光源发散角对航天级小型光电编码器信号的影响

Effect of divergence angle of light source on signal of small spaceborne photoelectric encoder

针对现有的光源发散角对信号影响不明确等问题,本文从光电编码器光电信号产生原理出发,理论分析了光源发散角对光通量的影响,仿真分析了不同发散角情况下的光场分布和光通量变化情况及其组成成分。构建了莫尔条纹光电信号并分析受发散角影响下的细分误差变化情况。实验结果表明:当将发散角为17°的光源更换为15°时,细分误差峰峰值可由0.74″降至0.56″,下降幅度达到24%。因此,光源发散角对于光电编码器输出信号的影响不可忽略,在选取光源时应该予以考虑。本文可用于预测其细分误差的大小和趋势,为航天级小型光电编码器初始光源的选取提供依据和参考。

Aiming at the problem that the influence of the light source divergence angle on signal is not clear,starting from the principle of photoelectric signal generation of photoelectric encoder,the effect of light source divergence angle on light flux is analyzed theoretically,and the distribution of light field,the change of light flux and its components under different divergence angle are simulated and analyzed.Moire fringe photoelectric signal is constructed and the variation of subdivision error affected by divergence angle is analyzed.Finally,experimental result shows that when the light source with divergence angle of 17°is replaced by 15°,the peak and peak value of subdivision error can be reduced from 0.74″to 0.56″,with a decrease of 24%.Therefore,the influence of the divergence angle of the light source on the output signal of the photoelectric encoder cannot be ignored,and it should be considered when selecting the light source.This paper can be used to preduct the size and trend of the subdivision error,and provide a basis and reference for the selection of the initial light source of the small spaceborne photoelectric encoder.