Luís Gomes

Current Trends in Remote Laboratories

Remote laboratories have been introduced during the last few decades into engineering education processes as well as integrated within e-learning frameworks offered to engineering and science students. Remote laboratories are also being used to support life-long learning and students autonomous learning activities. In this paper, after a brief overview of state-of-the-art technologies in the development of remote laboratories and presentation of recent and interesting examples of remote laboratories in several areas related with industrial electronics education, some current trends and challenges are also identified and discussed.

The Input-Output Place-Transition Petri Net Class and Associated Tools

Petri nets are a well-known formalism widely used in different application areas. Yet, the lack of adequate tools that can be integrated within engineering development frameworks are one major drawback. This paper identifies and justifies the characteristics of one class of Petri nets targeted for the modelling of automation systems and (networked) embedded systems, named as input-output Petri net (IOPT), and its representation using the Petri net markup language (PNML). The paper also presents a set of associated tools under development. This Petri net class, defined on top of the well-known place-transition Petri nets, is the common link across a set of tools under development, including a graphical editor, a state-space analyser for the verification of properties, conflict resolution through automatic arbiter generation, automatic code generators, simulator, among others. In this sense, the main goal of the proposed Petri net class and associated tools is to support the entire system development flow, from specification to implementation.

Current Trends in Industrial Electronics Education

Technology development creates many challenges in the education of industrial-electronics (IE)-related subjects. At the same time, it allows new educational paradigms to be implemented. The main contribution of this paper is to initiate a discussion for the needs and challenges of IE education both at university level and in lifelong learning, in order to meet the requirements of the emerging technologies of the 21st century. Educational challenges and opportunities are first identified and analyzed. Afterward, an overview of state-of-the-art learning methodologies and tools is presented. New educational paradigms and future directions are also identified.

From Petri net models to VHDL implementation of digital controllers

Modeling of discrete-event systems using Petri net models is well-studied. Also, their usage for specification of digital controllers is widely used. Yet, it is recognized that we have a lack of tools when facing support for the implementation of these models, namely for automatic code generation. The paper briefly presents the FORDESIGN project that aims to develop a set of tools to contribute for filling this gap within automation systems and (networked) embedded systems development. The set of tools is based on a Petri net class, named as Input-Output Petri Net (IOPT), and its representation using the Petri Net Markup Language (PNML). The paper presents some rules used by an automatic code generator able to produce VHDL code starting with the PNML representation of the Petri net model.

Net model composition and modification by net operations: a pragmatic approach

Different tools often implement a single Petri net refinement or composition concept in different ways. This situation is undesirable from an engineering point of view. Here, we present a set of operations on nets based on the concepts of net instances and fusion sets, supporting the specification of net structures abstractions and net model transformations in an integrated and generic way. The operations are illustrated by composing a net model for a medium-sized control system. The same operations are then used to specify modifications to the initial model

From IOPT Petri nets to C: An automatic code generator tool

This paper presents a tool for automatic generation of ANSI C code from models expressed in IOPT (Input-Output Place-Transition) Petri Nets. The inputs of the tool are PNML (Petri Nets Mark-up Language) files containing the IOPT Petri net models. The tool has two different interfaces: one relying on a simple graphical interface (amenable to be used by humans), and a second one with a command line interface (amenable to be used by humans as well as by other computational systems supporting tools interaction). The tool also allows the user to tune some parts of the automatically generated code considering some characteristics of the implementation platform improving the performance of the generated code. Generated code can be directly deployed into specific controllers; PIC low-cost microcontrollers as well as general purpose PCs have been used for validation.

Remote laboratory support for an introductory microprocessor course

Introductory microprocessor design courses can benefit from the usage of laboratory assignments, leading, normally, to high rates of laboratory space and time occupation. In this paper, a remote laboratory is proposed in order to alleviate the laboratorys physical occupation. An 8031 microcontroller based set-up was used to support a set of experiments. Local and remote accesses to the experiments are possible, supported by the LabView environment, and complemented by a specific virtual workbench adaptor to emulate user presence.

From use cases to system implementation: statechart based co-design

This paper proposes a methodology for embedded systems co-design, based on statechart models. The process starts with grabbing the system functionalities through use cases. A set of procedures addressing the implementation of statechart models is presented. The main goal of this set of procedures is to lift the structuring mechanisms presented in statecharts to the top level. In this sense, the complexity of statechart implementation will be similar to the complexity of communicating concurrent state machines and the platforms selected to support implementation will not need to have specific capabilities to directly support the structuring mechanisms of Harels statecharts. As a consequence, full direct implementation of statecharts is possible considering different types of implementation platforms, ranging from hardware-centric or software-centric to hardware-software partitioning through codesign techniques.

Behavioral Modeling for Embedded Systems and Technologies: Applications for Design and Implementation

The development of embedded systems offers a higher degree of abstraction, crucial to tackling the growing complexity and usage of model-driven approaches. Behavioral Modeling for Embedded Systems and Technologies: Applications for Design and Implementation provides an overview of innovative behavior models currently used for developing embedded systems, accentuating graphical and visual notations. This dynamic compilation presents an authoritative reference collection to the most significant models of computation currently in use for embedded systems design.

Optimizing urban traffic flow using Genetic Algorithm with Petri net analysis as fitness function

This paper describes a new methodology adopted for urban traffic stream optimization. By using Petri net analysis as fitness function of a Genetic Algorithm, an entire urban road network is controlled in real time. With the advent of new technologies that have been published, particularly focusing on communications among vehicles and roads infrastructures, we consider that vehicles can provide their positions and their destinations to a central server so that it is able to calculate the best route for one of them. Our tests concentrate on comparisons between the proposed approach and other algorithms that are currently used for the same purpose, being possible to conclude that our algorithm optimizes traffic in a relevant manner.