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RISS 인기검색어
- 검색키워드
- 저자 : Lichen Gu (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
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Yan Wang,Lichen Gu,Yuanbo Xu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.3
The bearing fault signal is a kind of weak signal, so it is easy to be submerged by background noise. As such, signature extraction is facing a great challenge; hence, an effective signature extraction method plays an essential role in bearing fault extraction. In this paper, a new method for bearing fault detection based on an alternative analytic energy operator and sparse Bayesian step-filtering (SBSF) was applied. The SBSF technique can remove much background noise from the raw signal and enhance the characteristics related to the bearing fault. Besides, it has also a high calculation efficiency. Afterward, an improved analytic energy operator, the symmetric high-order analytic energy operator (SHO-AEO), which is an enhanced demodulation technique that outperforms the conventional demodulation technique, was applied to detect bearing fault signatures from filtered signals. The proposed energy measure is formed using the original signal, its Hilbert transform, and its high-order derivatives. Unlike traditional energy operators, it includes the information of the real and imaginary parts of the analytic signal. As a demodulation technique, it is also tailored to extract both the amplitude and frequency modulations from the filtered signal. Furthermore, compared with the previous energy operators, it provides better anti-noise capability. Hence, the proposed fault detection method of combining the SHO-AEO and SBSF not only has high computational efficiency but also provides much better noise handling potential. Through simulated and real tests, this proposed method is demonstrated to be robust against various noise levels and to detect the bearing fault signature.
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On-line Measuring Method of Effective Bulk Modulus in Hydraulic System Based on Frequency Analysis
Chen, Yingshu,Wang, Nan,Gu, Lichen Korean Society for Fluid machinery 2018 International journal of fluid machinery and syste Vol.11 No.1
Based on the gas-liquid phase flow theory, an indirect method is proposed to on-line measure the effective bulk modulus by constructing the mathematical model which reveals the relationships of the effective bulk modulus, bubble volume fraction, pressure and natural frequency. The natural frequency of hydraulic fluid is a key parameter for measuring effective bulk modulus utilizing the model, so it is online measured by the proposed pseudo-excitation method. The frequency response function is obtained by solving the amplitude spectrum functions of pseudo-excitation signal and the response signal, and the natural frequency is obtained. The numerical simulation and experiment are carried out, and we can deduce from the analysis of simulation and experimental results that the effective bulk modulus in hydraulic system can be easily online measured by the proposed indirect method.
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On-line Measuring Method of Effective Bulk Modulus in Hydraulic System Based on Frequency Analysis
Yingshu Chen,Nan Wang,Lichen Gu 한국유체기계학회 2018 International journal of fluid machinery and syste Vol.11 No.1
Based on the gas-liquid phase flow theory, an indirect method is proposed to on-line measure the effective bulk modulus by constructing the mathematical model which reveals the relationships of the effective bulk modulus, bubble volume fraction, pressure and natural frequency. The natural frequency of hydraulic fluid is a key parameter for measuring effective bulk modulus utilizing the model, so it is online measured by the proposed pseudo-excitation method. The frequency response function is obtained by solving the amplitude spectrum functions of pseudo-excitation signal and the response signal, and the natural frequency is obtained. The numerical simulation and experiment are carried out, and we can deduce from the analysis of simulation and experimental results that the effective bulk modulus in hydraulic system can be easily online measured by the proposed indirect method.
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