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Cubesat Attitude Control Using Micronewton Electrospray Thruster Actuation
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Book Synopsis CubeSat Attitude Control Using Micronewton Electrospray Thruster Actuation by : Mark David Van de Loo
Download or read book CubeSat Attitude Control Using Micronewton Electrospray Thruster Actuation written by Mark David Van de Loo and published by . This book was released on 2014 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micronewton electrospray thrusters are a promising new actuator for CubeSat attitude control. Electrospray thrusters have advantages over current state of the art CubeSat attitude actuators in mass, volume, and their ability to produce translational acceleration in addition to control moments. An attitude determination and control system was designed for a 1U CubeSat assuming commercial-off-the-shelf attitude determination hardware components and six electrospray thrusters developed by the MIT Space Propulsion Laboratory. A high fidelity spacecraft dynamics simulation was constructed for analysis of the performance of the ADCS system. Attitude determination was tested with an engineering model of a 1U CubeSat, and the entire ADCS system was tested in simulation. Results of these preliminary tests show the use of electrospray thrusters as attitude actuators to be feasible, although significant work remains to complete a flight-ready ADCS system.
Book Synopsis Attitude Determination and Control System Design and Implementation for a 6U CubeSat Proximity Operations Mission by : Francisco J. Franquiz
Download or read book Attitude Determination and Control System Design and Implementation for a 6U CubeSat Proximity Operations Mission written by Francisco J. Franquiz and published by . This book was released on 2015 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this work is to discuss the attitude determination and control system (ADCS) design process and implementation for a 12 kg, 6U (36.6 cm x 23.9 cm x 27.97 cm) CubeSat class nano-satellite. The design is based on the requirements and capabilities of the Application for Resident Space Object Proximity Analysis and IMAging (ARAPAIMA) proximity operations mission. The satellite is equipped with a cold gas propulsion system capable of exerting 2.5 mN m torques in both directions about each body axis. The attitude sensors include an angular rate gyro and star tracker (STR), supplemented by the payload optical array cameras. The dynamic simulation of the satellite includes extensive environmental models and analyses that show how the satellite attitude is affected by aerodynamic drag, solar radiation pressure, gravity gradient torques, and residual magnetic moments. A mechanical propellant slosh model and a reaction torque analysis of the deployable solar panel hinges approximate the internal dynamics of the satellite. A trade study is presented to justify the use of a reaction control thruster actuated system over the more traditional reaction wheel configuration. Both actuation systems are modeled to hardware specifications and their propellant and energy requirements are examined alongside pointing performance. Two methods of accounting for sensor noise and sampling rates are presented. The first is an extended Kalman filter based on the nonlinear model of a rate gyro coupled with quaternion attitude kinematics. The second presents a gyro-less angular rate observer capable of extrapolating STR measurements to the desired frequency. An additional method uses images from the payload cameras to perform [camera] frame centering maneuvers and to address the possibility of bias in the controller reference signal. Four different controllers are described to reflect the chronological progression of the ADCS design. The first controller, designed to perform long angle maneuvers and target tracking, utilizes fixed gain eigenaxis control. The same controller is then augmented with a parallel proportional-integral-derivative (PID) type control law using scheduled gains. This configuration is designed to switch between eigenaxis and PID control during imaging procedures to take advantage of the integral control introduced by the PID algorithm. To reduce system complexity, a modified eigenaxis control law, which incorporates scheduled integral control but does not require a switch to PID control, is introduced. A discrete time equivalent of the modified eigenaxis control law is also developed. Additionally, a brief description of a detumbling control law is presented. Each of the four control laws is paired and tested with the different feedback and estimation methods discussed. An extensive showcase of numerical simulation results outlines the pointing performance of each system configuration and evaluates their capabilities of meeting a 1 arcmin pointing requirement. A comparison of the different properties and performance of each control system configuration precedes the selection of the discrete modified eigenaxis control law as the best alternative.
Book Synopsis Attitude Stablization for CubeSat by : Mohammed Chessab Mahdi
Download or read book Attitude Stablization for CubeSat written by Mohammed Chessab Mahdi and published by . This book was released on 2018 with total page 170 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 ProportionalIntegralDerivative 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.
Book Synopsis Optimization of CubeSat Attitude Control System and Propulsion Subsystems for Orbit Changes by : Matthew R. Lipscomb (2LT, USAF.)
Download or read book Optimization of CubeSat Attitude Control System and Propulsion Subsystems for Orbit Changes written by Matthew R. Lipscomb (2LT, USAF.) and published by . This book was released on 2012 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Theoretical and Experimental Investigation of Attitude Control for Underactuated Spacecraft by : Rajika Arosh Pati Arambage
Download or read book Theoretical and Experimental Investigation of Attitude Control for Underactuated Spacecraft written by Rajika Arosh Pati Arambage and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates the detumbling and attitude control capabilities of an underactuated 3U-CubeSat used for ESSENCE mission developed by York University. Three different types of actuatorsexternal thrusters, magnetorquers, and reaction wheelsare considered in the nonlinear rigid-body control problem. According to Brocketts theorem, a smooth or continuous feedback law does not exist in the attempt to stabilize the attitude dynamics, hence robust discontinuous control algorithms such as sliding mode control (SMC) and model predictive control (MPC) are considered. First, two thrusters are used to study the ability to detumble the spacecraft using SMC and nonlinear model predictive control (NMPC). Second, a comparison between the B-dot controller and NMPC in detumbling a spacecraft equipped with two magnetorquers is explored. SEET library in STK is utilized to obtain an accurate geomagnetic field model to model the space environment. Then, the use of two reaction wheels along the principal axes of the spacecraft to perform an attitude correction maneuver is studied using quaternion-based nonlinear control (QBNC) and NMPC. Finally, an air-bearing testbed with a floating satellite simulator that closely mimics the dynamics of a spacecraft is used to validate the use of NMPC for attitude control through experimentation. Air thrusters and a reaction wheel is used to perform two separate experiments to observe the performance of NMPC with each actuator. Design recommendations and challenges posed by underactuated configuration of the ESSENCE 3U-CubeSat are presented as a result of this thesis.
Book Synopsis Hardware and Software Implementation of a Low Power Attitude Control and Determination System for CubeSats by : Jesse Frey
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.
Book Synopsis Study and Design of a CubeSat Attitude Control System Based on a Brushless Motor by : Héctor Anadón Cónsul
Download or read book Study and Design of a CubeSat Attitude Control System Based on a Brushless Motor written by Héctor Anadón Cónsul and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the objective of being able to do an optic link between two CubeSats, a low cost attitude control system is studied and designed. The system requirements are set by the Electronics Department of the Universitat Politècnica de Catalunya, who fixed a combination of micro-controller, driver and motors that should suit with the needs of the project. With the objective of keeping it very low cost, the motor studied is a recycled motor from an HDD (Hard DriveDisk).The current state of the art in attitude control systems for CubeSats is studied and a decision is made regarding the needed components of our low cost system.The kinematic and dynamic equations of the system are determined and the reaction wheel ismodeled as simple as possible to develop a control law system for the CubeSat. An open-loop and closed-loop model are tested to prove their stability.In order to test our hardware, the driver is studied to identify all the different parameters that can be modified and the computer is set with the appropriate programs to be able to communicate with the driver. The motor specific parameters like the motor speed constant and the resistance are found and correctly set in the drivers to successfully run the motor at full speed.
Book Synopsis Attitude Estimation and Control of a Magnetically-actuated Earth-observing Cubesat by : Corey Miles
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"--
Book Synopsis Development of an Attitude Control System for CubeSat Application by : Joshua Francis Reginald O'Neill
Download or read book Development of an Attitude Control System for CubeSat Application written by Joshua Francis Reginald O'Neill and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Guidance, navigation, and control (GNC) systems are commonly found in vehicles, whether they be spacecraft, aircraft, seacraft or landcraft. These systems are designed to bring the vehicle to its desired position and/or orientation by sensing pose and making the necessary adjustments to onboard devices. With regard to satellites, GNC systems are divided into two segments: orbit control, which is concerned with the spacecraft's position, and attitude control, which is concerned with the spacecraft's orientation. The focus of this thesis is to develop the attitude control system of a CubeSat nanosatellite being designed for the University of Prince Edward Island's SpudNik-1 mission. The objective of this study was to progress the design of the attitude control system (ACS) from its conceptual design phase to a state where it is ready for assembly, integration, and testing. To accomplish this, the engineering design process was applied. Accordingly, the fundamentals of attitude control were first reviewed in literature. Then, the system-level requirements were evaluated and the current design's ability to meet them was assessed. After doing so, the necessary alterations were made to the conceptual design, such that it would meet the requirements, and the various methods of requirement verification were defined to verify that this is the case during the assembly, integration, and testing phase. Once the system-level design had been established, this process was repeated for the subsystem- and unit-level designs. In addition to contributing the detailed design of an attitude control system to the Spudnik-1 team, this work can also serve as a reference for other teams working toward space missions that require the use of an ACS by providing a comprehensive perspective that focuses on the identification, integration, and implementation of the major elements of an attitude control system. It not only offers detailed information on the definition, measurement, modeling, estimation, and control of a spacecraft's attitude, but also identifies: the connections between these concepts; the hardware used to implement the concepts in a real-world application; and the various considerations that should be taken during this implementation. Aside from familiarizing the reader with the methodology behind an ACS system, this work also describes the procedure that was used to develop the attitude control subsystem of the SpudNik-1 CubeSat. It details: how the requirements of the attitude control subsystem were identified from the spacecraft's mission and the corresponding system requirements; how the major components and concepts of the ACS are identified from the subsystem requirements, and integrated through the subsystem architecture; how the unit-level requirements are identified based on the subsystem-level design; and how the implementation of the various components and concepts is dependent on the unit level requirements. While a good deal of the design is standard with regard to CubeSats and other aerospace projects, the original aspects would relate to the in-house design of the reaction wheels and fine sun sensors. Being as there are a wide selection of ACS components available on the market, it is most common for CubeSat projects to procure their hardware. Although the lack of flight heritage did pose additional risk to the mission in comparison to using commercial equipment, the in-house design allowed the components to be both tailored to the mission and produced at a fraction of the cost. If the designs manage to gain flight heritage on-board of the SpudNik-1 CubeSat, then this work will provide readers with standard frameworks which will allow them to reap the same benefits, but at a lower level of risk.
Book Synopsis CubeSat Attitude Control Utilizing Low-power Magnetic Torquers & a Magnetometer by : Donald B. Mentch
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.
Book Synopsis Satellite Attitude Control Using Only Electromagnetic Actuation by : Rafal Wisniewski
Download or read book Satellite Attitude Control Using Only Electromagnetic Actuation written by Rafal Wisniewski and published by . This book was released on 1996 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Optimal Attitude Control Management for a Cubesat by : Michael James Develle (II.)
Download or read book Optimal Attitude Control Management for a Cubesat written by Michael James Develle (II.) and published by . This book was released on 2011 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: CubeSats have become popular among universities, research organizations, and government agencies due to their low cost, small size, and light weight. Their standardized configurations further reduce the development time and ensure more frequent launch opportunities. Early cubesat missions focused on hardware validation and simple communication missions, with little requirement for pointing accuracy. Most of these used magnetic torque rods or coils for attitude stabilization. However, the intrinsic problems associated with magnetic torque systems, such as the lack of three-axis control and low pointing accuracy, make them unsuitable for more advanced missions such as detailed imaging and on-orbit inspection. Three-axis control in a cubesat can be achieved by combining magnetic torque coils with other devices such as thrusters, but the lifetime is limited by the fuel source onboard. To maximize the mission lifetime, a fast attitude control management algorithm that could optimally manage the usage of the magnetic and thruster torques is desirable. Therefore, a recently developed method, the B-Spline-augmented virtual motion camouflage, is presented in this defense to solve the problem. This approach provides results which are very close to those obtained through other popular nonlinear constrained optimal control methods with a significantly reduced computational time. Simulation results are presented to validate the capabilities of the method in this application.
Book Synopsis Linear Time Varying Approach to Satellite Attitude Control Using Only Electromagnetic Actuation by : Rafał Wiśniewski
Download or read book Linear Time Varying Approach to Satellite Attitude Control Using Only Electromagnetic Actuation written by Rafał Wiśniewski and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Linear Time Varying Approach Satellite Attitude Control Using Only Electromagnetic Actuation by : R. Wisniewski
Download or read book Linear Time Varying Approach Satellite Attitude Control Using Only Electromagnetic Actuation written by R. Wisniewski and published by . This book was released on 1997 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Spacecraft Attitude Control System Performance Using Pulse-width Pulse-frequency Modulated Thrusters by : Robert S. McClelland
Download or read book Spacecraft Attitude Control System Performance Using Pulse-width Pulse-frequency Modulated Thrusters written by Robert S. McClelland and published by . This book was released on 1994 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many current satellites employ on-off thrusters to accomplish attitude control tasks which may include initial acquisition, rotational maneuvers, and on-orbit stabilization. This work shows that the use of pulse- width pulse-frequency (PWPF)-modulated thrusters provides several important advantages over conventional bang- bang thruster control methods, including less thruster activity and closer-to-linear actuation. The PWPF modulator is implemented in simulations using the Matrix/System build software package. Simulations assuming a rigid spacecraft are first performed to compare the performance of the PWPF-modulated thrust controller with that of conventional bang-bang and time-optimal bang-bang controllers. The discussion is then extended to the case of a spacecraft with structural flexibility, as is encountered quite often in three-axis stabilized vehicles with large fold-out solar arrays. Simulations for comparison of the controllers are performed using the flexible spacecraft dynamics model. The control loop design in the presence of flexibility and possible interaction with the PWPF modulator nonlinearity are addressed. Using a describing function model of the modulator, stability margin with respect to the structural mode limit cycle is predicted. Simulations are then conducted to verify the predicted stability margin.
Book Synopsis Spacecraft Attitude Control System Performance Using Pulse-width Pulse-frequency Modulated Thrusters by : Robert S. McClelland
Download or read book Spacecraft Attitude Control System Performance Using Pulse-width Pulse-frequency Modulated Thrusters written by Robert S. McClelland and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many current satellites employ on-off thrusters to accomplish attitude control tasks which may include initial acquisition, rotational maneuvers, and on-orbit stabilization. This work shows that the use of pulse- width pulse-frequency (PWPF)-modulated thrusters provides several important advantages over conventional bang- bang thruster control methods, including less thruster activity and closer-to-linear actuation. The PWPF modulator is implemented in simulations using the Matrix/System build software package. Simulations assuming a rigid spacecraft are first performed to compare the performance of the PWPF-modulated thrust controller with that of conventional bang-bang and time-optimal bang-bang controllers. The discussion is then extended to the case of a spacecraft with structural flexibility, as is encountered quite often in three-axis stabilized vehicles with large fold-out solar arrays. Simulations for comparison of the controllers are performed using the flexible spacecraft dynamics model. The control loop design in the presence of flexibility and possible interaction with the PWPF modulator nonlinearity are addressed. Using a describing function model of the modulator, stability margin with respect to the structural mode limit cycle is predicted. Simulations are then conducted to verify the predicted stability margin.
Book Synopsis Fuzzy Attitude Control of a Magnetically Actuated CubeSat by : Alex R. Walker
Download or read book Fuzzy Attitude Control of a Magnetically Actuated CubeSat written by Alex R. Walker and published by . This book was released on 2013 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of magnetic attitude control of a CubeSat is analyzed. Three controller types are examined: a Constant-Gain Simple PD controller, a Linear Constant-Gain Optimal PD controller (i.e. an LQR), and a Fuzzy Gain-Scheduled PD controller. Each subsequent controller type utilizes a more-complex design algorithm. The Simple PD controller is tuned by hand iteration, the LQR is tuned using rule-of-thumb algorithms, and the Fuzzy Gain-Scheduled PD controller is designed using a Genetic Algorithm operating on two Fuzzy Inference Systems. Though the basic structures of these three controllers are identical, the differing design processes lead to different controller performance. The use of a Genetic-Fuzzy System is of particular interest, because this demonstrates the use of an intelligent algorithm to automate the controller design process. The techniques presented herein are directly applicable to any magnetically actuated satellite that can be modeled as a rigid body, although the mass distribution, geometry, and orbit of the satellite will determine controller-specific constants.
