Download or read book A Method of Actuator Placement for Vibration Control of Large Space Structures written by Ricky Eugene Ort and published by . This book was released on 1983 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents several computationally simple techniques for choosing actuator placement on large space structures. Actuator and performance information can be represented as vectors (node shapes) in modal coordinates. The placement problem is stated as choosing a set of actuator node shapes to match the performance node shape. One method sequentially selects a set of actuator node shapes such that the norm of the component orthogonal to the already selected set is large. Another method sequentially selects actuator node shapes such that a large projection is obtained along the least squares residual vector resulting from the fit of the previously selected set to the performance node shape. These techniques are applied to a 100 meter cantilever beam. Good control authority over the primary modes is demonstrated. The second technique is modified to place actuators to achieve good control authority on primary modes while minimizing spillover effect. It is demonstrated that proper placement of actuators can limit spillover effect to selected modes.
Download or read book Actuator Placement Considerations for the Control of Large Space Structures written by Robert E Lindberg (Jr) and published by . This book was released on 1983 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: Actuator placement for the control of distributed-parameter systems such as large flexible space structures is considered in detail. The first focus is on the degree of controllability as defined in a previous work. Its behavior and approximation is considered via simple problems for which the exact value may be computed. The upper-bound approximation is found to be periodically exact for harmonic systems and acceptable for lightly damped systems. A method is proposed for avoiding the unacceptable behavior of the approximation when a problem has nearly repeated roots. Because the upper-bound approximation in the problem of a double-integral plant diverges, a new lower-bound approximation is developed based on discretization of the continuous-time system. The approximate degree of controllability in three forms (for time-optimal, energy-optimal, or fuel-optimal control policy) is applied to the problem of optimal actuator placement for control of transverse oscillation of a simply supported beam. Both predictable and unanticipated optimal solutions are encountered. The concept of a degree of control spillover is then developed, motivated by the limited fidelity inherent in structural models. A composite criterion incorporating both degree of controllability and degree of control spillover is again applied to the simply-supported-beam problem. Design freedom involving number and placement of actuators is next examined for the computationally simple Independent Modal Space Control (IMSC) design method. Actuator placement is then of prime importance in physically realizing the optimal control laws. Methods for actuator-placement optimization are developed for use with ISMC.
Download or read book Actuator Placement Considerations for the Control of Large Space Structures written by Robert E. Lindberg and published by . This book was released on 1982 with total page 234 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 1983 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Space Structures Systems in the Space Station Era written by and published by . This book was released on 1993 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selection of Actuator Locations for Static Shape Control of Large Space Structures by Heuristic Integer Programing written by and published by . This book was released on 1984 with total page 32 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 1983 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimal Active Control of Flexible Structures Applying Piezoelectric Actuators written by Neda Darivandi Shoushtari and published by . This book was released on 2013 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Piezoelectric actuators have proven to be useful in suppressing disturbances and shape control of flexible structures. Large space structures such as solar arrays are susceptible to large amplitude vibrations while in orbit. Moreover, Shape control of many high precision structures such as large membrane mirrors and space antenna is of great importance. Since most of these structures need to be ultra-light-weight, only a limited number of actuators can be used. Consequently, in order to obtain the most effcient control system, the locations of the piezoelectric elements as well as the feedback gain should be optimized. These optimization problems are generally non-convex. In addition, the models for these systems typically have a large number of degrees of freedom. Researchers have used numerous optimization criteria and optimization techniques to find the optimal actuator locations in structural shape and vibration control. Due to the non-convex nature of the problem, evolutionary optimization techniques are extensively used. However, One drawback of these methods is that they do not use the gradient information and so convergence can be very slow. Classical gradient-based techniques, on the other hand, have the advantage of accurate computation; however, they may be computationally expensive, particularly since multiple initial conditions are typically needed to ensure that a global optimum is found. Consequently, a fast, yet global optimization method applicable to systems with a large number of degrees of freedom is needed. In this study, the feedback control is chosen to be an optimal linear quadratic regulator. The optimal actuator location problem is reformulated as a convex optimization problem. A subgradient-based optimization scheme which leads to the global solution of the problem is introduced to optimize the actuator locations. The optimization algorithm is applied to optimize the placement of piezoelectric actuators in vibration control of flexible structures. This method is compared with a genetic algorithm, and is observed to be faster in finding the global optimum. Moreover, by expanding the desired shape into the structure's modes of vibration, a methodology for shape control of structures is presented. Applying this method, locations of piezoelectric actuators on flexible structures are optimized. Very few experimental studies exist on shape and vibration control of structures. To the best knowledge of the author, optimal actuator placement in shape control has not been experimentally studied in the past. In this work, vibration control of a cantilever beam is investigated for various actuator locations and the effect of optimal actuator placement is studied on suppressing disturbances to the beam. Also using the proposed shape control method, the effect of optimal actuator placement is studied on the same beam. The final shape of the beam and input voltages of actuators are compared for various actuator placements.
Download or read book Large Space Structures Systems in the Space Station Era written by and published by . This book was released on 1993 with total page 380 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 1992 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances and Trends in Structures and Dynamics written by Ahmed K. Noor and published by Elsevier. This book was released on 2013-10-22 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances and Trends in Structures and Dynamics contains papers presented at the symposium on Advances and Trends in Structures and Dynamics held in Washington, D.C., on October 22-25, 1984. Separating 67 papers of the symposium as chapters, this book documents some of the major advances in the structures and dynamics discipline. The chapters are further organized into 13 parts. The first three parts explore the trends and advances in engineering software and hardware; numerical analysis and parallel algorithms; and finite element technology. Subsequent parts show computational strategies for nonlinear and fracture mechanics problems; mechanics of materials and structural theories; structural and dynamic stability; multidisciplinary and interaction problems; composite materials and structures; and optimization. Other chapters focus on random motion and dynamic response; tire modeling and contact problems; damping and control of spacecraft structures; and advanced structural applications.
Download or read book Frontiers of Manufacturing Science and Measuring Technology III written by Wen Pei Sung and published by Trans Tech Publications Ltd. This book was released on 2013-09-03 with total page 2500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collection of selected, peer reviewed papers from the 2013 3rd International Conference on Frontiers of Manufacturing Science and Measuring Technology (ICFMM 2013), July 30-31, 2013, LiJiang, China. Volume is indexed by Thomson Reuters CPCI-S (WoS). The 518 papers are grouped as follows: Chapter 1: Practice of Design Engineering and Researches for Industry; Chapter 2: Applied Materials Engineering; Chapter 3: Measuring Technologies, Signal and Data Processing; Chapter 4: Control, Automation, Communication and Information Technologies; Chapter 5: Environmental Engineering, Urban Development, Transportation and Logistics; Chapter 6: Organization of Manufacture and Engineering Management.
Download or read book Low authority Control Synthesis for Large Space Structures written by J. N. Aubrun and published by . This book was released on 1982 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: The control of vibrations of large space structures by distributed sensors and actuators is studied. A procedure is developed for calculating the feedback loop gains required to achieve specified amounts of damping. For moderate damping (Low Authority Control) the procedure is purely algebraic, but it can be applied iteratively when larger amounts of damping are required and is generalized for arbitrary time invariant systems.
Download or read book Space Station Systems written by and published by . This book was released on 1987 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Actuator and Sensor Placement for Quasi static Control of Large Space Structures written by Saki Hakim and published by . This book was released on 1997 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA SP written by and published by . This book was released on 1991 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book vibration control of flexible structures using electromechanical transmission type actuators written by N. Harris MeClamroch and published by . This book was released on 1983 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
