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Novel repeatable launch locking/unlocking device for magnetically suspended momentum flywheel

MECHATRONICS 2018年 54卷 16-25页

作者： Liu, Qiang Wang, Kun Ren, Yuan Peng Peilan Ma Limei Yin, Zhaojing Beijing Inst Petrochem Technol Inst Precis Electromagnet Equipment & Adv Measure Beijing Peoples R China Beihang Univ Key Lab Inertial Technol Beijing Peoples R China Space Engn Univ Sch Aerosp Sci & Technol Beijing Peoples R China

Because one-shot launch locking/unlocking device (OSLLUD) cannot repeat locking/unlocking, and repeatable launch locking/unlocking device (RLLUD) has an insufficient reliability of implementing unlocking, a novel RLLUD consisting of a motor, wire rope and several same flexible brackets was proposed. The composition, operating principle and functional performance requirements were introduced. A single flexible bracket was equivalent to a cantilever beam-mass model, and its static and dynamic performances were analyzed. Design variables were selected according to the sensitivity analysis method. Unlocking force, the maximum stress and the first resonance frequency were concerned, and the flexible brackets were optimized through the comparison and the sequential quadratic programming methods. The RLLUD was manufactured according to the optimization results. The environmental mechanics tests of tri-axial swept-sine and random vibration were carried out to verify the protective effect of the novel RLLUD for magnetically suspended momentum flywheel (MSMFW) during launch. The results show that the maximum macroscopic vibration is less than the protection gap of the flywheel, and its locking protective effect is valid and sufficient.

关键词： Magnetically suspended momentum flywheel Launch locking/unlocking device Optimization design sequential quadratic programming method Finite element method

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Magnetic flux leakage modelling and optimisation of a CRAHMB for DC motor

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IET ELECTRIC POWER APPLICATIONS 2017年第2期11卷 212-221页

作者： Ren, Xiaojun Le, Yun Sun, Jinji Han, Bangcheng Wang, Kun Fundamental Sci Novel Inertial Instrument & Nav S Beijing 100191 Peoples R China Beihang Univ Sch Instrument Sci & Optoelect Engn Beijing 100191 Peoples R China Beijing Univ Aeronaut & Astronaut Beijing Engn Res Ctr High Speed Magnetically Susp Beijing 100191 Peoples R China

In this study, a combined radial-axial hybrid magnetic bearing (CRAHMB) with four poles is designed for high-speed brushless DC motor. Owing to the small distance of radial and axial unit of CRAHMB, the magnetic flux leakage (MFL) in both radial and axial directions is complex and serious. This study focuses on effective analytical model and optimisation of CRAHMB including flux leakage of permanent magnet circuit and control electromagnetic circuit. MFL analytical model was built based on equivalent magnetic circuit method. Under the condition of satisfying the maximum bearing capacity, the MFL coefficients were optimised with sequence quadratic programming method. A set of optimum parameters were suggested. MFL before and after optimisation are compared by finite element method. Finally, current stiffness calculated with optimised analytical model was verified on a DC motor experiment. The result shows the accuracies of both the axial and radial current stiffness are enhanced.

关键词： magnetic flux magnetic bearings brushless DC motors magnetic leakage permanent magnets magnetic circuits equivalent circuits quadratic programming finite element analysis magnetic flux leakage modelling optimisation CRAHMB combined radial-axial hybrid magnetic bearing high speed brushless DC motor permanent magnet circuit control electromagnetic circuit MFL analytical model equivalent magnetic circuit method maximum bearing capacity sequential quadratic programming method finite element method

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Geometry optimization for proton-exchange membrane fuel cells with sequential quadratic programming method

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JOURNAL OF POWER SOURCES 2009年第1期186卷 10-21页

作者： Xing, Xiu Qing Lum, Kah Wai Poh, Hee Joo Wu, Yan Ling Inst High Performance Comp Singapore 138632 Singapore

Integration between COMSOL Multiphysics (TM) and MATLAB (TM) offers a useful option for the self-automated geometry optimization in proton-exchange membrane fuel cells (PEMFCS). It overcomes the difficulties of automatically re-generating high-quality computational meshes and subsequently running the simulations to evaluate the objective function values using commercial software in computational fuel cell dynamics-based designs. Geometry optimization studies of an air-breathing PEMFC searching for the optimum channel ratio at the anode and the optimum open ratio at the cathode, are undertaken. A sequential quadratic programming method is selected to deal with the constrained design problems, while the objective functions are evaluated by running the three-dimensional simulation script of COMSOL (TM) under the MATLAB (TM) environment. Simulation results show that for the air-breathing PEM fuel cell operated at 353 K and one standard atmosphere pressure, when the anode channel ratio is fixed at 10%. the optimum cathode open ratios are very similar for the cell operated at voltages of 0.7 and 0.4V, namely, 49.8% for 0.7 V and 49.5% for 0.4 V. When the cathode open ratio is set at 80% with a cell voltage of 0.7 V, the optimum anode channel ratio is found to be 34.7%. (c) 2008 Elsevier B.V. All rights reserved.

关键词： Geometry optimization Proton exchange membrane fuel cell sequential quadratic programming method

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Optimization control for the far-distance rapid cooperative rendezvous of spacecraft with different masses

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AEROSPACE SCIENCE AND TECHNOLOGY 2015年第Sep.期45卷 449-461页

作者： Feng, Weiming Zhao, Di Shi, Lei Yang, Kun Zhao, Junfeng Shandong Univ Dept Engn Mech Jinan 260062 Peoples R China Washington Univ Dept Mech Engn & Mat Sci St Louis MO 63130 USA

In this study, the dynamics equation of orbital elements without singularities is used to describe the far-distance cooperative rendezvous of two spacecraft with different masses. The convergent costate vector is obtained using the particle swarm optimization with differential evolution (PSODE) hybrid algorithm to optimize the far-distance cooperative rendezvous process of the spacecraft. This vector is then used as the initial value for a sequential quadratic programming (SQP) algorithm to again optimize within a small range to obtain a convergent, stable solution. This study focuses on optimizing the control of the far-distance rapid cooperative rendezvous of spacecraft with different masses and explores the interactions between the magnitude of the thrust, the duration of the rendezvous, and the fuel consumption. Optimization simulation results indicate that when the rendezvous duration is limited to within a certain interval, the optimal process for the rendezvous of spacecraft with different masses is a cooperative manoeuvring type, and an increase in thrust will significantly save fuel. In the case of unrestricted rendezvous duration, as the thrust increases, the rendezvous time decreases, but there is little change in the total fuel consumption. (C) 2015 Elsevier Masson SAS. All rights reserved.

关键词： Cooperative rendezvous Active-passive rendezvous Optimization control Particle swarm and differential evolution hybrid algorithm sequential quadratic programming method

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Global and local convergence of a nonmonotone SQP method for constrained nonlinear optimization

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COMPUTATIONAL OPTIMIZATION AND APPLICATIONS 2014年第3期59卷 435-473页

作者： Shen, Chungen Zhang, Lei-Hong Wang, Bo Shao, Wenqiong Shanghai Finance Univ Dept Appl Math Shanghai 201209 Peoples R China Shanghai Univ Finance & Econ Dept Appl Math Shanghai 200433 Peoples R China Nanjing Univ Finance & Econ Sch Appl Math Shanghai 200092 Peoples R China Wayne State Univ Ind & Syst Engn Dept Detroit MI 48202 USA

In this paper, we propose a robust sequential quadratic programming (SQP) method for nonlinear programming without using any explicit penalty function and filter. The method embeds the modified QP subproblem proposed by Burke and Han (Math Program 43:277-303, 1989) for the search direction, which overcomes the common difficulty in the traditional SQP methods, namely the inconsistency of the quadratic programming subproblems. A non-monotonic technique is employed further in a framework in which the trial point is accepted whenever there is a sufficient relaxed reduction of the objective function or the constraint violation function. A forcing sequence possibly tending to zero is introduced to control the constraint violation dynamically, which is able to prevent the constraint violation from over-relaxing and plays a crucial role in global convergence and the local fast convergence as well. We prove that the method converges globally without the Mangasarian-Fromovitz constraint qualification (MFCQ). In particular, we show that any feasible limit point that satisfies the relaxed constant positive linear dependence constraint qualification is also a Karush-Kuhn-Tucker point. Under the strict MFCQ and the second order sufficient condition, furthermore, we establish the superlinear convergence. Preliminary numerical results show the efficiency of our method.

关键词： sequential quadratic programming method Non-monotonicity Convergence analysis RCPLD Strict MFCQ

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Shape and Thickness Optimization Performance of a Beam Structure by sequential quadratic programming method

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JOURNAL OF FAILURE ANALYSIS AND PREVENTION 2007年第1期7卷 50-55页

作者： Jarraya, A. Dammak, F. Abid, S. Haddar, M. Natl Sch Engn Dept Mech Engn Mech Modelling & Prod Res Unit Sfax 3038 Tunisia

Successful performance of beam structures is critical to failure prevention, and beam performance can be optimized by careful consideration of beam shape and thickness. Shape and thickness optimization of beam structures having linear behaviour is treated. The first problem considered is the thickness distribution of the beam where the optimization variable is the thickness of the control points. The second problem is the shape optimization where the optimization variables are the ordinates of the control points. The optimization criterion (function objective to be minimized) is defined starting with the Von Mises criterion expressed in plane constraints. The resolution of the mechanical problem is made by the finite element method, and the optimization algorithm is the sequential quadratic programming (SQP) method.

关键词： Finite elements Beams element Parameterization Optimization sequential quadratic programming method

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Bearing Capacity Calculation of Rock Foundation based on Nonlinear Failure Criterion

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IERI Procedia 2012年 1卷 110-116页

作者： Tang Jing Liu Yongbiao Sichuan College of Architecture Technology Deyang 618000 P.R. China

Conventional foundation bearing capacity calculation is based on Mohr-Coulomb linear failure criterion. But it is verified that almost all kinds of rock's strength envelope is nonlinear with normal stress through tests and is in compliance with modified Hoek-Brown nonlinear failure criterion. Therefore, program is composed by using Matlab software and nonlinear sequential quadratic programming method to calculate bearing capacity and analyze its affect factors according to the upper limit theory of limit analysis adopting Hoek-Brown nonlinear failure criterion and multi-tangential method. The result shows that the main affect factors of rock foundation's bearing capacity are GSI and mi of the rock, however, the dead weight γ ,over load q and excavation disturbance coefficient D affect the bearing capacity largely when GSI is small; after comparison with formers’ research, it is found that the bearing capacity is overestimated and having greater risk by using “single-tangential method” while the “mufti-tangential method is more rigorous in theory and whose result is more close to the actual value and more applicable.

关键词： Bearing capacity of rock foundation Hoek-Brown nonlinear failure criterion sequential quadratic programming method

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Bearing Capacity Calculation of Rock Foundation based on Nonlinear Failure Criterion

Bearing Capacity Calculation of Rock Foundation based on Non...

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2012 2nd Internationnall Conference on Mechanical, Industrial, and Manufacturing Engineering

作者： Tang Jing Liu Yongbiao Sichuan College of Architecture Technology

Conventional foundation bearing capacity calculation is based on Mohr–Coulomb linear failure criterion. But it is verified that almost all kinds of rock's strength envelope is nonlinear with normal stress through tests and is in compliance with modified Hoek-Brown nonlinear failure criterion. Therefore, program is composed by using Matlab software and nonlinear sequential quadratic programming method to calculate bearing capacity and analyze its affect factors according to the upper limit theory of limit analysis adopting Hoek-Brown nonlinear failure criterion and multi-tangential method. The result shows that the main affect factors of rock foundation's bearing capacity are GSI and im of the rock, however, the dead weight,over load q and excavation disturbance coefficient D affect the bearing capacity largely when GSI is small;after comparison with formers' research, it is found that the bearing capacity is overestimated and having greater risk by using "single-tangential method" while the "mufti-tangential method is more rigorous in theory and whose result is more close to the actual value and more applicable.

关键词： bearing capacity of rock foundation oek-Brown nonlinear failure criterion sequential quadratic programming method

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Portfolio adjusting optimization under credibility measures

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JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 2010年第5期234卷 1458-1465页

作者： Zhang, Xili Zhang, Wei-Guo Cai, Ruichu S China Univ Technol Sch Business Adm Guangzhou 510641 Peoples R China S China Univ Technol Sch Engn & Comp Sci Guangzhou 510641 Peoples R China

This paper discusses portfolio adjusting problems for an existing portfolio. The returns of risky assets are regarded as fuzzy variables and a class of credibilistic mean-variance adjusting models with transaction costs are proposed on the basis of credibility theory. Under the assumption that the returns of risky assets are triangular fuzzy variables, the optimization models are converted into crisp forms. Furthermore, we employ the sequential quadratic programming method to work out the optimal strategy. Numerical examples illustrate the effectiveness of the proposed models and the influence of the transaction costs in portfolio selection. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Portfolio adjusting Possibility theory Credibility measure Transaction costs sequential quadratic programming method

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Thrust allocation logic of dynamically positioned offshore vessel

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SHIPS AND OFFSHORE STRUCTURES 2010年第3期5卷 243-251页

作者： Jeyasenthil, Ramamoorthy Dasgupta, Jyotisman Larsen & Toubro Ltd Engn & Construct Div FSBU Bombay 400072 Maharashtra India

In dynamic positioning (DP) systems, 'thrust allocation' is the problem of determining the thrust and direction of each of the 'n' thrusters in an over-actuated offshore vessel from the desired forces and moment derived in the control law. This is formulated as a non-linear optimisation problem, where the objective is to minimise the use of control effort subject to the constraints, such as actuator rate and power constraints as well as other operational constraints. This paper presents the thrust allocation method for vessels equipped with azimuth thrusters, where the non-linear constrained allocation problem has been solved by the sequential quadratic programming (SQP) method. Simulation results are presented for a semi-submersible, where constraint compliance has been satisfactorily achieved.

关键词： thrust allocation azimuth thrusters dynamic positioning sequential quadratic programming method non-linear constrained optimisation

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