Carlos Machado

Omni-directional catadioptric vision for soccer robots

Abstract This paper describes the design of a multi-part mirror catadioptric vision system and its use for self-localization and detection of relevant objects in soccer robots. The mirror and associated algorithms have been used in robots participating in the middle-size league of RoboCup — The World Cup of Soccer Robots.

The Cultural Metaphor Revisited Exploring Dimensions, Complexities and Paradoxes through the Portuguese Fado

This article develops the Fado, a unique folk music form, as a cultural metaphor for Portugal. This process illustrates the value of the metaphoric methodology as a means to deepen understanding of national cultures. Findings yield three major insights. First, the Fado metaphor provides a rich illustration of the Portuguese cultural mindset, embraced by the population as an enduring representation of national identity. Second, the Fado metaphor enables us to incorporate cultural characteristics represented by several traditional dimensions frameworks to elucidate our understanding of significant cultural factors. Third, the cultural metaphor method breaks through the constraints imposed by dimensional research and enables us to understand intra-cultural variations in attitudes, behaviors, and values. Particularly, the identification of cultural paradoxes constitutes a major contribution of this work. Paradoxes described here capture the dialectic nature of Portuguese culture in the areas of Fatalism and Perseverance; Large Power Distance and Equality; Uncertainty Avoidance and Risk-Taking; Group Orientation and Isolation; and Private and Shared Space. Cet article fait du Fado, une forme musicale unique, une métaphore culturelle du Portugal. Ce processus illustre la valeur de la méthodologie métaphorique comme moyen d’enrichir la compréhension des cultures nationales. Il y a trois résultats intéressants. Tout d’abord, la métaphore du Fado illustre richement la mentalité culturelle portugaise. En un second lieu, cette métaphore nous permet d’intégrer des caractéristiques culturelles représentées par plusieurs cadres de dimensions traditionnelles afin d’élucider notre compréhension de facteurs culturels signifiants. Et enfin, la méthode permet de sortir des contraintes imposées par la recherche dimensionnelle et nous permet de comprendre les variations inter-culturelles dans les attitudes, les comportements et les valeurs. Plus particulièrement, l’identification des paradoxes culturels constitue une contribution majeure de ce travail. Les paradoxes décrits ici saisissent la nature dialectique de la culture portugaise dans les domaines du fatalisme et de la persévérance; de la distance avec le pouvoir et de l’égalité; de l’évitement de l’incertitude et de la prise de risque; de l’orientation du groupe et de l’isolation ; de l’espace privé et de l’espace partagé.

Sensors, Actuators and Communicators When Building a Ubiquitous Computing System

Ubiquitous computing systems are characterized by a collection of devices working together autonomically. Due to the fact that these systems are composed by a high number of devices, several problems arise. These problems range from management, compatibility to economic costs. In this paper some essential characteristics of sensors and actuators are proposed in order to allow them to be included in a ubiquitous computing system. It is also presented a way to build ubiquitous systems by integration of several independent systems, creating one system with new features that could not be found in the original ubiquitous systems.

MINHO Robot Football Team for 2001

This paper describes an autonomous robot football team. The work is being carried out since 1998. It describes the hardware used by the robots, the sensory system and interfaces, as well as the game strategy. Data acquisition for the perception level is carried out by the vision system, and the image processing system is described. Two cameras are used requiring sensorial fusion. With this architecture, an attempted is made to make the autonomous robots more real world intelligent. These robots have a kicker with controlled power, which allows passing the ball to a teammate with controlled distance and direction.

Virtual Teamwork: A Product of Globalization Implications for University Education

With globalization, virtual teamwork is becoming the predominant type of labour organization within multinational companies. Empirical studies on this new form of teamwork show that besides requiring specific knowledge, this teamwork requires social skills, as well as media and methodological competencies. Through the Bologna-Process European universities received clear directions to prepare young professionals for the challenges of the future working life by focusing on extra-curricular activities and developing personal key competencies. Accordingly, this essay outlines how to prepare students to work in a virtual team environment by making fundamental reforms to university education. A key element of proposed reforms is the introduction of Collaborative Computer Supported Learning as the leading didactic principle, especially in postgraduate studies.

Virtual Teamwork: A Product of Globalization

With globalization, virtual teamwork is becoming the predominant type of labor organization within multinational companies. Empirical studies on this new form of teamwork show that besides requiring specific knowledge, this teamwork requires social skills, as well as media and methodological competencies. The Bologna-Process has produced, for European universities, a clear framework on how to prepare young professionals for the challenges of their future working lives by focusing on extra-curricular activities and developing personal core competencies. Accordingly, this chapter outlines how to prepare students for work in a virtual team environment, which requires fundamental reforms to university education. A key element of proposed reforms is the introduction of Collaborative Computer Supported Learning as the leading didactic principle, especially in postgraduate studies.

Automatic velocity control in cutting-off machines

Usually, automatic cutting-off machines, of metallic pipes or bars, use constant cutting velocity. This mode of operation, constant cutting velocity combined with different profiles of materials to be cut, causes variable cutting forces to be applied to the saw. As a result, the cutting off machine is generally set for the worst expected conditions, otherwise excessive wear of the saw and machine will occur. Further, traditional cutting-off machines require adjustments to be made in order to automatically detect the completion of a cut. The objective of this project is the study of the application of control algorithms to the process of cutting-off metallic pipes or bars, with variable profiles, implemented in an industrial cutting-off machine, commercially available. The testes algorithms concern real-time cutting control and automatic detection of cut completion. The algorithms are implemented in a low cost programmable logic controller (PLC), allowing its adoption in industrial applications without significant increase on machine cost. All algorithms were developed having in mind safety issues relative to the operation of the cutting machine in order to prevent damage to the machine itself. Also, all process related relevant parameters are monitored on a personal computer using OPC (object linking and embedding-for process control).

Control of baker's yeast fermentation: PID and fuzzy algorithms

A MATLAB/SIMULINK-based simulator was employed for studies concerning the control of bakers yeast fed-batch fermentation. Four control algorithms were implemented and compared: the classical PID control, two discrete versions-modified velocity and position algorithms, and a fuzzy law. The simulation package was seen to be an efficient tool for the simulation and tests of control strategies of the nonlinear process.

Intelligent cutting-off of pipes and bars

Traditionally, automatic cutting-off machines, of metallic pipes or bars, use a constant cutting velocity mode. This mode of operation, constant cutting velocity combined with different profiles of materials to be cut, exposes the cutting saw to variable cutting forces. Therefore, the cutting off machine is usually set for the worst expected conditions, otherwise excessive wear of the saw and machine will occur. Further, traditional cutting-off machines require the adjustment of the position of a limit switch in order to automatically detect when the cut of a piece has been completed. The aim of this paper is to study the application of control algorithms to the process of cutting-off of metallic pipes or bars, with variable profiles implemented in an industrial cutting-off machine, commercially available. The presented algorithm concern real-time cutting control and automatic detection of the cutting end. The algorithms are implemented in a low cost programmable logic controller (PLC), allowing its use in industrial applications without significant increase on machine cost. All algorithms were developed having in mind safety issues relative to the operation of the cutting machine in order to prevent catastrophic failure. Also, all process related relevant parameters are monitored on a personal computer using OPC (object linking and embedding - for process control).

Robot Football Team from Minho University

This paper describes an Autonomous Mobile Robot team which plays football, developed by the Group of Automation and Robotics at the Industrial Electronics department of the University of Minho, in Guimaraes (Portugal). In this competition each team is free to use and/or build all the different electronics, sensory systems, playing algorithms, etc. as far as they cope with the rules imposed by the organisation. Instead of using several different sensors increasing electronics complexity, this team decided to use only one major sensor: a vision system with a small colour camera. All the image processing algorithms were developed from scratch and they consist on the heart of the whole project. This vision system uses an innovative approach: in order to see the whole field, a convex mirror was placed at the top of the robot looking downwards with the video camera looking upwards towards the mirror. This way, the robot can see all around itself with a top view, which means continuous vision of the ball, goals and other robots.