鉴于小角度测量的要求, 采用自准直角度测量技术, 建立自准直光路数学模型, 推导PSD探测像点坐标Y和平面镜偏转角α的方程。PSD小角度测量系统由前置放大、A/D转换电路、采样电路和液晶显示构成。PSD位置传感器输出两路角度信息数据, ADC完成模数转换, 由单片机进行数据运算, 最后, 位置和偏转角的求解结果在液晶屏上显示。仿真结果显示, 前置放大电路性能指标、单片机采样10-2 mrad量级精度均达到了系统的要求。

According to the requirements of small angle measurement, with the auto collimation angle measurement technology, an auto collimation optical path mathematical model is built and the equation about the photoelectric position detector (PSD) image point coordinate Y and the flat mirror deflection angle α is deduced. PSD small angle measurement system is composed of preamplifier, A/D conversion circuit, sampling circuit and liquid crystal display. PSD position sensors output duplex angle information data, the ADC circuit completes A/D conversion, the single chip microcomputer completes data operation, in the end, the results of the position and the deflection angle are displayed on LCD screen. Simulation results show that the preamplifier circuit performance and single chip microcomputer sampling of 10-2 mrad level precision both meet the system requirements.