基于FPGA的激光回波数据采集与传输系统  

Laser echo data acquisition and transmission system based on FPGA

作　　者：吴洋 徐广平[1] 耿林[1] 张伟健 WU Yang;XU Guang-ping;GENG Lin;ZHANG Wei-jian(North China Research Institute of Electro-Optics,Beijing 100015,China)

机构地区：[1]华北光电技术研究所,北京100015

出　　处：《激光与红外》2020年第11期1345-1351,共7页Laser & Infrared

摘　　要：传统的激光测距机只是通过测量激光发射主波和目标反射的回波的时间间隔来测量目标距离的。这种方法简单易行,但是没有充分利用信号波形所携带的信息,没有达到探测系统的最佳信噪比。为了提高信号的信噪比、增加激光测距机的作用距离,可以采用全波形高速采样的方案,这些激光全波形数据可用于后续处理的幅度累加、自相关、互相关等处理,能够有效地提高回波信号的信噪比。本文的工作是这种测距方案的一个重要组成部分,包括高速AD采样、FPGA的时序控制、数据采集和传输等部分。针对激光回波数据采集与实时传输的要求和AD采样芯片的多通道、数据量大、速率快的特点设计了基于现场可编辑逻辑门阵列(FPGA)、单时钟先进先出存储器FIFO(First-In-First-Out)和RS232接口总线的激光回波数据采集与实时传输系统。系统主要以FPGA和RS232协议为核心,主要研究采用状态机设计模块来将系统各个模块联结起来。由FPGA向AD芯片写入配置数据的同时,也接收AD芯片的输出数据并送入到FIFO存储器进行缓存和运算处理,处理好的数据由RS232总线发送给上位机进行数据处理。仿真实验结果表明系统逻辑准确,可以满足激光回波波形实时采集与传输的基本要求。The traditional laser rangefinder only measures the distance of the target by measuring the time interval between the main wave emitted by the laser and the echo reflected by the target.This method is simple and easy to implement,but it does not make full use of the information carried by the signal waveform and does not achieve the best signal-to-noise ratio of the detection system.In order to improve the signal-to-noise ratio of the signal and increase the range of the laser rangefinder,a full-wave high-speed sampling scheme can be used.These laser full-waveform data can be used for subsequent processing such as amplitude accumulation,autocorrelation,and cross-correlation,which can effectively improve the signal-to-noise ratio of the echo signal.The work of this article is an important part of this ranging scheme,including high-speed AD sampling,FPGA timing control,data acquisition and transmission.Aiming at the requirements of laser echo data acquisition and real-time transmission,and the characteristics of AD sampling chip′s multi-channel and large data volume fast rate,and a field-editable logic gate array(FPGA),single-clock first-in first-out memory FIFO(First-In-First-Out)and RS232 interface bus laser echo data acquisition and real-time transmission system.The system is mainly based on FPGA and RS232 protocol,and the main research is to use the state machine design module to connect the various modules of the system.When the FPGA writes the configuration data to the AD chip,it also receives the output data of the AD chip and sends it to the FIFO memory for buffering and arithmetic processing.The processed data is sent to the upper computer by the RS232 bus for data processing.The simulation experiment results show that the system logic is accurate and can meet the basic requirements of real-time acquisition and transmission of laser echo waveforms.

关 键 词：激光回波数据采集 AD采样 现场可编辑逻辑门阵列(FPGA) RS232总线 实时传输 

分 类 号：TN249[电子电信—物理电子学]