Design And Implementation Of The Vehicle-borne Mobile Satellite Antenna Stabilized Tracking System

With the development of satellite communication,mobile satellite communication system which can be used in vehicles,trains,ships,planes and other mobile carriers has became a good solution for mobile communication and has had a broad market space and good prospect of application.The key equipment of mobile satellite communication system is the antenna stabilized tracking system. Presently,the azimuth and pitching 2-axis mechanical construction has been used in most of vehicle -borne mobile satellite antenna stabilized tracking systems in our country,which only can make the antenna beam axis stable but cann't isolate antenna beam rolling.Besides,most designs have used hight precision gyroscopes as attitude measured sensors which cost a lot.This project makes two important changes to the existing antenna stabilized tracking system:firstly, 3-axis stabilized scheme has been adopted in order to aviod antenna beam rolling and improve communication quality;secondly, combination of MEMS(Micro Electron Mechanical System) sensors has been used to construct high accuracy attitude measured system,which can reduce the cost.Based on the engineering application,this paper firstly introduces the overall plan of satellite antenna stabilized tracking system , including mechanical structure of antenna pedestal, control strategy for isolating disturbances from vehicles,scanning and tracking strategy for searching satellite.Then types of electronic components and modules are choosen according to the system requirement and relative circuits are designed to lay foundation for the next reasearch.Subsequently,software design of system is introduced,includingμc/OS-II RTOS(real-time operating system) transplanted on MSP430F149 microcontroller , system missions planed and main functions of attitude measured system explained with the codes. After that,the initial alignment algorithm,dynamic tracking algorithm and 3-axis stabilized algorithm of antenna stabilized tracking system are discussed focusedly,what's more,the information fusion algorithm and attitude calculation of attitude measured system are introduced. At last,some problems that occurred during the debugging and working are discussed and the next step of work is pointed out in this paper.