Predicting Optimal Maneuvering Time Benefits for Satellite Attitude Control PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Predicting Optimal Maneuvering Time Benefits for Satellite Attitude Control PDF full book. Access full book title Predicting Optimal Maneuvering Time Benefits for Satellite Attitude Control by Yash D. Khatavkar. Download full books in PDF and EPUB format.
Author: Yash D. Khatavkar
Publisher:
ISBN:
Category : Aerospace engineering
Languages : en
Pages : 60
Get Book Here
Book Description
"A common goal of satellite control systems is to reduce the time required to change a spacecraft's attitude, which maximizes its mission capability. Time- optimal attitude control algorithms increase the agility of satellites such as imaging spacecraft, thus allowing a greater frequency of image collection. Eigenaxis based maneuvering, though common in industry and academia, fails to produce the minimum-time solution for actual satellites. Solving the optimal control problem is often challenging and requires evaluating multiple maneuver paths to ensure the shortest path is found for each spacecraft configuration. One of the primary difficulties in predicting optimal control benefits stems from the wide range of satellite configurations and infinite variation in inertia. To mitigate this issue, this research aims to determine an analytical relationship between satellite inertia and the time savings of using optimal control rather than eigenaxis maneuvering on spacecraft with a NASA standard four reaction-wheel configuration. To accomplish this, the development of a script using DIDO R optimization software determines minimum-time paths for satellite maneuvers. Each path was independently verified and validated using Pontryagin's minimization principle to ensure that they are physically feasible and that each solution is optimal. Additionally, this work demonstrates that inertia ratios can be used to characterize the attitude control performance of any spacecraft, allowing for the analysis of satellite inertias and their relationship to maneuver time reduction regardless of the scale of the spacecraft. The calculation of the agility envelope volume is then utilized in conjunction with the DIDO R script and various inertia ratios in order to investigate the mathematical relationship between satellite inertia and time savings from optimal control. The result of this work is a design-space tool that can be used by engineers to help determine whether or not to implement time-optimal control algorithms on any spacecraft in a simple and effective way."--from abstract.
Author: Yash D. Khatavkar
Publisher:
ISBN:
Category : Aerospace engineering
Languages : en
Pages : 60
Get Book Here
Book Description
"A common goal of satellite control systems is to reduce the time required to change a spacecraft's attitude, which maximizes its mission capability. Time- optimal attitude control algorithms increase the agility of satellites such as imaging spacecraft, thus allowing a greater frequency of image collection. Eigenaxis based maneuvering, though common in industry and academia, fails to produce the minimum-time solution for actual satellites. Solving the optimal control problem is often challenging and requires evaluating multiple maneuver paths to ensure the shortest path is found for each spacecraft configuration. One of the primary difficulties in predicting optimal control benefits stems from the wide range of satellite configurations and infinite variation in inertia. To mitigate this issue, this research aims to determine an analytical relationship between satellite inertia and the time savings of using optimal control rather than eigenaxis maneuvering on spacecraft with a NASA standard four reaction-wheel configuration. To accomplish this, the development of a script using DIDO R optimization software determines minimum-time paths for satellite maneuvers. Each path was independently verified and validated using Pontryagin's minimization principle to ensure that they are physically feasible and that each solution is optimal. Additionally, this work demonstrates that inertia ratios can be used to characterize the attitude control performance of any spacecraft, allowing for the analysis of satellite inertias and their relationship to maneuver time reduction regardless of the scale of the spacecraft. The calculation of the agility envelope volume is then utilized in conjunction with the DIDO R script and various inertia ratios in order to investigate the mathematical relationship between satellite inertia and time savings from optimal control. The result of this work is a design-space tool that can be used by engineers to help determine whether or not to implement time-optimal control algorithms on any spacecraft in a simple and effective way."--from abstract.
Author: Hui Yan
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
In this dissertation the solutions of the dynamics and real-time optimal control of magnetic attitude control and formation flying systems are presented. In magnetic attitude control, magnetic actuators for the time-optimal rest-to-rest maneuver with a pseudospectral algorithm are examined. The time-optimal magnetic control is bang-bang and the optimal slew time is about 232.7 seconds. The start time occurs when the maneuver is symmetric about the maximum field strength. For real-time computations, all the tested samples converge to optimal solutions or feasible solutions. We find the average computation time is about 0.45 seconds with the warm start and 19 seconds with the cold start, which is a great potential for real-time computations. Three-axis magnetic attitude stabilization is achieved by using a pseudospectral control law via the receding horizon control for satellites in eccentric low Earth orbits. The solutions from the pseudospectral control law are in excellent agreement with those obtained from the Riccati equation, but the computation speed improves by one order of magnitude. Numerical solutions show state responses quickly tend to the region where the attitude motion is in the steady state. Approximate models are often used for the study of relative motion of formation flying satellites. A modeling error index is introduced for evaluating and comparing the accuracy of various theories of the relative motion of satellites in order to determine the effect of modeling errors on the various theories. The numerical results show the sequence of the index from high to low should be Hill's equation, non- J2, small eccentricity, Gim-Alfriend state transition matrix index, with the unit sphere approach and the Yan-Alfriend nonlinear method having the lowest index and equivalent performance. A higher order state transition matrix is developed using unit sphere approach in the mean elements space. Based on the state transition matrix analytical control laws for formation flying maintenance and reconfiguration are proposed using low-thrust and impulsive scheme. The control laws are easily derived with high accuracy. Numerical solutions show the control law works well in real-time computations.
Author: Bing Xiao
Publisher: Springer Nature
ISBN: 9819728479
Category :
Languages : en
Pages : 273
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
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.
Author: Vil Cherd Teoh
Publisher:
ISBN:
Category :
Languages : en
Pages : 178
Get Book Here
Book Description
The research work is confined to the development of the optimal control for the purpose of attitude maneuvering and vibration suppression of the satellite. The scope of the thesis is described as follows the main objective of this work is to develop a detailed understanding of attitude maneuvering of satellite systems and identify the flexible mechanisms that affect the system dynamics. Hence, the external factors such as the atmospheric drag and gravitation effect are neglected; the center hub of the satellite is linearized as a rigid body as it consists of payload modules that are required to be fixed onto the body of the satellites; the deflection of the flexible panel is confined to small angle bending because the satellite attitude maneuvering is done gradually to maintain the stability of the system. Hence, the panel deflection motion is limited to the transverse deformation; the purpose of the research is to develop an optimal control law and compare the performance of the EQF controller of the attitude maneuvering of the satellite. Hence, assumption is made that the EQF controller is ideal and does not suffer any time delay uncertainty.
Author: C. Douglas McFarland
Publisher:
ISBN:
Category : Artificial satellites
Languages : en
Pages : 272
Get Book Here
Book Description
Author: J.R. Wertz
Publisher: Springer Science & Business Media
ISBN: 9400999070
Category : Technology & Engineering
Languages : en
Pages : 877
Get Book Here
Book Description
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.
Author: Stuart C. Brown
Publisher:
ISBN:
Category :
Languages : en
Pages : 68
Get Book Here
Book Description
Author: Kaushik Basu
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Spacecraft missions with requirements for tighter tolerances and that take advantage of improvingcomputational technology, and having more stringent control requirements, including time optimalsolutions are required.An inverse-dynamics method is used in conjunction with a particle swarm algorithm to findnear-minimum time reorientation maneuvers in the presence of path constraints. The methodemploys a quaternion formulation of the kinematics, using B-splines to represent the quaternions.The inverse particle swarm optimization provides a method to determine an initial starting point fora more accurate algorithm that uses a gradient-based method. The inverse method provides certainadvantages in this problem over other methods such as enforcement of boundary conditions and theincrease of computational efficiency by avoiding the use of numerical integrators.Once the technique is established, parallelization of the algorithm demonstrates the potential forflight hardware to be implemented that will aid in performing near real-time solutions. In total thesuperior terminating kinematic results and speed up of computing time from hours to just severalseconds will allow the implementation using space hardened Graphic Processor Units and FieldProgrammable Gate Arrays to perform autonomous guidance and navigation.
Author: Dong Ye
Publisher: Elsevier
ISBN: 0323954553
Category : Technology & Engineering
Languages : en
Pages : 278
Get Book Here
Book Description
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
