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.

Download or read book Hardware and Software Implementation of a Low Power Attitude Control and Determination System for CubeSats written by Jesse Frey and published by . This book was released on 2014 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years there has been a growing interest in smaller satellites. Smaller satellites are cheaper to build and launch than larger satellites. One form factor, the CubeSat, is especially popular with universities and is a 10 cm cube. Being smaller means that the mass and power budgets are tighter and as such new ways must be developed to cope with these constraints. Traditional attitude control systems often use reaction wheels with gas thrusters which present challenges on a CubeSat. Many CubeSats use magnetic attitude control which uses the Earth's magnetic field to torque the satellite into the proper orientation. Magnetic attitude control systems fall into two main categories: active and passive. Active control is often achieved by running current through a coil to produce a dipole moment, while passive control uses the dipole moment from permanent magnets that consume no power. This thesis describes a system that uses twelve hard magnetic torquers along with a magnetometer. The torquers only consume current when their dipole moment is flipped, thereby significantly reducing power requirements compared with traditional active control. The main focus of this thesis is on the design, testing and fabrication of CubeSat hardware and software in preparation for launch.

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 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 A flexible attitude control system for three axis stabilized nanosatellites written by Gordon, Karsten and published by Universitätsverlag der TU Berlin. This book was released on 2018-03-15 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates a new concept for the flexible design and verification of an ADCS for a nanosatellite platform. In order to investigate guidelines for the design of a flexible ADCS, observations of the satellite market and missions are recorded. Following these observations, the author formulates design criteria which serve as a reference for the conceptual design of the flexible ADCS. The research of the thesis was carried out during the development of TU Berlin's nanosatellite platform TUBiX20 and its first two missions, TechnoSat and TUBIN. TUBiX20 targets modularity, reuse and dependability as main design goals. Based on the analysis of design criteria for a flexible ADCS, these key design considerations for the TUBiX20 platform were continued for the investigations carried out in this thesis. The resulting concept implements the ADCS as a distributed system of devices complemented by a hardware-independent core application for state determination and control. Drawing on the technique of component-based software engineering, the system is partitioned into self-contained modules which implement unified interfaces. These interfaces specify the state quantity of an input or output but also its unit and coordinate system, complemented by a mathematical symbol for unambiguous documentation. The design and verification process for the TUBiX20 ADCS was also elaborated during the course of this research. The approach targets the gradual development of the subsystem from a purely virtual satellite within a closed-loop simulation to the verification of the fully integrated system on an air-bearing testbed. Finally, the concurrent realization of the investigated concept within the TechnoSat and TUBIN missions is discussed. Starting with the individual ADCS requirements, the scalability of the approach is demonstrated in three stages: from a coarse, but cost- and energy-efficient configuration to realize a technology demonstration mission with moderate requirements (TechnoSat) to a high-performance configuration to support Earth observation missions (TUBIN). Diese Dissertation untersucht ein neues Konzept zur flexiblen Entwicklung und Verifikation eines Lageregelungssystems für eine Nanosatellitenplattform. Als Grundlage für die Erarbeitung eines Leitfadens für die Entwicklung werden zunächst Beobachtung des Satellitenmarkts sowie konkreter Missionen zusammengetragen. Darauf aufbauend formuliert der Autor Entwurfskriterien für die Konzipierung eines flexiblen Lageregelungssystems. Die Dissertation wurde im Rahmen der Entwicklung der TUBiX20 Nanosatellitenplattform und ihrer ersten beiden Missionen, TechnoSat und TUBIN, an der TU Berlin durchgeführt. TUBiX20 verfolgt Modularität, Wiederverwendung und Zuverlässigkeit als Entwicklungsziele. Diese werden unter der Verwendung der vom Autor hergeleiteten Entwurfskriterien in dieser Arbeit im Kontext des Lageregelungssystems verfeinert. Das resultierende Konzept setzt dieses als verteiltes System von Geräten und einem hardware-unabhängigen Software-Kern um. Der Software-Entwurfstechnik Component-based software engineering folgend ist das System in unabhängige Module unterteilt, welche wiederum einheitliche Schnittstellen implementieren. Diese Schnittstellen spezifizieren die Zustandsgrößen für die Ein- und Ausgänge der Module inklusive Einheit, Koordinatensystem und mathematischem Symbol für eine eindeutige Darstellung. Der Entwurfs- und Verifikationsprozess für das TUBiX20 Lageregelungssystem wurde vom Autor im Rahmen der Arbeit untersucht. Hier verfolgt der Ansatz einen schrittweisen übergang von einem virtuellen Satelliten als Simulationsmodell bis hin zur Verifikation des integrierten Systems auf einem Lageregelungsteststand. Abschließend diskutiert die Arbeit die Realisierung des untersuchten Konzepts im Rahmen der Missionen TechnoSat und TUBIN. Beginnend mit den jeweiligen Anforderungen wird die Skalierbarkeit des Ansatzes in drei Stufen demonstriert: von einer groben, aber kosten- und energieeffizienten Konfiguration für eine Technologieerprobungsmission mit moderaten Anforderungen (TechnoSat) bis hin zu einer Konfiguration für hochgenaue Lageregelung als Basis für Erdbeobachtungsmissionen (TUBIN).

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 Attitude Estimation and Control of a Magnetically actuated Earth observing Cubesat written by Corey Miles and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Meteorix mission is a nanosatellite demonstration mission dedicated to the observation and characterization of meteors and space debris entering into the Earth's atmosphere. The scientific objectives of this mission require a high performance attitude determination and control system (ADCS). This thesis entails the development of attitude estimation and control algorithms for the Meteorix 3U cubesat. Attitude estimation and control requirements are outlined, given the mission's scientific objectives and the power needs of the satellite. A magnetometer-only multiplicative extended Kalmanfilter (MEKF) is formulated to estimate the satellite's attitude and angular velocity. Itis compared to a conventional gyro-based MEKF and uses the derivative of the magnetic field and the attitude dynamics model, in place of gyroscope measurements to update the angular velocity estimate. Results from Monte Carlo simulations show that the magnetometer-only MEKF outperforms a gyro-based MEKF in low angular velocity scenarios. A sliding mode controller is developed for attitude control using three magnetic actuators, while a single flywheel oriented in a momentum bias configuration provides gyroscopic stability. Using the attitude and angular velocity feedback from the magnetometer-only MEKF, the sliding mode control law offers better pointing accuracy than a standard proportional derivative (PD) magnetic feedback controller; it is also shown to be more robust to uncertainties and disturbances in a sensitivity study. The magnetometer-only MEKF suffers in the presence of model uncertainties such as flywheel misalignment and residual magnetic moment, and methods to improve the overall ADCSperformance are discussed"--

Download or read book Study of Magnetorquers Control Strategies for Energy Efficient Manoeuvres of a CubeSat written by David Poza Hernández and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the study and design of attitude control of a 1U CubeSat based on magnetorquers, with the aim of analyzing the most energy efficient control strategies. For this analysis, three different lowaltitude orbits are simulated using Simulink, taking into account a constant disturbance torque. Using two control algorithms, detumbling and Nadir pointing manoeuvers are performed. Once the controllers are adjusted and are able to stabilize the CubeSat, an energy balance is carried out to determine which parameters influence the orbital path. For this, the electrical system is designed consisting of a battery, solar panels installed on Cube- Sat faces as an energy source and magnetorquers that will consume current from the battery. The power consumed during the manoeuvers falls within the expected range and it is further observed that as the influence of the Earth's magnetic field on the orbit followed by the CubeSat increases, the shorter the stabilization time. That iswhy the best strategy to follow to carry out attitude control is to activate the controller when the magnetic field intensity is higher.

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 ALGORITHMS AND OPTIMAL CONTROL FOR SPACECRAFT MAGNETIC ATTITUDE MANEUVERS written by and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : This study focused on providing applicable control solutions for spacecraft magnetic attitude control system. Basically, two main lines are pursued; first, developing detumbling control laws and second, an improvement in the three-axis attitude control schemes by extending magnetic rods activation time. Spacecraft, after separation from the launching mechanism, experiences a tumbling phase due to an undesired angular momentum. In this study, we present a new efficient variant of the B-dot detumbling law by introducing a substitute of the spacecraft angular velocity, based on the ambient magnetic field data. This B-dot law preserves the orthogonality, among the applied torque, dipole moment and magnetic field vectors. Most of the existing variants of the B-dot law in the literature don't preserve this orthogonality. Furthermore, the problem of minimum-time spacecraft magnetic detumbling is revisited within the context of optimal control theory. Two formulations are presented; the first one assumes the availability of the angular velocity measurements for feedback. The second formulation assumes the availability of only the ambient magnetic field measurements in the feedback; the latter is considered another optimal-based B-dot law. A reduction in detumbling time is fulfilled by the proposed laws along with less power consumption for the proposed B-dot laws. In magnetic attitude maneuvers, magnetic rods and magnetometers usually operate alternatively, to avoid the magnetic rods' noise effect on magnetometers measurements. Because of that, there will be no control authority over the spacecraft during the magnetometer measurement period. Hence longer maneuver times are usually experienced. In this study, a control scheme that enables the extension of the magnetic rods' activation time is developed, regardless of the attitude control law. The key concept is replacing the real magnetic field measurement by a pseudo measurement, which is computed based on other sensors measurements. By applying a known command to the spacecraft and measuring the spacecraft response, it is possible to compute the ambient magnetic field around the spacecraft. The system mathematical singularity is solved using the Tikhonov regularization approach. Another developed approach estimates the magnetic field, using a relatively simple and fast dynamic model inside a Multiplicative Extended Kalman Filter. A less maneuver time with less power consumption are fulfilled. These control approaches are further validated using real telemetry data from CASSIOPE mission. This dissertation develops a stability analysis for the spacecraft magnetic attitude control, taking into consideration the alternate operation between the magnetic rods and the magnetometers. It is shown that the system stability degrades because of this alternate operation, supporting the proposed approach of extending the operation time of the magnetic rods.

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 Attitude Stabilization for CubeSat written by Mohammed Chessab Mahdi and published by Cambridge Scholars Publishing. This book was released on 2018-11-14 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores CubeSat technology, and develops a nonlinear mathematical model of a spacecraft with the assumption that the satellite is a rigid body. It places emphasis on the CubeSat subsystem, orbit dynamics and perturbations, the satellite attitude dynamic and modeling, and components of attitude determination and the control subsystem. The book focuses on the attitude stabilization methods of spacecraft, and presents gravity gradient stabilization, aerodynamic stabilization, and permanent magnets stabilization as passive stabilization methods, and spin stabilization and three axis stabilization as active stabilization methods. It also discusses the need to develop a control system design, and describes the design of three controller configurations, namely the Proportional–Integral–Derivative Controller (PID), the Linear Quadratic Regulator (LQR), and the Fuzzy Logic Controller (FLC) and how they can be used to design the attitude control of CubeSat three-axis stabilization. Furthermore, it presents the design of a suitable attitude stabilization system by combining gravity gradient stabilization with magnetic torquing, and the design of magnetic coils which can be added in order to improve the accuracy of attitude stabilization. The book then investigates, simulates, and compares possible controller configurations that can be used to control the currents of magnetic coils when magnetic coils behave as the actuator of the system.

Download or read book Hybrid Magnetic Attitude Controller for Low Earth Orbit Satellites Using the Time varying Linear Quadratic Regulator written by Nitin Seth and published by . This book was released on 2009 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Extreme Events in Geospace written by Natalia Buzulukova and published by Elsevier. This book was released on 2017-12-01 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme Events in Geospace: Origins, Predictability, and Consequences helps deepen the understanding, description, and forecasting of the complex and inter-related phenomena of extreme space weather events. Composed of chapters written by representatives from many different institutions and fields of space research, the book offers discussions ranging from definitions and historical knowledge to operational issues and methods of analysis. Given that extremes in ionizing radiation, ionospheric irregularities, and geomagnetically induced currents may have the potential to disrupt our technologies or pose danger to human health, it is increasingly important to synthesize the information available on not only those consequences but also the origins and predictability of such events. Extreme Events in Geospace: Origins, Predictability, and Consequences is a valuable source for providing the latest research for geophysicists and space weather scientists, as well as industries impacted by space weather events, including GNSS satellites and radio communication, power grids, aviation, and human spaceflight. The list of first/second authors includes M. Hapgood, N. Gopalswamy, K.D. Leka, G. Barnes, Yu. Yermolaev, P. Riley, S. Sharma, G. Lakhina, B. Tsurutani, C. Ngwira, A. Pulkkinen, J. Love, P. Bedrosian, N. Buzulukova, M. Sitnov, W. Denig, M. Panasyuk, R. Hajra, D. Ferguson, S. Lai, L. Narici, K. Tobiska, G. Gapirov, A. Mannucci, T. Fuller-Rowell, X. Yue, G. Crowley, R. Redmon, V. Airapetian, D. Boteler, M. MacAlester, S. Worman, D. Neudegg, and M. Ishii. Helps to define extremes in space weather and describes existing methods of analysis Discusses current scientific understanding of these events and outlines future challenges Considers the ways in which space weather may affect daily life Demonstrates deep connections between astrophysics, heliophysics, and space weather applications, including a discussion of extreme space weather events from the past Examines national and space policy issues concerning space weather in Australia, Canada, Japan, the United Kingdom, and the United States

Download or read book Orbital Mechanics for Engineering Students written by Howard D. Curtis and published by Elsevier. This book was released on 2009-10-26 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orbital Mechanics for Engineering Students, Second Edition, provides an introduction to the basic concepts of space mechanics. These include vector kinematics in three dimensions; Newton’s laws of motion and gravitation; relative motion; the vector-based solution of the classical two-body problem; derivation of Kepler’s equations; orbits in three dimensions; preliminary orbit determination; and orbital maneuvers. The book also covers relative motion and the two-impulse rendezvous problem; interplanetary mission design using patched conics; rigid-body dynamics used to characterize the attitude of a space vehicle; satellite attitude dynamics; and the characteristics and design of multi-stage launch vehicles. Each chapter begins with an outline of key concepts and concludes with problems that are based on the material covered. This text is written for undergraduates who are studying orbital mechanics for the first time and have completed courses in physics, dynamics, and mathematics, including differential equations and applied linear algebra. Graduate students, researchers, and experienced practitioners will also find useful review materials in the book. NEW: Reorganized and improved discusions of coordinate systems, new discussion on perturbations and quarternions NEW: Increased coverage of attitude dynamics, including new Matlab algorithms and examples in chapter 10 New examples and homework problems

Download or read book Space Vehicle Dynamics and Control written by Bong Wie and published by AIAA. This book was released on 1998 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt: A textbook that incorporates the latest methods used for the analysis of spacecraft orbital, attitude, and structural dynamics and control. Spacecraft dynamics is treated as a dynamic system with emphasis on practical applications, typical examples of which are the analysis and redesign of the pointing control system of the Hubble Space Telescope and the analysis of an active vibrations control for the COFS (Control of Flexible Structures) Mast Flight System. In addition to the three subjects mentioned above, dynamic systems modeling, analysis, and control are also discussed. Annotation copyrighted by Book News, Inc., Portland, OR

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: