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基于集合经验模式分解和K-奇异值分解字典学习的滚动轴承故障诊断 被引量:7
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作者 李继猛 李铭 +3 位作者 姚希峰 王慧 于青文 王向东 《计量学报》 CSCD 北大核心 2020年第10期1260-1266,共7页
针对经典K-奇异值分解算法构造的字典中原子形态受噪声、谐波干扰影响,进而降低冲击故障特征提取精度的问题,提出了基于集合经验模式分解和K-奇异值分解字典学习的冲击特征提取方法。该方法首先利用集合经验模式分解与Hurst指数对振动... 针对经典K-奇异值分解算法构造的字典中原子形态受噪声、谐波干扰影响,进而降低冲击故障特征提取精度的问题,提出了基于集合经验模式分解和K-奇异值分解字典学习的冲击特征提取方法。该方法首先利用集合经验模式分解与Hurst指数对振动信号进行预处理,剔除谐波干扰;其次,利用经典K-奇异值分解算法和预处理信号构造超完备字典;然后,利用K-均值聚类算法对字典中的原子进行筛选;最后,利用正交匹配追踪算法实现冲击故障特征的稀疏表示。实验分析和工程应用验证了所提方法的有效性和实用性。 展开更多
关键词 计量学 滚动轴承 故障诊断 稀疏表示 集合经验模式分解 k-奇异值分解字典学习 k-聚类
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基于子窗口字典学习的机织物纹理表征及应用
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作者 吴莹 李冠志 +1 位作者 占竹 汪军 《东华大学学报(自然科学版)》 CAS 北大核心 2019年第3期375-380,共6页
为了提高机织物纹理表征算法的稳定性,提出了以子窗口字典学习表征机织物纹理的算法。将整幅图像划分为多个子窗口样本,并将子窗口样本展成列向量,所有的列向量联合组成灰度数据矩阵。选定离散余弦变换(discrete cosine transform,DCT)... 为了提高机织物纹理表征算法的稳定性,提出了以子窗口字典学习表征机织物纹理的算法。将整幅图像划分为多个子窗口样本,并将子窗口样本展成列向量,所有的列向量联合组成灰度数据矩阵。选定离散余弦变换(discrete cosine transform,DCT)作为初始字典,对子窗口样本矩阵进行字典学习,最终得到了稳定的学习字典。选用均方根误差作为评价指标,对字典个数和子窗口大小进行优化。结果表明,应用学习得到的字典,不仅能近似重构机织物纹理样本图像,而且能在无监督的条件下自动识别织物的瑕疵。 展开更多
关键词 机织物纹理表征 字典学习 k-奇异值分解字典 瑕疵检测
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Impulsive component extraction using shift-invariant dictionary learning and its application to gear-box bearing early fault diagnosis 被引量:3
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作者 ZHANG Zhao-heng DING Jian-ming +1 位作者 WU Chao LIN Jian-hui 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第4期824-838,共15页
The impulsive components induced by bearing faults are key features for assessing gear-box bearing faults.However,because of heavy background noise and the interferences of other vibrations,it is difficult to extract ... The impulsive components induced by bearing faults are key features for assessing gear-box bearing faults.However,because of heavy background noise and the interferences of other vibrations,it is difficult to extract these impulsive components caused by faults,particularly early faults,from the measured vibration signals.To capture the high-level structure of impulsive components embedded in measured vibration signals,a dictionary learning method called shift-invariant K-means singular value decomposition(SI-K-SVD)dictionary learning is used to detect the early faults of gear-box bearings.Although SI-K-SVD is more flexible and adaptable than existing methods,the improper selection of two SI-K-SVD-related parameters,namely,the number of iterations and the pattern lengths,has an adverse influence on fault detection performance.Therefore,the sparsity of the envelope spectrum(SES)and the kurtosis of the envelope spectrum(KES)are used to select these two key parameters,respectively.SI-K-SVD with the two selected optimal parameter values,referred to as optimal parameter SI-K-SVD(OP-SI-K-SVD),is proposed to detect gear-box bearing faults.The proposed method is verified by both simulations and an experiment.Compared to the state-of-the-art methods,namely,empirical model decomposition,wavelet transform and K-SVD,OP-SI-K-SVD has better performance in diagnosing the early faults of a gear-box bearing. 展开更多
关键词 gear-box bearing fault diagnosis shift-invariant k-means singular value decomposition impulsive component extraction
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