摘要
在以CCD作为传感器测量线材外径的装置中,由于线材表面不光滑使光线产生散射,以及光源不是绝对的平行光等原因,都将引起在亮区与暗区过渡中的信号幅度介于高、低电平之间。为了准确取得数据,必须设定一个阈值,以鉴别它们应归属何种电平。本文提出应用浮动阈值法,对CCD输出信号的轮廊进行二值化,实际测试说明误差不大于一个光敏元的间距12μm,达到了提高精度的目的,而且电路也比较简单。
In the device using CCD transducer, to measure wire diameter, because of the seatter from the rough wire surface and the non-paralell light, the magnitudes of signals from the transition area (from dark to bright) are between high and low level. For precise deta, we must give a threshold value to decide which level they belong to. A method of floating threshold value is presented here to get binary value of the outlive of CCD output signal. By experiments, the error of measurement is no more than 12μm, which is the distance between two light-sensitive elements. And the circuit is rather simple.
关键词
浮动阈值法
信号处理
CCD
电路
method of floating threshold value, processing of CCD signal, improve the precision of measurement
