Research On Micro-Vibration Suppression Technology For Satellite Laser Communication System

With its excellent characteristics,laser communication technology has developed into a significant strategic communication technology,and it has been rapidly developed.In the satellite laser communication system,the stability of the communication link is the basis to ensure the stability and efficiency of laser communication,and the satellite platform micro-vibration is one of the most serious reasons for the impact on the laser communication link.Platform micro-vibration makes the optical antenna jitter and affects the beam pointing accuracy,which in turn affects the smooth communication link,so whether the satellite platform microvibration can be effectively controlled is the key to achieve stable communicationIn this thesis,a new compensation algorithm is proposed for the platform microvibration suppression in the satellite laser communication system,based on a control algorithm combining feedforward control by RBF neural network algorithm and PID feedback control,and the control effect of this method is analyzed and verified.Firstly,the development of satellite laser communication technology and the mainstream satellite platform micro-vibration suppression technology at home and abroad are introduced,the sources and features of micro-vibration are discussed in detail,and then by analyzing the existing suppression technology,the active compensation method is selected for micro-vibration suppression.The active compensation technique is to compensate the vibration by driving the fast steering mirror in the fine tracking system.Then the principle of the fast steering mirror,the key device in the control system,is analyzed,its mathematical model is established,and the factors affecting the performance of the fast steering mirror are explained.Secondly,the RBF composite control algorithm is proposed to address the limitations of feedforward vibration suppression scheme and LMS adaptive filtering algorithm,and the principle of the algorithm is analyzed and the performance of the algorithm is simulated in MATLAB,mainly compared with the classical PID control method.The simulation verifies the suppression effect of the RBF composite control algorithm on harmonic vibration at different frequencies and amplitudes,and it is known that the vibration suppression algorithm proposed in this paper has good compensation ability for single frequency harmonic vibration within 50 Hz and vibration at different amplitudes.Finally,based on the simulation results of the micro-vibration suppression algorithm,the harmonic vibration compensation scheme is designed for different frequencies and amplitudes,and the RBF composite control algorithm is used for harmonic vibration compensation experiments and compared with the PID control algorithm.The experimental results show that with this experimental system parameters,the suppression effect of RBF composite control algorithm decreases with the increase of frequency,but is significantly better than that of PID control algorithm.It also has good suppression effect for different amplitude of vibration.The theoretical simulation and simulation experiments prove that the RBF composite control algorithm proposed in this paper is feasible and provides an effective solution for satellite platform microvibration suppression.