以单频-线性频率调制连续波(S-LFMCW)激光作为发射信号,提出了一种基于卡尔曼滤波的高精度相干激光测距方法。对回波信号与本振信号进行拍频测量,获得了频差,通过模数转换和数字信号处理,利用频差信号解算出目标的距离和速度。最后采用卡尔曼滤波算法对测量值进行数据融合,获得了高精度的目标距离估计值。实验结果表明,所提方法适用于大范围动态相干测距激光雷达系统,系统的有效测距范围为8 m~2.7 km,测距精度在0.1 m以内。

A high-precision coherent laser ranging method based on Kalman filtering is proposed using a single-linear frequency modulated continuous wave (S-LFMCW) laser as the transmitting signal . By measuring the beat frequency between the echo signal and the local oscillator signal, the frequency difference is first obtained. The distance and speed of the target are then calculated with this frequency difference signal through analog-to-digital conversion and digital signal processing. Finally, the Kalman filter algorithm is used to fuse the measured data, and the target distance estimation is obtained with high accuracy. The experimental results show that the proposed method is suitable for large-scale dynamic coherent laser ranging lidar systems. The effective ranging range of the system is 8 m to 2.7 km, and the ranging accuracy is within 0.1 m.