Study on the Accuracy of High Precise Rotary Encoders

提出了一种新的高精度轴角编码器标定方法，并对标定误差进行了分析。利用该方法对几种高精度的轴角编码器进行了标定，明确了编码器的精度。(1)提出了一种高精度的标定方法--等分平均法。利用误差高阶傅立叶分量小的旋转编码器，该方法可以实现高精度的标定，算法简单，标定工作方便。(2)将该方法与前一种方法应用于该校准系统的主尺（磁尺）的校准。结果表明，检测误差傅立叶分量的标定方法对标定旋转编码器是有效的，并确定了标准尺的准确标定值为<plus-minus>0.7”。（3）采用以准确标定值为参考的误差修正记录方法对标准尺进行了重新记录，并制得了精度约为<plus-minus>0.2”的标准尺。（4）通过对几种高精度旋转编码器的标定，明确了以下几点。光电式编码器是日本精度最高的编码器，其精度为<plus-minus>0.4”。光电式编码器是目前世界上精度最高的编码器，其精度为<plus-minus>0.1”。磁性编码器的精度为<plus-minus>0.3”。高精度电磁感应式（旋转变压器）的精度之一是<plus-minus>8”，大部分是由检测线圈的数量和励磁量引起的周期性误差。

A new calibration method was proposed for high precise rotary encoders and the calibration error were discussed. Using this method, the calibration of some kinds of the highest precise rotary encoders have been done and the accuracy of these encoders have been cleared.The Followings are the Summary of Research Results.(1) The same dividing average method was proposed as a high precise calibration method. Using a rotary encoder of which high order fourier components of the error are small, the high precise calibration can be done with simple algorithm and easy calibration work by this method.(2) The method and the former method were applied to the calibration of the masterscale (magnetic scale) of this calibration system. The results were that the calibration methods which detect fourier components of the error were useful to calibrate rotary encoders and the accurate calibration value <plus-minus>0.7" of the masterscale was confirme(3) The error correction recording method referred to the accurate calibration value was applied to rerecording of the masterscale and the scale with the accuracy of about <plus-minus>0.2" has been mad(4) As the results of the calibration of some kinds of the highest precise rotary encoders, the followings were cleared. The accuracy of the photo-electric type encoder which is the highest precise one in Japan is <plus-minus>0.4". The accuracy of the photo-electric type encoder which is the highest precise one in the world is <plus-minus> 0.1". The accuracy of the magnetic type encoder is <plus-minus> 0.3". One of high precise electromagnetic induction type (resolver) is the accuracy of <plus-minus> 8" and the most part of the most part of the periodic error caused by the number of the detecting coil and the exciti