相干调频连续波激光雷达畸变补偿技术研究

Distortion Compensation Technology of Coherent Frequency Modulation Continuous Wave Lidar

扫描激光雷达在无人驾驶系统中起着不可替代的作用,是近几年的研究热点。由于多脉冲周期之间每个点的时刻皆不相同,激光雷达与成像目标之间的相对运动会造成目标三维图像重构的畸变,因此必须进行补偿才能够实现真正的高精度三维成像。为此,提出了一种基于相干调频连续波激光雷达速度测量对于运动产生畸变进行逐点补偿的方法。仿真与实验结果表明,速度相对误差和成像距离误差分别为0.52%和±4.76 cm。与传统加速度计方法相比,本文方法不依赖于加速度计等外部测量,具有更高的普适性,对于激光雷达的实际应用具有重要意义。

Scanning lidar plays an irreplaceable role in driverless system, which is a research hotspot in recent years. Because the time of each point is different between the multi pulse periods, and the relative motion between the lidar and the imaging target will cause the distortion of the three-dimensional(3 D) image reconstruction of the target, so it is necessary to compensate for the real high-precision 3 D imaging. In this paper, a point by point compensation method for motion distortion based on the velocity measurement of coherent frequency modulated continuous wave lidar is proposed. The simulation and experimental results show that the relative velocity error and imaging distance error are 0.52% and ±4.76 cm, respectively. Compared with the traditional accelerometer method, the proposed method does not rely on external measurement such as accelerometer, and has higher universality, which is of great significance for the practical application of lidar.