| Along with the development of information technology,people are more eager to make telecommunication in the mobile status by means of maritime satellite net.So making a research on the antenna tracking control system of the maritime satellite terminal has an important practical significance and broad market prospects.With the background of antenna controller design,the software of the mobile terminal antenna tracking control system is designed and optimized in this paper,based on the hardware design of others.CCS integrated development environment is used as a software development platform.The system software is designed to realize three main functions.The first function is to search maritime satellites automatically according to the received attitude angles and geographic information,as well as the satellite signal strength from the host.The second function is to carry out stable servo control based on three-axis gyroscope signals and satellite signal strength so as to isolate disturbance from the carrier.The last function is to ensure the timely and reliable communication between antenna control unit and host(BDU).The main contents of this paper include the software design in general,functional modules division,sub-modular software design and debugging,the overall software optimization etc.And the whole program is divided into several modules,such as auto-searching,stable tracking,motor driving,communication control,initialization and so on.In the satellite auto-searching module,Optimized and simplified stepping tracking arithmetic is used.Then the paper gives out an algorithm which is based on the existing stabilized platform and converts three-axis attitude angles of carrier into two-axis attitude angles of antenna in stable tracking module.At the same time the algorithm is combined with the signal strength from host so as to isolate disturbances caused not only by angular motion but also by linear motion of carrier.In the motor driving module,the step motor division drive technology is also introduced in detail and carried out to be.In order to ensure reliable communication between antenna controller and host,the paper studies the format of communication protocol and gives the flow chat.At the end of this paper,using IQmath function library instead of floating- point numeral operation shortens the program codes for fractional operation and improves the program operation speed significantly.In addition the research on how to improve the internal FLASH code running performance is also made and carried out in this paper. Furthermore,the paper discusses some problems that occurred during the debugging and the working,and points out the next step of the work. |
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