为了解决电磁振镜系统中镜面大角度偏转难以测量的问题，设计了一种基于四单元光电探测器（PD）与LED的光电式镜面角度传感装置。首先分析了镜面角度检测的基本原理，基于LED朗伯辐射模型，建立了镜面偏转角度的真实值与解算值之间数学模型；其次以非线性度为评价标准定义了系统检测范围；然后仿真分析了探测器水平位置、镜面中心与LED距离和LED半功率角对系统检测范围的影响；最后搭建了实验平台进行验证。仿真及实验结果表明：所建立的数学模型对使用朗伯型LED进行镜面角度检测是有效的；通过减小探测器与LED之间距离、增加镜面中心与LED距离和增大LED半功率角，可以提高系统的角度检测范围。

As the large angle deflection of a mirror is difficult to measure in an electromagnetic galvanometer system, a photoelectric mirror-angle-sensing device based on the quadrant photoelectric detector (PD) and LED was designed. First, the basic principle of mirror angle detection was analyzed, and based on the LED Lambertian radiation model, the mathematical model between the true value and the calculated value of the mirror deflection angle was established. Second, the system detection range was defined with the nonlinearity as the evaluation standard. Then, the influence of the detector's horizontal position, distance between the center of the mirror and the LED, and half-power angle of the LED on the detection range of the system were simulated and analyzed. Finally, an experimental platform was built for verification. The simulation and experimental results show that the established mathematical model is effective for mirror angle detection using Lambertian LED. With reduced distance between the detector and the LED, increased distance between the center of the mirror and the LED, and increased half-power angle of the LED, the angle detection range of the system can be improved.