| The shipborne satellite communication has wide application foreground as one of mobile satellite communication method. Its technology development mostly is restricted to shipborne mobile satellite communication antenna technology, thus the study of shipborne mobile communication antenna has practical significance. The study object of this thesis is a specified Ku/Ka dual-band shipborne satellite antenna, the study aim is to insure the antenna servo system tracking the satellite fast and accurately, completing the stable and reliable function of satellite communication network. The main research direction is antenna servo system hardware design and antenna monitoring software design.This thesis proposed the general system design of entire antenna servo and feed at first, briefly introduced system working principle and equipment component, and summarized entire antenna structure.In general scheme design of the thesis, the system tracking scheme with monopulse tracking plus conical scanning tracking scheme was determined to be adopted in the system. The servo system of 3-axes for stability and 2-axes for tracking model is determined, stability system adopted gyroscope feedback plus feed-forward offset to compensate self-stability, tracking system adopted Ku band conical scanning, Ka band monopulse tracking. Besides, the thesis made detailed instruction to some key equipment of servo system design such as gyroscope, servo amplifier selection, angles encoder scheme and antenna status angles acquiring device.This thesis described realization of servo system hardware and software in detailed. The hardware mainly includes antenna control unit, antenna drive unit, encoder and gyroscope etc. sub-systems. The software mainly includes antenna control program and antenna monitoring program. The thesis also detailed described the design of general framework, main program and sub-program modules of antenna monitoring program, and present the processing flow chart of each sub-program module.The thesis estimated the tracking accuracy of entire system, analyzed the error sources such as ship swing, component dead zone, drifting, steady wind and gust etc. aspects which influence antenna tracking accuracy, the conclusion showed the system main error comes from remain error of stable tracking ship swing, the final theoretical calculation result was less than system specification, satisfied the requirement. The detailed test method of antenna tracking accuracy was listed in the thesis, then settled and analyzed antenna tracking accuracy test data. The final conclusion indicated that the product performance could fully meet design requirement, this design could be adopted in engineering.Engaged engineering application, some area of the research in this thesis still needs to be consummated and improved. For example, the servo loop parameter could not be automatic adjusted in case of mechanical transmission variation. In the following task, the servo loop parameter automatic adjustable function will be consummated and improved base on failure diagnosing and automatic test function.The research in this thesis provided valuable experience for future shipborn servo control system design, but there is still plenty of work to be finished, the C/Ku/Ka triple frequencies multiplexing, multi-antenna integration research and forward reducing ship surface antenna quantity and dimension will be developed; research and consummate antenna calibration technology, modifying technology and tri-axis antenna pointing tracking arithmetic, for improving inertial navigation pointing tracking accuracy. |
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