407 O_2 センサ信号の FFT 解析による自動車用触媒装置の劣化診断

元データ 2002-03-14 社団法人日本機械学会


The object of this study is to investigate an on-board diagnostic method to detect the deterioration of a three-way catalyst under actual vehicle operating conditions. For this purpose, we analyzed the signal waves generated by two oxygen sensors placed on upstream and downstream positions of the catalytic converter. Transient operation experiments were carried out using engine dynamometer system equipped with a fresh catalyst or an aged catalyst. The signal data of two oxygen sensors were processed by the fast Fourier transformation method. As a result, we found that the power spectrum of the signal waves can be the index of catalyst deterioration degree. Furthermore, it was confirmed that the difference between the power spectrum of the upstream oxygen sensor signal and one of the downstream oxygen sensor signal, which was named the Δ power, is effective index for the detection of deteriorated catalyst under acceleration conditions.


野田 明 独立行政法人交通安全環境研究所
山本 敏朗 独立行政法人交通安全環境研究所