Incipient faults of gears and rolling bearings in rotating machineries are very difficult to identify using traditional envelope analysis methods.To address this challenge,this paper proposes an effective local spectr...Incipient faults of gears and rolling bearings in rotating machineries are very difficult to identify using traditional envelope analysis methods.To address this challenge,this paper proposes an effective local spectrum enhancement‐based diagnostic method that can identify weak fault frequencies in the original complicated raw signals.For this purpose,a traversal frequency band segmentation technique is first proposed for dividing the raw signal into a series of subfrequency bands.Then,the proposed synthetic quantitative index is constructed for selecting the most informative local frequency band(ILFB)containing fault features from the divided subfrequency bands.Furthermore,an improved grasshopper optimization algorithmbased stochastic resonance(SR)system is developed for enhancing weak fault features contained in the selected most ILFB with less computation cost.Finally,the enhanced weak fault frequencies are extracted from the output of the SR system using a common spectrum analysis.Two experiments on a laboratory planetary gearbox and an open bearing data set are used to verify the effectuality of the proposed method.The diagnostic results demonstrate that the proposed method can identify incipient faults of gears and bearings in an effective and accurate manner.Furthermore,the advantages of the proposed method are highlighted by comparison with other methods.展开更多
The receptor derived from the diethoxycarbonyl glycoluril was synthesized and characterized by IR,^(1)H NMR,MS techniques and X-ray single crystal analysis.Single crystal X-ray diffraction reveals that the receptor re...The receptor derived from the diethoxycarbonyl glycoluril was synthesized and characterized by IR,^(1)H NMR,MS techniques and X-ray single crystal analysis.Single crystal X-ray diffraction reveals that the receptor remains monomeric because of its bulky t-Bu groups on the side walls.Its unique binding properties for aromatic amides were studied through ^(1)H NMR and IR techniques.展开更多
基金sponsored by the National Natural Science Foundation of China(No.51875105).
文摘Incipient faults of gears and rolling bearings in rotating machineries are very difficult to identify using traditional envelope analysis methods.To address this challenge,this paper proposes an effective local spectrum enhancement‐based diagnostic method that can identify weak fault frequencies in the original complicated raw signals.For this purpose,a traversal frequency band segmentation technique is first proposed for dividing the raw signal into a series of subfrequency bands.Then,the proposed synthetic quantitative index is constructed for selecting the most informative local frequency band(ILFB)containing fault features from the divided subfrequency bands.Furthermore,an improved grasshopper optimization algorithmbased stochastic resonance(SR)system is developed for enhancing weak fault features contained in the selected most ILFB with less computation cost.Finally,the enhanced weak fault frequencies are extracted from the output of the SR system using a common spectrum analysis.Two experiments on a laboratory planetary gearbox and an open bearing data set are used to verify the effectuality of the proposed method.The diagnostic results demonstrate that the proposed method can identify incipient faults of gears and bearings in an effective and accurate manner.Furthermore,the advantages of the proposed method are highlighted by comparison with other methods.
基金This work was supported by the Hubei University of Technology,Science and Technology Department of Hubei Province(No.ZRY0981)the National Natural Science Foundation of China(No.21272086).
文摘The receptor derived from the diethoxycarbonyl glycoluril was synthesized and characterized by IR,^(1)H NMR,MS techniques and X-ray single crystal analysis.Single crystal X-ray diffraction reveals that the receptor remains monomeric because of its bulky t-Bu groups on the side walls.Its unique binding properties for aromatic amides were studied through ^(1)H NMR and IR techniques.
