In order to maintain vibration performances within the limits of the design, a vibration-based feature extraction method for dynamic characteristic using empirical mode decomposition （EMD） and wavelet analysis was p...In order to maintain vibration performances within the limits of the design, a vibration-based feature extraction method for dynamic characteristic using empirical mode decomposition （EMD） and wavelet analysis was proposed. The proposed method was verified experimentally and numerically by implementing the scheme on engine block. In the implementation process, the following steps were identified to be important： 1） EMD technique in order to solve the feature extraction of vibration signals; 2） Vibration measurement for the purpose of confirming the structural weak regions of engine block in experiment; 3） Finite element modeling for the purpose of determining dynamic characteristic in time region and frequency region to affirm the comparability of response character corresponding to improvement schemes; 4） Adopting a feature index oflMF for structural improvement based on EMD and wavelet analysis. The obtained results show that IMF of signal is more sensitive to response character corresponding to improvement schemes. Finally, examination of the results confirms that the proposed vibration-based feature extraction method is very robust, and focuses on the relative merits of modification and full-scale structural optimization of engine, together with the creation of new low-vibration designs.展开更多
研究了船舶螺旋桨噪声和轴系噪声的噪声包络调制检测(detection of envelope modulation on noise, DEMON)谱的轴频线谱相位特性,提出了一种新的船舶目标特征即船舶螺旋桨噪声与轴系噪声轴频线谱之间的相位差。通过对船舶辐射噪声中螺...研究了船舶螺旋桨噪声和轴系噪声的噪声包络调制检测(detection of envelope modulation on noise, DEMON)谱的轴频线谱相位特性,提出了一种新的船舶目标特征即船舶螺旋桨噪声与轴系噪声轴频线谱之间的相位差。通过对船舶辐射噪声中螺旋桨噪声和轴系噪声轴频线谱相位的分析,指出二者相位存在一个较稳定的相位差。通过建模和仿真验证了相位差提取的可行性,并据此提出一种船舶螺旋桨噪声与轴系噪声的轴频线谱相位差特征提取方法。利用文章提出的特征提取方法,对实验中获取的船舶辐射噪声数据进行相位差特征提取,研究了在不同航速和相同型号不同个体目标船舶两种条件下,相位差特征的稳定性和可分性。结果表明在一定的时间窗内,相位差特征在不同航速下具有较好的稳定性,在相同型号船舶间具有较好的可分性,可以为个体船舶目标识别提供参考。展开更多
基金Project(50975192) supported by the National Natural Science Foundation of ChinaProject(10YFJZJC14100) supported by Tianjin Municipal Natural Science Foundation of China
文摘In order to maintain vibration performances within the limits of the design, a vibration-based feature extraction method for dynamic characteristic using empirical mode decomposition （EMD） and wavelet analysis was proposed. The proposed method was verified experimentally and numerically by implementing the scheme on engine block. In the implementation process, the following steps were identified to be important： 1） EMD technique in order to solve the feature extraction of vibration signals; 2） Vibration measurement for the purpose of confirming the structural weak regions of engine block in experiment; 3） Finite element modeling for the purpose of determining dynamic characteristic in time region and frequency region to affirm the comparability of response character corresponding to improvement schemes; 4） Adopting a feature index oflMF for structural improvement based on EMD and wavelet analysis. The obtained results show that IMF of signal is more sensitive to response character corresponding to improvement schemes. Finally, examination of the results confirms that the proposed vibration-based feature extraction method is very robust, and focuses on the relative merits of modification and full-scale structural optimization of engine, together with the creation of new low-vibration designs.
文摘研究了船舶螺旋桨噪声和轴系噪声的噪声包络调制检测(detection of envelope modulation on noise, DEMON)谱的轴频线谱相位特性,提出了一种新的船舶目标特征即船舶螺旋桨噪声与轴系噪声轴频线谱之间的相位差。通过对船舶辐射噪声中螺旋桨噪声和轴系噪声轴频线谱相位的分析,指出二者相位存在一个较稳定的相位差。通过建模和仿真验证了相位差提取的可行性,并据此提出一种船舶螺旋桨噪声与轴系噪声的轴频线谱相位差特征提取方法。利用文章提出的特征提取方法,对实验中获取的船舶辐射噪声数据进行相位差特征提取,研究了在不同航速和相同型号不同个体目标船舶两种条件下,相位差特征的稳定性和可分性。结果表明在一定的时间窗内,相位差特征在不同航速下具有较好的稳定性,在相同型号船舶间具有较好的可分性,可以为个体船舶目标识别提供参考。
