| Antenna is an important part of satellite communication system,and also an important intermediary between navigation wave and electromagnetic wave.It plays a very important role in the signal transmission of airborne satellite communication system.In the traditional case,a satellite antenna can only track one satellite,but in practical engineering applications,sometimes it needs to collect the wavelengths of multiple frequency bands,and then combine them to finally meet the needs of electromagnetic waves of different frequencies.Therefore,it is necessary to study two different feeds of the same radar antenna to track the satellite signals of two different Ka / Ku frequency bands,and then process and analyze them It will become the development trend of airborne satellite tracking antenna in the future.In order to better and more stable satellite signal transmission,this paper studies the motion stability of airborne dual satellite tracking antenna platform.Based on the analysis of the antenna motion platform system structure,the servo stability,attitude stability and trajectory positioning accuracy are studied.The main research contents are as follows(1)Firstly,the basic principle,design idea and design scheme of airborne dual satellite tracking antenna motion platform are analyzed in detail.The transmission unit is designed and analyzed,and the motion principle of the whole antenna platform mechanism is clarified.(2)The motor is the power source of the antenna moving platform,so this paper studies the stability of the airborne double star tracking antenna moving platform from the perspective of servo stability.A compensation servo control algorithm based on feed-forward system and traditional PID algorithm is proposed.In order to reduce the interference and improve the servo stability of the moving platform,the compensation algorithm transforms the nonlinear interference of the antenna moving platform into linear input for compensation.(3)The attitude stability of the platform will be affected by external disturbances.In order to improve the attitude stability of the swing arm of the airborne dual satellite tracking antenna,the coordinate transformation formula of the stability vector is derived when the airborne antenna is interfered in the actual state,and the quantitative angle coefficient of the interference axis is modified.To improve the attitude stability of the swing arm of the airborne dual satellite tracking antenna.(4)The position of antenna feed is the focus position of airborne dual satellite antenna,and its good trajectory positioning accuracy plays an important role in stable satellite signal transmission.In order to solve the problem of trajectory error in the feeding process of airborne dual satellite tracking antenna,the antenna feed model is established,and the feed trajectory is fitted and modified by using the feedback neural network model,so as to improve the trajectory accuracy of antenna feed.So as to improve the trajectory positioning accuracy of airborne antenna in the process of motion.(5)Finally,the servo stability algorithm of airborne antenna platform,the attitude stability algorithm of antenna swing arm and the positioning accuracy algorithm of antenna feed trajectory are verified.According to the servo stability algorithm,the servo stability algorithm is verified by the way that the upper computer runs the servo motor through actual programming;according to the attitude stability and feed stability,MATLAB and Adams are used for joint simulation verification.It provides reference value for further research on improving the motion stability of airborne dual satellite tracking antenna. |
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