A System for Inertial Experiment Pointing and Attitude Control
A System for Inertial Experiment Pointing and Attitude Control

Author: Peter R. Kurzhals

Publisher:

Published: 1966

Total Pages: 76

ISBN-13:

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A system for inertial experiment pointing and attitude control (designated SIXPAC) of future manned spacecraft has been investigated. The SIXPAC concept consists of three double-gimbaled control moment gyros aligned with the axes of the spacecraft, and derives its control torques from precession of the gyro wheels. This system is readily mechanized, has inherent redundancy, and should provide a wider range of attitude control for manned spacecraft than the gyro systems previously considered. The SIXPAC can provide both the large range of control torques and the fine attitude holds associated with spacecraft experiments such as earth-surface tracking and mapping, photographic missions, and astronomical observations. Periodic aerodynamic and gravity-gradient torques can also be counteracted by the proposed system. Redundancies inherent to the three-gyro arrangement further allow reduced spacecraft control in case of failure or shutdown of one of the three gyros. The complete equations of motion for a spacecraft with the SIXPAC were developed, and were integrated numerically on a digital computer for an example mission with a possible Apollo applications concept. Results of this computer study were used to evaluate the spacecraft and control system response and to determine the power and fuel consumption of the SIXPAC. Characteristics time histories of the attitude and angular rates of the spacecraft are presented for a number of experiments that have been proposed for typical Apollo applications missions, and the performance of the gyro system is analyzed during the control tasks associated with these experiments.

Attitude Control of a Spacecraft with a Strapdown Inertial Reference System and Onboard Computer
Attitude Control of a Spacecraft with a Strapdown Inertial Reference System and Onboard Computer

Author: John Hrastar

Publisher:

Published: 1970

Total Pages: 36

ISBN-13:

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A strapdown inertial reference system and an onboard digital computer can be used to change the attitude of a spacecraft over large angles in an arbitrary direction. A study was conducted with an advanced Orbiting Astronomical Observatory (OAO) using a three-axis control law previously proven globally stable. The control system can reorient the spacecraft to an arbitrary inertial attitude with a single command by operating the three momentum wheels simultaneously. Reorientation, therefore, becomes a simple extension of a hold or pointing mode. The time required for reorientation with this system is considerably shorter than the time required for a series of single-axis slews. The spacecraft attitude and control law are continuously updated by the onboard computer's using information provided by the strapdown inertial reference system. The use of a computer and inertial reference system with characteristics of systems presently under development demonstrates the feasibility of orientation with such a reference system. The basic system is not limited to the OAO but may be adapted for other three-axis-stabilized spacecraft.

Spacecraft Modeling, Attitude Determination, and Control
Spacecraft Modeling, Attitude Determination, and Control

Author: Yaguang Yang

Publisher: CRC Press

Published: 2019-02-06

Total Pages: 159

ISBN-13: 0429822138

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This book discusses all spacecraft attitude control-related topics: spacecraft (including attitude measurements, actuator, and disturbance torques), modeling, spacecraft attitude determination and estimation, and spacecraft attitude controls. Unlike other books addressing these topics, this book focuses on quaternion-based methods because of its many merits. The book lays a brief, but necessary background on rotation sequence representations and frequently used reference frames that form the foundation of spacecraft attitude description. It then discusses the fundamentals of attitude determination using vector measurements, various efficient (including very recently developed) attitude determination algorithms, and the instruments and methods of popular vector measurements. With available attitude measurements, attitude control designs for inertial point and nadir pointing are presented in terms of required torques which are independent of actuators in use. Given the required control torques, some actuators are not able to generate the accurate control torques, therefore, spacecraft attitude control design methods with achievable torques for these actuators (for example, magnetic torque bars and control moment gyros) are provided. Some rigorous controllability results are provided. The book also includes attitude control in some special maneuvers, such as orbital-raising, docking and rendezvous, that are normally not discussed in similar books. Almost all design methods are based on state-spaced modern control approaches, such as linear quadratic optimal control, robust pole assignment control, model predictive control, and gain scheduling control. Applications of these methods to spacecraft attitude control problems are provided. Appendices are provided for readers who are not familiar with these topics.

Scientific and Technical Aerospace Reports
Scientific and Technical Aerospace Reports

Author:

Publisher:

Published: 1981

Total Pages: 1370

ISBN-13:

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Spacecraft Attitude Determination and Control
Spacecraft Attitude Determination and Control

Author: J.R. Wertz

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 877

ISBN-13: 9400999070

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Roger D. Werking Head, Attitude Determination and Control Section National Aeronautics and Space Administration/ Goddard Space Flight Center Extensiye work has been done for many years in the areas of attitude determination, attitude prediction, and attitude control. During this time, it has been difficult to obtain reference material that provided a comprehensive overview of attitude support activities. This lack of reference material has made it difficult for those not intimately involved in attitude functions to become acquainted with the ideas and activities which are essential to understanding the various aspects of spacecraft attitude support. As a result, I felt the need for a document which could be used by a variety of persons to obtain an understanding of the work which has been done in support of spacecraft attitude objectives. It is believed that this book, prepared by the Computer Sciences Corporation under the able direction of Dr. James Wertz, provides this type of reference. This book can serve as a reference for individuals involved in mission planning, attitude determination, and attitude dynamics; an introductory textbook for stu dents and professionals starting in this field; an information source for experimen ters or others involved in spacecraft-related work who need information on spacecraft orientation and how it is determined, but who have neither the time nor the resources to pursue the varied literature on this subject; and a tool for encouraging those who could expand this discipline to do so, because much remains to be done to satisfy future needs.