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55th AIAA Aerospace Sciences Meeting

作者： Vegh, J. Michael Macdonald, Tim Wendor, Andrew D. Alonso, Juan J. Department of Aeronautics & Astronautics Stanford University StanfordCA94305 United States

ISBN: (数字)9781624104473

ISBN: (纸本)9781624104473

This paper compares the computational cost and robustness of a number of different algorithms for the sizing and optimization of aircraft. In particular, three classes of aircraft will be investigated, each with a different level of propulsion system complexity. The first is a conventional turbofan-powered aircraft. A lithium-air battery-powered aircraft, incorporating both energy and power constraints is second. Third is an aluminum-air/lithium-ion battery powered aircraft, which switches to different energy systems depending on the overall propulsion system power requirements. Several different aircraft design problem formulations will be considered for each of these aircraft. Sizing loops as well as deter- mining constraints such as fuel margin by exposing them to the optimizer will both be explored. Results suggest that integrating surrogate models to inform the sizing loop leads to substantially fewer function evaluations than a simple successive substitution, while maintaining a relative insensitivity to a poorly-informed initial guess that optimizer-sizing algorithms lack. © 2017 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Commercial Aircraft Propulsion System Energy Systems Hybrid Electric Aircraft sequential quadratic programming Algorithm Performance Lithium Air Battery Aircraft Sizing Fossil Fuels Turbofan

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Multi-carrier optimal power flow of energy hubs by means of ANFIS and SQP 42

Multi-carrier optimal power flow of energy hubs by means of ...

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42nd Conference of the Industrial Electronics Society, IECON 2016

作者： Kampouropoulos, Konstantinos Andrade, Fabio Sala, Enric Espinosa, Antonio Garcia Romeral, Luis Fundació CTM Centre Tecnològic Manresa Spain Electrical and Computer Engineering Department University of Puerto Rico Mayagüez Puerto Rico MCIA Research Center Universitat Politècnica de Catalunya Terrassa Spain

ISBN: (纸本)9781509034741

Due to the climate change and the decrease in fossil fuel reserves, the industrial and tertiary sectors have been focused on the implementation of advanced energy management systems in order to improve their energy efficiency and reduce their overall emissions. One way to achieve that goal, which is also the focus of this work, is by optimizing the energy use in their operation processes. This paper presents a hybrid optimization method, combined by neuro-fuzzy inference systems and the quadratic programming optimization method, to calculate the short-term demand forecasting of a multi-carrier energy system and to optimize its energy flow. The objective of the optimization is to fulfill the system's energy demands and minimize a set of established optimization criteria. Moreover, the algorithm considers the system's dynamics and inertias in order to guarantee that the obtained results present a feasible and stable operation strategy for the energetic plant. The method has been applied and validated under real conditions in a car manufacturing plant of Spain, in the framework of a FP7 European research project using online production and consumption data. © 2016 IEEE.

关键词： Adaptive neuro-fuzzy inference system Energy optimization Energy prediction Multi-carrier energy systems Power systems sequential quadratic programming

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Research on airfoil design space and the application of niching techniques in airfoil design 55

Research on airfoil design space and the application of nich...

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55th AIAA Aerospace Sciences Meeting

作者： Gao, Chong Gao, Zhenghong Li, Siyi Wang, Chao National Key Laboratory of Aerodynamic Design and Research Northwestern Polytechnical University Youyi West Road No. 127 Xi’an710072 China

ISBN: (数字)9781624104473

ISBN: (纸本)9781624104473

Design space of the RAE2822 airfoil is investigated. We find that there exists an optimum region in airfoil design space where considerable number of optimal airfoils locate. In this region, optimal airfoils have similar aerodynamic force coefficients, but distinctive geometries which result in different aerodynamic performances. To find multiple optimal airfoils in the whole design space, we introduce niching techniques into airfoil design and propose a gradient-enhanced niching particle swarm optimization algorithm (GE-NichingPSO). GE-NichingPSO employs a priority-ranked fitness sharing technique to enhance its ability to locate multiple optima. In order to speed up convergence, GE-NichingPSO is incorporated with a gradient-based algorithm. Numerical experiments show that GE-NichingPSO has obvious advantage in finding multiple optima over two famous niching PSOs. The proposed approach is used to solve the drag minimization of the RAE2822 airfoil in transonic viscous flow provided by AIAA aerodynamic design optimization discussion group (ADODG). Ten diverse optimal airfoils are obtained simultaneously, confirming the effectiveness of niching techniques in airfoil design. © 2017 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Supercritical Airfoils Aerodynamic Force Coefficients Particle Swarm Optimization Viscous Flow Aerodynamic Performance sequential quadratic programming Computational Fluid Dynamics Airfoil Geometry Surrogate Model Particle Numbers

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NONLINEAR programming SOLVERS FOR HYBRID FINITE ELEMENT

NONLINEAR PROGRAMMING SOLVERS FOR HYBRID FINITE ELEMENT

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作者： Thukral, Payal PennState University Libraries

学位级别：Master of Science

The focus of this work is on analyzing and developing nonlinear solvers for performing nonlinear structural analysis for large displacements in both elastic and inelastic cases. The response of a structure to a load application is shown by its equilibrium path which may include snap back and snap through behavior. Material and geometric nonlinearities are taken into consideration while developing the response path of a multi-element structure with sections discretized using fiber elements. Traditionally, Newton’s method is employed for solving the system of nonlinear equations but it comes with certain challenges. The response determination becomes difficult when stiffness matrix becomes singular at turning point. It also requires the calculation of the inverse of a Hessian matrix, which is costly. Newton’s method gives quadratic convergence but as the scale of the structure increases, resorting to Newton’s method becomes *** limitations motivate us to explore new solvers. Hence, in this study we analyze and develop various nonlinearly constrained optimization solvers for a recently suggested hybrid finite element. In particular, we compare the performance of conjugate gradient method with or without preconditioning, sequential quadratic programming method and augmented Lagrangian method. For the case of structural response with snap back and snap through behavior, a new method called the implicit path continuation method is developed to ensure path continuation and solution convergence. The various solvers are then validated by obtaining responses of three benchmark structural problems with large displacements and rotations, and comparing the results with the conventional Newton’s method and a variant of Newton’s method with submatrices.

关键词： Nonlinear finite element analysis Newton's method Nonlinear programming sequential quadratic programming Crisfield's arc length method Conjugate gradient method Path continuation

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A Convex OPF Approximation for DC Networks Considering Voltage-Dependent Load Models

A Convex OPF Approximation for DC Networks Considering Volta...

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2020 IEEE Andescon Conference

作者： Montoya, Oscar Gil-Gonzalez, Walter Garces, A. Casilimas-Pena, A. Garrido, V. M. Univ Dist Francisco Jose de Caldas Engn Fac Bogota Colombia Inst Univ Pascual Bravo Fac Ingn Medellin Colombia Univ Tecnol Pereira Dept Elect Power Engn Pereira Colombia Univ Tecnol Bolivar Smart Energy Lab Cartagena Colombia

ISBN: (纸本)9781728193656

This paper addresses the problems of power flow and optimal power flow a nalysis considering voltage-dependent load models from the convex point of view. First, Taylor series expansion method is employed for linearizing the power flow equations generating a set of affine hyperplanes. Second, the sequential quadratic programming (SQP) approach is employed for adjusting the linearization point to eliminate the voltage estimation error between the exact and proposed convex models recursively. Two voltage-dependent load models are considered in our power flow and optimal power flow proposals which based on the exponential and polynomial models. General algebraic modeling system (GAMS) and its nonlinear optimization packages are employed for comparison purposes. Two DC-test systems with 6 and 21 nodes are used to validate the performance of the SQP proposed. The proposed SQP approach is implemented in MATLAB software with quadprog toolbox.

关键词： Direct-current networks optimal power flow analysis sequential quadratic programming Taylor's based series expansion method

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Hybrid PSO-SQP Algorithm for Solving System Reliability Allocation Optimization

Hybrid PSO-SQP Algorithm for Solving System Reliability Allo...

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2015 International Conference on Materials Engineering and Information Technology Applications(MEITA 2015)

作者： TANG Cheng GUO Shu-xiang MO Yan-yu Science College Air Force Engineering University Aeronautics and Astronautics Engineering College Air Force Engineering University

ISBN: (纸本)9781510812055

System reliability allocation is an important ingredient in system reliability design, and it is also a decision-making issue of reliability engineering. To achieve the optimization of system reliability allocation, an optimization model for system reliability allocation, which takes the system cost as the objective function, is constructed through the general cost function. In order to overcome the shortcomings of particle swarm optimization(PSO) appearing in reliability allocation optimization, the premature and/or slow speed of convergence in later period, the sequential quadratic programming(SQP) was introduced to improve the PSO algorithm. The algorithm uses PSO as the global optimizer while the SQP is employed for accelerating the local search. Thus, the particles are able to search the whole space while searching for local optimization fast, which not only assures the convergence of the algorithm, but also increases the probability of obtaining the global optimum. Applied the algorithm to the problem of system reliability allocation, the simulation results show that it has excellent global search capability and provides rational optimization results compared to the existing approaches.

关键词： system reliability reliability allocation particle swarm optimization sequential quadratic programming

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APPLICATION OF HYBRID AERO-ENGINE MODEL FOR INTEGRATED FLIGHT/PROPULSION OPTIMAL CONTROL

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Transactions of Nanjing University of Aeronautics and Astronautics 2012年第1期29卷 16-24页

作者：王健康张海波孙健国李永进南京航空航天大学能源与动力学院

The real-time capability of integrated flight/propulsion optimal control （IFPOC） is studied. An appli- cation is proposed for IFPOC by combining the onboard hybrid aero-engine model with sequential quadratic pro- gramming （SQP）. Firstly, a steady-state hybrid aero-engine model is designed in the whole flight envelope with a dramatic enhancement of real-time capability. Secondly, the aero-engine performance seeking control including the maximum thrust mode and the minimum fuel-consumption mode is performed by SQP. Finally, digital simu- lations for cruise and accelerating flight are carried out. Results show that the proposed method improves real- time capability considerably with satisfactory effectiveness of optimization.

关键词： integrated flight/propulsion optimal control aero-engine hybrid model performance seeking con- trol sequential quadratic programming

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Low-thrust transfer orbit design based on Lyapunov feedback control law

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IMACS Multiconference on Computational Engineering in Systems Applications (CESA 2006)

作者： Ren Yuan Cui Pingyuan Luan Enjie Harbin Inst Technol Deep Space Explorat Res Ctr POB 3030Sci Pl Harbin 150006 Peoples R China China Natl Space Adm Beijing Peoples R China

ISBN: (纸本)9787302139225

A novel low-thrust orbit transfer design method is presented which is based on the knowledge of optimal thrust direction and optimal location for changing each of the orbit elements and the concept of Lyapunov feed back control. In this method, a set of equinoctial elements is utilized to avoid the singularities in dynamical equation of classical orbit elements. A thruster switch law is derived by analyzing the effectivity of the changing of each orbit elements. The thrust will be cut-off if the effectivity is below a specified level. When on, the thrust is a constant. The two-body dynamics model is used in this method. The method needs few input parameters. By sequential quadratic programming (SQP), these parameters could be adjusted and performance index could be maximized. This method is a simple way to estimate key parameters of a low-thrust orbit transfer and could also give an accurate initial guesses for the future optimization.

关键词： Lyapunov feed back control low-thrust sequential quadratic programming

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Aircraft Optimal Separation Allocation Based on Global Optimization Algorithm

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Transactions of Nanjing University of Aeronautics and Astronautics 2022年第6期39卷 707-720页

作者： REN Xuanming TANG Xinmin College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China College of Transportation Science and Engineering Civil Aviation University of ChinaTianjin 300300P.R.China

A dynamic programming-sequential quadratic programming(DP-SQP)combined algorithm is proposed to address the problem that the traditional continuous control method has high computational complexity and is easy to fall into local optimal *** solve the globally optimal control law sequence,we use the dynamic programming algorithm to discretize the separation control decision-making process into a series of sub-stages based on the time characteristics of the separation allocation model,and recursion from the end stage to the initial *** sequential quadratic programming algorithm is then used to solve the optimal return function and the optimal control law for each *** simulations of the combined algorithm and the traditional algorithm are designed to validate the superiority of the combined ***-following and cross-conflict simulation examples are created to demonstrate the combined algorithm’s adaptability to various conflict *** simulation results demonstrate the separation deploy strategy’s effectiveness,efficiency,and adaptability.

关键词： optimal separation allocation sequential quadratic programming dynamic programming globally optimal control optimal control law

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Fourier Pseudospectral Method for Trajectory Optimization with Stability Requirements

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2020年第11期43卷 2073-2090页

作者： Laad, Dhruv Elango, Purnanand Mohan, Ranjith Indian Inst Technol Madras Dept Aerosp Engn Chennai 600036 Tamil Nadu India

Periodic trajectories that satisfy stability-based requirements are useful in many engineering applications. In this work, a time-domain approach using Fourier collocation for solving the Floquet eigenvector boundary value problem, and consequently estimating Floquet exponents and eigenvectors, is introduced. This method is incorporated into a Fourier pseudospectral trajectory optimization framework for generating open-loop stable solution, and for improving the damping of a specific mode identified using the information from Floquet eigenvectors. These applications are illustrated on the dynamic soaring solutions of three- and six-degree-of-freedom aircraft models, and numerical results highlighting the effectiveness of the pseudospectral Floquet computation over the traditional time-march approach are also presented.

关键词： Trajectory Optimization Pseudospectral Methods Dynamic Soaring Lyapunov Equation Boundary Value Problems Three Degrees of Freedom Fixed Wing Aircraft Numerical Optimization sequential quadratic programming Aircraft Dynamics

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