High-precision spot positioning algorithm based on four-quadrant detector

Inherent errors and random errors are consisting in four-quadrant detector when used for azimuth measurement. Many spot fitting algorithms are proposed to solve the inherent errors caused by the structure of the four-quadrant detector itself, which can reduce the errors in a way. In order to further improve the spot positioning accuracy and eliminate the influence caused by random errors such as background light and thermal noise, we first perform Kalman filtering on the output of the four quadrants when we perform experiments to calibrate parameters. Build an experimental platform, and experimentally verify that the Kalman filtering of the output of the four quadrants before bringing in the spot positioning algorithm can improve the accuracy of the composite fitting algorithm, thereby improving the positioning accuracy.