用于CCD立靶的双光幕触发系统研究

Dual-screen triggering system for CCD vertical target

针对靶场测试当中CCD立靶测量系统需要稳定可靠触发的需求,提出一种双光幕触发系统。采用镜头式光幕探测器配合高亮度LED慢散射光源组成触发探测光幕,利用2个同样的光幕探测器配合测时装置组成区截测速系统,根据测得的速度值判定飞越探测光幕的目标是否为真实弹丸,并决定是否输出触发信号。根据速度值V和触发光幕至CCD探测光幕的距离计算出弹丸飞越至探测光幕的时间,然后在弹丸飞越将近至探测光幕的时刻输出触发信号。该方案不但可以提高系统的稳定性,避免非真实目标对系统的干扰,还可以为后续CCD图像采集系统在准确时刻提供触发信号。经实验证明,所设计的双光幕触发系统的速度测量误差不大于0.4%,完全满足CCD立靶测量系统需要精确触发的要求。

On the request of the stable and reliable trigger required in charge-coupled device (CCD) vertical target measurement system in the condition of firing range ,a dual-screen trig-ging system was presented .The trigging detecting screen was composed of lens-type screen detector ,working with the high-intensity LED slow-scattering light ,and the velocity-measur-ing system consists of two identical screen detectors working together with chronometer ,and then it judged whether the projectile passing through the screen was real based on the measured velocity and whether to output the trigging signal or not .The time for projectile flying from impacting screen to detecting screen was achieved according to the velocity value V and the dis-tance between impacting screen and detecting screen ,and then the triggering signal was output while the projectile was approaching to CCD detecting screen .The proposed scheme can im-prove the stability of the system ,prevent the system from being interfered by unreal targets , and can transmit trigging signal at the precise time to follow-up CCD image-acquisition system . It has been proved by experiment that the speed measurement error of the designed dual-screen triggering system is not more than 0 .4% ,fully meeting the demand of the stable and reliable trigger requirement of the CCD vertical target .