为了保证高精度光电编码器在恶劣工作环境下的精确测量，建立一种基于高分辨力数字电位计+DSP+CPLD的莫尔条纹光电信号自动补偿系统。首先，介绍了自动补偿系统的工作原理及构成，并设计了系统使用过程中的工作模式；融合莫尔条纹信号各个偏差的补偿算法，建立了光电信号细分误差的综合补偿模型；然后，具体阐述了系统的硬件设计、相关软件设计，并分析了补偿系统自身存在的系统误差；最后，以24位光电编码器为实验对象，对该补偿系统进行测试分析，实验结果表明：自动补偿系统可实现编码器精码信号直流电平漂移、等幅性偏差、正交性偏差及二次、三次、五次谐波偏差的综合补偿，可使实际的静态细分误差减小0.61″。该系统可用在编码器的工作现场，实现莫尔条纹信号细分误差的自动修正。

In order to ensure the measurement accuracy of precise photoelectric encoders in harsh working environment, a kind of automatic compensation system based on the high-resolution digital potentiometer, DSP and CPLD for the Moire fringe photoelectric signal was established. Firstly, the principle and composition of automatic compensation system was introduced. Meanwhile, the compensation algorithms for the components of Moire fringe signal deviation was integrated. And the compensation model for photoelectric signal subdivision error was established. The system hardware design and software design were expounded. The system error of the compensation system was further analyzed. A 24 bit photoelectric encoder was selected as the experimental object to analyze and test the compensation system. The experimental results show that DC level drift, amplitude deviation, orthogonality deviation, and the second, third and fifth harmonic deviation are simultaneously compensated. The actually static subdivision error is reduced to 0.61″. The compensation system can realize the automatic correction of Moire fringe signal subdivision error in the working state.