光幕测速法中微弱光信号的分析与检测

构建了弹丸通过光幕的几何模型,提出了用于检测微弱光信号的边沿提取法,设计了由预处理电路、级联滤波放大电路和整流电路三部分组成的模拟电路,通过滤波的方式可有效滤除自然光和蚊虫噪声的干扰,实现微弱信号提取。该方法还可有效克服弹丸属性对测量的影响,增强检测系统的适应性。仿真实验表明,电路可以有效提取放大微弱的光信号,信噪比达到20 dB以上,满足探测的要求。

Analysis and Detection of Weak Optical Signal in Light Curtain Velocimetry

A geometric model of the projectile through the light curtain is built and the edge extraction method is used to detect the weak optical signals.The designed analog circuit consists of three parts:the pre-processing circuit,the cascade filter amplifier and the rectifier circuit.Effective signals can be extracted by filtering the interference of natural light and insert noise.The method can overcome the impact of projectile properties and enhance the adaptability of detection system.Simulation results show that the circuit can effectively extract and amplify the weak optical signals,and the signal to noise ratio can reach up to 20 dB,meets the requirement of detection.