基于自适应窗口与压缩幅值的瞬时转频估计

Instantaneous Frequency Estimation Based on AdaptiveWindow and Compressive Amplitude

针对变转速工况下轴承信号的时频分布能量发散、噪声和谐波干扰强导致其转频难以获取的问题,提出一种基于自适应窗口和压缩幅值的瞬时转频估计方法。首先,通过自适应窗口在频率轴方向搜索出脊线窗口避免噪声和谐波的干扰;其次,在脊线窗口内用压缩幅值方法集中发散的脊线能量;然后,用惩罚函数法提取脊线,实现转频的精确估计;最后,根据采用轴承实验台收集的数据验证了所提出方法的有效性和鲁棒性。结果表明,相比于传统方法,采用所提方法估计瞬时转动频率使误差降低约8%。

Aiming at the problem that the time-frequency distribution of the bearing signal under the condition of variable rotation speed is difficult to obtain due to the energy divergence,strong noise and harmonic interference,an instantaneous frequency estimation method based on adaptive window and compressive amplitude is proposed.Firstly,the ridge window is searched in the frequency axis direction through the adaptive window to avoid the interference of noise and harmonics.Secondly,the divergent ridge energy is concentrated in the ridge window using the compressed amplitude method.Then,the ridge line is extracted by the penalty function method to achieve accurate estimation of the transponder frequency.Finally,the effectiveness and robustness of the proposed method are verified by using the data collected from the bearing test bench.The results show that,compared with the traditional method,the error value of the instantaneous rotational frequency estimated by the proposed method is reduced by about 8%.