激光干涉波形解调测量振动相位新方法

A new method of vibration phase measurement based on the laser interference wave demodulation

激光干涉频比计数法广泛应用于绝对法振动标准装置,针对频比计数法只能测量振幅不能得到振动相位,提出一种利用激光干涉条纹与振动台运动位移之间的关系,实现测量振动相位的新方法,并给出激光干涉波形解调测量振动相位的数学模型。该方法基于零差的迈克尔逊激光干涉仪,利用高速采集器同步采集激光干涉信号和传感器信号,并在Lab VIEW虚拟仪器开发平台上,软件解调振动波形,实现振动幅值和振动相位的实时测量。测量结果与正弦逼近法相一致。

Laser interference frequency ratio counting method is widely used in vibration standard devices using absolute method. For the frequency ratio counting method can only measure the vibration amplitude, and cannot get the vibration phase, this article introduces a new method of measuring vibration phase based on the relationship of laser interference fringes and displacement of vibration, and puts forward the mathematical model of the phase measurement based on the laser interference wave demodulation. The new method is based on homodyne Michelson laser interferometer, uses high-speed automatic synchronization acquisition sensor signal and laser interference signal. It used the LabVIEW development platform to get the vibration amplitude and phase information through software demodulation vibration displacement of the laser waveform. The method realizes the real-time measurement of the vibration phase. The measured results agree with the sinusoidal approximation method.