目前基于 PSD的光电探测应用大多是以激光入射, 有效信号远强于背景, 为了满足更大的测量需求, 本文提出了一种基于 PSD的强背景下探测闪光点空间位置的方法。设计了预处理电路将 PSD产生的微弱电流信号转换为电压信号并经过高速 AD转换为数字信号, 分析了背景信号对 PSD测量结果的影响, 提出了在软件中减去背景和暗电流以提取有效信号并对其进行精确计算的方法。用 LED做闪光点在不同室外背景下进行了相关实验, 结果表明: 该方法可以实现 200 kHz的高速测量, 有效去除了不同背景和暗电流的影响, 强背景下测量线性误差在 ±1.2%以内。

Current applications for photoelectric detection based on PSD were mostly with the incidence of laser, whose effective signal was highly stronger than that of background. A method of light-spot space position measurement under strong background based on PSD technology was proposed to enlarge the range of measurement. The pre-processing circuit was designed to convert the weak current signal from PSD to a voltage signal and finally to a digital signal from high-speed AD transformation. Influence on the results of PSD measurement form the background signal was analyzed. A method for extracting effective signal and accurate calculation for it was proposed by subtracting background and dark current signal. Related experiments with LED light-spot under different outdoor backgrounds show that this method can achieve 200 kHz high-speed measurement. Because of eliminating the influence from different background and dark current signal, linearity error of the measurement under strong background can reach the range of ±1.2%.