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Showing 1 to 17 of 17 for “"Spacecraft Attitude Control"”.
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Use of thermal reradiative effects in spacecraft attitude control.
Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics. Thesis. 1966. M.S.
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A Permanent Magnetic Dipole Reaction Sphere Actuator for Spacecraft Attitude Control
… prototype reaction sphere actuator for spacecraft attitude (orientation) control. Reaction spheres rotate spacecraft either with an equal-and-opposite torque about their rotation axis when accelerated about that axis, similar to reaction wheels, or with a more ecient gyroscopic torque …
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NONLINEAR OBSERVER/CONTROLLER DESIGNS FOR SPACECRAFT ATTITUDE CONTROL SYSTEMS WITH UNCALIBRATED GYROS
Gyroscopes, or gyros, are vital sensors in spacecraft onboard attitude control systems. Gyro measurements are corrupted, though, due to errors in alignment and scale factor, biases, and noise. This work proposes a class of adaptive nonlinear observers for calibration of spacecraft gyros. Observers …
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Hamilton-Jacobi-Bellman equation for stochastic optimal control: Applications to spacecraft attitude control
This study aims to address the problem of attitude control of spacecraft in presence of thrust uncertainty, which leads to stochastic accelerations. Spacecraft equipped with electric propulsion and other low thrust mechanisms, often experience random fluctuations in thrust. These stochastic …
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The Distributed Spacecraft Attitude Control System Simulator: From Design Concept to Decentralized Control
A spacecraft formation possesses several benefits over a single-satellite mission. However, launching a fleet of satellites is a high-cost, high-risk venture. One way to mitigate much of this risk is to demonstrate hardware and algorithm performance in groundbased testbeds. It is typically …
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Investigation of Nonlinear Control Strategies Using GPS Simulator And Spacecraft Attitude Control Simulator
In this dissertation, we discuss the Distributed Spacecraft Attitude Control System Simulator (DSACSS) testbed developed at Virginia Polytechnic Institute and State University for the purpose of investigating various control techniques for single and multiple spacecraft. DSACSS is comprised of two …
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A fluid loop actuator for active spacecraft attitude control - A Parametric Sizing Model and the Design, Verification, Validation and Test with a Prototype on an Air Bearing
Active spacecraft attitude control by using a pumped fluid as the inertial mass has potential advantages over reaction wheels, including high torque, lower power consumption, reduced jitter and prolonged lifetime. Previous work addressed conceptual and mission-specific control aspects, and one …
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Internal Torques and Forces in Gyrostats with Magnetically Suspended Rotors
… bearings have several potential applications in spacecraft design. Based on the gyrostat model, we develop equations that describe the internal torques and forces that occur between the body and one of the attached wheels. We evaluate the transverse torques for the torque--free gyrostat and a …
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System Integration and Attitude Control of a Low-Cost Spacecraft Attitude Dynamics Simulator
The CalPoly Spacecraft Attitude Dynamics Simulator mimics the rotational dynamics of a spacecraft in orbit and acts as a testbed for spacecraft attitude control system development and demonstration. Prior to this thesis, the simulator platform and several subsystems had been designed and …
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Attitude control of a spacecraft using two SGCMGs
This thesis presents new methods for controlling spacecraft using Control-Moment Gyros (CMGs). CMGs generate torque to change and maintain a spacecraft's orientation. The CMG control system is used specifically to provide three-axis altitude stabilization, precision pointing control and …
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Constrained H̳₂ design via convex optimization with applications
A convex optimization controller design method is presented which minimizes the closed-loop H2 norm, subject to constraints on the magnitude of closed-loop transfer functions and transient responses due to specified inputs. This method uses direct parameter optimization of the closed-loop Youla or …
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Simulation development and analysis of attitude-control system architectures for an astronaut mobility unit
Control-moment gyroscopes (CMGs) are spacecraft attitude-control actuators which control the spacecraft's orientation and pointing. CMGs operate on electrical power and therefore obey the the conservation of angular momentum. Single-gimbal CMGs are equipped with a high-speed flywheel which can be …
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On the dynamics of rigid multi-body systems in orbit
… missions is the implementation of an appropriate spacecraft attitude control system. For multi-body space systems, the mechanical couplings have significant effects on the attitude dynamics. These effects, added to the high performance requirements and the number of strict constraints that, in …
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Advancements in the Design and Development of CubeSat Attitude Determination and Control Testing at the Virginia Tech Space Systems Simulation Laboratory
… involved in the development of CubeSats lies the attitude determination and control of the satellite. The importance of a properly functioning attitude determination and control system (ADCS) on any satellite is vital to the satisfaction of its mission objectives. Due to this importance, …
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The constrained discrete-time state-dependent Riccati equation technique for uncertain nonlinear systems
… is to introduce a relatively general nonlinear controller/estimator synthesis framework using a special type of the state-dependent Riccati equation technique. The continuous time state-dependent Riccati equation (SDRE) technique is extended to discrete-time under input and state constraints, …
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Coupled Attitude And Orbital Control System Using Spacecraft Simulators
… and rotational motion are coupled for spacecraft performing formation flying missions. This motion is coupled because orbital control is dependent on the spacecraft attitude for vectored thrust. Formation flying spacecraft have a limited mass and volume for propulsion systems. We want …