| 摘 要: 针对旋转机械多工况下,振动子序列起始点位置(初相位)不同导致序列无法准确对齐的问题,提出了一种基于改进变分模态提取的振动子序列对齐方法。使用短时傅里叶变换确定初始中心频率,通过映射关系计算惩罚因子,使得变分模态提取可以自适应地获取不同工况下振动子序列中的所需模态。对所需模态进行曲线拟合计算出初相位值,并根据相位差对序列进行裁剪,实现序列对齐。实验结果表明,该方法对齐后序列之间的动态时间扭曲(DTW)平均距离减少了64.79%。且相较于对比方法,所提方法的对齐效果更好。 |
| 关键词: 振动子序列 序列对齐 变分模态提取 短时傅里叶变换 动态时间扭曲 |
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中图分类号: TP391
文献标识码: A
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| Vibration Subsequence Alignment Method Based on Improved Variational Mode Extraction |
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FENG Jiahao1, PANG Aiping1, YANG Wen2
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(1.College of Electrical Engineering, Guizhou University, Guiyang 550025, China;
2.Xichang Satellite Launch Center, Xichang 615600, China)
fengjh2000@126.com; appang@gzu.edu.cn; whutyw@126.com
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| Abstract: To address the issue of inaccurate alignment of vibration subsequences caused by varying initial phase positions under multiple operating conditions of rotating machinery, a vibration subsequence alignment method based on improved variational mode extraction is proposed. This method uses the shor-t time Fourier transform to determine the initial center frequency and calculates the penalty factor through a mapping relationship, enabling variational mode extraction to adaptively obtain the required modes in vibration subsequences under different operating conditions. The initial phase value is then calculated by performing curve fitting on the required modes, and the sequences are trimmed based on the phase difference to achieve alignment. Experimental results show that the average Dynamic Time Warping(DTW) distance between sequences after alignment is reduced by 64.79% . Moreover, compared to comparison methods,the proposed method achieves better alignment performance. |
| Keywords: vibration subsequence sequence alignment variational mode extraction shor-t time Fourier transform dynamic time warping |
