基于零空间追踪算法的铣削功率信号分析

An Analysis of Power Signal in Milling Based on Null Space Pursuit

功率信号因获取简便、成本低等特点被广泛应用在切削过程监控中,因此对功率信号的特征进行深入分析非常必要。利用零空间追踪算法(Null Space Pursuit,NSP)分解铣削功率信号,分析分量及其能量分布的特征;通过计算能量分布与相关系数的相关程度,探究NSP的自适应性。分析结果表明,铣削功率信号的NSP分量包含大量有关铣削过程的信息,分量能量集中在前4阶;铣削参数恒定时,功率信号可分为静态分量和动态分量两部分;NSP分解铣削功率信号的自适应性良好。

Power signal has been widely used in cutting condition monitoring because of its easy access and low costs. Therefore, it is essential to perform a deep analysis on the features of power signals. Decomposition of power signals was implemented by using null space pursuit （NSP） method, further more, characteristics of subcomponents obtained from the decomposition and its energy distribution were analyzed in the paper. The adaptability of NSP was also explored. Analysis results showed that the NSP subcomponents of power signals in milling were rich in cutting process related information, and the energy of the original signals concentrated on the first four subcomponents. It was also found that when milling parameters kept constant, a power signal could be divided into two parts： static component and dynamic component. Experiments demonstrated that NSP had an excellent adaptability when being applied in decomposing power signals in milling.