为提高光电编码器的分辨力，并缩小体积，提出一种基于图像处理技术的面阵图像式光电编码器。根据光电编码器的性能指标要求设计了光学码盘；然后，通过互补金属氧化物半导体（CMOS）图像传感器采集旋转码盘的图案，由复杂可编程逻辑控件(CPLD)，数字信号处理器(DSP)组成的处理电路接收图像数据，通过图形识别算法得到粗码角度，并采用改进的基准线质心算法，计算亚像素级的精码角度信息。最后由粗码和精码组成光电编码器测角数据。实验结果表明，设计码盘直径为45 mm的图像式光电编码器，在不配备光学镜头的前提下，采用精码细分技术，可实现4096份细分，测角分辨力达到5″，角度测量误差峰峰值为51″。且改进质心算法能有效地抑制噪声，提高测量精度。该图像式编码和精码细分技术可以提高编码器的分辨力，缩小编码器体积，减轻重量。满足航空航天领域对小型化光电编码器的需求。

In order to improve the optical encoder′s resolution and reduce its volume, an optical pattern rotary encoder based on the image processing technology with an array image sensor is studied. Optical pattern code disc is designed according to the required performance of the optical encoder. The pattern of the spinning disc is acquired by the complementary metal oxide semiconductor (CMOS) image sensor. The processing circuit composed by complex program mable logic device (CPLD) and digital signal processor (DSP) receives the image data, gets the coarse code by the pattern recognition algorithm, and calculates the precision code with sub-pixel size by the improved baseline centroid algorithm. The optical encoder′s angular output is made up of the coarse code and the precision code. In the experiment, this method in an optical pattern rotary encoder whose diameter is 45 mm is applied. Without any additional optical lens, the results show that the encoder′s angular resolution reaches 5″ and the number of subdivision is up to 4096. The peak to peak value of the angle measurement error is 51″. The improved centroid algorithm can suppress the noise and improve the measurement accuracy. The optical pattern rotary encoder can get high resolution, reduce the volume and weight using this pattern code and electronic subdivision technology. It can be used in space flight.