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PARAMETER INSENSITIVE CONTROL UTILIZING EIGENSPACE METHODS

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1991年第6期14卷 1208-1214页

作者： FENNELL, RE ADAMS, WM CHRISTHILF, DM LOCKHEED ENGN & SCI CO HAMPTONVA 23666 NASA LANGLEY RES CTRINST COMP APPLICAT SCI & ENGNHAMPTONVA 23665

An eigenspace assignment approach to the design of parameter insensitive control laws for linear multivariable systems is Presented. The control design scheme utilizes constrained optimization techniques to exploit the flexibility in eigenvector assignments to reduce control system sensitivity to changes in system parameters while maintaining performance and robustness requirements;it thus provides a systematic approach for choosing values for eigensystem design variables. In a design example, the methods are applied to the problem of symmetric flutter suppression in an aeroelastic vehicle. In this example, the flutter mode is sensitive to changes in dynamic pressure and eigenspace methods are used to reduce the parametric sensitivity of a stabilizing minimum energy/linear quadratic regulator controller and associated observer. Numerical results indicate that the methods provide feedback control laws that make the stability of the nominal closed-loop system less sensitive to changes in dynamic pressure while maintaining acceptable control power constraints.

关键词： linear Quadratic Regulator Feedback Control System Dynamic Pressure Control Systems Aerodynamic Force Bending Moment sequential linear programming Singular Value Decomposition Atmospheric Turbulence Nonlinear programming

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On the convergence of successive linear-quadratic programming algorithms

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SIAM JOURNAL ON OPTIMIZATION 2005年第2期16卷 471-489页

作者： Byrd, RH Gould, NIM Nocedal, J Waltz, RA Univ Colorado Dept Comp Sci Boulder CO 80309 USA Rutherford Appleton Lab Computat Sci & Engn Dept Chilton England Northwestern Univ Dept Elect & Comp Engn Evanston IL 60208 USA

The global convergence properties of a class of penalty methods for nonlinear programming are analyzed. These methods include successive linear programming approaches and, more speciffically, the successive linear-quadratic programming approach presented by Byrd et al. [Math. Program., 100 (2004), pp. 27-48]. Every iteration requires the solution of two trust-region subproblems involving piecewise linear and quadratic models, respectively. It is shown that, for a fixed penalty parameter, the sequence of iterates approaches stationarity of the penalty function. A procedure for dynamically adjusting the penalty parameter is described, and global convergence results for it are established.

关键词： sequential linear programming global convergence theory nonlinear optimization penalty parameter updates

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OPTIMUM DESIGN OF STRUCTURES WITH MULTIPLE CONSTRAINTS

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AIAA JOURNAL 1988年第1期26卷 78-85页

作者： CANFIELD, RA GRANDHI, RV VENKAYYA, VB WRIGHT STATE UNIV DAYTONOH 45435

Automated design of large aerospace structures requires efficient optimization algorithms because of a large number of design variables and design constraints. Most of the difficulties associated with large structural design are solution convergence and computer resources requirements. Practical aerospace structures generally involve limitations on gage sizes, displacements, stresses, and frequencies. The objective of this study was to determine what techniques are reliable and efficient for optimization of a complex design problem. The study examined the relative numerical performance of various optimization methods as candidates for a hybrid algorithm using optimality criteria and mathematical programming methods. Several optimization programs were used to design truss- and wing-type structures, and the iteration history for each technique is presented. The computer programs using the method of feasible directions and a modified Newton’s method of unconstrained minimization were the most reliable mathematical programming methods. © 1988 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.

关键词： Broyden Fletcher Goldfarb Shanno Lagrange Multipliers Trusses Structural Optimization Computer Programs Finite Element Modeling High Aspect Ratio Compressive Stress Structural Weight sequential linear programming

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Simultaneous structural/control optimum design of composite plate with piezoelectric actuators

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1997年第6期20卷 1111-1117页

作者： Kim, Y Kum, D Nam, C HANKUK AVIAT UNIV DEPT AERONAUT & MECH ENGNKOYANG 411791SOUTH KOREA

An integrated structural/control design for the vibration suppression of a composite plate with segmented piezoelectric (PZT) actuators is examined, The electric power used by the PZT materials becomes a very important factor for real application to the control of flexible structures, The method to predict power required for the control is presented, and the power is used as a part of the objective functions, The structural weight, the state error energy, control energy, stability robustness, and the electric power required for vibration control are considered as the objective function. The locations of the PZT actuators are considered as control design variables, The ply orientation and thickness coefficients of the laminated composite plate are considered as structural design variables, The improved compromise multiobjective optimization by using a reduction factor of performance indices is applied to solve this optimization problem, The sequential linear programming method with move limits is used, The sensitivity analysis, which is required in the optimization process, is performed for the eigenstructure assignment control scheme and the performance indices with respect to the design parameters, The optimized results showed a significant amount of reduction in the structural weight as well as the control performance indices. The required electric power is also decreased.

关键词： Piezoelectric Actuators Electric Power Vibration Suppression Vibration Control Structural Weight Structural Design Sensitivity Analysis Laminated Composites sequential linear programming Closed Loop System

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Approximations in optimization of damage tolerant structures

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AIAA JOURNAL 2000年第3期38卷 517-524页

作者： Garcelon, JH Haftka, RT Scotti, SJ Univ Florida Dept Aerosp Engn Mech & Engn Sci Gainesville FL 32611 USA NASA Langley Res Ctr Met & Thermal Struct Branch Hampton VA 23681 USA

Approximations for structural response and design sensitivities significantly reduce the computational cost of structural optimization. To be useful, the approximation must be accurate and computationally efficient. Damage tolerant design puts even more stringent computational demands on optimization procedures and approximations due to the large structural changes inherent in damage. A robust approximation is evaluated and extended to include design sensitivities. It is implemented in an optimization procedure and tested. It is shown that this approximation is accurate and efficient for damage tolerant optimum design of complex structural models. Last, a qualitative measure is developed and tested that estimates the computational savings using these approximations.

关键词： Structural Response Structural Optimization Structural Modeling Stiffness Matrices High Speed Civil Transport sequential linear programming Taylor Series Aircraft Structures Critical Loading linear programming

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Efficiency of bio- and socio-inspired optimization algorithms for axial turbomachinery design

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APPLIED SOFT COMPUTING 2018年 64卷 282-306页

作者： Chikh, Mohamed Abdessamed Ait Belaidi, Idir Khelladi, Sofiane Paris, Jose Deligant, Michael Bakir, Farid Univ Boumerdes Lab Energet Mecan & Ingn Boumerdes Algeria Arts & Metiers ParisTech Lab Dynam Fluides Paris France Univ A Coruna GMNI Coruna Spain

Turbomachinery design is a complex problem which requires a lot of experience. The procedure may be speed up by the development of new numerical tools and optimization techniques. The latter rely on the parameterization of the geometry, a model to assess the performance of a given geometry and the definition of an objective functions and constraints to compare solutions. In order to improve the reference machine performance, two formulations including the off-design have been developed. The first one is the maximization of the total nominal efficiency. The second one consists to maximize the operation area under the efficiency curve. In this paper five optimization methods have been assessed for axial pump design: Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Cuckoo Search (CS), Teaching Learning Based Optimization (TLBO) and sequential linear programming (SLP). Four non-intrusive methods and the latter intrusive. Given an identical design point and set of constraints, each method proposed an optimized geometry. Their computing time, the optimized geometry and its performances (flow rate, head (H), efficiency (eta), net pressure suction head (NPSH) and power) are compared. Although all methods would converge to similar results and geometry, it is not the case when increasing the range and number of constraints. The discrepancy in geometries and the variety of results are presented and discussed. The computational fluid dynamics (CFD) is used to validate the reference and optimized machines performances in two main formulations. The most adapted approach is compared with some existing approaches in literature. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Optimization Axial turbomachine Inverse design Bio- and socio-inspired optimization algorithms sequential linear programming

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Parametric analysis of fiber-reinforced laminated momentum wheel rotors

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JOURNAL OF SPACECRAFT AND ROCKETS 2002年第4期39卷 580-588页

作者： Hassan, RA Younan, MYA Arafa, HA Bahei-El-Din, YA American Univ Dept Engn Cairo 11511 Egypt Cairo Univ Dept Struct Engn Giza 12316 Egypt Cairo Univ Mech Design & Prod Dept Giza 12316 Egypt

The objective is to analyze the parameters involved in the design of a graphite-reinforced-epoxy rotor that is made from axisymmetric laminated concentric rings with interferences. This design is proposed for use in a momentum wheel that is used for attitude stabilization of geosynchronous satellites. The formulation of the problem is addressed in the domain of the elasticity theory under plane stress conditions. An analytic model is developed by solving the nonhomogeneous variable-coefficients total differential equilibrium equation using the displacement formulation (Navier's approach). Four parameters of interest are investigated: the number of concentric rings, the amount of radial interferences, reinforcement volume fraction in each ring, and the lamination angle of the fibers in the hoop-radial plane with respect to the global hoop direction of the rings. The parametric analysis shows that the amount of interferences between the neighboring rings should be kept at the minimum values required to keep the rings in contact at maximum operating speeds. The analysis also proves that by increasing the amount of reinforcement volume fraction, the minimum interferences needed can be reduced proportionally. Finally, it was found that, at the required operating high speeds, the graphite fibers should be aligned in the circumferential direction and that the number of rings the rotor consists of should be kept at a minimum.

关键词： Stress Distribution Factor of Safety Stiffness Matrices Magnetic Bearings Energy Storage System Satellites Tsai Wu Failure Criterion Laminated Composites Material Properties sequential linear programming

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A sequential cutting plane algorithm for solving convex NLP problems

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2006年第2期173卷 444-464页

作者： Still, Claus Westerlund, Tapio Abo Akad Univ Dept Math FIN-20500 Turku Finland Abo Akad Univ Proc Design Lab FIN-20500 Turku Finland

In this paper we look at a new algorithm for solving convex nonlinear programming optimization problems. The algorithm is a cutting plane-based method, where the sizes of the subproblems remain fixed, thus avoiding the issue with constantly growing subproblems we have for the classical Kelley's cutting plane algorithm. Initial numerical experiments indicate that the algorithm is considerably faster than Kelley's cutting plane algorithm and also competitive with existing nonlinear programming algorithms. (c) 2005 Elsevier B.V. All rights reserved.

关键词： convex programming nonlinear programming cutting plane algorithms sequential linear programming

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Optimization of a hybrid electromagnetic system with magnetic modulation

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INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS 2022年第3期69卷 333-345页

作者： Yatchev, Ivan Balabozov, Iosko Gueorgiev, Vultchan Hadzhiev, Ivan Tech Univ Sofia Dept Elect Apparat 8 Kl Ohridski Blvd Sofia 1000 Bulgaria Tech Univ Sofia Dept Elect Supply Elect Equipment & Elect Transpo Sofia Bulgaria Tech Univ Sofia Fac Elect & Automat Plovdiv Branch Plovdiv Bulgaria

The paper presents optimization of a newly developed hybrid electromagnetic system with magnetic flux modulation, for which patent application has been submitted. The efficiency of the system has been taken as objective function. The optimization factors include both geometrical and electrical parameters. Finite element method and three-dimensional coupled time-dependent electromagnetic field-electrical circuit analysis has been used for the solution of the forward problem. Response surface methodology and sequential linear programming are employed for the optimization.

关键词： 3D Field-circuit FEA hybrid electromagnetic system magnetic flux modulation response surface methodology sequential linear programming

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Optimization of a permanent magnet needle actuator

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COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING 2012年第3期31卷 1018-1028页

作者： Yatchev, Ivan Rudnicki, Marek Hinov, Krastyo Gueorgiev, Vultchan Tech Univ Sofia Fac Elect Engn Dept Elect Apparat Sofia Bulgaria Tech Univ Lodz Inst Comp Sci PL-90924 Lodz Poland

Purpose - The purpose of this paper is to solve the optimization problem for a permanent magnet linear actuator with moving magnet for driving a needle in a knitting machine. The optimization is carried out with respect to the maximal average force along the stroke. Design/methodology/approach - The optimization factors are the dimensions of the permanent magnet and the pole length. For obtaining the objective function for each parameter combination, the static force-stroke characteristic is computed. Three-dimensional finite element analysis is employed for obtaining the electromagnetic force. The objective function is then approximated by secondary models on the basis of design of experiment. The optimization is carried out using sequential linear programming. Findings - Optimal solution to the problem has been obtained and the force-stroke characteristic of the optimal actuator is given. Originality/value - The proposed approach employs sequential linear programming with move limits using trust region concept, 3D finite element analysis, design of experiments and secondary models for optimization of a permanent magnet linear actuator for individual needle driving in a knitting machine.

关键词： Electric machines Actuators Optimization techniques Permanent magnet actuators Response surface methodology sequential linear programming 3D finite element method

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