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结合旋转机械升降速阶段振动信号的特点,提出了一种无转速计的旋转机械Vold-Kalman阶比跟踪方法。该方法利用能量重心法对振动信号进行频谱校正,估计瞬时频率,获得参考轴转速信号,再对振动信号进行Vold-Kalman阶比跟踪,提取阶比分量。与需要转速计的经典Vold-Kalman阶比跟踪方法相比,该方法无需鉴相装置,完全用软件方式实现,算法精度高。仿真和应用实例分析结果表明此方法能够在时域中准确地提取幅值和频率变化的阶比分量。 相似文献
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介绍了利用相关法实现振动信号幅值和相位准确提取的方法,开发了基于LabVIEW的转子现场动平衡测试分析系统,详细论述测试系统的总体结构、软件框架及分析处理流程、LabVIEW程序的具体实现等内容,并利用分析系统对现场电主轴进行了实验验证,取得了较好的结果。 相似文献
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为了测量恒定转速上叠加的随机波动转速引起的振动,分析了回转机械转轴瞬时转速的表达关系,采用激光多普勒测量转轴瞬时转速的方法,测出了恒定转速上叠加的随机波动转速引起的振动。提出了一种信号处理方法,有效地克服了激光多普勒信号信噪比小、信号有时出现丢失的现象。对某电机(振动由于偏心引起的,最大转速为4000r/min)升降速阶段的振动进行测试。结果表明,此方法能够测试出恒定的转速上叠加的随机波动转速引起的振动。 相似文献
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建立了齿轮故障系统试验装置,对齿轮传动系统在各种转速与故障状态下进行测试分析,获取了有关振动信号,对齿轮系统的无故障、齿根裂纹、分度圆裂纹、齿面磨损四种状态信号进行特征提取,并对提取的信号进行基于经验模态EMD分解的小波阈值去噪处理,然后对预处理后的信号进行时频分析与诊断。结果表明,采用基于EMD的小波阈值去噪方法比单纯采用小波阈值去噪对测试信号进行预处理,能提高信噪比,并更加有效的提取出故障特征,而在EMD的小波阈值去噪的基础上,再与时频分析方法相结合能够较好的识别不同运转状况下不同种类的故障,如齿根裂纹、分度圆裂纹、齿面磨损等,可用于对实际工程工作的齿轮系统进行故障诊断。 相似文献
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提出了一种稳健全息阶比谱方法,用于提取变速器变速过程的微弱故障特征。首先分析了转速波动对传统阶比方法分析精度的影响,构造了基于转速调整的改进阶比方法,对水平与垂直方向加速过程信号的改进阶比谱进行全息分析,构成稳健全息阶比谱,并与单测点改进阶比谱结果对比。试验表明,改进阶比谱能有效抑制转速波动对等角度采样的影响,提高了阶比谱分析精度,有效增强了全息阶比谱的稳健性;相对于任一方向单测点阶比谱,稳健全息阶比谱既能分析变速过程信号,又能融合多点信息,其量化参数能更准确评价诊断对象的技术状态,证明稳健全息阶比谱是一种全面、可靠提取变速过程微弱故障特征的有效方法。 相似文献
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提出一种利用短波信号进行远程火箭弹转速测量的方法,利用弹丸在旋转、飞行过程中,由于接收点所处位置的不同,接收的短波信号幅值会呈规律性变化,通过提取变化周期即可测得弹丸转速. 具体分析了该系统方法的原理,描述了弹上短波接收系统的组成. 在地面设置近垂直入射天波传播"NVIS"天线,消除短波通信静区,弹上安装铁氧体加载螺旋线圈天线接收短波信号,利用原有弹载计算机进行数据处理. 并对弹上短波天线接收的信号进行仿真. 采用该方法可以解决在转速测量中误差累计的问题. 相似文献
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Dan-chen Zhu Yong-xiang Zhang Qun-wei Zhu 《Journal of Failure Analysis and Prevention》2018,18(1):2-7
With rotating speed of rotating machinery, it is difficult to maintain stability in practical work which brings many difficulties to the condition monitoring of rotating machinery. When rolling element bearings work under variable speed, the corresponding vibration will contain obvious non-stationary characteristics, along with the presence of strong background noise, which makes it difficult for some traditional spectrum analysis methods to identify the characteristic frequency of bearings fault. In spite of the existence of strong non-stationary characteristics, the bearing fault signal has some hidden periodic components in the angle domain which makes it possible to extract the fault feature of bearings by means of spectral correlation analysis. Therefore, a fault feature extraction method based on Teager–Kaiser energy operator (TKEO) and fast spectral correlation (Fast-SC) in angle domain is proposed in this paper; Fast-SC is a newly proposed spectral correlation calculation method which can effectively improve the efficiency of computing; Teager–Kaiser energy operator can enhance the transient impact which also has a fast computing speed. In this paper, the instantaneous speed of each time is estimated by the time–frequency analysis method based on short-time Fourier transform and then, the original time-domain signal is resampled in angle domain; the TKEO is used to strengthen the fault impact components in signal; finally, the Fast-SC is applied to the strengthened signals, the enhanced envelope spectrum is calculated, and the fault features of rolling bearings are extracted. The effectiveness of the method is verified by measured signals. 相似文献
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风力机叶片载荷谱及疲劳寿命分析 总被引:18,自引:0,他引:18
研究了大型风力机玻璃钢叶片载荷谱和疲劳寿命的工程估算方法。运用片条理论分析了影响风力机叶片疲劳寿命的气动载荷分布;应用多体动力学方法,分析了旋转叶片动力刚化效应产生的原因及其对叶片振动模态的影响;根据模态叠加法,计算了叶片在气动力、重力和旋转惯性力等确定性载荷作用下的动应力响应;探讨了玻璃钢叶片的疲劳性能、破坏准则及疲劳寿命估计方法;提出了一种基于 Palmgren Miner 线性累积损伤法则的玻璃钢叶片安全寿命估计方法。通过所设计的 1.5MW 变速变桨距风力机叶片疲劳寿命估计的算例表明,该方法是可靠和实用的。 相似文献
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HU Zhi-wei TANG Yong LI Li-li 《国际设备工程与管理》2014,(2):122-128
Conclusion is that the soft threshold de-noising effect is better than hard threshold de-noising though the signal to noise ratio and Root Mean Square error. After analyzing, de-noising and reconstructing signal through wavelet packet from Matlab software, the average value of peak extracted from signal reconstruction is gotten to provide data for dynamic balance. Making use of the influence coefficient method to adjust drum of CTP dynamic balance, the program of Matlab is used to find phase position and weight of the mass block quickly, which can provide evidence for software for dynamic balance developed. 相似文献