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基于最小二乘法的转子不平衡振动信号的提取 总被引:1,自引:0,他引:1
不平衡振动是旋转机械失效的重要原因,实现精确平衡必须从强噪声中提取出与主轴转速同频的不平衡量振动信号,因此,不平衡振动信号的准确提取是进行转子动平衡的前提。基于最小二乘法的原理,通过建立提取转子振动不平衡信号的数学模型,提出了一种准确提取转子不平衡振动信号的方法。基于该方法,并通过Matlab仿真分析,有效提取了转子振动不平衡信号。研究表明,基于最小二乘法的转子振动不平衡信号提取方法能够准确提取转子不平衡振动的幅值和相位信息,该方法可用于转子不平衡振动监测及动平衡等方面。 相似文献
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针对难以通过在现场大型旋转机械上预设不平衡,研究不平衡量辨识方法问题,研发了转子不平衡故障模拟试验台及转子不平衡响应测量分析系统。研制了由无刷直流电动机及其驱动器、滚动轴承、转轴、偏心转盘等组成的轴承-转子系统,通过改变配重在转盘上的安装位置模拟了转子不平衡故障;设计了由电涡流传感器、光电传感器、数据采集卡等组成的测量与分析系统硬件,利用LabVIEW开发了基于截取脉冲分析法的转子不平衡响应测量与分析系统专用软件,实现了转子键相脉冲和不平衡响应信号的采集与存储以及不平衡响应幅值和相位的分析;考虑测量噪声,设计了基于LabVIEW的仿真实验。研究结果表明:截取分析的周期不同,识别误差也不同,但幅值相对误差最大为2.023 9%,相位绝对误差最大为2.441 9°。 相似文献
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提出了一种控制转子不平衡量方位的气浮平衡测定方法来提高对空心薄壁不完整球形超导转子平衡量测定的精度.采用在转子内部增加重量的方法来改变转子的不平衡量大小,使得该转子的不平衡量的方位角处于精确测量范围内,当增重量变化时其测量值也会发生相应的变化,通过静不平衡计算的相关公式即可得出其静不平衡量.该方法能够提高这种超导球形转子平衡测定的精度,不破坏转子的加工精度,不影响转子的电磁特性、超导特性等.测量转子偏心距的波动大小在±6 μm之内,偏心距Z轴分量的波动在±8 μm之内,同时可有效提高超导重力计等基于该类型超导转子的仪器的工作性能和测量精度,对于其它无机械支撑轴转子的平衡测定也有一定借鉴意义.测量过程中采用的设备简单,实验周期短,测量结果精度较高. 相似文献
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针对动平衡测量中实际存在的转速波动问题,提出一种基于经验模态分解(empirical mode decomposition,简称EMD)和瞬时频率估计的不平衡信号提取方法。与传统的平稳信号分析方法不同,该方法采用3次样条插值法从键相信号中获取转子的瞬时频率,由瞬时频率构造不平衡信号,进而采用最小二乘法(least square method,简称LSM)辨识出不平衡信号的幅值和相位。为提高幅值和相位估计的精度,采用EMD算法对振动信号进行滤波处理后,再从中抽取数据样本。仿真和实验结果表明,该方法能够有效克服转速波动和干扰信号对不平衡信号提取精度的不利影响,提高不平衡量测量精度和稳定性,非常适合于工程应用。 相似文献
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针对某机组在安装调试阶段出现振动超标问题,应用多通道信号采集系统测量轴系振动特性,进行故障机理与相关因素分析,采用转子动平衡的措施校正补偿发动机转子热不平衡响应,有效地抑制了机组振动发散超标现象。 相似文献
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Clarence W.DE SILVA 《Instrumentation》2019,(4):72-84
An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t... 相似文献
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The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci... 相似文献
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针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。 相似文献
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针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。 相似文献
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A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load. 相似文献
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INTEGRAL EQUATION METHOD'S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES 总被引:1,自引:0,他引:1
LI Cheng ZHENG Yanping 《机械工程学报(英文版)》2008,21(6):115-118
The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value. 相似文献
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针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。 相似文献
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The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar... 相似文献
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The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods.... 相似文献
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30 keV Ga+ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z2, and shows a non-monotonic relationship between contrast and Z2. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z2, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory. 相似文献