Trabalho de Conclusão de Curso de Graduação
Análise do gráfico de controle CUSUM para a filtragem de sinais utilizando coeficientes wavelet
Fecha
2018Autor
Guterres, Tiarles da Rocha Moralles
Institución
Resumen
The Fourier transform has long been one of the few available signal processing options.
However, in the last decades different types of transform have become efficient alternatives
for filtering, compression and other types of signal analysis. In this work, the Daubechies
wavelet transform will be one of the tools for filtering signals with different noise levels. In
a signal corrupted by additive noise, the high frequency components are the most compromised,
and they require a more rigorous treatment for a more faithful reconstruction of
the ideal signal. The present work investigates the feasibility of using cumulative sum control
chart (CUSUM) as a technique to determine the cut-off thresholds for the truncation
process of the wavelet coefficients, resulting from the wavelet transform. The proposed
methodology will be validated through numerical simulations for different signals and different
associated noise levels, called scenarios. In the end, was finded a configuration that
adapts in the major of this scenarios, showing the competivity of CUSUM chart for signal
filtering, using wavelet coefficients, to analise and compare your efficiency with classic algorithms
for signal statistical filtering.