主动式激光光幕测速系统天幕干扰抑制方法

Active laser light curtain speed measuring system sky curtain interference suppression method

主动式激光光幕测速系统中,天空背景光经光学系统变换形成天幕,严重干扰系统信号输出,影响系统灵敏度。通过对系统接收光能量数学建模分析,提出改进方法,设计了可调狭缝光阑,分析了在不同天空背景亮度下,不同狭缝光阑的位置及宽度对系统接收光能量的影响。通过调节光阑相对位置与宽度,有效抑制天幕对系统影响,并进行了相应试验。结果表明:当激光光幕厚度为2 mm,狭缝光阑位于焦平面,狭缝宽度为0.15 mm时,改进前后系统信噪比提高1.8倍,系统灵敏度最高,抑制天幕效果最好。

In active laser light curtain speed measurement system,sky background light is transformed to form sky screen by optical system.Sky screen seriously interferes output of system signal and affect system sensitivity.Through mathematical modeling and analysis of received light energy of system,an improved method is proposed,and adjustable slit diaphragm is designed.The influence of position and width of different slit diaphragm on light energy received by the system is analyzed under different sky background brightness.By adjusting the relative position and width of the diaphragm,the influence of the sky screen on the system is effectively suppressed,and corresponding experiments are carried out.The results show that when the thickness of the laser light curtain is 2 mm,the slit diaphragm is located on the focal plane,and the slit width is 0.15 mm,the signal-to-noise ratio is increased by 1.8 times after improvement,the system sensitivity is the highest,and the skyscreen suppression effect is the best.