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Time-frequency Feature Extraction Method of the Multi-Source Shock Signal Based on Improved VMD and Bilateral Adaptive Laplace Wavelet

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Chinese Journal of Mechanical Engineering 2023年第2期36卷 166-179页

作者： Nanyang Zhao Jinjie Zhang zhiwei mao Zhinong Jiang He Li Beijing Key Laboratory of High-end Mechanical Equipment Health Monitoring and Self-Recovery Beijing University of Chemical TechnologyBeijing 100029China

Vibration signals have the characteristics of multi-source strong shock coupling and strong noise interference owing to the complex structure of reciprocating ***,it is difficult to extract,analyze,and diagnose mechanical fault *** accurately extract sensitive features from the strong noise interference and unsteady monitoring signals of reciprocating machinery,a study on the time-frequency feature extraction method of multi-source shock signals is *** the characteristics of reciprocating mechanical vibration signals,a targeted optimization method considering the variational modal decomposition(VMD)mode number and second penalty factor is proposed,which completed the adaptive decomposition of coupled *** at the bilateral asymmetric attenuation characteristics of reciprocating mechanical shock signals,a new bilateral adaptive Laplace wavelet(BALW)is established.A search strategy for wavelet local parameters of multi-shock signals is proposed using the harmony search(HS)method.A multi-source shock simulation signal is established,and actual data on the valve fault are obtained through diesel engine fault *** fault recognition rate of the intake and exhaust valve clearance is above 90%and the extraction accuracy of the shock start position is improved by 10°.

关键词： Shock Signal processing Wavelet VMD Fault diagnosis Diesel engine

基于变分时频分解与随机森林的柴油机气门故障诊断方法

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北京化工大学学报（自然科学版） 2024年第4期51卷 99-106页

作者：柯希成刘永豪赵南洋莫航锋茆志伟中核武汉核电运行技术股份有限公司武汉430223 福建福清核电有限公司福清350318 北京化工大学机电工程学院高端机械装备健康监控与自愈化北京市重点实验室北京100029

柴油机气门间隙异常作为常见的柴油机故障,对其进行状态监测和诊断对柴油机的高效正常运行具有重要意义。针对柴油机气门间隙异常典型故障,提出一种基于变分时频分解与随机森林算法的气门故障诊断方法。首先,由于不同气门故障所引起的... 详细信息

柴油机气门间隙异常作为常见的柴油机故障,对其进行状态监测和诊断对柴油机的高效正常运行具有重要意义。针对柴油机气门间隙异常典型故障,提出一种基于变分时频分解与随机森林算法的气门故障诊断方法。首先,由于不同气门故障所引起的冲击信号存在冲击差异,利用变分时频分解方法可以自适应提取冲击信号中的单频率单冲击成分的特点,实现振动信号的分解并进行特征值提取;然后,利用随机森林算法对特征值进行训练;最后,在柴油机试验台上通过调整气门间隙开展模拟试验。实际试验结果表明,所提方法在气门间隙异常故障诊断中的整体准确率为96.42%,验证了所提方法的有效性。

关键词：故障诊断变分时频分解随机森林特征提取气门故障

维普期刊数据库博看期刊

Transcriptome-wide Analysis Of Vernalization Reveals Conserved and Species-specific Mechanisms in Brachypodium

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Journal of Integrative Plant Biology 2013年第8期55卷 696-709页

作者： Qing Huan zhiwei mao Jingyu Zhang Yunyuan Xu Kang Chong Key Laboratory of Plant Molecular Physiology Institute of Botanythe Chinese Academy of Sciences University of Chinese Academy of Sciences the Chinese Academy of Sciences

Several temperate cereals need vernalization to promote flowering. Little, however, is known about the vernalization-memory-related genes, and almost no comparative analysis has been performed. Here, RNA- Seq was used for transcriptome analysis in non-vernalized, vernalized and post-vernalized Brachypodium distachyon （L.） Beauv. seedlings. In total, the expression of 1,665 genes showed significant changes （fold change 〉4） in response to vernalization. Among them, 674 putative vernalization-memory-related genes with a constant response to vernalization were significantly enriched in transcriptional regulation and monooxygenase-mediated biological processes. Comparative analysis of vernalization-memory-related genes with barley demonstrated that the oxidative-stress response was the most conserved pathway between these two plant species. Moreover, Brachypodium preferred to regulate transcription and protein phosphorylation processes, while vernalization-memory-related genes, whose products are cytoplasmic membrane-bound-vesicle-located proteins, were preferred to be regulated in barley. Correlation analysis of the vernalization-related genes with barley revealed that the vernalization mechanism was conserved between these two plant species. In summary, vernalization, including its memory mechanism, is conserved between Brachypodium and barley, although several species-specific features also exist. The data reported here will provide primary resources for subsequent functional research in vernalization.

关键词： Brachypodium comparative analysis RNA-Seq vernalization.

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大功率晶闸管整流器均流测量方法研究

仪表技术 2024年第1期 44-47页

作者：李亚武旭王林森茆智伟中国科学院等离子体物理研究所安徽合肥230031

随着电力电子技术的发展,大功率晶闸管整流器电源单机容量越来越大,其桥臂并联支路晶闸管数量越来越多,对桥臂并联支路的均流系数要求越来越高。介绍了传统的晶闸管整流器均流测量的几种方法并加以比较分析,提出了一种罗氏线圈与配套积... 详细信息

随着电力电子技术的发展,大功率晶闸管整流器电源单机容量越来越大,其桥臂并联支路晶闸管数量越来越多,对桥臂并联支路的均流系数要求越来越高。介绍了传统的晶闸管整流器均流测量的几种方法并加以比较分析,提出了一种罗氏线圈与配套积分器测量桥臂均流电流的新方法。罗氏线圈不仅结构简单,便于绕制,重量轻方便安装,而且价格低,能够实现与主回路电气隔离。该方法已成功应用于核聚变领域,测量精度控制在1%以内。

关键词：晶闸管整流器均流系数罗氏线圈

Fault diagnosis of diesel engine valve clearance under variable operating condition based on soft interval SVM

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High Technology Letters 2021年第2期27卷 111-120页

作者： Jiang Zhinong Lai Yuehua mao zhiwei Zhang Jinjie Lai Zehua Key Laboratory of Engine Health Monitoring-Control and Networking of Ministry of Education Beijing University of Chemical TechnologyBeijing 100029P.R.China Beijing Key Laboratory of High-End Mechanical Equipment Health Monitoring and Self-Recovery Beijing University of Chemical TechnologyBeijing 100029P.R.China China Nuclear Control Systems Engineering Co.Ltd Beijing 102401P.R.China

The fault detection and diagnosis of diesel engine valve clearance can effectively improve the availability and safety of diesel engine and have extremely important value and *** engines generally operate in various stable operating conditions,which have important influence on the fault ***,many fault diagnosis methods have been put forward under specific stable operating condition based on vibration *** the result of great impact caused by operating conditions,corresponding diagnosis models cannot deal with the fault diagnosis under different operating conditions with required *** this paper,a fault diagnosis of diesel engine valve clearance under variable operating condition based on soft interval support vector machine(SVM)is ***,the fault features with weak condition sensitivity have been extracted according to the influence analysis of fault on vibration ***,soft interval constraint has been applied to SVM algorithm to reduce the random influence of vibration signal on fault *** addition,different machine learning algorithms based on different feature sets are adopted to conduct the fault diagnosis under different operating conditions for *** results show that the proposed method is applicable for fault diagnosis under variable operating condition with good accuracy.

关键词： diesel engine fault diagnosis operating condition support vector machine(SVM)

Theoretical investigation on self-recovery regulation method for diesel engine misalignment through co-simulation

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High Technology Letters 2021年第3期27卷 238-248页

作者： Jiang Zhinong Wang Zijia mao zhiwei Zhang Jinjie Wang Chenguang Huang Yifei Diagnosis and Self-Recovering Engineering Research Center Beijing University of Chemical TechnologyBeijing 100029P.R.China Beijing Bohua Anchuang Technology Co. LtdBeijing 101399P.R.China

Misalignment is one of the most common faults for the diesel *** order to eliminate the misalignment fault of the diesel engine in the process of operation,a targeting self-recovery regulation system is constructed by using a movable base and displacement *** is monitored and detected in real time,the value of misalignment is calculated rapidly and accurately,andintelligent decision is ***,the base is moved reversely with a definite target to drive the shaft to translate or rotate,so that the shafts can be recovered to alignment online.A co-simulation model for the self-recovery system is established which consists of a dynamic model of the crankshaft system and control *** self-recovery regulation process of misalignment is *** simulation results show that the system can accurately calculate the misalignment values,with an error of less than 5%,and can automatically eliminate the misalignment fault of the diesel engine *** research results provide theoretical support for the self-recovery regulation of misalignment fault,and due to the universality of structure and principle,the self-recovery system is not only suitable for diesel engine,but also for other rotating machineries.

关键词： diesel engine misalignment fault monitoring and detection targeting self-recovery co-simulation

Research on full-period acquisition method for diesel engine based on self-adaptive correlation analysis

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High Technology Letters 2020年第3期26卷 270-277页

作者： Zhao Haipeng mao zhiwei Zhang Jinjie Lai Yuehua Wang Zijia Jiang Zhinong Key Laboratory of Engine Health Monitoring-Control and Networking of Ministry of Education Beijing University of Chemical TechnologyBeijing 100029P.R.China Beijing Key Laboratory of High-End Mechanical Equipment Health Monitoring and Self-Recovery Beijing University of Chemical TechnologyBeijing 100029P.R.China

Full-period signal acquisition of vibration signal plays a vital role in the health monitoring and fault diagnosis of modern industrial equipment group. The traditional full-period signal acquisition methods usually need not only a reference signal generated from special key phase device but also a reserved position, which is only suitable for a small number of particular equipment. A novel full-period signal acquisition method without key phase is proposed to construct the time-frequency method with strong energy concentration called the synchrosqueezing generalized S-Transform(SGST), combining together the Teager energy operator(TEO) and self-adaptive correlation analysis(SACA) based on the vibration signals of both gear and cylinder head. Actual vibration signals of diesel engine are employed to verify the feasibility and effectiveness of the proposed method by comparing with traditional method with special key phase device. By comparisons, the results show that full-period signal acquisition method without key phase has approximate accuracy for diesel engine under different working conditions.

关键词： diesel engine key phase full-period acquisition vibration signal

Research on mechanical wear life feature fusion prediction method based on temporal pattern attention mechanism

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High Technology Letters 2023年第1期29卷 12-21页

作者：江志农 CHEN Yuyang ZHANG Jinjie LI Zhaoyang mao zhiwei ZHI Haifeng LIU Fengchun Beijing Key Laboratory of Health Monitoring and Self-Healing of High-end Mechanical Equipment Beijing University of Chemical TechnologyBeijing 100029P.R.China Key Laboratory of Engine Health Monitoring-control and Networking Ministry of EducationBeijing University of Chemical TechnologyBeijing 100029P.R.China China North Engine Research Institute(Tianjin) Tianjin 300400P.R.China

In order to solve the problem of low prediction accuracy when only vibration or oil signal is used to predict the remaining life of gear wear,a gear wear life feature fusion prediction method based on temporal pattern attention mechanism is ***,deep residual shrinkage network(DRSN)is used to extract the features of the original vibration time series signals with low signal-tonoise ratio,and the vibration features associated with gear wear evolution are ***,the extracted vibration features and the oil monitoring data that can intuitively reflect the wear process information are jointly input into the bi-directional long short-term memory neural network based on temporal pattern attention mechanism(TPA-BiLSTM),the complex nonlinear relationship between vibration features,oil features and gear wear process evolution is further explored to improve the prediction *** gear life cycle dynamic response and wear process signals are obtained based on the gear numerical simulation model,and the feasibility of the proposed method is ***,the proposed method is applied to the residual life prediction of gear on a test bench,and the comparison between different methods proved the validity of the proposed method.

关键词： prediction of gear remaining useful life information fusion numerical simulation neural network oil monitoring

Regulating catalyst morphology to boost the stability of Ni–Mo/Al_(2)O_(3) catalyst for ebullated-bed residue hydrotreating

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Green Energy & Environment 2021年第2期6卷 283-290页

作者： Huihong Zhu zhiwei mao Bin Liu Tao Yang Xiang Feng Hao Jin Chong Peng Chaohe Yang Jifeng Wang Xiangchen Fang Dalian Re search Institute of Petroleum and Petrochemicals SINOPECDadian116045China State Key Lab of Heavy Oil Processing China University of PetroleumQingdao266580China State Key Lab of Chemical Engineering East Chind University of Science and TechnologoyShanghui200237China

Hydrotreating of vacuum residue by ebullated-bed shows tremendous significance due to more stringent environmental regulations and growing demand for lighter fuels. However, enhancing the catalyst stability still remains as a challenging task. Herein, two Ni–Mo/Al_(2)O_(3) catalysts with distinct morphologies(i.e., spherical and cylindrical) were first designed, and the morphology effect on deactivation was systematically elucidated employing multi-characterizations, such as HRTEM with EDX mapping, electron microprobe analysis, FT-IR, TGA and Raman. It is found that spherical catalyst exhibits superior hydrotreating stability over 1600 h. The carbonaceous deposits on spherical catalyst with less graphite structure are lighter, and the coke weight is also smaller. In addition, the metal deposits uniformly distribute in the spherical catalyst, which is better than the concentrated distribution near the pore mouth for the cylindrical catalyst. Furthermore, the intrinsic reason for the differences was analyzed by the bed expansion experiment. Higher bed expansion rate together with the better mass transfer ability leads to the enhanced performance. This work sheds new light on the design of more efficient industrial hydrotreating catalyst based on morphology effect.

关键词： Deactivation Ebullated-bed Hydrotreating Vacuum residue Morphology