光子计数激光雷达时间-数字转换系统

时间测量系统在激光雷达中主要用于激光脉冲飞行时间的测量,其性能直接影响着激光雷达的各项指标.基于FPGA设计了一种应用于光子计数激光雷达的时间-数字转换(Time-to-Digital Converter,TDC)系统,利用延迟线内插在FPGA内部实现了高精度的时间测量,通过实验分析,研究了TDC系统的性能及其应用于光子计数激光雷达后的效果.实验结果表明,TDC系统的时间分辨率达到29 ps,测时精度37 ps,能够实现9通道的高精度事件计时功能,用于光子计数激光雷达后,整个激光雷达系统的测时精度为421 ps,达到6.3 cm的距离测量精度,能够实现高精度高分辨率的激光三维成像.

A time to digital converter used in photon-counting LIDAR

Timing system was used to measure the time of flight(TOF) of laser pulse in light detection and ranging(LIDAR). Performance of a LIDAR system is directly influenced by the properties of the timing system. A time to digital converter(TDC) based on FPGA was designed for photon counting LIDAR. By integrating the delay line interpolation into FPGA, the designed TDC could measure the TOF with fine accuracy and resolution. The performance of the TDC and its application in photon counting LIDAR were analyzed and studied experimentally. Event timing of 9 channels was implemented with this TDC, with a resolution of 29 ps and a timing accuracy of 37 ps. Using a LIDAR system equipped with the TDC, three dimensional imaging can be realized with time accuracy of 421 ps and 6.3 cm resolution in space.