摘要
为了将双谱用于转速波动下的齿轮故障诊断,提出一种基于线调频小波路径追踪的阶比双谱分析方法。该方法首先将分析信号的时间跨度在不同尺度下进行等分,形成不同的时间支撑区,然后用多尺度线调频基函数对信号进行投影分解,通过从不同的时间支撑区内投影系数最大的基函数中寻找出使分解信号能量最大的基元函数组合,获得信号包含的能量最大的信号分量,进而得到齿轮啮合频率分量的估计,最后将啮合频率除以齿轮的齿数得到齿轮的转速信号,根据提取的转速信号对时域振动信号进行等角度重采样,对重采样信号进行双谱分析即得到阶比双谱。仿真分析表明,该方法能在低信噪比条件下准确提取转速信号,从而使得双谱估计能合理应用于转速波动下的齿轮故障诊断,应用实例进一步验证了阶比双谱的有效性和优越性。
In order to perform faults detection of gears with rotational speed fluctuations,using the bispectrum analysis,a novel order bispectrum analysis method based on chirplet path pursuit was proposed.In the method,the time span of signals was divided equally under different scales,resulting in different support regions of time.Then,the vibration signals were projected onto the multi-scale chirplet base functions.By finding the combination of base functions,possessing the largest projection coefficient,the signal component with the largest energy of the original vibration signal was acquired,and the estimation of gear meshing frequency component was achieved.Further,the rotational speed signal of gear was obtained by dividing the gears meshing frequency by the number of teeth.According to the extracted rotational speed signal,the vibration signal at constant angle increment was resampled.The order spectrum then was acquired by analyzing the resampled signals with bispectrum.The simulation experiment results show that the proposed method can accurately extract the rotational speed signal with low signal-to-noise ratio,proving that the bispectrum estimation of gear fault signal under rotational speed undulation is reasonable.The further experiments in applications confirmed the validity and the superiority of the proposed bispectrum analysis.
出处
《振动与冲击》
EI
CSCD
北大核心
2010年第9期33-37,共5页
Journal of Vibration and Shock
基金
高等学校博士学科点专项科研基金项目(20060532009)
国家自然科学基金(50875078)
教育部长江学者与创新团队发展计划项目(531105050037)
关键词
双谱分析
线调频小波
阶比跟踪
故障诊断
信噪比
bispectrum analysis
chirplet
order tracking
fault diagnosis
signal-to-noise ratio
