and present Edinburgh research on planning and infused it with perspectives from design rationale, requirements engineering, and process knowledge sharing. The implementation has been applied to a portfolio of scenarios which include process examples from business, manufacturing, construction and military operations. An archive of this work is available at: http://www.aiai.ed.ac.uk/~oplan/cpf

Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018