直升机旋翼动平衡测量方法研究

为实现直升机旋翼在高速旋转过程中动平衡值的测量,提出了一种基于阶次跟踪的测量方法。该方法首先利用阶次跟踪原理对旋翼转速信号进行等角度重采样,确定重采样的时刻值;然后利用等角度重采样时刻值,对经三次多项式最小二乘法曲线拟合后的振动信号进行二次重采样,得到旋翼振动阶次重采样信号;最后利用离散傅里叶变换方法对其进行阶次谱分析,得到旋翼的动平衡值。该方法有效克服了传统频谱分析方法在分析非平稳信号中存在的频率混叠及能量泄露等问题;同时,该测量方法通过软件实现具有较好的可移植性,能与其他直升机减振分析模块一起使用。通过在仿真试验台及试验机上进行验证试验,结果表明,该方法能有效测量直升机旋翼的动平衡值。

Measurement Method of Helicopter Rotor Dynamic Balance

In order to achieve the measurement of the dynamic balance value of the helicopter rotor during high-speed rotation,a measurement method based on order tracking is proposed.Firstly,the principle of order tracking was used to resample the rotor speed signal at an equal angle to determine the time value of the resampling.Then,based on the time value of equal angle resampling,the rotor vibration signal after cubic polynomial least square curve fitting was resampled twice to obtain the order resampling signal of rotor vibration.Finally,the order spectrum analysis of the resampled vibration signal was used to obtain the dynamic balance value of the rotor by the discrete Fourier transform method.The method effectively overcomes the problems such as frequency aliasing and energy leakage existing in the analysis of non-stationary signals in traditional spectrum analysis methods.At the same time,the computing module has good portability and can be used with other helicopter vibration damping software modules.The experimental results show that this method can effectively measure the dynamic balance value of the helicopter rotor.