面向大振幅、长周期振动校准的零差正交激光干涉测振方法

Homodyne quadrature laser interferometry measurement method for large amplitude, long cycle vibration calibration

针对零差正交干涉测量应用于超低频超大振幅标准振动台性能测试时非正交相移误差补偿困难、所需采样率极高的问题,提出了一种欠采样零差正交激光干涉测振方法。在设计消偏振分光测量光路的基础上,提出波片偏航调整方法,进行非正交相移误差的硬件实时补偿;提出基于运动状态预估的卡尔曼正交信号解调算法,对深度欠采样的干涉条纹进行相位信号解调,以大幅降低所需的采样率及产生的数据量。实验和仿真结果表明,文中方法可大幅降低零差正交干涉的非正交相移误差及其对波片角度偏差的灵敏度,且在测量超低频振动时,卡尔曼正交信号解调算法所需的采样率和每通道数据采集点数降低至奈奎斯特采样定理的0.056%。文中提出的欠采样零差正交激光干涉测振方法较好地满足超低频超大振幅标准振动测试的需求。

In order to carry out performance testing of ultra-low frequency standard vibration table with large amplitude,an undersampling homodyne quadrature laser interferometry measurement method was proposed in this paper.Based on the design of depolarization beam splitting measurement optical path,a wave plate yaw adjustment method was proposed to compensate hardware of the quadrature phase error in real time.The Kalman quadrature signal demodulation algorithm based on motion state estimation was presented to demodulate the interference fringes of deep undersampling to reduce the sampling rate and the amount of data produced.The experimental and simulation results show that the quadrature phase error and its sensitivity to the angle deviations of wave plates are significantly reduced,the sampling rate of the Kalman quadrature signal demodulation algorithm and number of samples per channel are reduced to 0.056%of Nyquist sampling theorem for measuring ultra-low frequency vibration.The undersampling homodyne quadrature laser interferometry measurement method proposed in this paper can meet the requirements of ultra low frequency and ultra large amplitude standard vibration measurement.