Study On Closed-loop Control Technology Of Laser Scanning System

Laser has good coherence,directivity,monochrome and other advantages,widely used in military,industrial,medical,science and education,aerospace and other fields.Especially in the military field,laser radar,laser guidance,laser countermeasures and other High-tech,has become more and more mature,and it has become an important symbol of the modernization of weapons,and has attracted the attention of various countries.Rapid laser scanning and positioning is the core technology of many laser weapon systems,the methods for realizing beam scanning mainly include rotary mirror scanning,holographic grating scanning,galvanometer scanning,MEMS array scanning,among them,galvanometer scanning has become the most widely used laser scanning method because of its advantages of strong anti-electromagnetic interference ability,fast scanning speed,high positioning accuracy and reliable and stable performance.In view of the urgent need of the laser rapid scanning,tracking and precise positioning technology of the integrated laser countermeasure system,the closed-loop control technology of the double galvanometer laser fast two-dimensional scanning system is deeply studied in this paper,some valuable results and conclusions are obtained.The main research contents and results are as follows:1.The overall scheme of the two-dimensional laser scanning control system with double galvanometer is designed.The system control command is issued by the host computer,after the STM32 microcontroller receives the instruction,two digital sequences are generated according to the scanning function of the galvanometer,and converted into analog voltage signals of-10 V to +10V through the TI DAC8563,and two CTI Micro Max 671 XX series single-axis servo-driven laser scanning modes are input respectively,which controls the deflection of two CTI 6210 H scanning galvanometers,and the laser beam scans spatially according to the scanning mode corresponding to the scanning function.2.The working principle of two-dimensional laser scanning system with double galvanometer is analyzed,and the mathematical model of scanning control algorithm is established,the mapping relationship between the deflection angle of the galvanometer and each point in the scanning plane is determined.The advantages and disadvantages of progressive scanning,rectangular scanning,rectangular spiral scanning,spiral scanning,rose-shaped scanning and Lissa-shaped scanning are compared and analyzed,the control program is written for the first three scanning modes and is tested experimentally,the results show that the rectangular spiral scanning has the shortest scanning time under the condition of the same scanning frequency and scanning range,thus the rectangular spiral scanning is determined as the scanning mode of the system.3.Two-dimensional laser scanning system with double galvanometer and echo-receiving experimental device for the integrated reconnaissance and interference laser countermeasure system are completed.The scanning control and echo signal preprocessing circuit are constructed by using STM32 as the core controller,and the control of DAC8563 is realized by SPI bus,and the analog control signal is produced,which is used to control the galvanometer scanning,after receiving the echo signal through APD,it is converted to digital signal by ADC and transmitted to the host computer data processing software through serial port,the experimental results show that the designed scanning scheme is feasible.4.The scanning control program,SPI communication program,serial communication program and AD / DA conversion control program based on STM32 single chip computer are written and tested,and tests the double galvanometer scanning control module and the echo signal receiving module,the test results show that the relevant software of the whole system is reliable and stable,which can meet the requirements of practical application.5.The pillow-shape error,nonlinear error,focusing error,compound distortion error and system error of the two-dimensional laser scanning control system with double galvanometer are analyzed in detail,and the corresponding correction methods are proposed.