三角波调制在激光测距中的应用研究

Triangular-Wave Modulation in a Laser Ranging System

提出了一种基于最小二乘拟合的三角波调幅激光测距方法,设计了具有光程差的参考信号和测量信号两路信道,采用改进的最小二乘直线拟合算法对两路回波信号进行拟合,得到了关于三角波的拟合参数和奇异特征点;根据两路信号特征点所携带的时移信息之间的关系,可用所提方法进行测距。在10 kHz三角波调制频率的实验条件下,采用几何理论计算得出所提测距方法在测量距离为10 m时的平均测量精度能达到3.2 mm。实验结果证明了该测距方法的有效性,在短距离激光测距方面具有一定的应用前景。

In this study, a novel least-squares-based method is proposed to measure the distance using a triangular-wave amplitude modulation laser. Further, we designed two channels comprising a reference signal and a measured signal that exhibit an optical path difference. Their return signals were fitted using the improved least-squares-based straight-line fitting algorithm, and a series of fitting parameters and singular characteristic points were obtained for the triangular-wave. Subsequently, we estimated the detection distance using the proposed theoretical algorithm based on the relation of the time shift information associated with the characteristic points of two signals. The average measurement error associated with this laser ranging system is 3.2 mm at a 10-m measurement range in case of a triangular-wave modulation frequency of 10 kHz, demonstrating the reliability of the proposed method. Furthermore, the proposed method exhibits certain application potential with respect to short-scale laser ranging.