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A New Method for Initial Parameters Optimization of Guided Projectiles

INTERNATIONAL JOURNAL OF AEROSPACE ENGINEERING 2013年第1期2013卷 22.1-22.7页

作者： Bi-Ming, Feng Wan-Sheng, Nie Acad Equipment Beijing 101416 Peoples R China

A new algorithm was developed for the initial parameters optimization of guided projectiles with multiple constraints. Due to the relationship between the analytic guidance logic and state variables of guided projectiles, the Radau pseudospectral method was used to discretize the differential equations including control variables and state variables with multiple constraints into series algebraic equations that were expressed only by state variables. The initial parameter optimization problem was transformed to a nonlinear programming problem, and the sequential quadratic programming algorithm was used to obtain the optimal combinations of initial height and range to target for the final velocity of guided projectiles maximum with constraints. Comparing with the appropriate initial conditions solved by Monte Carlo method and the flight characteristics solved by integrating the original differential equations in the optimal initial parameters computed by the new algorithm, the feasibility of new algorithm was validated.

关键词： Monte Carlo technique algorithms projectiles Parameter optimization State variable new methods Differential equations flight characteristics INITIAL CONDITIONS sequential quadratic programming

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Constraint incorporation in optimization

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MATHEMATICAL programming 2007年第3期110卷 615-639页

作者： Levy, Adam B. Bowdoin Coll Dept Math Brunswick ME 04011 USA

Numerical methods for solving constrained optimization problems need to incorporate the constraints in a manner that satisfies essentially competing interests;the incorporation needs to be simple enough that the solution method is tractable, yet complex enough to ensure the validity of the ultimate solution. We introduce a framework for constraint incorporation that identifies a minimal acceptable level of complexity and defines two basic types of constraint incorporation which (with combinations) cover nearly all popular numerical methods for constrained optimization, including trust region methods, penalty methods, barrier methods, penalty-multiplier methods, and sequential quadratic programming methods. The broad application of our framework relies on addition and chain rules for constraint incorporation which we develop here.

关键词： constrained optimization numerical optimization penalty methods barrier methods trust region methods penalty-multiplier methods sequential quadratic programming variational analysis

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INPUT-SHAPED CONTROL OF 3-DIMENSIONAL MANEUVERS OF FLEXIBLE SPACECRAFT

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1993年第6期16卷 1061-1068页

作者： SINGH, T VADALI, SR TEXAS A&M UNIV SYST DEPT AEROSP ENGN COLL STN TX 77843 USA

This paper deals with the control of three-dimensional rotational maneuvers of flexible spacecraft. A spacecraft model with a cylindrical hub and four symmetric appendages is considered. The appendages are long and flexible, leading to low-frequency vibration under any control action. To provide a comprehensive treatment of input-shaped controllers (time-delay filters), both open-loop and closed-loop maneuvers are considered. For the open-loop maneuver, a five-switch, near-minimum-time bang-bang controller is designed based on the rigid-body model. The design procedure accounts for the presence of the time-delay filter for determining the switch times. In addition, a combination of a Lyapunov controller with the time-delay control technique is proposed to take advantage of the simple feedback control strategy and augment it with a technique that can eliminate the vibratory motion of the flexible appendages more efficiently.

关键词： Flexible Spacecrafts Open Loop Controller Feedback Control Time Optimal Control sequential quadratic programming Nonlinear Systems Damping Ratio Robots Spacecraft Configurations Euler Bernoulli Beams

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Optimized Control Allocation of an Articulated Overactuated Solar Sail

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2020年第12期43卷 2321-2332页

作者： Abrishami, Arya Gong, Shengping Tsinghua Univ Sch Aerosp Engn Beijing 100084 Peoples R China

This research is dedicated to introducing a novel structure for small-sized solar sail by using rotatable vanes and reflectivity control devices. The overactuated design that is proposed for the solar sail resulted in a mixed-integer-continuous and nonlinear optimization for control allocation. Trying to solve this complex problem by common numerical and analytical approaches, either the desired torque has been found at the expense of a long and noneligible length of time or they failed to converge at a certain extremum. Thus, addressing the desired torque to the space of possibilities has been accomplished by formulating the attainable moments of forces of each vane by a modified egg-shaped equation in three dimensions. The optimization problem of the control allocation has been solved to minimize the overall changes in vane angles as object function by a hybrid optimization. The accuracy of value matching between the target and the actual torques and the huge improvement in time consumption to achieve optimized control allocation is evaluated in the results.

关键词： Light Sails Reflectivity sequential quadratic programming Genetic Algorithm Attitude Control System Computer Programs Nonlinear programming Japan Aerospace Exploration Agency Cartesian Coordinate System Center of Pressure

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A quadraticALLY CONVERGENT sequential programming METHOD FOR SECOND-ORDER CONE PROGRAMS CAPABLE OF WARM STARTS

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SIAM JOURNAL ON OPTIMIZATION 2024年第3期34卷 2943-2972页

作者： Luo, Xinyi Wachter, Andreas Northwestern Univ Dept Ind Engn & Management Sci Evanston IL 60208 USA

We propose a new method for linear second-order cone programs. It is based on the sequential quadratic programming framework for nonlinear programming. In contrast to interior point methods, it can capitalize on the warm-start capabilities of active-set quadratic programming subproblem solvers and achieve a local quadratic rate of convergence. In order to overcome the nondifferentiability or singularity observed in nonlinear formulations of the conic constraints, the subproblems approximate the cones with polyhedral outer approximations that are refined throughout the iterations. For nondegenerate instances, the algorithm implicitly identifies the set of cones for which the optimal solution lies at the extreme points. As a consequence, the final steps are identical to regular sequential quadratic programming steps for a differentiable nonlinear optimization problem, yielding local quadratic convergence. We prove the global and local convergence guarantees of the method and present numerical experiments that confirm that the method can take advantage of good starting points and can achieve higher accuracy compared to a state-of-the-art interior point solver.

关键词： nonlinear optimization second-order cone programming sequential quadratic programming

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Algorithms for Secrecy Guarantee With Null Space Beamforming in Two-Way Relay Networks

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2014年第8期62卷 2111-2126页

作者： Yang, Yunchuan Sun, Cong Zhao, Hui Long, Hang Wang, Wenbo Beijing Univ Posts & Telecommun Minist Educ Wireless Signal Proc & Network Lab Key Lab Universal Wireless Commun Beijing 100088 Peoples R China Beijing Univ Posts & Telecommun Sch Sci Beijing 100876 Peoples R China

In this paper, we consider a two-way relay network with two sources and multiple cooperative relays in the presence of an eavesdropper. To guarantee the secrecy, a null space beamforming scheme is applied, where the relay beamforming vector lies in the nullspace of the equivalent channel of relay link from two sources to the eavesdropper. Our goal is to obtain the optimal beamforming vector as well as two sources' transmit power subject to various criteria. We propose three different approaches and solve them in an alternating iterative way, where subproblems for solving beamforming and sources' power are formulated in each iteration, respectively. First, we minimize the total transmit power under secrecy rate constraint at two sources. For beamforming vector subproblem, two different methods, semi-definite programming (SDP) and sequential quadratic programming (SQP), are proposed, where we analyze and verify SQP has lower complexity than SDP. Second, we maximize the secrecy sum rate, subject to total transmit power constraint. The beamforming vector subproblem is equivalent to a generalized Rayleigh quotient problem with rank constraint. Third, the problem of minimum per-user secrecy rate maximization under the total power constraint is investigated for user fairness. An iterative procedure utilizing the SDP with bisection search method is proposed to solve beamforming subproblem. In each approach the subproblem with two sources' power is formulated as a single variable problem and solved by Newton's method with line search. Simulation results demonstrate the validity of proposed approaches and algorithms for both symmetric and asymmetric scenarios.

关键词： Null space beamforming physical layer security semi-definite programming sequential quadratic programming

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Optimal Variable Amplitudes Input Shaping Control for Slew Maneuver of Flexible Spacecraft

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2017年第12期40卷 3255-3263页

作者： Wang, Jie Li, Dongxu Jiang, Jianping Natl Univ Def Technol Coll Aerosp Sci & Engn 47 Yanwachi St Changsha 410073 Hunan Peoples R China

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A novel concept for multi-objective optimization of composite power transmission shafts

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JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING 2024年第8期46卷 1-11页

作者： Maalawi, Karam Y. Nasr, Mohamed F. EL-Bayoumi, Mahmoud A. Natl Res Ctr Engn & Renewable Energy Res Inst Mech Engn Dept Cairo 12622 Egypt

Shafts made of advanced composite materials and their applications in different fields are gaining momentum due to their optimized properties. This paper presents various multi-objective optimization (MOO) models for the structural design of slender, thin-walled spinning shafts made of advanced composite materials. The proposed mathematical formulation ensures the attainment of simultaneous and balanced improvements in the major design objectives, including minimal mass and maximum stability against whirling and torsional buckling under behavioral and side constraints. A hybrid genetic algorithm (GA) and sequential quadratic programming (SQP) are implemented to find the needed optimal solutions. Design variables encompass the fiber volume fraction, orientation angle, and thickness of each layer of the cross-section. A case study that addresses the optimization of a pinned-pinned slender shaft made of carbon/epoxy composites is presented. The new approach exhibited its capacity to overcome the uncertainty in ranking and selecting a solution from the set of Pareto-optimal solutions as it determines a unique optimal solution that has a nearly equal optimization gains for the selected design objectives.

关键词： Multi-objective optimization Drive shafts Composite materials Genetic algorithm sequential quadratic programming

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Optimal earth-moon trajectories using combined chemical-electric propulsion

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1997年第2期20卷 253-258页

作者： Kluever, CA University of Missouri–Columbia/Kansas City Kansas City Missouri 64110-2499

Minimum-fuel, three-dimensional Earth-moon trajectories are obtained for spacecraft using both chemical and electric propulsion stages. The problem involves maximizing the final spacecraft mass delivered to a circular, polar midlunar orbit, The mission definition involves a chemical-stage boost from low-Earth orbit into a coasting ballistic trajectory followed by a lunar capture trajectory performed by the electric propulsion stage. For this analysis, the ballistic orbit transfer and the powered orbit transfer to a circular orbit within the lunar sphere of influence are modeled by the dynamics of the classical restricted three-body problem, and two body-centered coordinate frames are utilized, The subsequent descending three-dimensional spiral trajectory to circular polar midlunar orbit is computed via Edelbaum's analytic equations in order to eliminate the need to numerically simulate the numerous near-circular lunar orbits, Two classes of current-term electric propulsion thrusters are utilized (arcjet and plasma thrusters) along with current-term launch vehicle configurations, Numerical results are presented, and the optimal chemical-electric propulsion transfers exhibit a substantial reduction in trip time compared to Earth-moon transfers using electric propulsion alone.

关键词： Electric Propulsion Earth Moon Solar Electric Propulsion Launch Vehicles Arcjet Thruster Exhaust Velocity sequential quadratic programming Trajectory Optimization Nonlinear programming

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OPTIMAL-DESIGN OF FRAME STRUCTURES USING MULTIVARIATE SPLINE APPROXIMATION

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AIAA JOURNAL 1994年第10期32卷 2090-2098页

作者： WANG, LP GRANDHI, RV Wright State University Dayton Ohio 45435

The objective of this work is to demonstrate the efficiency and applicability of the optimization algorithm using a multivariate spline approximation. In the present algorithm, based on the function values and first-order derivatives of the constraints available at the intermediate points of optimization, an explicit approximation of constraint functions is created by using the least squares spline algorithm. The nonlinearity of the function is adaptively updated using feedback information from the previous two iterations for finding the order of spline approximation. In addition, constraint deletion and design variable linking concepts are employed in solving the approximate problem by using the quasianalytical sequential quadratic programming and dual methods. The behavior constraints include stresses, displacements, and local buckling in the optimum design of frame structures. To demonstrate the broad applicability of the optimization algorithm, the cross-sectional dimensions are directly selected as the design variables for frame problems having thin-walled rectangular and tube cross-sectional members, and the cross-sectional areas are selected as design variables for an I-section problem.

关键词： sequential quadratic programming Factor of Safety Taylor Series Material Properties Finite Element Analysis Helicopters Allowable Stress Structural Optimization Structural Analysis Spline Interpolation

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