The sensitivity and uniformity of the detection area in a light screen are crucial for velocity measurement accuracy.This study focuses on a light light screen with a light source consisting of an array of light-emitting diodes(LEDs)and a receiving array of photodiodes in a transmissive configuration.The aim is to explore compensation methods for achieving uniform sensitivity in the light screen.To address the issue of lower sensitivity at the edge areas of the receiving photodiodes,which results in uneven sensitivity across the light light screen,a method of non-uniformly arranging the receiving photodiodes at the edges of the light screen is proposed to mitigate the edge effect.Two schemes for non-uniform arrangement of photodiodes are considered:linear spacing variation and exponential spacing variation,and based on which simulations and experimental validations are conducted for a light screen with dimensions of 1 140 mm X 1 000 mm.The results indicate that both linear and exponential spacing variations of photodiodes at the edges can alleviate the edge effect,with the exponential variation being more effective.
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