摘要
对旋转机械振动信号进行信号处理,能够有效提取特征进行故障诊断。振动信号模型来自旋转机械运动学和动力学机理,以数学形式表达,可以指导信号处理方法的设计。随着故障机理研究和信号处理方法研究的推进,研究人员对信号模型进行了发展,并基于这些信号模型设计了相应的信号处理方法。首先,介绍了一般化的信号模型,包括周期信号模型、循环平稳信号模型、自适应谐波模型、波形函数模型、任意阶谐波模型等,以及对应的信号处理方法;其次,分别介绍定工况和变工况条件下针对轴承和齿轮的典型振动信号模型及对应信号处理方法;最后,对振动信号模型的研究发展进行总结和展望,旨在回顾旋转机械故障诊断所涉及的信号模型,并说明其在信号处理算法设计和故障诊断特征提取中的价值和意义。
旋转机械常应用于能源电力、化工机械、军事装备和航空航天等对经济发展、国防安全具有重要意义的关键行业。随着工业信息化、智能化进程的推进,对旋转机械设备可靠性运行的要求愈发严格。因此,发展有效的旋转机械设备故障诊断与状态评估方法具有重要意
在旋转机械运行过程中,设备的振动响应包含了丰富的结构状态信息。由于振动信号便于采集、测量准确,基于振动信号分析的旋转机械故障诊断方法一直受到关注和研究。当旋转机械运行于定工况时,振动信号呈现出一定的周期性。当旋转机械运行于变转速等变工况时,信号原本的周期性受到破
信号模型是一种对物理世界中测量信号的数学抽象,利用较为简单的代数形式作为复杂的旋转机械振动信号的代表和简化。例如,无阻尼单自由度系统自由振动位移响应的简谐波模型,其特征包括振动幅度(幅值)、周期大小(频率)和初始时刻的位置(初相位)。对于这样的简谐波,使用傅里叶变换可以清晰地得到其全部特征。实际的旋转机械振动信号要复杂得多,但是信号模型的意义是相同的:①信号模型来自于旋转机械故障机理,是对故障激发振动的动力学过程的数学抽象;②信号模型能够帮助研究人员抓住振动信号中的关键特征;③信号模型能够指导研究人员选择合适的信号处理方法,实现更准确高效的特征提取。因此,振动信号模型对旋转机械故障诊断具有重要的意义。
目前,针对机械故障诊断的信号处理方法研究有很多。Randall
笔者主要回顾旋转机械振动信号模型,并针对旋转机械中最具代表性,也是最容易产生退化的基础件,即轴承和齿轮进行介绍。考虑到实际生产应用中旋转机械常处于变工况状态,笔者分别在定工况和变工况2种情况下介绍轴承和齿轮的振动信号模型。
周期信号模型是有限个简谐波的叠加,表示为
(1) |
其中:每个谐波分量都具有3个属性,即幅值、频率和初相位。
当谐波分量的频率存在有限的最小公倍数时称为周期信号模型,当最小公倍数无穷大时,称为准周期信号模型。该模型描述的分量称为确定性分量,其在频谱上呈现为一种离散分布。
循环平稳信号模型来自于随机过程理论,是指信号的统计特征随时间周期性变化。从宽泛的意义上讲,如果随机过程的一阶矩或期望以T为周期,即
(2) |
则被称为一阶循环平稳过程。
类似的,当信号的期望具有周期性,其自相关函数也具有周期性时,即
(3) |
则被称为二阶循环平稳过程。
假设的傅里叶展开能够收敛到,即
(4) |
循环自相关函数为
(5) |
其中:为循环频率。
如果循环频率不是严格的比例关系,此时自相关函数可以表示为
(6) |
其中:A为循环频率的集合。
在循环频率处的循环自相关函数表示为
(7) |
循环自相关函数关于时延变量的傅里叶变换
(8) |
被称为循环频率处的循环谱,又称为谱相关密度函数。循环谱表示了处于和的2个频率成分统计相关性的时间平
周期信号和循环平稳信号可以认为是非平稳信号的特例。在一些非平稳信号分析方法中,引入了一定的经验性假设来描述非平稳信号。例如,经验模态分解中定义本征模态函数满足2个条
Daubechies
(9) |
其中:,为瞬时幅值;为瞬时相位。
信号整体可以建模为本征模态函数的和
(10) |
各本征模态函数的瞬时频率表示为
(11) |
该模型被称为自适应谐波模型,其瞬时频率和瞬时幅值与信号相适应。一般而言,瞬时幅值和瞬时频率的变化应远小于瞬时相位的变化,这意味着在一个较小的时间窗口内,信号可以近似认为是幅值为、频率为的简谐波。
对于自适应谐波模型中具有时变特性的分量,一个有效的分析手段是获得信号的时频分
还有一些研究聚焦于获得少量分量的时域波形。针对具有紧支撑傅里叶谱的分量,Gille
考虑到自然界中大量的信号具有一定的波形,W
(12) |
其中:;,且和的变化远慢于的变化。
波形函数模型是自适应谐波模型的一种推广,将其中的简谐波函数扩展为一般的周期函数。假设信号中不含直流分量,每个波形函数可以利用其傅里叶展开表示为
(13) |
时变波形函数可以表示为
(14) |
各个谐波分量的瞬时频率都是波形函数基频分量的整数倍。相比于自适应谐波模型,波形函数模型中的每个分量都包含了若干个本征模态函数,减少了表示信号所需要的项。
W
(15) |
这实际上放宽了对组成波形函数的谐波分量瞬时频率与基频分量瞬时频率关系的限
考虑到在一些场景下信号中各个分量的瞬时频率虽然同步变化,但其分量间的比例可能十分复杂,且任意分量的瞬时幅值都有占优的可能,Li
(16) |
其中:;,为各个分量的相对阶次。
各个分量的瞬时频率可表示为
(17) |
其中:为相对趋势函数。
实际上,在任意阶谐波模型中没有基频的概念,即不一定存在。该模型要求所有分量的瞬时频率都能够拆解为相对阶次和相对趋势函数的乘积。
任意阶谐波模型的另一个特征是可以构造伪时域来同时消除所有分量瞬时频率的变化。假设伪时域为,则各个分量相对于伪时间的瞬时频率为
(18) |
当为常数时,所有分量的瞬时频率都为常数。从时域向伪时域的映射称为时间规
对于符合任意阶谐波模型特征的信号,Guan
当滚动体撞击外圈或内圈上的缺陷时,产生的冲击会激发整个结构的高频共振。当滚动体上的缺陷撞击内圈或外圈时也会发生同样的情况。一个典型的滚动轴承振动信号可以建
(19) |
其中:s(t)为冲击波形;ak和Tk分别为幅值和单次冲击的起始时间。
如果每两次冲击的时间间隔都为T,则,此时轴承振动信号模型为周期性模型。在实际轴承中,滚动体在保持架间隙内可以进行随机周向运动,每个滚动体到达缺陷的时间存在变化,即
(20) |
其中:为滚动体延迟或提前到达缺陷的时间差,此时轴承振动信号模型为循环平稳模
滚动体全体的滑移可能导致保持架的速度存在随机性。如果单独考虑这种整体运动的随机性,则
(21) |
其中:为每两次冲击的时间间隔。
此时,轴承振动信号模型为伪循环平稳模
假设滚动体和保持架不发生滑移,幅值均为1,则周期性冲击信号表示为
(22) |
其中:表示卷积;为脉冲函数。
根据卷积定理,其傅里叶变换表示为
(23) |
轴承振动信号特征如图2所示。轴承冲击分量的频谱为系统频响函数和等间隔脉冲函数的乘积。这意味在频谱上可以观察到轴承故障特征分量及其倍频成分(如图2(b)所示),然而滚动体和保持架的滑移都弱化了这种周期性(如图2(e)所示)。系统的频响函数一般在高频处幅值较高,由于越高阶的谐波受随机效应影响越大,在频谱的高频处很难直接观察到轴承故障特征分量,因此学者们使用包络谱或平方包络谱分析轴承振动信号。以平方包络谱为例,假设相邻2次冲击在时间上没有重叠,则
(24) |
其中:为模长;表示的共轭。
其傅里叶变换表示为
(25) |
其中:。
平方包络谱为等间隔脉冲和系统频响函数自相关函数的乘积(如图2(c)所示)。与频响函数相比,自相关函数的能量主要集中在靠近0的位置,此处受滚动体和保持架滑移的影响较小,所以平方包络谱能够清晰地反映轴承故障特征频率(如图2(f)所示
考虑振动中存在随机性,Antoni
需要说明的是,滚动体和保持架的滑移使轴承信号与齿轮振动信号存在天然的区别。当转速恒定时,齿轮振动信号频谱一般为离散的确定性分量。基于信号特征差别,学者们提出了将轴承振动信号与齿轮等具有离散频率分量的旋转机械振动信号分离的方法,例如随机/离散分
齿轮故障在啮合处激发的振动信号可以建模为调幅调频信
(26) |
其中:K为考虑的调幅调频项的最高阶次;,为调幅项;,为调频项;,,分别为幅值调制和频率调制的幅度;c为依赖于信号幅值的无量纲常数;和分别为啮合频率和故障特征频率;,和分别为谐波分量、幅值调制和频率调制的初相位;N和L分别为幅值调制和频率调制的最高阶次。
忽略调幅调频中的高阶项时,
(27) |
在不考虑传递路径的影响时,故障引发的振动信号在频谱上存在于啮合频率及其边频带处,其中边频带的频率分量间隔为。对于定轴齿轮系统(直齿轮、斜齿轮和锥齿轮等),
假设太阳轮为行星齿轮系统的输入,行星架为输出且传感器安装在固定的齿圈或齿轮箱壳体上,行星齿轮箱的3条传递路
与轴承易发生滚动体和保持架滑移从而减弱信号的周期性不同,齿轮稳定的啮合关系使其信号的周期性较为确定。因此,大量关于齿轮振动信号的分析是基于其周期性的。文献[
除了利用周期性在频谱上分析特征分量,还有学者直接提取齿轮啮合的调幅特征和调频特征。Feng
在变转速工况下,轴承的瞬时角速度随时间不断变化,假设角度变量与时间变量的关系为
(28) |
其中:为轴承的名义角速度;为速度波动。
在角域,
(29) |
其中:为角度域上冲击开始的角度。
假设只考虑滚动体滑移引入的随机误差,则
(30) |
与时域下的轴承振动信号模型基本相同,使用角域重采样方法获得角域轴承振动信号后,可利用时域下定工况的信号处理方法进行分
(31) |
其中:;为第i-1次到第i次冲击间的平均角速度。
在该模型中,冲击波形仍然是在时域内定义,转速的变化主要用来确定2次冲击的时间差。考虑到这种差异,Borghesani
一些学者尝试将时域下的循环平稳框架进行推
(32) |
其中:复指数由角度表示;傅里叶系数由时间表示。
当在时域平稳时,
(33) |
在定工况下,轴承振动信号中的周期性冲击在频谱或包络谱上形成等间隔的频率成分,而在变工况下,这些频率成分转变为具有瞬时频率和瞬时幅值的非平稳信号分量。利用针对非平稳信号的时频分析方法,可以获得变工况条件下轴承振动信号的时频分布,或者直接将故障特征分量的时域波形提取出来进行故障诊断。Huang
在定工况条件下,齿轮振动信号频谱结构表现为啮合频率及其高次谐波,而特征频率会对啮合频率进行调制,形成啮合频率及其谐波周围的边频带。当转速发生变化时,这些啮合频率及边频带变成具有瞬时幅值和瞬时频率的时变非平稳信号分量。当输入转速变化时,
(34) |
与轴承振动信号在变工况条件下的信号处理方法类似,基于角域重采样的阶次跟踪方法也广泛应用在变工况齿轮振动信号的分析
齿轮振动信号包含具有瞬时频率和瞬时幅值的非平稳分量,时频分布和分量分解也能提供用于齿轮故障诊断的关键特征。Li
考虑到变工况条件下齿轮振动信号中分量瞬时频率随转速同步变化,Zhang
笔者介绍了一般性的信号模型,包括周期性信号、循环平稳信号、自适应谐波模型、波形函数模型和任意阶谐波模型等。在旋转机械故障诊断的背景下,介绍的一般化信号模型需要与具体对象特征相关联。
笔者主要考虑2种有代表性的旋转机械部件:轴承和齿轮。在定工况条件下,振动信号特征以一系列频域分量的形式呈现出来。轴承滚动体和保持架的滑移现象导致其频谱分量出现模糊效应。齿轮由于啮合关系的相对稳定,在频域呈现确定性离散分量。在变工况下,轴承和齿轮转速发生变化,信号引入了时变特性,进一步提升了信号分析的难度。
选择合适的信号模型是特征提取的基础。例如,利用二阶循环平稳特性建模轴承振动信号,能够很好地描述滚动体和保持架滑移引入的随机效应。基于循环平稳理论建立的轴承振动信号分析方法,例如平方包络谱分析和谱相关分析等,能够获得更好的效果。相比较而言,齿轮故障信号本身为调幅调频信号,可利用时频分析方法直接提取其调幅调频特征,也可以根据周期性调幅调频特征与谐波簇的对应关系,在频谱上进行特征提取。
目前,变工况条件下轴承和齿轮的振动信号模型大多为定工况条件下的特征与一般化非平稳信号模型相结合的产物。此时,特征提取方法一般是基于一定的时频分析方法,例如:时频分布、分量分解和时间规整等。此外,选择合适的非平稳信号模型是重要的。例如,通过考虑旋转机械振动信号中分量瞬时频率的关系,可以大大减小所需要估计的信息量,提升信号分析方法的效率。
变工况条件下的信号模型的定义较为宽松。例如,自适应谐波模型中的瞬时频率和瞬时幅值并不唯一,这会给分析结果带来歧
目前,大部分信号模型属于唯象模型,虽然能在很大程度上代表信号特征,但由于忽略了部分信息,仍与实际信号存在差异。信号模型应更多考虑旋转机械的动力学特征,如传递路径影
参考文献
CHEN X F, WANG S B, QIAO B J, et al. Basic research on machinery fault diagnostics: past, present, and future trends[J]. Frontiers of Mechanical Engineering, 2018, 13(2): 264-291. [百度学术]
王国彪, 何正嘉, 陈雪峰, 等. 机械故障诊断基础研究 "何去何从"[J]. 机械工程学报, 2013, 49(1): 63-72. [百度学术]
WANG Guobiao, HE Zhengjia, CHEN Xuefeng, et al. Basic research on machinery fault diagnosis-what is the prescription[J]. Journal of Mechanical Engineering, 2013, 49(1): 63-72. (in Chinese) [百度学术]
GAO Y, GUO Y, CHI Y L, et al. Order tracking based on robust peak search instantaneous frequency estimation[J]. Journal of Physics: Conference Series, 2006, 48: 479. [百度学术]
QIAN S E, CHEN D P. Joint time-frequency analysis[J]. IEEE Signal Processing Magazine, 1999, 16(2): 52-67. [百度学术]
RANDALL R B, ANTONI J, SMITH W A. A survey of the application of the cepstrum to structural modal analysis[J]. Mechanical Systems and Signal Processing, 2019, 118: 716-741. [百度学术]
PEETERS C, LECLÈRE Q, ANTONI J, et al. Review and comparison of tacholess instantaneous speed estimation methods on experimental vibration data[J]. Mechanical Systems and Signal Processing, 2019, 129: 407-436. [百度学术]
陈是扦, 彭志科, 周鹏. 信号分解及其在机械故障诊断中的应用研究综述[J]. 机械工程学报, 2020, 56(17): 91-107. [百度学术]
CHEN Shiqian, PENG Zhike, ZHOU Peng. Review of signal decomposition theory and its applications in machine fault diagnosis[J]. Journal of Mechanical Engineering, 2020, 56(17): 91-107. (in Chinese) [百度学术]
MIAO Y H, ZHANG B Y, LIN J, et al. A review on the application of blind deconvolution in machinery fault diagnosis[J]. Mechanical Systems and Signal Processing, 2022, 163: 108202. [百度学术]
ZHOU P, CHEN S Q, HE Q B, et al. Rotating machinery fault-induced vibration signal modulation effects: a review with mechanisms, extraction methods and applications for diagnosis[J]. Mechanical Systems and Signal Processing, 2023, 200: 110489. [百度学术]
GARDNER W A, NAPOLITANO A, PAURA L. Cyclostationarity: half a century of research[J]. Signal Processing, 2006, 86(4): 639-697. [百度学术]
ANTONI J, BONNARDOT F, RAAD A, et al. Cyclostationary modelling of rotating machine vibration signals[J]. Mechanical Systems and Signal Processing, 2004, 18(6): 1285-1314. [百度学术]
HUANG N E, SHEN Z, LONG S R, et al. The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis[J]. Proceedings of the Royal Society of London Series A: Mathematical, Physical and Engineering Sciences, 1998, 454: 903-995. [百度学术]
PAREY A, EL BADAOUI M , GUILLET F, et al. Dynamic modelling of spur gear pair and application of empirical mode decomposition-based statistical analysis for early detection of localized tooth defect[J]. Journal of Sound and Vibration, 2006, 294(3): 547-561. [百度学术]
WANG J, DU G F, ZHU Z K, et al. Fault diagnosis of rotating machines based on the EMD manifold[J]. Mechanical Systems and Signal Processing, 2020, 135: 106443. [百度学术]
DAUBECHIES I, LU J F, WU H T. Synchrosqueezed wavelet transforms: an empirical mode decomposition-like tool[J]. Applied and Computational Harmonic Analysis, 2011, 30(2): 243-261. [百度学术]
IATSENKO D, MCCLINTOCK P V E, STEFANOVSKA A. Linear and synchrosqueezed time-frequency representations revisited: overview, standards of use, resolution, reconstruction, concentration, and algorithms[J]. Digital Signal Processing, 2015, 42: 1-26. [百度学术]
OBERLIN T, MEIGNEN S, PERRIER V. Second-order synchrosqueezing transform or invertible reassignment towards ideal time-frequency representations[J]. IEEE Transactions on Signal Processing, 2015, 63(5): 1335-1344. [百度学术]
PHAM D H, MEIGNEN S. High-Order synchros-queezing transform for multicomponent signals analysis‑ with an application to gravitational-wave signal[J]. IEEE Transactions on Signal Processing, 2017, 65(12): 3168-3178. [百度学术]
PENG Z K, MENG G, CHU F L, et al. Polynomial chirplet transform with application to instantaneous frequency estimation[J]. IEEE Transactions on Instrumentation and Measurement, 2011, 60(9): 3222-3229. [百度学术]
YANG Y, PENG Z K, DONG X J, et al. General parameterized time-frequency transform[J]. IEEE Transactions on Signal Processing, 2014, 62(11): 2751-2764. [百度学术]
YANG Y, ZHANG W M, PENG Z K, et al. Multicomponent signal analysis based on polynomial chirplet transform[J]. IEEE Transactions on Industrial Electronics, 2013, 60(9): 3948-3956. [百度学术]
WANG S B, CHEN X F, CAI G G, et al. Matching demodulation transform and SynchroSqueezing in time-frequency analysis[J]. IEEE Transactions on Signal Processing, 2014, 62(1): 69-84. [百度学术]
WANG S B, CHEN X F, SELESNICK I W, et al. Matching synchrosqueezing transform: a useful tool for characterizing signals with fast varying instantaneous frequency and application to machine fault diagnosis[J]. Mechanical Systems and Signal Processing, 2018, 100: 242-288. [百度学术]
GILLES J. Empirical wavelet transform[J]. IEEE Transactions on Signal Processing, 2013, 61(16): 3999-4010. [百度学术]
DRAGOMIRETSKIY K, ZOSSO D. Variational mode decomposition[J]. IEEE Transactions on Signal Processing, 2014, 62(3): 531-544. [百度学术]
FENG Z P, CHEN X W, LIANG M. Iterative generalized synchrosqueezing transform for fault diagnosis of wind turbine planetary gearbox under nonstationary conditions[J]. Mechanical Systems and Signal Processing, 2015(52/53): 360-375. [百度学术]
CHEN S Q, PENG Z K, YANG Y, et al. Intrinsic chirp component decomposition by using Fourier series representation[J]. Signal Processing, 2017, 137: 319-327. [百度学术]
CHEN S Q, DONG X J, PENG Z K, et al. Nonlinear chirp mode decomposition: a variational method[J]. IEEE Transactions on Signal Processing, 2017, 65(22): 6024-6037. [百度学术]
WU H T. Instantaneous frequency and wave shape functions (I)[J]. Applied and Computational Harmonic Analysis, 2013, 35(2): 181-199. [百度学术]
IATSENKO D, MCCLINTOCK P V E, STEFANOVSKA A. Nonlinear mode decomposition: a noise-robust, adaptive decomposition method[J]. Physical Review, E: Statistical, Nonlinear, and Soft Matter Physics, 2015, 92(3): 032916. [百度学术]
COLOMINAS M A, WU H T. Decomposing non-stationary signals with time-varying wave-shape functions[J]. IEEE Transactions on Signal Processing, 2021, 69: 5094-5104. [百度学术]
LI T Q, HE Q B, PENG Z K. Parameterized resampling time-frequency transform[J]. IEEE Transactions on Signal Processing, 2022, 70: 5791-5805. [百度学术]
BARANIUK R G, JONES D L. Unitary equivalence: a new twist on signal processing[J]. IEEE Transactions on Signal Processing, 1995, 43(10): 2269-2282. [百度学术]
GUAN Y P, LIANG M, NECSULESCU D S. Velocity synchronous linear chirplet transform[J]. IEEE Transactions on Industrial Electronics, 2019, 66(8): 6270-6280. [百度学术]
LI M F, WANG T Y, CHU F L, et al. Scaling-basis chirplet transform[J]. IEEE Transactions on Industrial Electronics, 2021, 68(9): 8777-8788. [百度学术]
ZHANG D, FENG Z P. Proportion-extracting chirplet transform for nonstationary signal analysis of rotating machinery[J]. IEEE Transactions on Industrial Informatics, 2023, 19(3): 2674-2683. [百度学术]
BORGHESANI P, SMITH W A, RANDALL R B, et al. Bearing signal models and their effect on bearing diagnostics[J]. Mechanical Systems and Signal Processing, 2022, 174: 109077. [百度学术]
RANDALL R B, ANTONI J. Rolling element bearing diagnostics: a tutorial[J]. Mechanical Systems and Signal Processing, 2011, 25(2): 485-520. [百度学术]
ANTONI J, RANDALL R B. Differential diagnosis of gear and bearing faults[J]. Journal of Vibration and Acoustics, 2002, 124(2): 165-171. [百度学术]
ANTONI J, RANDALL R B. A stochastic model for simulation and diagnostics of rolling element bearings with localized faults[J]. Journal of Vibration and Acoustics, 2003, 125(3): 282-289. [百度学术]
WANG D, PENG Z K, XI L F. The sum of weighted normalized square envelope: a unified framework for kurtosis, negative entropy, Gini index and smoothness index for machine health monitoring[J]. Mechanical Systems and Signal Processing, 2020, 140: 106725. [百度学术]
RANDALL R B, ANTONI J, CHOBSAARD S. The relationship between spectral correlation and envelope analysis in the diagnostics of bearing faults and other cyclostationary machine signals[J]. Mechanical Systems and Signal Processing, 2001, 15(5): 945-962. [百度学术]
ANTONI J. Cyclic spectral analysis in practice[J]. Mechanical Systems and Signal Processing, 2007, 21(2): 597-630. [百度学术]
ANTONI J, XIN G, HAMZAOUI N. Fast computation of the spectral correlation[J]. Mechanical Systems and Signal Processing, 2017, 92: 248-277. [百度学术]
RANDALL R B. Detection and diagnosis of incipient bearing failure in helicopter gearboxes[J]. Engineering Failure Analysis, 2004, 11(2): 177-190. [百度学术]
ANTONI J. Fast computation of the kurtogram for the detection of transient faults[J]. Mechanical Systems and Signal Processing, 2007, 21(1): 108-124. [百度学术]
MOSHREFZADEH A, FASANA A. The autogram: an effective approach for selecting the optimal demodulation band in rolling element bearings diagnosis[J]. Mechanical Systems and Signal Processing, 2018, 105: 294-318. [百度学术]
WANG D, TSE P W, TSUI K L. An enhanced Kurtogram method for fault diagnosis of rolling element bearings[J]. Mechanical Systems and Signal Processing, 2013, 35(1/2): 176-199. [百度学术]
ANTONI J. The infogram: entropic evidence of the signature of repetitive transients[J]. Mechanical Systems and Signal Processing, 2016, 74: 73-94. [百度学术]
FENG Z P, ZUO M J. Vibration signal models for fault diagnosis of planetary gearboxes[J]. Journal of Sound and Vibration, 2012, 331(22): 4919-4939. [百度学术]
INALPOLAT M, KAHRAMAN A. A theoretical and experimental investigation of modulation sidebands of planetary gear sets[J]. Journal of Sound and Vibration, 2009, 323(3/5): 677-696. [百度学术]
BRAUN S. The extraction of periodic waveforms by time domain averaging[J]. Acta Acustica United with Acustica, 1975, 35(2): 69-77. [百度学术]
MCFADDEN P D. A revised model for the extraction of periodic waveforms by time domain averaging[J]. Mechanical Systems and Signal Processing, 1987, 1(1): 83-95. [百度学术]
MCFADDEN P D. A technique for calculating the time domain averages of the vibration of the individual planet gears and the sun gear in an epicyclic gearbox[J]. Journal of Sound and Vibration, 1991, 144(1): 163-172. [百度学术]
MARK W D. Time-synchronous-averaging of gear-meshing-vibration transducer responses for elimination of harmonic contributions from the mating gear and the gear pair[J]. Mechanical Systems and Signal Processing, 2015(62/63): 21-29. [百度学术]
RANDALL R B. Vibration signals from rotating and reciprocating machines[M]∥RANDALL R B. Vibration-based Condition Monitoring: Industrial, Automotive and Aerospace Applications. 2nd ed. New York: John Wiley & Sons Ltd., 2021: 25-61. [百度学术]
FENG Z P, LIANG M, ZHANG Y, et al. Fault diagnosis for wind turbine planetary gearboxes via demodulation analysis based on ensemble empirical mode decomposition and energy separation[J]. Renewable Energy, 2012, 47: 112-126. [百度学术]
KONG Y, WANG T Y, CHU F L. Meshing frequency modulation assisted empirical wavelet transform for fault diagnosis of wind turbine planetary ring gear[J]. Renewable Energy, 2019, 132: 1373-1388. [百度学术]
WANG T Y, LIANG M, LI J Y, et al. Rolling element bearing fault diagnosis via fault characteristic order (FCO) analysis[J]. Mechanical Systems and Signal Processing, 2014, 45(1): 139-153. [百度学术]
ZHAO M, LIN J, XU X Q, et al. Tacholess envelope order analysis and its application to fault detection of rolling element bearings with varying speeds[J]. Sensors, 2013, 13(8): 10856-10875. [百度学术]
BONNARDOT F, RANDALL R B, ANTONI J. Enhanced unsupervised noise cancellation using angular resampling for planetary bearing fault diagnosis[J]. International Journal of Acoustics and Vibration, 2004, 9(2): 51-60. [百度学术]
BORGHESANI P, RICCI R, CHATTERTON S, et al. A new procedure for using envelope analysis for rolling element bearing diagnostics in variable operating conditions[J]. Mechanical Systems and Signal Processing, 2013, 38(1): 23-35. [百度学术]
ABBOUD D, BAUDIN S, ANTONI J, et al. The spectral analysis of cyclo-non-stationary signals[J]. Mechanical Systems and Signal Processing, 2016, 75: 280-300. [百度学术]
HUANG H, BADDOUR N, LIANG M. Bearing fault diagnosis under unknown time-varying rotational speed conditions via multiple time-frequency curve extraction[J]. Journal of Sound and Vibration, 2018, 414: 43-60. [百度学术]
CHEN S, XIE B, WANG Y, et al. Non-stationary harmonic summation: a novel method for rolling bearing fault diagnosis under variable speed conditions[J]. Structural Health Monitoring, 2023, 22(3): 1554-1580. [百度学术]
ZHANG W Y, WU T H, ZHANG B Q, et al. Multiple squeezing based on velocity synchronous chirplet transform with application for bearing fault diagnosis[J]. Mechanical Systems and Signal Processing, 2023, 188: 110006. [百度学术]
BONNARDOT F, EL BADAOUI M , RANDALL R B, et al. Use of the acceleration signal of a gearbox in order to perform angular resampling (with limited speed fluctuation)[J]. Mechanical Systems and Signal Processing, 2005, 19(4): 766-785. [百度学术]
COATS M D, RANDALL R B. Order-tracking with and without a tacho signal for gear fault diagnostics[C]∥Proceedings of Acoustics 2012. Fremantle, Australia: Australian Acoustical Society, 2012: 1-8. [百度学术]
LECLÈRE Q, ANDRÉ H, ANTONI J. A multi-order probabilistic approach for instantaneous angular speed tracking debriefing of the CMMNO׳14 diagnosis contest[J]. Mechanical Systems and Signal Processing, 2016, 81: 375-386. [百度学术]
LI T Q, PENG Z K, XU H, et al. Parameterized domain mapping for order tracking of rotating machinery[J]. IEEE Transactions on Industrial Electronics, 2023, 70(7): 7406-7416. [百度学术]
LI C, LIANG M. Time–frequency signal analysis for gearbox fault diagnosis using a generalized synchrosqueezing transform[J]. Mechanical Systems and Signal Processing, 2012, 26: 205-217. [百度学术]
杨宇, 罗鹏, 程军圣. 广义变分模态分解及其在齿轮箱复合故障诊断中的应用[J]. 中国机械工程, 2017, 28(9): 1069-1073. [百度学术]
YANG Yu, LUO Peng, CHENG Junsheng. GVMD and its applications in composite fault diagnosis for gearboxes[J]. China Mechanical Engineering, 2017, 28(9): 1069-1073. (in Chinese) [百度学术]
ZHANG D, FENG Z P. Enhancement of adaptive mode decomposition via angular resampling for nonstationary signal analysis of rotating machinery: Principle and applications[J]. Mechanical Systems and Signal Processing, 2021, 160: 107909. [百度学术]
YU X L, YANG Y, HE Q B, et al. Multiple frequency modulation components detection and decomposition for rotary machine fault diagnosis[J]. IEEE Transactions on Instrumentation and Measurement, 2022, 71: 1-10. [百度学术]
LI T Q, HE Q B, PENG Z K. Mono-trend mode decomposition for robust feature extraction from vibration signals of rotating Machinery[J]. Mechanical Systems and Signal Processing, 2023, 200: 110583. [百度学术]
PICINBONO B. On instantaneous amplitude and phase of signals[J]. IEEE Transactions on Signal Processing, 1997, 45(3): 552-560. [百度学术]
YU X L, HUANGFU Y F, HE Q B, et al. Gearbox fault diagnosis under nonstationary condition using nonlinear chirp components extracted from bearing force[J]. Mechanical Systems and Signal Processing, 2022, 180: 109440. [百度学术]