图像式光电编码器高分辨力细分算法及误差分析

A High-Resolution Subdivision Algorithm for Photographic Encoders and Its Error Analysis

为实现高分辨力角位移测量,提出了一种基于线阵图像探测器的角度细分方法。为消除安装调试时图像探测器与圆心距离变化产生的影响,提出了一种具有较强适应性的高分辨力细分算法;建立了该细分算法的数学模型,并进行了误差分析。根据实际应用,建立了由码盘偏心和图像探测器安装角度引起误差的模型,并分析许多因素对细分算法的影响;根据误差分析结果,给出了减小图像式光电编码器细分误差的建议。结果表明,在码盘圆周刻划线数大于或等于128时,细分算法的误差较小,可以被忽略。研究结果可为研制小型图像式光电编码器提供理论依据。

In order to realize high resolution angular measurement,a subdivision method based on the photographic sensor is proposed.A more adaptable high-resolution subdivision algorithm is proposed to eliminate the subdivision error caused by the irregular distance between the photographic sensor and the grating center during installation and adjustment of the encoder.The mathematical model of the proposed subdivision algorithm is established,and the error of the method is analyzed.Based on practical working conditions,an error model which takes many aspects into consideration is built and the effect of various elements on the subdivision algorithm is analyzed.According to the error analysis results,how to reduce the subdivision error of photographic encoders is recommended.Experimental results show that the subdivision error can be ignored when the line number of circular grating is more than or equal to 128.The results can provide theoretical foundation for develop the miniature photographic encoder.