分形在钻头磨损切削力特征提取中的应用

针对钻削过程切削力的变化特点,提出一种用分维数描述信号复杂性的新方法.从工程应用角度介绍了离散时间序列盒维数和信息维数的计算方法,通过对三种仿真信号分维数的计算,揭示出分维数与信号复杂程度之间的内在联系,并通过实验研究了刀具在整个磨损历程中切削力信号分维数的变化规律.结果表明:随着钻头磨损的增加,切削力信号分维数呈下降趋势,运用切削力信号的分维数特征可有效实现钻头磨损状态的监测.

Fractal Based Feature Extraction of Cutting Force and Its Application in Tool Wear Monitoring

The paper presents a new method of describing signal complexity using fractal dimension according to the change characteristic of the cutting force in the drilling process. From the point of view of engineering application, it introduces the algorithm of box dimension and information dimension for discrete time series and reveals the inherence relation between the fractal dimension and signal complexity by calculating the fractal dimensions of three simulating signals. It also researches into the changing rules of the fractal dimension in the whole course of tool wear through experiments. The results show that along with the increase of tool wear, the fractal dimension of the cutting force signal assumes the falling trend, and the tool wear monitoring can be realized effectively by using the fractal dimensions as the feature of the cutting force signal.