基于相位拼接的调频连续波激光雷达跳模影响消除方法

Mode Hopping Elimination Method of FMCW Lidar Based on Phase Splicing

摘要:

为了消除激光跳模对调频连续波激光测距的影响,提出了一种基于重采样信号相位拼接的跳模影响消除方法。该方法利用重采样信号相位展开求导的结果来定位激光跳模发生的时间,并对重采样信号跳模处两端的峰值进行相位拼接来去除跳模段的重采样信号。通过对相位拼接后的重采样信号进行Chirp-Z变换可以得到不受激光跳模影响的目标距离谱。系统对光程约为21.16m的延时光纤进行多次测量,实验效果证明此方法可以消除调频激光跳模对距离测量的影响,并实现了12μm的测距标准差。

Abstract:

To eliminate the influence of laser mode hopping on FMCW ranging, a mode hopping elimination method based on resampled signal phase splicing is proposed in this paper. It uses the result of the phase derivation of the resampled signal to locate the time when laser mode hopping occurs, and phase splices the peaks at both ends of the resampled signal to remove the signal in the mode hopping section. By performing Chirp-Z transformation on the resampled signal after phase splicing, the target distance spectrum not affected by laser mode hopping can be obtained. The system performs multiple measurements on the delay fiber of 21.16m. Experimental results show that this method can eliminate the influence of laser mode hopping on the distance measurement, and improve the measurement standard deviation to 12μm.