再生切削颤振系统动态响应谐参数辨识

Harmonic parameter identification of dynamic response in regenerative machining chatter system

考虑多重再生切削效应,建立了切削系统在随机噪声激励下的时滞动力学模型及递推求解算法。利用基于互四阶累积量的谐参数联合估计TLS-ESPRIT方法,讨论了再生型切削系统动态响应的频率、相邻两转切削间相移和互功率的辨识,揭示了在动态失稳切削中这些谐参数的演变特征以及多频再生型切削颤振现象。研究结果表明,基于互四阶累积量的谐参数估计TLS-ESPRIT方法可抑制噪声,具有优越的参数估计性能,能够在动态失稳切削中抽取再生型切削不稳定性的演变特征。

A delayed dynamics model was built for the machining system under the excitation of the stochastic noise taking the multiple-regenerative cutting effect, and a recursive algorithm for the solution was proposed. Using the TLS-ESPRIT algorithm based on the combination estimation of the harmonic parameter of the cross 4th order eumulant, the frequencies of the dynamic response of the regenerative machining system, the phase shifts between the successive cuts and the cross power identification were discussed, and the evolution features of these spectrum parameters and the multi- frequency regenerative machining chatter phenomenon during the dynamically destabilizing machining were revealed. The simulation and experiment results demonstrate that the TLS-ESPRIT algorithm can suppress the hybrid colored noise, retrieve the harmonic parameters with excellent estimation, and extract the evolution features of the instability of the regenerative machining chatter system.