基于ITD和切片双谱的滚动轴承局部损伤故障诊断

Fault Diagnosis for Local Damage Rolling Bearings Based on ITD and Slice Bi- Spectrum

针对滚动轴承局部损伤故障诊断问题,提出一种基于本征时间尺度分解(ITD)和切片双谱的故障诊断方法。首先利用ITD方法将轴承故障信号分解为若干个合理旋转(PR)分量,然后对PR分量进行包络解调,并计算其切片双谱,提取轴承故障信号由于二次相位耦合产生的非线性特征,确定轴承故障类型。为加快分解速度并减少分解运算量,对ITD方法迭代终止条件进行改进。对仿真信号的分析表明,ITD方法对信噪比较低的信号具有很好的分解效果,并验证了切片双谱在抑制噪声和剔除非二次相位耦合谐波方面的优势。

Aiming at the fault diagnosis about local damage rolling bearings,a fault diagnosis method is presented based on intrinsic time- scale decomposition（ ITD） and slice bi- spectrum. Firstly,the fault signal of bearings is decomposed into some proper rotation（ PR） components by using ITD method. Then the PR components are demodulated by the envelope analysis,and a slice bi- spectrum is computed to extract the non- linear feature deriving from the quadratic phase coupling and determine the fault types of bearings. In order to accelerate the decomposition rate and reduce the amount of computation,the iterative stopping conditions of ITD method is improved. The analysis of simulation signals shows that ITD method has a good result in decomposing the lower SNR signal,and the advantage of slice bi- spectrum in inhibiting the noise and eliminating non- quadratic phase coupling harmonic components is verified.