一种基于VMD的颤振试飞模态参数辨识方法

A Modal Parameter Identification Method for Flutter Flight Test Based on VMD

颤振试飞信号具有非平稳、模态密集、信噪比(SNR)低的特点。近年来,新发展的变分模态分解方法在处理该类信号时能有效避免模态混叠,且有较好抗噪能力。故将变分模态分解法和希尔伯特变换结合,提出了一种可用于颤振试飞脉冲响应的时频域模态参数辨识新方法,称为VMD-HT方法。通过仿真算例验证和实际颤振试飞中的应用,表明该方法能准确稳定地辨识出脉冲信号的模态参数,且对于不同部位传感器数据的辨识结果聚集度更高,在实际型号试飞中取得了良好效果。

The signal of flutter flight test has the characteristics of non-stationary, dense mode and low SNR.Variational mode decomposition method, which was developed in recent years, can avoid mode mixing effectively and have a good resistant ability to noise.Therefore, by combining variational mode decomposition method and Hilbert transform, a new modal parameter identification method of time-frequency domain for impulse response in flutter flight test was proposed in this paper, which is called VMD-HT method.The simulation examples and the application in the actual flutter flight test showed that this method can accurately and stably identify the modal parameters of the impulse signal, and the identification results for the sensor data in different positions have higher aggregation, which has achieved good results in the actual flutter flight test.