Research On High Precision Laser Positioning Technology Based On Four Quadrant Detector

Laser has the advantages of good directionality,strong coherence,and good monochromaticity.It is widely used in many fields such as laser communication,laser guidance and optical tweezers.High precision laser positioning technology is the basis of laser application systems.Among the photodetectors commonly used for positioning,the four-quadrant detector(QD)has the advantages of high position resolution,high response frequency,and simple processing circuit.Therefore,the research of highprecision laser positioning technology based on four-quadrant detector has good research value and application prospect.Due to the actual application,the spot shape feature has a great influence on the positioning accuracy of the four-quadrant detector,and the traditional positioning algorithm based on the Gaussian circle energy distribution only has a good effect under the ideal state.In order to improve the positioning accuracy of the four-quadrant detector when the spot shape is not ideal,the paper proposes a method based on Gaussian elliptic energy distribution model,and improves the optical path design of the traditional four-quadrant detector based positioning system.It is proved by simulation and experimental analysis.The scheme can effectively improve the positioning accuracy when the elliptical spot is incident,and researches new ideas for the subsequent positioning technology.This paper focuses on high-precision laser positioning technology research,the main work is divided into the following three aspects:Firstly,the basic principle,development and practical application value of laser positioning technology are introduced.The current research status of laser positioning at home and abroad and the research status of four-quadrant detector based positioning technology are summarized.The innovations and improvements of current research are pointed out.Aspect.In order to better study the algorithm,the paper introduces the basic knowledge of laser positioning technology based on four-quadrant detector and its positioning system composition and evaluation index.Secondly,the effects of the current localization algorithm are analyzed,and the common localization algorithms are studied.The algorithm based on circular model localization algorithm,Gaussian distribution based positioning algorithm,polynomial fitting based localization algorithm and database query based positioning algorithm are analyzed.The advantages and disadvantages of different algorithms in actual laser positioning applications are analyzed by derivation and simulation..Finally,in order to solve the problem of low accuracy of traditional positioning algorithm,a new positioning algorithm based on Gaussian elliptical spot energy distribution is proposed.The main contributions of the positioning algorithm based on Gaussian elliptical spot energy distribution are:(1)improving the optical path design of QD-based laser positioning system;(2)solving the problem of acquiring complex model parameters by combining image processing;(3)The neural network improves the traditional polynomial fitting method and further improves the positioning accuracy.The simulation and experimental analysis show that the proposed algorithm can effectively improve the positioning accuracy of the elliptical spot and provide a new idea for the subsequent research to improve the accuracy of QD positioning.