Análise experimental do ensaio veicular de imunidade a campos eletromagnéticos radiados em câmara semi-anecóica de pequeno porte

Abstract

A few years ago, the self-driven vehicles were essentially provided withmechanical systems, used to perform many type of control functions.In the last decades, the development of the technology of the information,the electro-electronic systems of command, control and servomechanisms endowed the vehicles with a huge amount of functions that reflected in a increase in performance, reduction in the emissions of pollutant, autonomy and comfort. As a consequence of that technological progress, there was a great increase in the occupation of the electromagnetic spectrum emitted by vehicles. The electromagnetic compatibility is the science that looks for to organize the occupation of the electromagnetic spectrum, in a way to guarantee the operation of the vehicles facing the large and growing use of electronic systems in our civilization. Nowadays, the elementary concept used to guarantee the electromagnetic compatibility of a system or equipment is the verification of the maxima levels of electromagnetic emissions generated by the own equipment, and all the electric equipments that coexist in that same environment, and the minimum immunity or susceptibility level to electromagnetic disturbances. Thus, when there is a margin between emission and immunity levels, it will exist at least theoretically a numerical limit that guarantees the electromagnetic compatibility between the equipments and systems installed in a common environment. FIAT Autom´oveis S/A company, in conjunction with Brazilian universities, international technical institutes and the National Council of Scientific and Technological Development (CNPq), implanted a research project for the creation of national expertise and improvement of its laboratorial facilities on electromagnetic compatibility issues.The project FIAT-CNPq 550525-2003/3 entitled Correlation of Electromagnetic Fields Measurements Irradiated in Semi-anechoic Chambers of Full and Reduced Dimensions, proposes the accomplishment of electromagnetic fields immunity tests of vehicles using a reduced size semi-anechoic chamber. In this work, it will be presented, a set of experiments performed in three different electromagnetic atmospheres (semi-anechoic chamber of small load,semi-anechoic chamber of great load and OATS - (Open Area Test Site)that were carried out as an indispensable part of the research project justmentioned. The goal here is to demonstrate the capacity of scientific and methodological organization to construct knowledge starting from empirical experimentation, as well as to supply data for the verification of the reliability of the solution of electromagnetic fields problems modeled by the computational tool HFSS High Frequency Structure Simulator, and also contributing to the virtual validation of the research project.From the analysis of the data collected in the experiments, we hope tocontribute towards the possibility to perform electromagnetic fields immunity tests of on-board electronic systems, using a semi-anechoic chamber of small load. It is expected that those results, added to the contributions of the other members of the team, can foment a technological product for immediate use in the local automobile plant aiming the development and experimental and virtual validation of projects through the creation of a methodology of experimental tests that guarantee, respecting the effective international criteria, the quality of their products.