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OPTIMAL SELECTION OF WEIGHTING MATRICES IN INTEGRATED DESIGN OF STRUCTURES CONTROLS

AIAA JOURNAL 1993年第4期31卷 714-720页

作者： SUNAR, M RAO, SS Purdue University West Lafayette Indiana 47907

A methodology is developed for the optimal selection of state and input weighting matrices, Q and R, respectively, of the linear quadratic regulator (LQR) method in the integrated design of structures/controls. An optimal control problem is set up in such a way that design variables are the diagonal entries of Q and R, the objective function is the trace of the solution matrix to the algebraic Riccati equation of the LQR method, P matrix;and constraints are imposed on the closed-loop eigenvalues to satisfy minimum stability conditions for the control system. The procedure finds the optimal diagonal Q and R that enables the actively controlled system to meet the prespecified stability and performance bounds. Furthermore, the resulting Q and R yield the minimum possible performance index and hence the control effort is substantially reduced. The proposed method is integrated with a substructure decomposition scheme which results in substantial savings on the numerical computations with very little loss in the accuracy of the original system response. It is found that for trusslike space structures, the proposed optimization scheme is mostly affected by the changes in the diagonal terms of R and the changes in the velocity diagonal terms of Q of the controlled system. The method is expected to be very useful for large-scale systems and is illustrated with the help of two example problems.

关键词： Linear Quadratic Regulator Trusses Flexible Structures Structural Modeling Algebraic Riccati Equation Multivariable Control Stiffness Matrices Vibration Suppression Young's Modulus optimization algorithm

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VEHICLES KNOWLEDGE-BASED DESIGN ENVIRONMENT

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JOURNAL OF SPACECRAFT AND ROCKETS 1993年第3期30卷 342-347页

作者： GILLAM, A The Aerospace Corporation Los Angeles California 90009

The Vehicles design environment is a knowledge-based system that assists designers in studying tradeoffs, evaluating alternative designs, and identifying design drivers. The environment is composed of 1) analysis tools, such as parametric analysis and what-if analysis capabilities;2) subsystem sizing and performance models;3) a historical data base (of satellites that have already been built);and 4) an extensible architecture in which new models, tools, and design concepts may be added. We have found that building in flexibility, both for the designer to explore a variety of space system design solutions as well as for the software developers to continually enhance Vehicles' capabilities is essential. The analysis tools, which have been very well received by the design community, include the capability to study parametric sensitivities, trace the derivation of results, and compare multiple design concepts. An integrated design environment, one that offers a variety of analysis and information handling tools, gives the designers the ability to view a design from different perspectives and across functional, organizational, and other boundaries.

关键词： LANDSAT Knowledge Based Approach Space Systems Design RADAR Transmitting Antennas optimization algorithm Concurrent Engineering Sensitivity Analysis Software Architecture FORTRAN

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ROBUSTNESS BOUNDS FOR LINEAR-SYSTEMS UNDER UNCERTAINTY - EIGENVALUES INSIDE A WEDGE

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1993年第4期16卷 695-701页

作者： ALT, TR JABBARI, F UNIV CALIF IRVINE DEPT MECH & AEROSP ENGNIRVINECA 92717

This paper deals with robustness bounds for linear systems with uncertainty, where both stability and a measure of performance robustness are desired. Here, performance robustness is defined by guaranteeing that the eigenvalues of the perturbed system remain in a specific region in the complex plane such as a wedge. Using standard Lyspunov techniques, for analysis, bounds on the uncertain parameters are obtained that guarantee that the system eigenvalues remain in the desired region, whereas for synthesis, bounds and state feedback gains can also be obtained that place the closed loop system eigenvalues in the desired region. An optimization algorithm is also presented that was successfully used in the examples.

关键词： Closed Loop System optimization algorithm Damping Ratio Dual Keel Space Station Vibration Control Systems Computing Nastran

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COMPUTATION OF MAXIMIZED GUST LOADS FOR NONLINEAR AIRCRAFT USING MATCHED-FILTER-BASED SCHEMES

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JOURNAL OF AIRCRAFT 1993年第5期30卷 763-768页

作者： SCOTT, RC POTOTZKY, AS PERRY, B NASA Langley Research Center Hampton Virginia 23681 Lockheed Engineering and Sciences Company Hampton Virginia 23665

This article describes and illustrates two matched-filter-theory-based schemes for obtaining maximized and time-correlated gust loads for a nonlinear airplane. The first scheme is computationally fast because it uses a simple one-dimensional search procedure to obtain its answers. The second scheme is computationally slow because ft uses a more complex multidimensional search procedure to obtain its answers, but it consistently provides slightly higher maximum loads than the first scheme. Both schemes are illustrated with numerical examples involving a nonlinear control system.

关键词： Mach Number Model Aircraft Nonlinear Control Atmospheric Turbulence Nonlinear Systems optimization algorithm Computing Federal Aviation Administration Linear Quadratic Gaussian Aeroservoelasticity

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An efficient gradient method based on perturbation analysis and the batch means method

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Journal of the Chinese Institute of Engineers 1993年第1期16卷 13-28页

作者： Chih‐ Ming Liu Shu‐ Kuang Chao

In this study, we want to develop an efficient optimization algorithm based on Perturbation Analysis (PA) and compare the performance of PA with the traditional Finite Difference (FD) gradient method. While the FD estimate is a very time‐consuming gradient method, PA is a very promising algorithm in terms of the computational time. This is the major advantage of PA over FD. In this study, we use the property that PA only requires one simulation run to obtain other advantages of PA as a gradient method. First, we deal with the problem of initialization bias for the estimate of gradients of system performance. Second, we compare the efficiency of PA and FFD (which represents FD) in introducing the control variates variance reduction technique. Third, we propose a new method for determining the simulation run length at each iteration in an optimization algorithm. In the above three areas, we show that PA is better than FD. Finally, we combine PA and BM (batch means method) to obtain a more efficient gradient method, PA‐BM.

关键词： perturbation analysis batch means method finite difference estimate optimization algorithm

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Introduction to Dynamics and Control of Flexible Structures

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丛书名： AIAA Education Series

1993年

作者： John L. Junkins Youdan Kim

ISBN: (数字)9781600862076

ISBN: (纸本)9781563470547

Effective control laws for mechanical systems are best designed by professionals who understand both the basic mechanics of the system under consideration and the control methodology being used to design the control law. This textbook blends two traditional disciplines: engineering mechanics and control engineering. Beginning with theory, the authors proceed through computation to laboratory experiment and present actual case studies to illustrate practical aerospace applications. Intended for first-year graduate students in engineering and applied science, this book will help structural dynamists and control engineers gain broad competence in mechanics and control. A solutions manual is available for professors.

关键词： Aeronautics algorithms and Data Structures Applied Mathematics Autonomous Systems Avionics Avionics Computers Beam (Structures) Classical Mechanics Computational Fluid Dynamics Computer Networks Computer Programming and Language Computer Storage Devices Computing System Computing and Informatics Computing, Information, and Communication Control Systems Control Theory Data Science Elementary Algebra Embedded Systems Energy Energy Forms Energy Forms, Production and Conversion Feedback Control Finite Element Method Flexible and Active Structures Fluid Dynamics General Physics Geometry Functions Guidance, Navigation, and Control Systems Inverse Problems Kalman Filter Mathematical Analysis Mathematical optimization Mechanical and Structural Vibrations Numerical Analysis Optimal Control Theory optimization algorithm Riccati Equations Robotics Robots Sensors Signal Processing Spacecraft Guidance and Control Structural Analysis Structural Design and Development Structural Engineering Structural Kinematics and Dynamics Structural Modeling and Simulation Structural System Structures, Design and Test Transducers Vibration Control

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optimization Of Observation And Control Processes

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丛书名： AIAA Education Series

1992年

作者： Mihkail Naumovi Krasilshikov Veniamin Vasily Malyshev Valeri Ivanovic Karlov

ISBN: (数字)9781600862229

ISBN: (纸本)9781563470400

This book generalizes the classic theory of the regression experiment design in the case of Kalman-type filtering in controllable dynamic systems. A new approach is proposed for optimization of the measurable parameters structure, of navigation mean modes, of the observability conditions, of inputs for system identification, etc. The developed techniques are applied for enhancing efficiency of spacecraft navigation and control.

关键词： Acoustic Noise Acoustics Aerospace Sciences algorithms and Data Structures Applied Mathematics Astrodynamics Astronautics Boundary Element Method Computational Fluid Dynamics Computing and Informatics Computing, Information, and Communication Continuum Mechanics Control Systems Control Theory Coordinate System Data Science Design of Experiments Elementary Algebra Fluid Dynamics General Physics Guidance, Navigation, and Control Systems Inverse Problems Kalman Filter Materials and Structural Mechanics Mathematical optimization Mechanical and Structural Vibrations Meteoroids Monte Carlo Method Nonlinear Control Theory Numerical Analysis Optimal Control Theory optimization algorithm Orbital Maneuvers Planetary Science and Exploration Planets Riccati Equations Satellites Solar Physics Solar Wind Solid Mechanics Space Orbit Space Science and Technology Space Systems and Vehicles Spacecraft Design Spacecraft Guidance Spacecraft Guidance and Control Spacecrafts Statistical Analysis Structural Design and Development Structural Engineering Structural Mechanics Structures, Design and Test Vibration Measuring Instruments

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AERODYNAMIC SHAPE DESIGN AND optimization - STATUS AND TRENDS

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JOURNAL OF AIRCRAFT 1992年第6期29卷 1020-1026页

作者： DULIKRAVICH, GS Pennsylvania State University University Park Pennsylvania 16802

A limited number of aerodynamic shape design concepts have been surveyed and an attempt has been made to classify them. Characteristics, both positive and negative, of the more prominent methods were outlined. Future research is expected to concentrate on the use of Navier-Stokes equations and applications to three-dimensional configurations. Interdisciplinary constrained optimization is expected to play a more prominent role in the immediate future. Adjoint operator/control theory and its variations are the most promising concepts for interdisciplinary aerodynamic shape design which involves a large number of variables. This theory is expected to constitute the major development area in future research.

关键词： Control Theory Navier Stokes Equations Aerodynamic Configurations Incompressible Viscous Flow Wing Body Combination Sensitivity Analysis Angle of Attack Turbomachinery Cascades Aeroplane optimization algorithm

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DEMONSTRATION OF STRUCTURAL optimization APPLIED TO WIND-TUNNEL MODEL DESIGN

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JOURNAL OF AIRCRAFT 1992年第5期29卷 966-968页

作者： FRENCH, M KOLONAY, RM Wright Laboratory Wright-Patterson Air Force Base Ohio 45433

One of the most important tasks in the design of an aeroelastically scaled wind-tunnel model wing is making sure the stiffness charactersistics are correct. The engineer must design a model structure whose stiffness characteristics match known values. These known values are derived by scaling the stiffness characteristics of the full-size structure that the model represents. In the paper a general purpose finite element based analysis and optimization program was used to design a structure made up of beam and plate elements. Using only the widths of the beam elements as design variables, a design was obtained that satisfied the stiffness constraints, and a sample structure was manufactured.

关键词： Wind Tunnel Models Structural optimization Finite Element Modeling Aeroelastic Models Beam (Structures) optimization algorithm Composite Materials Aerospace Engineering Lift Coefficient Wing Geometry

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SHAPE-SENSITIVITY ANALYSIS AND DESIGN optimization OF LINEAR, THERMOELASTIC SOLIDS

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AIAA JOURNAL 1992年第2期30卷 528-537页

作者： HOU, GJW SHEEN, JS CHUANG, CH Old Dominion University Norfolk Virginia 23529

In this study, a numerical scheme is developed for shape-sensitivity analysis and design optimization of linear, quasistatic, thermoelastic solids. In this scheme, the finite-element method is used as the analyzer for analyzing stress, temperature, shape sensitivity, and design velocity field. Based upon the method of material derivatives, both the techniques of the direct-differentiation method and the adjoint-variable method are applied to derive the shape-sensitivity equations. The shape-optimization formulations discussed here include boundary integrals of displacements and heat fluxes as well as domain integrals of stresses and areas. Numerical results show that the proposed scheme works well in terms of accuracy.

关键词： Mixed Boundary Condition Finite Element Modeling Material Derivatives Fixed Beam Shape optimization Thermal Stress Analysis Thermal Boundary Condition optimization algorithm Material Properties Thermal Insulation

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