直升机旋翼动平衡振动信号的等角度重采样算法研究

目的 准确测量直升机旋翼基频振动的强度和相位,开展对基于振动信号降噪的等角度采样算法研究。方法 基于直升机旋翼动平衡检测的经典架构,提取桨毂传导过来的啮齿咬合振动信号,作为等相位采样的标尺,从而将振动数据从等时间采样,转换为等角度采样,减少转速微弱波动导致的相位非均匀采样对快速傅里叶变换的影响。结果 针对某型现役直升机在满速下获得的主旋翼测试数据,在经过上述方法进行重采样后,测量结果的滚动平均振动强度和相位的波动性明显降低,振动波动小于±0.01IPS,相位波动小于±10°。结论 在采用加速度传感器的条件下,通过采用啮齿咬合高频信号作为标尺,对振动信号进行等角度重采样可以提高测量的精确度。

Research on Helicopter Rotor Balance Detection and Vibration Signal Equal-angle Resampling Algorithm

In order to accurately measure the intensity and phase of helicopter rotor fundamental frequency vibration, this paper has carried out the research on equal angle sampling algorithm based on vibration signal noise reduction. Based on the classical architecture of helicopter rotor dynamic balance detection, the meshing vibration signal transmitted from the rotor hub is extracted as the scale of equal phase sampling, so as to convert the vibration data from equal time sampling to equal angle sampling, thus reducing the impact of phase non-uniform sampling caused by the weak fluctuation of speed on the FFT. For the main rotor test data of a helicopter in service at full speed, the rolling average vibration intensity and phase fluctuation of the measured results are significantly reduced after resampling by the above methods. The measured results of a helicopter show that the vibration fluctuation is less than ±0.01IPS and the phase fluctuation is less than ±10°. Under the condition of using the acceleration sensor, the precision of measurement can be improved by using the high frequency signal of meshing as the scale and resampling the vibration signal at the same angle.