Design And Realization Of Airborne Laser Communication Automatic Tracking Control System

The prerequisite for the realization of the airborne laser communication system is the establishment of the communication double-ended link and the stable tracking and pointing of the receiving and transmitting visual axis,so it is necessary to complete the design of a beam acquisition,pointing and tracking system with good performance.Based on the background of airborne laser communication,this paper has carried out in-depth research on the automatic tracking system.The research contents include the following points:1.The automatic tracking system was investigated.For the selection and performance status of different servo motors in the APT system,a detailed comparative study was completed.At the same time,the calculation method of the four-quadrant detector offset under different energy distribution models was researched.In addition,the center positioning algorithm of the through-hole four-quadrant detector was described,which used the principle of spot detection to complete the capture,alignment and tracking of the beam signal.2.In order to solve the problem of limited load of airborne platform,a lightweight and rapidly deployable APT system was designed by using stepper motor,mirror and four-quadrant detector,which was carried on a six-rotor UAV to form a complete UAV airborne laser communication system.3.In the acquisition process,a simple and convenient algorithm was designed for the slow scanning speed and long scanning time of the two-dimensional motor turntable.This algorithm realizes the free adjustment of the scanning speed of the stepper motor by changing the duty cycle of the pulse width modulation waveform.In the tracking process,there was a through hole in the center of the four-quadrant detector used in this system.Based on the original four-quadrant detector center positioning algorithm.A spot detection algorithm suitable for this system was proposed,which solves the problem that the spot energy at the central through hole cannot be detected.Build an indoor simulation airborne experiment platform,and conduct multiple experiments,and finally realize the beam capture,alignment and tracking in the indoor simulation environment,and its tracking accuracy was 2.42?rad.Through theoretical introduction and experimental verification,it was proved that the designed tracking algorithm has good automatic tracking performance for the airborne laser communication system,and verified the feasibility of the airborne laser communication automatic tracking system.