提高光电轴角编码器细分精度的改进粒子群算法

为提高光电轴角编码器的细分精度及莫尔条纹光电信号的细分倍数，设计了一种基于改进粒子群算法的信号正弦性修正方法。首先，根据莫尔条纹光电信号的数学模型，分析信号质量指标对细分误差的影响；并从编码器的制作、调试、使用等环节出发，指出信号细分误差产生的根本原因；然后，对改进粒子群算法的基本原理和实现步骤做了具体阐述；最后，以21 位光电编码器为实验对象，依据其精码转换的方波信息实现精码信号的自适应采样，同时应用改进算法对采集的编码器原始光电信号进行数据预处理，通过辨识信号模型中的3 个待定参量，直接实现信号等幅性偏差、稳定性偏差、正交性偏差的修正；对算法处理后的莫尔条纹信号进行细分精度检测，实验结果表明:编码器细分误差峰值由19.08降低到2.86，细分精度明显提高。

Improved PSO algorithms for improving the subdivision accuracy of photoelectric rotary encoder

In order to ensure the subdivision accuracy of the photoelectric rotary encoder and subdivision multiple of the Moire fringe photoelectric signal, the method based on improved particle swarm algorithm (PSO) to correct sinusoidal character of photoelectric signal was designed. On the basis of the mathematical model of the Moire fringe photoelectric signal, the influence of signal quality to subdivision error was analyzed. And from several aspects, such as production, debugging and application, the basic reason of the appearance of signal subdivision error was pointed out. The principle and realization steps of improved PSO were elaborated. A 21-bit encoder was selected as the experimental object. Adaptive sampling of precise code signal was realized according to square wave information from precise code conversion. The collected original Moire fringe photoelectric signal was pretreated using improved PSO.Three to be defined parameters of signal model were identified. And signal amplitude deviation, stability deviation, orthogonal deviation were directly corrected. Moire fringe signal was processed using improved PSO and the subdivision accuracy was tested. The experimental results show that the peak value of subdivision error is reduced from 19.08 to 2.86. The subdivision accuracy of the photoelectric rotary encoder is ensured.