关键词: OPAX 方法；经验模态分解；阈值降噪；振动源识别；改进 OPAX 方法；电动汽车

Abstract: The vibration signal required by the extended transfer path analysis (OPAX) method is the working condition data of the vehicle, but the noise signal is mixed in the experiment, which has a certain impact on the analysis and identification accuracy. To solve this problem, the OPAX method is improved by using empirical mode decomposition threshold noise reduction. Taking an electric vehicle as the research object, the load parametric identification is carried out by using the frequency response function and working condition data, and then the vibration source in the electric vehicle is identified. The results show that under the uniform acceleration condition, the energy absorption effect of the rear mount z direction on the vibration of motor, reducer and other excitation sources is poor. The fitting response of the improved OPAX method is compared with that of the OPAX method, It is found that the fitting response of the improved OPAX method is more consistent with the measured response, which shows that the improved OPAX method can more accurately identify the vibration sources affecting the vibration in the vehicle.

Key words: OPAX method; Empirical mode decomposition; Threshold noise reduction; Identification of vibration source; Improved OPAX method; Electric vehicle