Over the past few years, the teaching of industrial robotics associated with hands on practice has become an indispensable methodology for the subject. However, a majority of the robots applicable for the undergraduate or graduate levels are very expensive or have a closed hardware and software architecture. This restricts content exploration by the students in order to understand the matters related to robotics. In this article, an educational experience related to robotic education is described. It involves the design and development of an robot manipulator with four degrees of freedom. In addition, the activities in which the students participated during the execution of this work are presented. The robot developed could be an ideal platform for the research and teaching of robotics.

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On this work, a device was made in order to help the visualization by the student of a PID temperature control and thus fix the concepts learned in the classroom. This device was built primarily with a PIC18F4550 microcontroller, a mini cooler from a PC, a heat resistor, LM35 temperature sensors, liquid crystal display, USB connector, transistors, LEDs, potentiometers, resistors and capacitors. The USB connection is responsible for recording the microcontroller firmware (bootloader mode), for interfacing with a supervisory software, and to supply the system. The heat resistor provides heat to the system. On the other hand, the cooler has the function of removing heat from the system. The liquid crystal display helps the student to check the temperature, the constants of the controller (Kp, Ki and Kd) and the set point temperature or the cooler voltage. The potentiometers provide the option to run the system in open loop, that is, they serve to make the control of the heat supplied by the heat resistor and the cooler voltage manually. Both the heat resistor and the cooler are controlled via transistors switched by PWMs (Pulse Wide Modulation). A computer program was developed in C Sharp language to display the temperature over time measured by the sensors. The program also is used to adjust the constants Kp, Ki and Kd of the controller and the temperature set point. The microcontroller firmware allows the system to operate in both open and closed loop modes. This work allows the student to learn in practice the control actions when the controller parameters are changed, contributing to improve the acknowledgment of Control Engineering.

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This work proposes a new methodology for the detection of discontinuities in the weld bead applied in Shielded Metal Arc Welding (SMAW) processes. The detection system is based on two sensors—a microphone and piezoelectric—that acquire acoustic emissions generated during the welding. The feature vectors extracted from the sensor dataset are used to construct classifier models. The approaches based on Artificial Neural Network (ANN) and Support Vector Machine (SVM) classifiers are able to identify with a high accuracy the three proposed weld bead classes: desirable weld bead, shrinkage cavity and burn through discontinuities. Experimental results illustrate the system’s high accuracy, greater than 90% for each class. A novel Hierarchical Support Vector Machine (HSVM) structure is proposed to make feasible the use of this system in industrial environments. This approach presented 96.6% overall accuracy. Given the simplicity of the equipment involved, this system can be applied in the metal transformation industries.

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Abstract    Nowadays, dropping out of engineering courses practically occurs in all universities of the world. Over the past few years, active learning has been recognized by the educational community as the most effective learning method. In this paper we will discuss the educational experience associated with the design and development of a low-cost robot manipulator with six degrees of freedom to motivate the students of Control and Automation Engineering during a semester of Industrial Robotics subject. In addition, the activities in which the students participated during the execution of this work are presented. The robot developed could be used as a platform for the research and teaching of robotics.Keywords    Fixed robot manipulator, education, kinematics.Resumo    Hoje em dia, a evasão dos cursos de engenharia ocorre praticamente em todas as universidades do mundo. Ao longo dos últimos anos, a aprendizagem ativa tem sido reconhecida pela comunidade educacional como o método de aprendizagem mais eficaz. Neste artigo vamos discutir a experiência educacional associada à concepção e desenvolvimento de um robô manipulador de baixo custo com seis graus de liberdade para motivar os alunos de Engenharia de Controle e Automação, durante um semestre da disciplina de Elementos de Robótica. Além disso, são apresentadas as atividades efetuadas pelos alunos durante a execução do trabalho. O robô desenvolvido pode ser utilizado como uma plataforma para pesquisa e ensino de robótica. Palavras-chave   Robô manipulador fixo, educação, cinemática. IntroduçãoA robótica é um campo relativamente novo da tecnologia moderna que cruza as fronteiras tradicionais de engenharia. De acordo com Spong et al. (2005), a robótica envolve o estudo da engenharia elétrica, engenharia mecânica, engenharia industrial e de sistemas, ciência da computação, economia e matemática. Devido à natureza multidisciplinar desse campo, o ensino de robótica é mais efetivo quando conceitos teóricos são associados a experimentos tangíveis. Fazer essa associação tornar-se efetiva requer uma maneira pragmática de aplicação do material tradicional de robótica em trabalhos de laboratórios motivadores (Wood, 2008).Nos últimos anos, tem se tornado cada vez mais comum o uso de robôs como plataformas experimentais nas universidades e nos institutos de pesquisa. Entretanto, a maioria dos sistemas disponíveis é destinada à robótica móvel e há poucas empresas que desenvolvem robôs manipuladores para cursos de robótica industrial. No catálogo da Quanser (2013) existem disponíveis três modelos de robôs, sendo dois em cadeia cinemática fechada (o Hexapod e o robô planar de 2 graus de liberdade -GDL) e um em cadeia cinemática aberta (Omni Bundle). Como os sistemas da Quanser são caros para as universidades dos países em desenvolvimento, Galvan et al. (2006) propôs o uso do LEGO® MINDSTORMS® devido ao seu custo acessível, permitindo aos alunos adquirir experiência no projeto cinemático de robôs manipuladores fixos. Embora tenha sido um esforço no sentido d...

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