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Attitude control of a spacecraft using two SGCMGs

IP.com Disclosure Number: IPCOM000128065D
Original Publication Date: 1998-Dec-31
Included in the Prior Art Database: 2005-Sep-14
Document File: 4 page(s) / 16K

Publishing Venue

Software Patent Institute

Related People

Kwon, Hyuk-Sang: AUTHOR [+3]

Related Documents

http://theses.mit.edu:80/Dienst/UI/2.0/Describe/0018.mit.theses/1998-244: URL

Abstract

This thesis presents new methods for controlling spacecraft using Control-Moment Gyros (CMGs). CMGs generate terq!ie to change and maintain a spacecraft's orientation. The CMG control system is used specifically to provide three-axis attitude 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 Gimbal 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 DGCAIGs: the torque amplification feature and ease of manufacture. The technical literature discusses attitude control of large spacecraft using three or more SGCMGs. As a case study, the attitude control of -. 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 attitude 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 are used to control the attitude of the, spacecraft was studied and presented. Thesis Supervisor: Seth Lloyd Title: Assistant Professor of Mechanical Engineering 2

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 This record is the front matter from a document that appears on a server at MIT and is used through permission from MIT. See http://theses.mit.edu:80/Dienst/UI/2.0/Describe/0018.mit.theses/1998-244 for copyright details and for the full document in image form.

Attitude Control of a Spacecraft Using two SGCMGs

by

Hyuk-Sang Kwon
Bachelor of Science in Mechanical Engineering, The University of Iowa 1995 Submitted in partial fulfillment of the requirements for the degree of Master of Science in Mechanical Engineering

at the Massachusetts Institute of Technology

Feb, 1998
SIGNATURE OF author: [[signature omitted]]

Department of Mechanical Engineering

Feb, 1998
CERTIFIED BY: [[SIGNATURE OMITTED]]

Seth Lloyd Assistant Professor of Mechanical Engineering Thesis Supervisor ACCEPTED BY: [[SIGNATURE OMITTED]]

Ain A. Sonin Departmental Committee on Graduate Students ARCHIVES MASSACHUSETTS INSTITUTE OF TECHNOLOGY LIBRARIES APR 27 1998

Massachusetts Institute of Technology Page 1 Dec 31, 1998

Page 2 of 4

Attitude control of a spacecraft using two SGCMGs

Attitude Control of a Spacecraft Using two SGCMGs

by

Hyuk-Sang Kwon

Submitted to the Department of Mechanical Engineering on Jan 23, 1998 in partial fulfillment of the requirements for the degree of Master of Science in Mechanical Engineering

Abstract

This thesis presents new methods for controlling spacecraft using Control-Moment Gyros (CMGs). CMGs generate terq!ie to change and maintain a spacecraft's orientation. The CMG control system is used specifically to provide three-axis attitude 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 Gimbal 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 DGCAIGs: the torque amplification feature and ease of manufacture. The technical literature discusses attitude control of large spacecraft using three or more SGCMGs.

As a case study, the attitude control of -. 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 attitude 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 are used to control the attitude of the, spacecraft was studied and presented.

Thesis Supervisor: Seth Lloyd Title: Assistant Professor of Mechanical Engineering

Acknowledgments

I thank god first. And I thank my parents, teachers and friends; especially, Rick Nelson, and Seth Ll...