Download or read book Satellite Attitude Control for Steady State Disturbance Using Only Magnetic Torquers written by Maria Korkor Hagan and published by . This book was released on 2000 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Satellite Attitude Control Using Magnetic Torquers a Periodic Time Varying Control Problem written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellite attitude controllers have been designed for a rigid spacecraft whose only actuators are magnetic torque rods. This effort's goals have been to develop a new class of lightweight, moderate accuracy attitude controllers and to evaluate and further develop general methods for the control of time varying systems. Three different classes of controllers have been developed and simulation tested. one based on linear quadratic regulator techniques, one based on sliding mode like concepts, and one based on new H infinity techniques for time varying systems. These H infinity controllers achieve the best performance. In addition to the controller design studies. the issue of attenuation of constant 3 axis disturbances has been addressed. Disturbance attenuation is difficult for this system because it can apply torques only about the 2 axes that are perpendicular to the Earth's magnetic field. It is a challenge to determine how best to counteract a low frequency 3 axis disturbance torque, on average, via judicious use of the fact that the Earth's magnetic field direction varies in time as the spacecraft moves along its orbit. Pointing accuracies on the order of 1 deg or better have been demonstrated in the presence of typical levels of disturbance torque.
Download or read book Spacecraft Attitude Determination and Control written by J.R. Wertz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 877 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Model based Fault Recovery for the Attitude Control Subsystem of a Satellite Using Magnetic Torquers written by Jessica Nathalia Parra Bernal and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Attitude Dynamics and Control of Satellites with Fluid Ring Actuators written by Nona Abolfathi Nobari and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Successful mission of a satellite depends on maintaining a fixed orientation with respect to the Earth. However, the attitude angles of a satellite can be perturbed because of various natural disturbance sources, such as the Earth's gravity gradient, solar radiation pressure, and the Earth's magnetic field. Modeling the attitude dynamics and developing a controller to stabilize the attitude motion are quite important steps in the design of satellites. Although several actuators exist to control the attitude motion, a novel type considered in the thesis, shows promise of producing a high torque to mass ratio. This potential justifies the in-depth study reported. The novel actuator in question consists of a ring containing fluid, whose flow is regulated by a pump. The control torque is produced due to the variation of the angular velocity of the fluid. In this thesis, first, a redundant actuator system composed of four fluid rings in a pyramidal configuration is studied. The dynamical model of the system is developed for a satellite travelling either in a circular or an elliptical orbit. The dynamical analysis of this system leads to an underdetermined system of nonlinear differential equations, whose solution without considering the control input (the torque produced by the pump pressure) shows that the fluid rings can damp out the attitude disturbances of a satellite in a circular orbit and the roll-yaw disturbances in an elliptical orbit. However, this passive damping effect is fairly slow; an active controller is hence designed in the next step. The effect of the failure of one fluid ring on the performance of the attitude control subsystem (ACS) of a satellite is also studied. It is observed that even in the case of failure of one fluid ring, the satellite can be stabilized by slight modification of the active controller. Later, a sliding mode controller is designed to cope with the uncertainties existing in the fluid model and in other parameters of the system. Although the results achieved are quite satisfactory, the chattering that exists in the steady response of the system is not desirable; hence a switching controller consisting of a sliding mode and a PID control law is designed to eliminate this chattering effect. Next, the theoretical results obtained are validated by conducting several experiments. Although the experimental results confirm the theory developed in this thesis, the large torque-to-mass ratio expected is revealed to be only possible at the cost of a quite high input voltage to the pumps regulating the flow. Therefore, two novel applications of fluid rings are proposed: as an actuator for spin stabilized satellites, or as an auxiliary actuator in satellites with magnetic torquers.Using fluid rings in spin stabilized satellites is proposed in the thesis, as an alternative to the commonly used micro-thrusters. Here, two fluid rings are mounted on the satellite while their axes of symmetry are aligned with the roll and yaw axes. To examine the feasibility and performance, a dynamical model of this spinning satellite with two fluid rings is developed. A controller is then designed to stabilize the attitude motion of this satellite.The second novel actuator system developed here consists in using fluid rings as complementary actuators in satellites with two magnetic torquers. The dynamical model is formulated, and a controller is designed to investigate the performance of this system. The simulation of the system without the fluid ring shows that the satellite attitude can be stabilized by using only two magnetic torquers, however, slowly. Upon adding the active fluid ring actuator to the system, the stabilization time is reduced by a factor of 10. The failure of the fluid ring and each magnetic torquer is also studied." --
Download or read book Study of a Satellite Attitude Control System Using Integrating Gyros as Torque Sources written by John S. White and published by . This book was released on 1961 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Satellite Attitude Control Utilizing the Earth s Magnetic Field written by John S. White (writer on artificial satellites.) and published by . This book was released on 1961 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The torque developed by the interaction of current-carrying coils with the earth's magnetic field can be used as a means of attitude control. The degree to which the attitude of a vehicle can be maintained utilizing this torque depends on the fluctuations of the magnetic field at the satellite as the satellite orbits about the earth. Due to the nature of the torque developed only two vehicle axes can be c ntinuously controlled simultaneously. With the principle described, either a two- or three-coil system can be used to control vehicle attitude about two axes. Intermittent control about three axes can be obtained. (Author).
Download or read book Spacecraft Attitude Dynamics and Control written by Vladimir A. Chobotov and published by Krieger Publishing Company. This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the basic concepts, methods and mathematical developments which are necessary to understand spacecraft attitude dynamics and control. This book contains essential elements of kinematics, rigid body dynamics, linear control theory, environmental effects, and the theory of the stability of motion.
Download or read book Advanced Attitude Control of Satellite written by Bing Xiao and published by Springer Nature. This book was released on with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fast Satellite Attitude Maneuver and Control written by Dong Ye and published by Academic Press. This book was released on 2022-08-02 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fast Satellite Attitude Maneuver and Control introduces the concept of agile satellites and corresponding fast maneuver attitude control systems, systematically and comprehensively presenting recent research results of fast maneuver attitude control for agile satellites by using advanced nonlinear control techniques. This reference book focuses on modeling and attitude control, considering different actuator combinations, actuator installation deviation, actuator fault, and flexible appendage coupling effect for agile satellites. The book provides a unified platform for understanding and applicability of agile satellites fast maneuverer and stabilization control for different purposes. It will be an excellent resource for researchers working on spacecraft design, nonlinear control systems, vehicle systems and complex control systems. Unifies existing and emerging concepts concerning nonlinear control theory, fault tolerant, and attitude control for agile satellites Provides a series of the latest results, including, but not limited to, fast maneuverer and stabilization control, hybrid actuator control, nonlinear attitude control, fault tolerant control, and active vibration suppression towards agile satellites Comprehensively captures recent advances of theory, technological aspects and applications of fast maneuverer and stabilization control in agile satellites Addresses research problems in each chapter, along with numerical and simulation results that reflect engineering practice and demonstrate the focus of developed analysis and synthesis approaches Contains comprehensive, up-to-date references, which play an indicative role for further study
Download or read book Models of Venus Atmosphere 1968 written by Robert A. Schiffer and published by . This book was released on 1968 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Spacecraft Attitude Determination and Control written by F. Landis Markley and published by Springer. This book was released on 2014-05-31 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores topics that are central to the field of spacecraft attitude determination and control. The authors provide rigorous theoretical derivations of significant algorithms accompanied by a generous amount of qualitative discussions of the subject matter. The book documents the development of the important concepts and methods in a manner accessible to practicing engineers, graduate-level engineering students and applied mathematicians. It includes detailed examples from actual mission designs to help ease the transition from theory to practice and also provides prototype algorithms that are readily available on the author’s website. Subject matter includes both theoretical derivations and practical implementation of spacecraft attitude determination and control systems. It provides detailed derivations for attitude kinematics and dynamics and provides detailed description of the most widely used attitude parameterization, the quaternion. This title also provides a thorough treatise of attitude dynamics including Jacobian elliptical functions. It is the first known book to provide detailed derivations and explanations of state attitude determination and gives readers real-world examples from actual working spacecraft missions. The subject matter is chosen to fill the void of existing textbooks and treatises, especially in state and dynamics attitude determination. MATLAB code of all examples will be provided through an external website.
Download or read book Spacecraft Dynamics and Control written by Marcel J. Sidi and published by Cambridge University Press. This book was released on 2000-07-03 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellites are used increasingly in telecommunications, scientific research, surveillance, and meteorology, and these satellites rely heavily on the effectiveness of complex onboard control systems. This 1997 book explains the basic theory of spacecraft dynamics and control and the practical aspects of controlling a satellite. The emphasis throughout is on analyzing and solving real-world engineering problems. For example, the author discusses orbital and rotational dynamics of spacecraft under a variety of environmental conditions, along with the realistic constraints imposed by available hardware. Among the topics covered are orbital dynamics, attitude dynamics, gravity gradient stabilization, single and dual spin stabilization, attitude maneuvers, attitude stabilization, and structural dynamics and liquid sloshing.
Download or read book ACS Without an Attitude written by Harold L. Hallock and published by Springer. This book was released on 2017-05-03 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book de-emphasizes the formal mathematical description of spacecraft on-board attitude and orbit applications in favor of a more qualitative, concept-oriented presentation of these topics. The information presented in this book was originally given as a set of lectures in 1999 and 2000 instigated by a NASA Flight Software Branch Chief at Goddard Space Flight Center. The Branch Chief later suggested this book. It provides an approachable insight into the area and is not intended as an essential reference work. ACS Without an Attitude is intended for programmers and testers new to the field who are seeking a commonsense understanding of the subject matter they are coding and testing in the hope that they will reduce their risk of introducing or missing the key software bug that causes an abrupt termination in their spacecraft’s mission. In addition, the book will provide managers and others working with spacecraft with a basic understanding of this subject.
Download or read book Analysis of a Magnetic Three Axis Stabilized Attitude Control System for the NPSAT1 Spacecraft written by Todd A. Zirkle and published by . This book was released on 2001-09 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NPSAT1 satellite uses an active magnetic torque rod system, with a magnetometer for attitude determination, to maintain 3-axis stabilization, with a slightly gravity gradient friendly structure, This thesis will examine the performance of three combinations of programs and simulation models for the NPSAT1 satellite attitude control system. The models include a magnetic control law with a reduced order estimator to generate torque commands to achieve spacecraft nadir pointing and a magnetic rate (Bdot) control law to reduce spacecraft angular rates. The performances of two Bdot mode switching designs are compared Also, a case is made for the benefits of performing the system's reduced estimator prior to mode switching. All of the control methods analyzed appear to be valid control methods to achieve three-axis attitude stabilization using only magnetic torquers for active control. The most efficient control method analyzed incorporates a hand-off method from a magnetic rate (Bdot) control loop to a magnetic control loop. The results of this analysis indicates that the best use of this method is to perform the Bdot hand-off following the achievement of a predetermined combined angular rate.
Download or read book Magnetic Attitude Control of Rigid Axially Symmetric Spinning Satellites in Circular Earth Orbits written by Phillip C. Wheeler and published by . This book was released on 1965 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CubeSat Attitude Control Utilizing Low power Magnetic Torquers a Magnetometer written by Donald B. Mentch and published by . This book was released on 2011 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: The CubeSat Project has lowered development time and costs associated with university satellite missions that conform to their 10 centimeter cube design specification. Providing attitude control to a spacecraft, of such small volume, with a very limited power budget has been a challenge around the world. This work describes the development of an attitude control system based on a very low-power magnetic torquer used in conjunction with a magnetometer. This will be the first flight use of this torquer which is composed of a hard magnetic material wrapped inside of a solenoid. By discharging a capacitor through the solenoid, the magnetic dipole moment of this permanent magnet can be reversed. The completed attitude control system will make the first use of the low-power magnetic torquer to arrest satellite tip-off rates. It will then make the first known use of a dual axis magnetic dipole moment bias algorithm to achieve three-axis attitude alignment. The complete system is standalone for high inclination orbits, and will align the spacecraft to within 5 degrees of ram, nadir, and local vertical, without any requirement for attitude determination. The system arrests tip-off rates of up to 5° per second (in all 3 axes) for a satellite in a 600 kilometer polar orbit expending 0.56 milliwatts of power. Once in the proper alignment, it utilizes 0.028 milliwatts to maintain it. The system will function for low inclination orbits with the addition of a gravity boom. The system utilizes the magnetometer to calculate spacecraft body rates. This is the only known use of a magnetometer to directly measure spacecraft body rates without prior knowledge of spacecraft attitude.