外触发方式下相机同步抓拍系统研究  

Research of Camera Synchronous Capture System Under External Trigger Mode

作　　者：李超[1] 刘树昌[1] 刘鹏[2] 周大勇[1] 王雪[1] 

机构地区：[1]长春理工大学电子信息工程学院,吉林长春130022 [2]长春理工大学空地激光通信技术国防重点学科实验室,吉林长春130022

出　　处：《测试技术学报》2014年第4期339-344,共6页Journal of Test and Measurement Technology

基　　金：总装备部测试基金资助项目(KYC-JC-XM-2011-023)

摘　　要：脉冲激光检测系统中,由于激光器发射的激光脉冲频率低,且脉宽仅为纳秒级,所以在远距离测试时,很难控制数字CCD(Charge Coupled Device)相机的精准曝光时刻.为了克服触发信号与激光脉冲信号不同步的问题,本文提出了"光触发,电同步"与"超前预测"相结合的方法.以BD2(BeiDou2 Navigation Satellite System)/GPS(Global Positioning System)模块提供的精确秒脉冲pps(pulse per second)信号作为时钟基准,同时结合FPGA(Field Programmable Gate Array)高速的特点,实现数字CCD相机对激光光斑图像的准确捕获,控制数字CCD相机的最佳积分时间.实验结果表明,该方法不仅提高了数字CCD相机的抓拍精度,也提高了图像的信噪比.As the laser pulse frequency is low and the pulse＇s width is ns grade in the pulse laser detection system, it＇ s difficult to control the accurate exposure moment of the digital CCD camera. In order to overcome the difficulty that the trigger signal for the digital CCD camera and the laser pulse signal are not synchronous, a method that combining the ＂light trigger, electrical synchronization＂ with advanced prediction is put forward. BD2/GPS module provided the PPS pulse signal as the clock reference, combined with the FPGA＇ s high speed characteristic, so the digital CCD camera could capture the laser spot image exactly, and control the best integral time of the digital CCD camera. The experiment indicates that this method can improve the capturing precision of the digital CCD camera and the SNR of laser spot image.

关 键 词：同步抓拍 超前预测 外触发方式 FPGA 光触发 电同步 

分 类 号：TB82[一般工业技术—摄影技术]