共查询到19条相似文献,搜索用时 171 毫秒
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针对内燃机缸盖振动信号信噪比低且呈宽带、非平稳、时变特性,本文首先采用了基于软阈值的小波紧缩降噪方法进行处理,从而有效地突出了缸盖在不同时刻所受到激励的响应信号;然后,对降噪后的时域响应信号分别建立二阶AR模型,以模型参数作为模式识别特征参数;最后,采用感知器神经网络对特征参数进行识别与分类.由于缸盖振动信号信噪比的有效提高,使得对缸盖振动信号的时域识别和分类取得了很好的结果.通过对实验数据的处理,进一步验证了方法的有效性. 相似文献
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转子组件是旋转机械的核心部件,转子组件稳定运行对旋转机械的安全而言意义重大;转子在高速运行时会产生振动信号,这些信号能全面反映出旋转机械的工作状态;文中以高速转子组件为研究对象,利用自主研发的采集模块进行振动信号数据测最;通过对转子振动信号的在线监测能对转子故障进行准确的判断,迅速找出故障原因;实验中主要对振动信号进行了自功率谱、振动烈度和轴心轨迹的分析,实验结果表明,系统能对转子组件的典型故障进行准确诊断,为旋转机械安全运行提供了保证. 相似文献
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谢周敏 《数字社区&智能家居》2009,(26)
利用微震测量技术、数据采集技术与信号处理技术可以建立一套监测各种振动信号的系统,广泛应用于各种振动事件的监测与报警。该文介绍了该系统的软件的设计思路与实现的效果。采用VC++,基于MFC类库开发了一套振动信号监测与分析软件,实现数据实时采集、信号分析处理、振动事件判别报警、数据存储回放等功能。 相似文献
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基于奇异值分解和小波包分析的液压泵振动信号特征提取方法 总被引:1,自引:0,他引:1
针对液压泵故障特征提取问题,提出了一种基于奇异值分解和小波包变换的液压泵振动信号特征提取方法.通过奇异值分解将噪声非均匀分布的液压泵振动信号正交分解为噪声分布相对均匀的分量,对各分量进行小波包阈值去噪,重构去噪后分量,对去噪后信号进行小波包分解,提取各频带能量特征.以齿轮泵为例,将该方法对齿轮泵的气穴故障、齿轮磨损和侧板磨损3种常见故障和正常状态的振动信号进行特征提取分析,结果表明,该方法可有效提取齿轮泵故障特征. 相似文献
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在对振动信号研究的基础上,采用现代计算机测量与控制技术开发了一种新型的振动信号监测系统;硬件以嵌入式微控制器LPC1768作为核心控制芯片,配合891-2型测振仪完成振动信号的采集和传输;软件采用LabVIEW虚拟仪器技术设计完成,实现了振动信号的时域分析、频域分析以及实时显示等功能;系统采用USB2.0总线实现数据传输,有效提高了传输速度,方便现场工作;试验测试表明,系统性能稳定,传输速度快,采集精度高,可适用于各种振动信号的工程监测,具有一定的实用和推广价值。 相似文献
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针对某型直升机需要对振动信号进行安全监控的问题,设计了一种基于机载实时处理的振动监控系统,以机载振动实时处理设备为核心,并通过MATLAB软件仿真选取最优的算法,利用该系统与原有的测试系统共同实施机载端的振动安全监控,解决了振动信号实时监控中带宽不足的技术难题。试验结果表明,该方案设计合理,具有实时性好、可靠性高的优点,振动数据实时处理结果与事后处理结果基本一致。该系统的成功设计保证了直升机的试飞安全,可推广至其他飞机的飞行试验中使用。 相似文献
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Gerotor pumps, as well known, are widely used in lubrication circuits of internal combustion engines for their simplicity, high efficiency and low costs.In this paper an experimental characterization of a Gerotor pump is shown. The research is a collaboration between the Hydraulic Power Research Group (HPRG) of the University of Naples “Federico II” and the Istituto Motori of CNR.The aim of this research is to investigate the possibility of using simple data to acquire, as vibrational data, on the pump under investigation to detect possible cavitation problem by implementing a proper mathematical procedure to this aim. As been demonstrated that these pumps are particularly subject to cavitation.The gerotor pumps are much subject to cavitate than expected, especially under particular operating conditions of the engine. Cavitation is also correlate to vehicle dynamics particularly with the recent tendency to reduce the mass of oil in the sump. Therefore, the research to avoid cavitation is crucial nowadays. Consequently this study has been firstly performed with an experimentation on the pump by monitoring the delivered oil flow-rate and the adsorbed torque on the pump shaft. An accurate analysis of the pressure oscillations in cavitation conditions, has been, also, conducted. Then, an accelerometer sensor has been properly located to study the cavitation with a fault diagnosis system based on vibration detection.The experimental tests have been performed on a test bench of the Hydraulic Laboratory of the University of Naples “Federico II” in Italy. The bench allows testing the pump working by varying the shaft speed, the oil temperature, the suction and the delivery pressure. The main measured parameters are shaft torque, oil flow rate, mean suction and delivery pressure and the instantaneous suction and delivery pressure.As expected, tests revealed the high influence of the suction pressure on the delivered oil flow rate, while no significant influence has been noted on the adsorbed torque. Furthermore, the pressure oscillations in the pump delivery are highly influenced by the suction pressure.A non intrusive accelerometer has been installed during the experimentation on the oil pump. Since the vibration due to cavitation is the main concern of this study, the accelerometer has been mounted at the suction port in the radial direction.More precisely, the paper presents a fault diagnosis system based on vibration detection. Firstly, a Fast Fourier Transform of the vibration signal has been computed. The investigation has been made with and without the presence of cavitation varying the pump rotation speeds. Limitations due to the detecting of the on line cavitation problems by monitoring the FFT vibration spectra have been overcame by implementing an alternative method based on stochastic approach.This diagnosis method of accelerometer time series analysis based on an Auto Regressive and Moving Average (ARMA) method has been used to determine the pump failure. The diagnosis results have demonstrated the ability of the proposed mathematical technique in the identification of cavitation phenomena proving that the proposed approach is a useful methodology to detect the presence of fault. The approach can predict, with good accuracy, pump failure in real time operation. In addition, a threshold vibration level in decibel scale is also fixed. 相似文献
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考虑到移动设备运行中状态信号采集和传榆的难度提出了一种新的故障诊断监控系统。该系统通过基于W77E58高速单片机的数据采集终端对移动设备的状态信号进行采集,采用无线传输方式快速传递数据。并可对数据信号进行故障诊断和精密分析。它具备快速获取大量数据、高精度数据转换、程控放大、程控五阶低通滤波等功能。该系统在固内某大型钢铁企业炼铁厂运料小车的振动状态监测项目实际应用中得以验证。 相似文献
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现有快速灭弧开关故障在线监测方法缺乏足够的数据积累,在大数量快速灭弧开关情况下存在着故障监测实时性差的缺陷,为此提出基于多元状态感知监测技术的快速灭弧开关故障在线监测方法研究;通过多元状态感知监测技术合理布置振动传感器,获取快速灭弧开关多元振动信号,利用小波变换方法降噪处理开关多元振动信号,以此为基础,提取灭弧开关多元振动信号特征因子;求取多元特征因子权重,得到灭弧开关融合特征向量,构建故障诊断模型,通过灭弧开关故障诊断实现了快速灭弧开关故障的在线监测;通过测试结果显示:与现有代表方法相比较,提出方法在大数量快速灭弧开关情况下,快速灭弧开关故障监测时间较短,具备更好的实时性,适合大力推广使用。 相似文献