光电轴角编码器细分信号误差及精度分析

Errors and precision analysis of subdivision signals for photoelectric angle encoders

高分辨力光电编码器通常利用码盘精码两路正交的正、余弦信号,通过细分达到高分辨力。为使细分技术更加完善,本文对细分误差进行了专题研究。分别对信号直流分量误差、幅值误差、相位误差、谐波分量误差、噪声误差和量化误差等进行了数理分析,通过对细分误差的特性分析,得出了误差规律及其计算公式,形成了比较完整的光电编码器细分误差及精度分析的数理结果。结果表明,一般情况下细分精度在1.5%左右。文章指出,利用码盘精码通过细分提高分辨力,应在码盘选择、轴系设计、信号提取、电路设计、工艺调试等各个环节充分考虑细分误差的影响。研究结果可用于在产品设计时,合理进行误差分析与分配,预估产品的精度,为减小设计误差提供参考。

High-resolution photoelectric encoder usually achieves a high resolution by the subdivision of two-way orthogonal sine and cosine signals from a fine disk code.In order to improve the subdivision technology,this paper researches the subdivision errors specially.The signal DC component errors,magnitude errors,phase errors,harmonic errors,noise errors and quantization errors are analyzed,respectively.Based on properties of subdivision errors,the laws of errors and their computing formulae are obtained,then,the fairly complete mathematical results of subdivision errors and precision analysis for photoelectric encoders are formed.The results show that the subdivision precision is about 1.5% generally.It points out that it should pay more attention to the effects of subdivision errors on different technological steps such as code selection,axis design,signal extraction,circuit design and adjusting method,when the subdivision is used to improve the encoder accuracy.The research results are useful for analyzing and distributing errors,forecasting product accuracy and reducing design errors in the product design.