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7th IEEE International Conference on Control, Mechatronics and Automation(ICCMA)

作者： Dogruer, C. U. Hacettepe Univ Dept Mech Engn Ankara Turkey

ISBN: (纸本)9781728137872

In this paper, modal control was used to control the active suspension of a quarter-car model. Modal control can be designed to alter the dynamics of any mode of a system without disturbing the remaining modes. Therefore, in this study, modal control was used to alter the complex eigenvalue of the body-bounce mode of a quarter-car suspension model and thereby by optimizing a measure of the frequency response functions from road disturbance to sprung and unsprung mass displacements, the ride-comfort of a vehicle was improved. It has been shown that modal control can be used in a direct manner to change the dynamics of a vehicle suspension i.e. soft suspension, stiff suspension depending on the driver attitude that affects the vehicle stability and road conditions i.e. urban driving, off-road driving.

关键词： Quarter-Car Model Active Suspension Modal Control MM-Max Optimization sequential quadratic programming

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Parametric Surfaces with Volume of Solid Control for Optimisation of Three Dimensional Aerodynamic Topologies

Parametric Surfaces with Volume of Solid Control for Optimis...

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AIAA Science and Technology (SciTech) Forum and Exposition

作者： Payot, A. D. J. Rendall, T. C. S. Allen, C. B. Univ Bristol Dept Aerosp Engn Bristol Avon England

ISBN: (数字)9781624105784

ISBN: (纸本)9781624105784

This paper presents a topologically flexible parameterisation method suitable for the optimisation of 3 dimensional aerodynamics using traditional boundary fitted meshes. This parameterisation extends the restricted-snake volume of solid (RSVS) parameterisation previously developed by the authors. This is achieved by extending restricted snakes, a parametric active contour method, into a restricted surface capable of efficiently evolving arbitrary complex topologies handling collisions with no floating point arithmetic. This is integrated with a surface generation rule which allows smooth shapes with intuitive parameterisation of topology. The 3D-RSVS is presented along with results displaying its smooth behaviour, it's ability to produce shapes of aerodynamic interest and it's topological flexibility. A hierarchical approach to the volume of solid design variables is presented for the RSVS, allowing automatic design of the grids on which VOS are specified. An optimisation framework is proposed and some example 2 dimensional optimisation results are presented.

关键词： Aerodynamic Shape Optimization sequential quadratic programming Computational Fluid Dynamics Numerical Optimization Reynolds Averaged Navier Stokes Image Segmentation Structural Optimization Airbus A380 Aircraft Configurations Singular Value Decomposition

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Computational Design and Optimization of Wind Farms using Analytical Derivatives

Computational Design and Optimization of Wind Farms using An...

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AIAA Aviation Forum and Exposition

作者： Ashuri, T. Bista, S. Hosseini, S. E. Khan, M. S. Hamidi, R. Jalilzadeh Arkansas Tech Univ Dept Mech Engn Coll Engn & Appl Sci Russellville AR 72801 USA Arkansas Tech Univ Dept Elect Engn Coll Engn & Appl Sci Russellville AR 72801 USA

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

This paper presents a multidisciplinary framework for computational design and optimization of coupled offshore wind farm layout and support structure using analytical derivatives. Gradient-based optimization with exact analytical derivatives scales well with large design problems, and it is the preferred approach over gradient-free techniques. We used the second order Larsen model to simulate the wake in the wind farm. Combined with an energy production model and Weibull wind distribution function, the annual energy production of the wind farm is computed. Timoshenko beam elements model the support structure including the soil-structure interaction. Airy's wave theory with Wheeler stretching is utilized for modeling the wave kinematics and to obtain the hydrodynamic loads using Morison's equation. Cost models are used to evaluate the levelized cost of energy as the objective function. The design constraints are the support structure buckling, modal-frequency, and stresses. To evaluate the effectiveness of the proposed approach, we performed an optimization of a feasible baseline design consisting of 6 Vestas V80 wind turbines. Compared to the baseline design, our results show that the coupled layout and support structure approach reduces the levelized cost of energy by 1.4%. This efficient computational framework allows the concurrent design of the wind farm layout and support structure with thousands design variables, and it suitable for detailed design of offshore wind farms.

关键词： Blade Element Momentum Theory Energy Generation Aerodynamic Loads Morison Equation sequential quadratic programming Turbulent Boundary Layer Multidisciplinary Design Optimization Sensitivity Analysis Electrical Systems Stiffness Matrices

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Market Applications in the Electricity Market of the Russian Federation

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INTERNATIONAL JOURNAL OF PUBLIC ADMINISTRATION 2019年第15-16期42卷 1363-1369页

作者： Davidson, Mikhail R. Labutin, Gleb, V Moscow MV Lomonosov State Univ Fac Computat Math & Cybernet Moscow Russia Consultnext LLC Moscow Russia JSC Syst Operator United Power Syst Markets Dev Dept Moscow Russia

A unique specificity of Russian wholesale electricity market is the economic dispatch model based on explicit nonlinear power flow equations underlying the market applications. This paper presents the solution method used for the market applications that is presently employed by the commercial operator and the system operator of the Russian energy system. It is proved to be an adequate and reliable scheduling market technology. Empirical observations on the model properties that impact the rate of convergence and review of the convergence results are presented.

关键词： Day ahead market balancing market optimal power flow sequential quadratic programming

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Particle-Based Optimization of a Conceptual Wing with Gradient Information

Particle-Based Optimization of a Conceptual Wing with Gradie...

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AIAA Science and Technology (SciTech) Forum and Exposition

作者： Dettwiller, Ian D. England, William Foster, Justin Garon, Elyse Freeman, Elton US Army Engineer Res & Dev Ctr ERDC Informat Technol Lab Vicksburg MS 39180 USA

ISBN: (数字)9781624105784

ISBN: (纸本)9781624105784

A new, particle-based optimization strategy for global optimization is presented. The new approach is used for minimizing weight through sizing optimization of the interior components of a conceptual wing subject to Von Mises stress constraints. The goal of the particle-based optimization scheme is to produce a methodology for high-dimensional global optimization. Performance of the new optimization scheme is compared to particle swarm optimization, differential evolution, and sequential quadratic programming with multiple starting points on a pair of global optimization benchmark problems. The particle-based strategy is shown to rapidly converge to global solutions to the unconstrained problems, even as dimensionality is increased. Finally, the particle-based optimization strategy is shown to be capable of successfully optimizing the conceptual wing.

关键词： Global optimization Wings stress constraints conceptual Benchmark testing sequential quadratic programming Point pairs Particle swarm optimization

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Large-scale multidisciplinary design optimization: review and recommendations

Large-scale multidisciplinary design optimization: review an...

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AIAA Aviation Forum and Exposition

作者： Hwang, John T. Ha, Tae H. Jain, Arnav, V Univ Calif San Diego Dept Mech & Aerosp Engn La Jolla CA 92093 USA

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

Large-scale multidisciplinary design optimization is the solution of engineering design problems using numerical optimization involving large numbers of design variables and disciplines. Efficient and exact derivative computation is necessary for scalability, but it is time-consuming to implement, especially with complex, multidisciplinary models. The recent emergence of a modular framework-based approach to assist in multidisciplinary derivative computation has led to a rapid increase in methods and applications for large-scale multidisciplinary design optimization. This paper provides an overview of the state-of-the-art approach, surveys recent applications, and provides recommendations for future applications. The recommendations are based on experience from prior applications as well as benchmarking studies involving satellite system design, eVTOL air taxi system design, the vortex lattice method, finite element analysis, and an optimal control problem. In particular, the recommendations deal with the choice of MDO architecture, optimization algorithm, the impact of exact versus approximate derivative computation, constraint aggregation, and optimal control.

关键词： Multidisciplinary Design Optimization Trajectory Optimization sequential quadratic programming Numerical Optimization Satellites Computational Fluid Dynamics Finite Element Analysis Thrust Specific Fuel Consumption Finite Difference Approximation Blade Element Momentum Theory

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A robust implementation of a sequential quadratic programming algorithm with successive error restoration

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OPTIMIZATION LETTERS 2011年第2期5卷 283-296页

作者： Schittkowski, K. Univ Bayreuth Dept Comp Sci D-95440 Bayreuth Germany

We consider sequential quadratic programming methods for solving constrained nonlinear programming problems. It is generally believed that these methods are sensitive to the accuracy by which partial derivatives are provided. One reason is that differences of gradients of the Lagrangian function are used for updating a quasi-Newton matrix, e.g., by the BFGS formula. The purpose of this paper is to show by numerical experimentation that the method can be stabilized substantially. The algorithm applies non-monotone line search and internal and external restarts in case of errors due to inaccurate derivatives while computing the search direction. Even in case of large random errors leading to partial derivatives with at most one correct digit, termination subject to an accuracy of 10(-7) can be achieved in 90% of 306 problems of a standard test suite. On the other hand, the original version with monotone line search and without restarts solves only 30% of these problems under the same test environment. In addition, we show how initial and periodic scaled restarts improve the efficiency in situations with slow convergence.

关键词： SQP sequential quadratic programming Nonlinear programming Line search Restart Numerical algorithm Noisy functions

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Sinogram restoration based on shape property in computed tomography

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Informatics in Medicine Unlocked 2020年 20卷

作者： Ri, Hwisong Kim, Jongchol Lee, Muchol Hwang, Hyok Pak, Jonghyok Department of Electronic Engineering Kim Chaek University of Technology Pyongyang 999093 North Korea Department of Control Science University of Science Pyongyang 999093 North Korea Northeastern University Department of Humanities and Law Shenyang 430074 Liaoning China

Low-dose computed tomography (CT) image sequences, obtained to reduce the risk of radiation exposure, can be seriously degraded by quantum noise and other kinds of mechanical and electrical effects. In order to overcome this problem, we firstly present a sinogram restoration algorithm based on nonlinear optimization programs (NLP), including sequential quadratic programming (SQP) and the interior point method (IPM). Then, the reconstructed image is obtained by a filtered back-projection (FBP) from smoothed projection data. A real-time scan was provided by applying CUDA, which improves calculation speed and precision. The effectiveness and practicability of the proposed method are validated by utilizing a digital phantom and by real clinical data experiments. The advantage of the proposed method over other techniques is demonstrated by means of the peak signal-noise ratio (PSNR) and Euclidean distance from the original image. The experimental results show that the proposed algorithm has excellent performance for low-dose CT imaging analysis. © 2020

关键词： CT Interior point method Nonlinear optimization program sequential quadratic programming Shape property Sinogram

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Discrete-Time Optimal Attitude Control of a Spacecraft with Momentum and Control Constraints

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2018年第1期41卷 199-211页

作者： Phogat, Karmvir Singh Chatterjee, Debasish Banavar, Ravi Indian Inst Technol Syst & Control Engn Room 101ACRE Bldg Bombay 400076 Maharashtra India

An algorithm is proposed to solve optimal control problems arising in attitude control of a spacecraft under state and control constraints. First, the discrete-time attitude dynamics are derived by employing discrete mechanics. Then, the orientation transfer, with initial and final values of the orientation and momentum and the time duration being specified, is posed as an energy-optimal control problem in discrete time, subject to momentum and control constraints. Using variational analysis directly on the Lie group SO(3) (the set of 3 x 3 special orthonormal matrices), first-order necessary conditions for optimality are derived, leading to a constrained two-point boundary value problem. This two-point boundary value problem is solved via a novel multiple shooting technique that employs a root-finding Newton algorithm. Robustness of the multiple shooting technique is demonstrated through a few representative numerical experiments.

关键词： Attitude Dynamics Spacecrafts Pontryagin's Maximum Principle Boundary Value Problems Rotational Kinematics Direct Multiple Shooting Method Attitude Kinematics Quaternions sequential quadratic programming Pseudospectral Methods

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Intelligent computing to solve fifth-order boundary value problem arising in induction motor models

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NEURAL COMPUTING & APPLICATIONS 2018年第7期29卷 449-466页

作者： Ahmad, Iftikhar Ahmad, Fayyaz Raja, Muhammad Asif Zahoor Ilyas, Hira Anwar, Nabeela Azad, Zarqa Univ Gujrat Dept Math Gujrat Pakistan Univ Gujrat Dept Stat Gujrat Pakistan COMSATS Inst Informat Technol Dept Elect Engn Attock Campus Attock Pakistan

In this study, biologically inspired intelligent computing approached based on artificial neural networks (ANN) models optimized with efficient local search methods like sequential quadratic programming (SQP), interior point technique (IPT) and active set technique (AST) is designed to solve the higher order nonlinear boundary value problems arise in studies of induction motor. The mathematical modeling of the problem is formulated in an unsupervised manner with ANNs by using transfer function based on log-sigmoid, and the learning of parameters of ANNs is carried out with SQP, IPT and ASTs. The solutions obtained by proposed methods are compared with the reference state-of-the-art numerical results. Simulation studies show that the proposed methods are useful and effective for solving higher order stiff problem with boundary conditions. The strong motivation of this research work is to find the reliable approximate solution of fifth-order differential equation problems which are validated through strong statistical analysis.

关键词： Induction motor model Active set technique Interior point technique sequential quadratic programming Artificial neural networks

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