共查询到20条相似文献,搜索用时 203 毫秒
1.
2.
3.
非线性齿轮系统单齿故障动力学特性 总被引:2,自引:1,他引:1
针对齿轮系统运行过程中具有非线性动力学特性,借鉴混沌振子检测理论中根据系统相轨变化检测信号的原理,分析了齿轮单齿故障冲击信号出现的成因及其出现故障后非线性动力学特性的变化,建立了基于冲击分析的非线性齿轮系统单齿故障动力学模型。通过分析发现,齿轮系统模型在一定的参数条件下,其动力学特性会进入混沌状态。而在相同参数条件下,出现单齿冲击故障并达到一定程度后,齿轮系统会在故障冲击的激励下进入大周期运动,从而表现出明显异于无故障条件下齿轮系统的动力学特性。仿真结果表明,该方法能有效区别齿轮系统单齿故障状态。 相似文献
4.
转子系统在故障状态下的振动信号往往呈现很强的非线性,其在频域上主要表现为不同频率之间相互耦合,产生合频、差频等组合频率。为了解决传统频谱分析只关注信号中的频率成分及其幅值大小,而忽略信号相位信息的问题,采用双谱方法对振动信号进行分析。双谱包含信号相位信息并且对非线性敏感,可以将早期故障的微弱非线性放大,检测出频谱中不同频率之间的非线性相位耦合关系。通过对ZT-3转子实验台植入不同类型的故障,采集系统在不同状态下的加速度信号,从振动信号的双谱中提取各频段的信息熵,采用模糊聚类方法进行故障识别。结果表明,双谱熵作为特征参量可以准确识别转子系统的故障类型,验证了方法的可行性。 相似文献
5.
为深入认识摩擦对航空相机扫描镜系统频率响应特性的影响,获得更准确描述该系统真实动态的模型,使用随机相位多正弦信号测量了扫描镜系统的频率响应特性并进行了线性近似参数模型辨识.首先,介绍扫描镜系统辨识的实验平台与激励信号选择.然后,使用奇-奇频率随机相位多正弦信号分别测量扫描镜系统在非激励频率处和激励频率处的输出对输入信号幅值的依赖,从而定量评估摩擦非线性的影响.最后,基于信号采样均值及噪声采样方差、协方差估计辨识了扫描镜系统线性近似参数模型.实验结果表明,扫描镜系统的摩擦非线性主要出现在奇频率处,高于噪声10dB;系统的频率响应特性依输入信号幅值不同而各异,在低于20 rad/s频率区该差别尤为显著.由于摩擦非线性影响,扫描镜系统需要使用3阶模型描述;与正弦扫描方法相比,基于多正弦信号激励获得的参数模型可更好地描述扫描镜系统真实动态特性.得到的结果为控制器的设计奠定了基础. 相似文献
6.
采用突变理论对非线性转子系统碰摩故障的突变性能进行了定量研究,用平均法推导了非线性转子系统碰摩故障的频率响应方程,建立了碰摩故障的尖点突变流形和分叉集,确定了激励频率、偏心距、轴刚度非线性系数等导致系统突变的重要影响因子,分析了影响因子变化与突变发展的规律,提出了避免突变发生的预防措施,并通过数值计算方法验证了以上分析结论. 相似文献
7.
8.
考虑齿轮啮合动态刚度、传递误差、齿侧间隙等非线性因素,将时变刚度按5次谐波展开,齿侧间隙按3次多项式拟合,运用多尺度方法分析了单对直齿轮传动系统的谐波共振响应特性,讨论了系统在非共振硬激励下消去长期项的条件,给出了系统中存在的多种频率因子,发现了系统中存在2阶、3阶超谐波共振和1/2阶、1/3阶次谐波共振,推导了稳态振动下的频率响应方程,并绘制了频率响应曲线,分析了静态激励、动态激励、参数激励以及系统中阻尼对稳态响应的不同影响作用。 相似文献
9.
通过调幅激励下非线性电路响应随凋幅信号变化火系(解轨迹)的跟踪,提出一种基于相干检测解轨迹跟踪的非线性电路故障诊断方法.利用解轨迹与Volterra响应间的故障信息等价性,将非线性故障诊断问题变换到线性子电路上分析;南解轨迹与调幅信号间的相干性.通过相位驻留法提取动态电路的静态特征,并建立统一的故障诊断方程.最后通过实例仿真说明该方法的有效性. 相似文献
10.
11.
《Mechanical Systems and Signal Processing》2014,42(1-2):283-299
This paper presents a nonlinear decoupling approach based on the Modified Generalized Frequency Response Functions (MGFRFs) and the nonlinear feature of phase invariance, for the pure nonlinearity-input nonlinear system. The MGFRFs are defined by combining the ‘homotopy’ GFRFs and phase information of the system input. The nonlinear feature of phase invariance is extracted based on MGFRFs. The decoupling approach is proposed based on MGFRFs and extended from the pure tone excitation to the multi-tone excitations by considering phase invariance. Numerical simulation and experimental investigation were carried out, whose results have shown that nonlinear feature of phase invariance is correct and reasonable and the proposed decoupling approach is valid and feasible. The proposed decoupling approach can be employed to identify the excitation sources and to estimate nonlinear system parameters for the pure nonlinearity-input nonlinear vibration system. 相似文献
12.
本文提出一种模拟电路故障诊断法。利用二元树的信息传递性实现模拟电路的故障定位,寻找系统Y在N个故障状态X下的最大故障信息量J0,采用序贯法一直寻找不同故障条件下子系统特征xj的最大信息量Ji,最终找到一个故障特征群R;构造系统最大故障信息二元树,从故障特征群中快速定位故障点,实现模拟电路故障的有效诊断。最后给出一个诊断实例验证了该方法。 相似文献
13.
14.
In this study, the concept of Output Frequency Response Functions (OFRFs) is applied to represent the transmissibility of nonlinear isolators in frequency domain. With the OFRFs estimated from numerical simulation responses, an explicit analytical relationship between the transmissibility and the nonlinear characteristic parameters is derived for a wide class of nonlinear isolators that have nonlinear anti-symmetric damping characteristics and a comprehensive pattern about how the nonlinear damping characteristic parameters might affect the force and displacement transmissibility is built for the vibration isolators. The results reveal that it is reasonable to analyze the force and displacement transmissibility of the nonlinear isolators by simply investigating the fundamental harmonic components of the force and displacement outputs of the nonlinear isolators, and the introduction of a nonlinear anti-symmetric damping into vibration isolators can significantly suppress both the force and displacement transmissibility over the resonant frequency region, but has almost no effect on the transmissibility at non-resonant regions. These conclusions are of significant importance in the analysis and design of the nonlinear vibration isolators with nonlinear anti-symmetric damping. 相似文献
15.
16.
Z.K. Peng Z.Q. Lang C. WoltersS.A Billings K. Worden 《Mechanical Systems and Signal Processing》2011,25(3):1045-1061
Nonlinear Output Frequency Response Functions (NOFRFs) are a series of one-dimensional functions of frequency recently proposed by the authors to facilitate the analysis of nonlinear systems in the frequency domain. The present study is concerned with a feasibility study of the application of the well-known Nonlinear Auto-Regressive Moving Average with eXogenous Inputs (NARMAX) modelling method and the NOFRFs-based analyses to the detection of damage in engineering structures. The new technique includes three steps. First, a NARX model is established by applying the NARMAX modelling method to input and output data collected from a test on an inspected structure. Then, the NOFRFs and an associated index for the inspected structure are determined from the established NARX model. Finally, structural damage detection is conducted by comparing the values of the NOFRF index of the inspected structure with the values of the index for a damage-free structure. An experimental application to the detection of damage in aluminium plates demonstrates the potential and effectiveness of the new damage detection technique. 相似文献
17.
In this paper, a novel fault detection and identification (FDI) scheme for a class of nonlinear systems is presented. First of all, an augment system is constructed by making the unknown system faults as an extended system state. Then based on the ESO theory, a novel fault diagnosis filter is constructed to diagnose the nonlinear system faults. An extension to a class of nonlinear uncertain systems is then made. An outstanding feature of this scheme is that it can simultaneously detect and identify the shape and magnitude of the system faults in real time without training the network compared with the neural network-based FDI schemes. Finally, simulation examples are given to illustrate the feasibility and effectiveness of the proposed approach. 相似文献
18.
19.
《机械工程学报(英文版)》2019,32(5)
Hydraulic systems have the characteristics of strong fault concealment,powerful nonlinear time-varying signals,and a complex vibration transmission mechanism;hence,diagnosis of these systems is a challenge.To provide accurate diagnosis results automatically,numerous studies have been carried out.Among them,signal-based methods are commonly used,which employ signal processing techniques based on the state signal used for extracting features,and further input the features into the classifier for fault recognition.However,their main deficiencies include the following:(1)The features are manually designed and thus may have a lack of objectivity.(2) For signal processing,feature extraction and pattern recognition are conducted using independent models,which cannot be jointly optimized globally.(3) The machine learning algorithms adopted by these methods have a shallow architecture,which limits their capacity to deeply mine the essential features of a fault.As a breakthrough in artificial intelligence,deep learning holds the potential to overcome such deficiencies.Based on deep learning,deep neural networks(DNNs) can automatically learn the complex nonlinear relations implied in a signal,can be globally optimized,and can obtain the high-level features of multi-dimensional data.In this paper,the main technology used in an intelligent fault diagnosis and the current research status of hydraulic system fault diagnosis are summarized and analyzed.The significant prospect of applying deep learning in the field of intelligent fault diagnosis is presented,and the main ideas,methods,and principles of several typical DNNs are described and summarized.The commonality between a fault diagnosis and other issues regarding typical pattern recognition are analyzed,and research ideas for applying DNNs for hydraulic fault diagnosis are proposed.Meanwhile,the research advantages and development trend of DNNs(both domestically and overseas) as applied to an intelligent fault diagnosis are reviewed.Furthermore,the fault characteristics of a complex hydraulic system are summarized and discussed,and the key problems and possible research ideas of applying DNNs to an intelligent hydraulic fault diagnosis are presented and comprehensively analyzed. 相似文献
20.
电机电流信号常用于分析电动机本身的故障问题,但对其应用于与电机相连机构的故障分析的研究较少。提出一种基于储能电机电流分析的万能式断路器操作机构故障诊断方法。首先采用Hilbert幅值解调法和改进的小波包阈值法相结合获取交流电流信号的包络线,以解决随机噪声干扰造成的所提取包络线粗糙的问题;然后通过包络线提取电流信号的时间量、电流量以及峭度作为不同故障状态电流波形的特征参数;最后融合模糊聚类和量子粒子群优化的相关向量机实现对断路器正常状态、传动齿轮卡涩、储能弹簧卡涩以及脱落的4种状态的辨识。构建了基于电流分析的万能式断路器故障诊断系统,在不同工况下进行了验证,结果表明该方法能有效提取操作机构储能相关部件的故障特征,实现了对操作机构储能相关部件的故障诊断。 相似文献