基于接触模型和峭度最优Laplace小波的滚动轴承量化诊断

Quantitative damage diagnosis for rolling bearing based on contact vibration model and optimum kurtosis-Laplace wavelet

研究了滚动轴承损伤量化诊断中的正反问题。通过对轴承界面相互作用的动态接触理论及摩擦学系统行为的研究,运用振动传递路径表征物理模型。该模型计及负荷分布、游隙的影响,考虑接触滑移、分离作用,由表面轮廓变化描述局部损伤扩展,由测量信号修正模型参数,实现真实工况下轴承服役与数值模拟的有机结合。通过正问题求解构造峭度最优Laplace小波来提取无量纲指标,进而形成损伤矩阵数据库。将反问题计算转化为多维优化问题,利用灰色关联度寻优求解出与输入值最近的样本点,进而测出轴承损伤的位置和具体尺寸。最后的实例分析表明,此方法具有较好的精度和鲁棒性,且易于在工程实践中推广。

The positive and inverse problems of quantitative damage diagnosis for rolling bearing are studied. The physical model was characterized according to the vibration transmission path by studying the interactions of bearing interface based on dynamical contact theory and tribology. The influences of the load distribution and play, and the contact slippage, separation, local fault enlargement depicted by surface profile changes were considered in the model. Model parameters were modified based on the measured signals, thus integrating active service with numerical simulation in the case of real operation. By solv- ing the positive problem the optimum kurtosis-Laplace wavelet was constructed to obtain the dimensionless index, thus forming the damage matrix database. The inverse problem could be transferred into multi-dimension optimization one. Using optimization for grey degree of association the samples which are the most close to the inputs were obtained and furthermore the damage location and size could be determined. Practical experimental data verifies the validity and robustness of the quantitative diagnosis method, which is easy to popularize for engineering application to diagnose the defects in bearing system.