Design and Simulation of the Attitude Controller for Gravity Gradient Satellite

• Main Authors: Rong-Tang Chang, 張榕瑭
• Other Authors: Chun-Mo Lee
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/52283616904727155616

碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 97 === In this thesis﹐the design and simulation of the attitude control system of the gravity gradient satellite are presented﹐The designed satellite requirement is to use the gravity gradient boom and the magnetic coils controlling the attitude of a satellite at 500 km altitude﹐25 degree inclination orbit. The satellite attitude controller is designed by the theory of Linear Quadratic Regulator (LQR) and then applied to the control of the nonlinear dynamics of the satellite under the influence of the earth's magnetic field and the external disturbing torques﹐The simulation is divided into three modes. The first mode is the despin mode﹐which is to reduce the angular rates to very low values, especially the spin rate﹐right after the satellite is separated from the launcher for erecting a comparatively weak extendible boom. The second mode is the normal mode, in which the satellite is controlled by its gravity gradient boom. The third mode is the detumbling mode﹐in which the earth pointing accuracy of the satellite can be restored by use of active magnetic control torque. The simulation shows satisfactory results.