非接触式异步振动参数辨识仿真研究

Simulation Research on Non-Contact Asynchronous Vibration Parameters Identification

简要介绍了叶尖定时测振原理,基于单自由度振动原理,利用三角函数和最小二乘法建立了异步振动重构方法。为提取重构方法中关键参数-相位差,通过分析传统FFT算法和全相位FFT算法的优缺点,建立了融合传统FFT算法与全相位FFT算法的相位差提取方法。数值仿真表明:异步共振频率计算值与真实值的差值为0.06 Hz,误差为0.017%;幅值计算值与真实值的差值为0.1 um,误差为0.05%。建立的异步振动重构方法合理可行,能够满足工程试验的需求。

The principle of vibration measurement based on blade tip timing is briefly introduced in this paper;based on the single degree of freedom vibration principle, an asynchronous vibration reconstruction method is established by using the trigonometric functions and the least squares. In order to extract the phase difference, which is the key parameter of the reconstruction method, a phase difference extraction method combining the traditional FFT algorithm with the all-phase FFT algorithm is established by analyzing the advantages and disadvantages of the traditional FFT algorithm and the all-phase FFT algorithm. The numerical simulation results show that the difference between the calculated value and the true value of the asynchronous resonance frequency is 0.06 Hz, with an error of 0.017%;while difference between the calculated value and the true value of the amplitude is 0.1um, with an error of 0.05%. It is concluded that the asynchronous vibration reconstruction method is reasonable and feasible, and it can meet the needs of engineering test.