Research On Two-dimensional Laser Beam Scanning And Tracking System Based On Four Quadrant Detector

In the process of using laser as energy carrier to charge long-distance mobile devices such as UAVs,in order to ensure that the receiving end can precisely receive the laser beam emitted from the transmitting end,a laser beam two dimensional scanning tracking system based on four quadrant detector is studied and designed.The system uses a monitoring and control computer,a control cabinet and a two-axis turntable to construct a closed-loop control system,by discretizing the tracking process,the offset of the spot center of the incident laser relative to the center of the four-quadrant detector can be measured in real time,which realizes real-time laser tracking of the moving target.On this basis,a new location algorithm of four-quadrant detector based on micro-motion is proposed to further improve the tracking accuracy of the laser beam two-dimensional scanning tracking system.Firstly,the basic structure and working principle of several commonly used photoelectric position detector such as PSD(Position Sensitive Detector),CCD(Charge Coupled Device),CMOS camera and four quadrant detector are introduced,and their performance,characteristics,applications,and so on are compared,and finally the four-quadrant detector are selected as the photodetector of the two-dimensional laser beam scanning system in this paper.On this basis,the overall structure of the two-dimensional laser scanning system is given,and the working principle and performance of each part of the scanning and tracking system are introduced.Secondly,the principle of real-time tracking to the moving target by laser beam two-dimensional scanning system is further introduced.Through the detailed study and research on Arduino nano module and wireless data transmission module,the transmit and receive modules for real-time wireless transmission of the four-quadrant detector positioning signals are designed.Then,using the classical sum-difference location algorithm,the initial measurement of the offset between the center of the tracking laser beam and the four-quadrant detector center is experimentally performed.in order to further improve the tracking accuracy of the system,a new location algorithm based on the micro-motion method is proposed.The experimental test and evaluation of the four-quadrant detector positioning accuracy based on this algorithm are compared with the positioning accuracy of classical sum-difference location algorithms.This subject innovatively adopts the idea of directly placing the four-quadrant detector on the moving target and transmitting the position offset signal by wireless way to realize the scanning and tracking,and facilitates the collection of the position offset signal.The research results of this subject can provide an effective method for the power transmission of long-distance mobile devices such as UAVs,micro-satellites and so on.