Automatic quality monitoring of resistance spot welding process.

Neste trabalho é proposto e avaliado um sistema capaz de monitorar de forma não-destrutiva, não-invasiva, individualizada, em tempo real e em ambiente industrial, a qualidade de soldas produzidas através do processo de solda a ponto resistiva (PSPR), diminuindo ou mesmo eliminando a necessidade dos testes destrutivos, reduzindo custos e aumentando a produtividade. Este sistema de monitoramento é baseado em reconhecimento de padrões, através de redes neurais artificiais do tipo Perceptron multicamadas. As características do processo usadas na entrada da rede neural são os parâmetros ajustados de um modelo matemático parametrizável, criado com o intuito de refletir as propriedades fundamentais da grandeza do processo passível de ser medida e monitorada em tempo real, neste caso a curva de resistência dinâmica. Estes valores ajustados dos parâmetros do modelo são ainda relacionados com os estados ou condições do processo, de forma a permitir a identificação de possíveis causas para falhas detectadas. Para avaliar e validar este sistema, usaram-se dados reais obtidos na produção de lotes de contatos elétricos através do PSPR. Os resultados obtidos mostram que o sistema proposto é capaz de monitorar satisfatoriamente a qualidade do processo investigado, com erro médio quadrático de 16,5 N, na estimação da força de cisalhamento suportada pela solda, no pior caso. O sistema também mostrou-se capaz de identificar a causa para soldas cuja qualidade estimada foi considerada baixa, com taxa de acerto acima de 97%. Esse sistema proposto não contém especificidades de nenhum processo produtivo e, portanto, tem potencial para ser aplicado em outros processos, além do PSPR.In this work a non-destructive, non-invasive, individualized, real-time system has been proposed and evaluated to monitor the quality of welds produced by resistance spot welding process (RSWP) in industrial environment. This system is able to reduce or eliminate the need for destructive tests, leading to cost reduction and increase in productivity. This monitoring system is based on pattern recognition with multilayer Perceptron artificial neural networks (ANN). The process features used as input of the ANN are adjusted parameters of a parametric mathematic model created to reflect the fundamental properties of the process variable that is measurable in real time, in this work, the dynamic resistance curve. The adjustable model parameters values are related with the process states and conditions, so that it is possible to identify the causes for detected bad quality. In order to evaluate and validate the proposed system, real data obtained in the production of electric contacts by RSWP were used. The results show that the proposed system is capable of properly monitoring the investigated process quality, with a mean square error of 16.5 N, in the estimation of the shear force supported by the weld, in the worst case. The system proved to be able to identify the causes for detected bad quality, with a reliability of more than 97%. The proposed system contains no productive process specificities, and, therefore, can be applied to other processes

Improvement and evaluation of the MS2SV for mixed systems design described in abstraction high level

This paper presents an important improvement of the MS2SV tool. The MS2SV performs the translation of mixed systems developed in MATLAB / Simulink for a structural or behavioral description in VHDL-AMS. Previously, the MS2SV translated only models of the LIB MS2SV library. This improvement allows designer to create your own library to translation. As case study was used a rudder controller employed in an unmanned aerial vehicle. For comparison with the original model the VHDL-AMS code obtained by the translation was simulated in SystemVision environment. The results proved the efficiency of the tool using the translation improvement proposed in this paper

Computational tool to support design of DAC Converter model AD7528 with the object code in XML

Based on literature review, electronic systems design employ largely top-down methodology. The top-down methodology is vital for success in the synthesis and implementation of electronic systems. In this context, this paper presents a new computational tool, named BD2XML, to support electronic systems design. From a block diagram system of mixed-signal is generated object code in XML markup language. XML language is interesting because it has great flexibility and readability. The BD2XML was developed with object-oriented paradigm. It was used the AD7528 converter modeled in MATLAB / Simulink as a case study. The MATLAB / Simulink was chosen as a target due to its wide dissemination in academia and industry. From this case study it is possible to demonstrate the functionality of the BD2XML and make it a reflection on the design challenges. Therefore, an automatic tool for electronic systems design reduces the time and costs of the design

A utilização de kits de robótica educacional como recurso pedagógico

This work carried out under the extension FEG ROBÓTICA’s project has the purpose of showing the use of educational robotics kits, as a teaching instrument for children, by electing characteristics and showing robotics as a tool to the process of technologic knowledge transmission. The concepts of robotics shown were worked as workshops, with children from 6 to 9 years old, held in the Casa do Puríssimo Coração de Maria, a religious and civil association with confessional, with educational, bountiful, social and nonprofit characteristics.Este trabalho realizado no âmbito do projeto deextensão FEG ROBÓTICA tem como objetivorelatar a utilização de kits de robótica educacional,como instrumento de ensino para crianças,apresentando suas características e mostrando arobótica como ferramenta facilitadora do processode transmissão de conhecimento tecnológico.Os conceitos de robótica apresentados foramtrabalhados em forma de oficinas, com crianças de06 a 09 anos, na Casa do Puríssimo Coração deMaria, uma associação civil e religiosa, de caráterconfessional, educacional, beneficente e deassistência social, sem fins econômicos elucrativos