Results 11 to 20 of about 612 (102)
Feature extraction of coal mine ventilator vibration signals based on improved variational mode decomposition [PDF]
The vibration signal of coal mine ventilator is a non-stationary multicomponent signal. Traditional methods for feature extraction of non-stationary signals suffer from poor adaptability and limited ability to identify weak characteristics of early ...
GUO Yanfei, TAO Long
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Monitoring and Analysis of Vibration and AE Signals in Hard Milling of Mold Steel [PDF]
, 2015 硬切削作为绿色切削的重要组成部分,已成为金属切削的一个研究热点。为了对硬切削过程进行监测,建立了一套信号采集系统,通过该系统采集模具钢铣削过程中的振动信号和声发射信号,并从时域、频域对其进行了分析研究。研究结果表明:模具钢硬铣削过程的振动信号和声发射信号的时域波形呈现不同的特点;振动信号和声发射信号的均方根值随切削速度的增大均呈明显的增大趋势,而受每齿进给量和铣削深度影响很小;随着切削速度的提高,振动信号各频段的幅值均增大,但频谱分布基本不变;随切削速度的提高,声发射信号的频谱成分增多 ...
仲为武, 王希
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An Localization and Classification Recognition Technology of DAS Signal based on Classifier Confidence [PDF]
【Objective】In order to solve the problems of low events recognition rate and weak positioning accuracy in distributed fiber vibration sensor system, a pattern recognition algorithm based on classifier confidence distribution of adjacent sensor nodes is ...
CAI Chao +8 more
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Gaoya dianqi, 2020 换流变有载分接开关（on-load tap-changer,OLTC）是调整换流变工作电压的核心设备,其安全稳定运行对于保障换流变的安全具有重要意义。振动信号检测技术是分析换流变OLTC内部零部件故障的主要手段。为了实现换流变OLTC振动信号检测技术的工程应用,在江苏省某换流站开展了该技术的应用研究。分析了换流变OLTC典型振动信号的时域和频域特征,基于S变换研究了振动信号的时频域联合分布。提取了时域有效值、时域峭度、传动轴动作时间;频率重心;S变换能量熵等特征参量。基于所提出的特征参量 ...
陆云才 +4 more
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Qtech-413 粘弹阻尼材料在盾构隧道中减振性能研究 [PDF]
, 2016 根据盾构隧道的结构特点,用Qtech-413 粘弹阻尼材料对盾构管片标准块进行约束阻尼处理,通过单点锤击振动实验,得到处理前后结构的时域波形、固有频率、复合损耗因子等振动特性。实验结果显示:经过约束阻尼处理后,盾构管片振动加速度幅值降低了26.7%,振动时长降低了50%;各阶固有频率均有所降低,且随着频率的增加,降幅逐渐增加;各阶复合损耗因子均有所升高,高频增幅比低频增幅更大;振动总级值降低了10 dB 左右。因此,Qtech-413 粘弹阻尼材料应用于盾构隧道能降低振动加速度幅值、振动时间 ...
黄舰 +1 more
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Marine fire pump motor bearings fault feature enhancement and diagnosis based on adaptive SSA and improved TEO [PDF]
ObjectiveThe working environment of marine fire pump motor bearings is complex with low fault diagnosis accuracy. To address these issues, this study proposes a fault feature enhancement and diagnosis method for marine fire pump motor bearings based on ...
Baozhu JIA, Xuewei SONG, Zhiqiang LIAO
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Analysis and experimental study on the vibration characteristics of the spiral drum of a shearer based on two-way coupling method [PDF]
In order to study the vibration characteristics of shearer’s spiral drum under various occurrence conditions，the coal-rock contact model was optimized by taking the MG2×55/250–BWD thin seam shearer as the engineering object, and discrete element model of
Lijuan ZHAO +3 more
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Gaoya dianqi, 2017 断路器机械振动信号分析中,提取振动事件是一种有效的信号时域分析方法和实现断路器故障诊断的可靠途径。振动信号与语音信号类似均属于瞬时非平稳信号,因此将语音信号处理中常用的短时能量法应用于振动信号分析中,在给出窗函数及窗长度选用原则后,对不同状况下采集的振动信号从提高信号信噪比、凸显振动事件、提取事件发生时刻等方面与包络法进行了分析与比较,结果表明,短时能量法不仅能明显提高信号信噪比,更是一种提取振动事件发生时刻的有效方法。
王静君 +5 more
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, 2003 针对高精度磨削加工中磨床系统振动监控及主轴、砂轮平衡的需要,提出基于虚拟仪器设计的振动信号采集及分析系统。该系统由单片机的信号采集单元和上位计算机处理系统组成,具有加工状态实时监控、信号采集存储、信号分析处理、平衡计算、控制输出等功能。试验结果表明 ...
王振忠, 郑琳, 郭隐彪
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Gaoya dianqi, 2019 运行中的变压器表面振动信号受多种因素影响,准确把握其特征是振动法分析变压器的基础工作。文中基于小波变换图谱分析技术,分析对比一台正常运行中的变压器表面不同位置、不同时刻振动信号。变压器表面不同位置振动信号分析结果表明,振动基频的2倍频频率分量振幅最大,振动基频2倍频频率分量间相关性最强,并且保持稳定的相位差;不同负载电流条件下的振动信号分析表明,振动信号高频部分主要受源自电流激励的绕组振动影响;同位置不同方向振动信号对比分析说明,垂直表面方向振动最为剧烈且频谱分量最为丰富 ...
徐卫 +6 more
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