汽车传动轴振动信号分形维数计算

Study on Chaotic Behavior of Vibration Signal of Automotive Transmission Shaft

讨论了确定混沌时间序列嵌入维数的平均最近邻域发散度方法,并根据从时间序列中计算分形维数的方法,计算了一组不同平衡度汽车传动轴振动信号分形维数。计算表明,汽车传动轴振动信号具有分形特征;在时间序列具有较大噪声时,平均最近邻域发散度法能很好地确定其嵌入维数,具有良好的收敛性;在其他条件不变时,传动轴的不平衡度与其振动信号的分形维数值呈线性关系,当时间序列样本点达到一定数目时。

Chaotic vibration is one of the newest research fields and the fractal dimension calculation of chaotic vibration has not a good method which is accepted publicly. This paper describes the method for calculating embedding dimension with Average Nearest Neighbor Divergence(). Then according to the method of calculating a time series fractal dimension the fractal dimension of vibration signals of automotive propeller shaft is calculated. The results show that the vibration signals of automotive propeller shaft have fractal feature and by using the DIV method the fractal dimension of the time series with heavier noise could be estimated well and there is a good convergence. When other conditions unchang, the imbalance degree of automotive propeller shaft has a linear relationship with the fractal dimension. When the number of sample date points is big enough, the calculation result is rather stable.