Download or read book Moving bank Multiple Model Adaptive Estimation and Control Applied to a Large Flexible Space Structure written by Robert Brent Moyle (CAPT, USAF.) and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Robustness Analysis of Moving bank Multiple Model Adaptive Estimation and Control of a Large Flexible Space Structure written by Daniel F. Jr Van Der Werken (CAPT, USAF.) and published by . This book was released on 1988 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Robustness Analysis of Moving Bank Multiple Model Adaptive Estimation and Control of a Large Flexible Space Structure written by Daniel F Van Der Werken (Jr) and published by . This book was released on 1988 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: For this thesis, the truth model consists of 24 states, and the filter model consists of 6 states. The object is to determine whether or not the state mismatch between the filter and truth models seriously degrades or totally confounds the adaptation process. The system model used is a rotating two-bay flexible space structure, approximating a space structure that has a hub with extending appendages. The mass of the hub is greater than the mass of the appendage, and finite element analysis is used to develop the mathematical model. The system is developed in physical coordinates, transformed to modal coordinates, and the method of singular perturbations is used to provide a reduced filter model. The two dimensional parameter space consists of variations of the mass and stiffness matrices for the two-bay truss. Results indicate stable and accurate state estimation when the bank is initially centered on the true parameter. Stable control and accurate parameter estimation are not achieved. When the bank is initially centered at an incorrect parameter, stable and accurate state estimation is not demonstrated. These results indicate a total confounding of the adaptation process due to the unmodeled states, since accurate estimation and control can be generated when there are no such unmodeled states. Keywords: Kalman filters; Moving bank algorithms; Adaptive estimation; Multiple model adaptive control; Adaptive filters, Theses. (EDC).
Download or read book Moving Bank Multiple Model Adaptive Algorithms Applied to Flexible Spacecraft Control written by Paul G. Filios and published by . This book was released on 1985 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Critical to the performance of the moving-bank multiple model adaptive estimator is the decision logic used to determine which elemental filters are implemented in the bank, and when to change this decision. The decision logics discussed focus on three situations: initial acquisition of the unknown parameter values through reducing bank discretization; tracking the unknown parameter values through bank movement; and reacquisition of the unknown parameters following a large jump change in their values through expanding bank discretization. Ambiguity function analysis is used to predict performance in these situations. The system to be controlled is a simplified model of a large scale space structure. Its equations of motion are developed and placed in state space form, the states being the positions and velocities of the rigid body mode and the second and fourth bending modes. The state space matrices describing the system are computed based on nominal values for all physical parameters with the exception of the mass density of the structure arms and their modulus of elasticity. These two parameters are allowed to vary in discrete steps establishing the parameter space. It is then attempted to control the states to the quiescent state, using moving-bank multiple model adaptive algorithms. The results indicate that, although the system under study did not have a great need for adaptive estimation and control the multiple model adaptive estimator performs essentially identically to a single filter artificially knowledgeable of the uncertain parameter values.
Download or read book Control of a Large Space Structure Using Multiple Model Adaptive Estimation and Control Techniques written by and published by . This book was released on 1993 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this thesis is to apply moving-bank multiple model adaptive estimation and control (MMAE/MMAC) algorithms to an actual space structure (SPICE) being examined at Phillips Laboratory at Kirtland AFB, NM. The structure consists of a large platform and a smaller platform connected by three legs in a tripod fashion. Kalman filtering and LQG control techniques are utilized as the primary design tool. Implementing a bank of filters increases the robustness of the LQG controller when uncertainties exist in the system model, whereas the moving bank is utilized to reduce the computational load. Several reduced-order models are developed from the truth model using modal analysis and modal cost analysis. The MMAE/MMAC design with a dramatically reduced-order filter model provides an excellent method to estimate a wide range of parameter variations and to quell oscillations in the structure. Multiple model adaptive estimation, Multiple model adaptive control, LQG Control, Flexible space structure, Parameter identification.
Download or read book Robustness of a Moving Bank Multiple Model Adaptive Controller for a Large Space Structure written by Michael R. Schore and published by . This book was released on 1989 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: The robustness of moving-bank multiple model adaptive estimation (MMAE) and control (MMAC) algorithms is analyzed in this thesis. The mismatch of a 24-state truth model and a 6-state filter model are evaluated on the basis of MMAE/MMAC performance. A model developed using finite element analysis is used to approximate a large space structure which has a large central hub with appendages radiating out from it. The mass of the hub is considered to be much larger than the mass of the flexible structure. The model is developed in physical coordinates and then transformed into modal coordinates. To obtain a reduced order filter model, the method of singular perturbations is used. The actual positions and velocities of various physical points on the structure are used in the evaluation of the MMAE/MMAC algorithm performance. The results of this study of model mismatching indicates that the MMAE provides accurate position and velocity estimates even in the face of a 6-state to 24-state model mismatch. When a non-adaptive filter is used with a mismatched parameter location, the performance suffers slightly. The use of an adaptive estimator does provide improved performance in the face of uncertain parameter location. Stable control was obtained with the use of MMAC. For the case of nonadaptive filter and mismatched parameter location, the control algorithm behaved in a possible destructive manner. By allowing the filter to adapt to the initial parameter location, the MMAC algorithm provided stable control of the structure, even in the face of large disturbances. (AW).
Download or read book Multiple Model Adaptive Control of a Large Flexible Space Structure with Purposeful Dither for Enhanced Identifiability written by and published by . This book was released on 1993 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dithering techniques for enhancing uncertain parameter identification with moving-bank Multiple Model Adaptive Estimation (MMAE) and Control (MMAC) algorithms are analyzed in this thesis. The dithering techniques and multiple- model adaptive algorithms are applied to the SPICE 2 flexible space structure. The dithering techniques studied include purposefully constructed square wave, sine wave (fixed and swept frequency) and wide-band noise wave forms. Purposeful rigid-body slew commands are also used in order to excite the structure's flexible bending modes. Dither inputs into the structure are performed in an effort to enhance the open-loop identifiability of the uncertain parameter, namely a scalar multiplier on the undamped natural frequencies of the flexible bending modes. Correct identification of this parameter enables the MMAE and MMAC algorithms to quell any vibrations induced into the structure, in the face of varying parameter values. The results of this study indicate that purposefully constructed dither signals do enhance parameter identification significantly. The parameter identification enhancement due to rigid-body slew command input was shown to be less effective than that with sinusoid and wide band noise dither inputs, however.
Download or read book Moving Bank Multiple Model Adaptive Estimation Applied to Flexible Spacestructure Control written by Drew A. Karnick and published by . This book was released on 1986 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: A significant problem in estimation and control is the uncertainty of parameters in the mathematical model used in the design of controllers and/or estimators. These parameters may be unknown, varying slowly, or changing abruptly due to a failure in the physical system. These changes in parameters often necessitate the identification of parameters within the mathematical model and changing the mathematical model during a real-time control problem. This is often referred to as adaptive control and/or estimation. This thesis investigates methods of adaptive control implementing a moving-bank multiple model adaptive estimator. Keywords: algorithms; truss models; computerized simulation; adaptive control systems; adaptive filters; perturbations.
Download or read book Large Space Structures Systems in the Space Station Era written by and published by . This book was released on 1991 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technology for Large Space Systems written by and published by . This book was released on 1986 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Technology for Large Space Systems A Bibliography with Indexes supplement 20 written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Division and published by . This book was released on 1989 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Automatic Control in Aerospace 1994 Aerospace Control 94 written by D. Schaechter and published by Elsevier. This book was released on 2014-05-23 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important, successful area for control systems development is that of state-of-the-art aeronautical and space related technologies. Leading researchers and practitioners within this field have been given the opportunity to exchange ideas and discuss results at the IFAC symposia on automatic control in aerospace. The key research papers presented at the latest in the series have been put together in this publication to provide a detailed assessment of present and future developments of these control system technologies.
Download or read book Control and Dynamic Systems V31 Advances in Aerospace Systems Dynamics and Control Systems Part 1 of 3 written by C.T. Leonides and published by Elsevier. This book was released on 2012-12-02 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: Control and Dynamic Systems: Advances in Theory in Applications, Volume 31: Advances in Aerospace Systems Dynamics and Control Systems, Part 1 of 3 deals with significant advances in technologies which support the development of aerospace systems. It also presents several algorithms and computational techniques used in complex aerospace systems. The techniques discussed in this volume include: moving-bank multiple model adaptive estimation, algorithms for multitarget sensor tracking systems; algorithms in differential dynamic programming; optimal control of linear stochastic systems; and normalized predictive deconvulation. This book is an important reference for practitioners in the field who want a comprehensive source of techniques with significant applied implications.
Download or read book Space Station Systems written by and published by . This book was released on 1986 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Report 1989 90 written by New Brunswick. Department of Transportation and published by . This book was released on 1991 with total page 1272 pages. Available in PDF, EPUB and Kindle. Book excerpt: General activity review of associated branches and agencies to the Department which includes corporate securities registrations, a list of tenders received, and general financial data. Branches and agencies reviewed are responsible for motor vehicle activity, highway construction, traffic engineering, telecommunications and public utilities.
Download or read book Large Space Structures Systems in the Space Station Era written by and published by . This book was released on 1990 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
