Extraction of high contributing vibration mode to the loudness of industrial sewing machine radiated noise using operational TPA

Abstract

In this study, we analyzed the factor increasing the loudness of an industrial sewing machine radiated noise using operational transfer path analysis (OTPA). At first, radiated noise of a sewing machine was recorded and the loudness was calculated to evaluate the noise level considering human auditory perception characteristics. The reduction target frequency band was then determined according to the specific loudness. Subsequently, the vibration acceleration at around the machine was measured and vibration mode analysis was conducted to understand the vibration characteristics of the machine and the factor increasing the noise at the target frequency band. In addition, OTPA principal component model was applied to the sewing machine to estimate the high contributing vibration mode to the radiated noise at the target frequency band. Finally, the loudness at the target frequency band could be decreased well by applying intensive countermeasure to the obtained high contributing vibration mode by the analyses.