車内音のみを用いた自動車騒音寄与分離手法に関する基礎検討

抄録

In this study, to separate contributions of vehicle interior noise using only response point signals, we tried to apply independent component analysis (ICA). To verify and consider applicability of ICA in contribution separation, we used engine and wind noises and mixed them in three conditions (synchrony / asynchrony / asynchrony with frequency characteristic), and carried out contribution separation using ICA to these mixed response signals. As results, the contribution was calculated accurately using time domain ICA in case the source signals were mixed synchrony, but the accuracy of this method became low when the signals were mixed asynchrony. However, frequency domain ICA could separate the contributions correctly. In case of the source signals were mixed asynchrony with frequency characteristic, permutation problem, in which the calculated contribution signal does not have the continuity among frequency, occurred. Then, we considered a permutation solution method using non-Gaussian characteristic of each calculated contributions. By applying the method, the contribution could be calculated accurately. Consequently, the proposed method using frequency domain ICA with the permutation solution was clarified to have an ability which separates contributions of vehicle interior noise using only response point signals.