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