Research On Coarse Tracking Technology Of Satellite Laser Communication Based On Adaptive Linear Active Disturbance Rejection Control

Satellite laser communication is an important technology for realizing high-speed communication between satellites and ground and building a backbone network between satellites.Compared with satellite microwave communication,satellite laser communication has the advantages of fast speed,wide bandwidth,no frequency band limitation,smaller size,anti-interference and Features of good confidentiality.Starting from the successful experiment of satellite laser communication,its research depth,test range,communication speed,etc.have been continuously improved,and with the society's demand for high-speed communications,it has moved towards commercialization.The realization of satellite laser communication requires high-precision aiming,capturing,and tracking(PAT)technology.The beam divergence of the laser is extremely narrow,and the receiving field of view in the space environment is limited.A stable beam tracking is required to achieve high-speed data communication.Coarse tracking technology is used as An important part of PAT technology is involved in all aspects of aiming,capturing,and tracking,and during the tracking process,it is necessary to ensure that the beam is within a very small field of view to ensure stable tracking of the precision tracking system.With the development of satellites in low orbit and miniaturization,the space environment faced by satellite laser communications has become more complex,and the requirements for coarse tracking technology have become more refined and strict.This paper proposes adaptive linear active disturbance rejection control(ALADRC),which suppresses the influence of on-board interference on the coarse tracking system through a control algorithm.This article first investigates the development of satellite laser communication,especially the development of coarse tracking technology in the development process,and analyzes the specific requirements of satellite laser communication for the coarse tracking system for the development and use of coarse tracking.Introduce the PAT system,analyze the composition and working process of the PAT system,and explain the role of coarse tracking in the work,get the system block diagram of the coarse tracking,and give a brief introduction to the control scheme used in the development of the coarse tracking technology.And introduced in detail the important components of adaptive anti-disturbance technology,linear auto-disturbance rejection control and adaptive control.Analyze the interference factors on the satellite and explain the working environment of the coarse tracking system.Establish a servo motor simulation model to realize the tuning and simulation of control parameters from the servo motor to the coarse tracking system.Through theoretical research and actual simulation,the tracking performance of classic PI control,linear autodisturbance rejection control,and adaptive anti-disturbance control is analyzed.Through the analysis of the simulation results,the adaptive anti-disturbance can track performance better than PI control in interference situations.In the case of parameter perturbation,system stability can be effectively ensured.Finally,the effectiveness of adaptive antidisturbance control is verified through experiments,and it is concluded that adaptive antidisturbance control can effectively suppress the adverse effects of external interference and parameter perturbation on the coarse tracking system.