摘 要:综合考虑再生切削效应和模态耦合效应,建立了随机扰动激励下两自由度切削加工系统的时滞动力学模型。分析了刚度主轴方位对切削稳定性叶瓣的影响。将切削系统的动态响应作为观测数据,基于互四阶累积量的谐参数联合估计ESPRIT方法,考察了刚度主轴方位对模态耦合再生切削系统动态响应的互功率、频率和相移等谐参数的影响,揭示了这些谐参数关于刚度主轴方位角的一些新依赖特征。
Abstract: Both regenerative cutting and mode-coupling principles are taken into consideration to model the delayed dynamics of regenerative machining system under stochastic excitation. The influencing of the orientation of principal stiffness axes on machining instability lobes is analyzed. The dynamic responses of machining system are sampled as the observation data. The cross fourth-order cumulant based ESPRIT approach to jointly estimating harmonic parameters is proposed, which is applied to investigate the influence of the orientation of principal stiffness axes into the harmonic parameters of dynamic response in mode-coupled regenerative machining system. Several novel dependent characteristics of the harmonic parameters on the orientation of principal stiffness axes is disclosed, these harmonic parameters includes the frequency, phase shift and cross power of the dynamic machining responses.
Key words: machine tool; regenerative machining; mode-coupling principle; dynamic stability; cross high-order cumulants.