Attitude control of a spacecraft using two SGCMGs
Author(s)
Kwon, Hyuk-Sang, 1971-
DownloadFull printable version (3.414Mb)
Alternative title
Attitude control of a spacecraft using two single Gimbal control moment gyroscopes
Advisor
Seth Lloyd.
Terms of use
Metadata
Show full item recordAbstract
This thesis presents new methods for controlling spacecraft using Control-Moment Gyros (CMGs). CMGs generate torque to change and maintain a spacecraft's orientation. The CMG control system is used specifically to provide three-axis altitude stabilization, precision pointing control and maneuvering capability. Two types of CMGs are used in spacecraft attitude control purpose. Classified by the number of gimbals, they are Double Jimbal Control Moment Gyroscope (DGCMG) and Single Gimbal Control Moment Gyroscope (SGCMG). An SGCMG is often chosen as a torque actuator because an SGCMG has two major advantages over DGCMGs: the torque amplification feature and ease of manufacture. The technical literature discusses altitude control of large spacecraft using three or more SGCMGs. As a case study, the altitude control of rigid spacecraft using two SGCMGs is considered. In this paper, the simplified two-SGCMGs model was made and simulated. The system of interest is nonholonomic and the control strategy is related to motion planning. I demonstrate that often only two SGCMGs are necessary to control the altitude of a spacecraft. This is true when failure of one of the control momentum gyroscopes occurs, two actuators can be used to control the attitude of a rigid spacecraft and arbitrary reorientation maneuvers of the spacecraft can be accomplished. The control strategy where two SGCMGs arc used to control the attitude of the spacecraft was studied and presented.
Description
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998. Includes bibliographical references (leaves 53-54).
Date issued
1998Department
Massachusetts Institute of Technology. Department of Mechanical EngineeringPublisher
Massachusetts Institute of Technology
Keywords
Mechanical Engineering