Research Of Attitude Determination Based On Four-axis Satellite Antenna Attitude Stabilization System

When the ship is sailing on the sea, the attitude of the ship is changing all the time because of ocean current and waves. These changes influence the receiving efficiency of satellite antenna, even make the satellite antenna lose its signal. It will make the installing of the satellite antenna on the ship hard. This paper analyzed the kinematics feature of four-axis framework baced on a material four-axis framework in the laboratory. Aiming at the requirements of world-wide navigation and combining the feature of four-axis framework, it designed a four-axis framework attitude compensation algorithm. And it tried to put forward a kind of evaluation system in order to evaluate the frequency response and cost based on real framework parameters.This thesis mainly completes the works as follows:Firstly, this paper introduce the key technique of satellite antenna, includes technological analysis of stabillized platform control system, research of attitude measurement and introduction of MEMS technology. Meanwhile, it introduces the domestic and international evolution of stabillized platform control system.Secondly, it introduces the key technique of attitude sabilization system, and deduces the basic knowledge of inertial measurement technique, inchudes coordinate system, attitude angle, and attitude transfer matrix of coordinate system. This paper analyze the principle of the main part of inertial measurement unit, includes accelerometer, gyroscope and magnetometer. Then it introduces various kinds of attitude representing methods. This part lays the foundation for follow-up framework attitude derivation.Thirdly, from the construction and the control method, the paper analyse the advantage and disadvantages of double-axis framework and three-axis framework. Then on the basis of analysis result, the paper describes the structure advantages of four-axis framework, and makes the discussion of installation site of inertial measurement unit. Due to these descriptions, it comes to a conclusion that the four-axis framework has structural advantage both on zenithal tracking and polarizing angle concompensation.Fourthly, basing on the relativeness between vehicle and satellite in the geographic coordinate system, the paper calculates the ground obserbation angle of satellite. Meanwhile,the inertial measurement unit measures the attitude of the antenna. Then it designs four-axis framework attitude compensation algorithm. This algorithm makes full use of the advantages of four-axis framework to decrease the motion quantity of single axis, and makes the compensation rapidly.Finally,there is a new attitude compensation evaluation standard being proposed. The standard bases on the dynamic and rapidity,and is built on the real framework parameters in the laboratory. Using this standard, the paper evaluates the four-axis framework attitude compensation algorithm. It verifies the superiority of four-axis framework attitude compensation algorithm by means of data comparision.