Nanjing, China
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Wu L.,Nanjing University of Aeronautics and Astronautics | Wu L.,Nanhang Jincheng College | Sun Y.,Nanjing University of Aeronautics and Astronautics | Huang B.,Nanjing University of Aeronautics and Astronautics | And 2 more authors.
CGNCC 2016 - 2016 IEEE Chinese Guidance, Navigation and Control Conference | Year: 2016

This paper proposes a dynamic model and performance analysis method of hose-drogue aerial refueling system based on Kane equation by rigid multibody dynamics. In this method, the hose is divided into finite segment rigid joint of bars. To depict spatial state of each hose-bar, system generalized coordinates and generalized rates are defined. A set of multi-level recursive formulas and dynamic equations are derived to describe the dynamic properties of the hose-drogue under a prescribed motion of tanker. To calculate the external aerodynamic loads of each hose-bar, the effects of tanker wake, steady flow and atmospheric turbulence are considered. Numerical simulation results show a good correctness of the dynamic model by steady-state characteristics of the balance drag trajectory of hose-drogue in different flight conditions. Furthermore, the dynamic characteristics of the hose-drogue resulting from atmospheric turbulence are investigated. © 2016 IEEE.


Zhan L.,Nanhang Jincheng College | Ji X.,Nanhang Jincheng College
Proceedings - 2016 8th International Conference on Intelligent Human-Machine Systems and Cybernetics, IHMSC 2016 | Year: 2016

In this paper, An image fusion method based on Nonsnbsampled Contonrlet Transform (NSCT) is proposed. First, the CT and MR images are decomposed in mnlti-scale and mnlti-directional to get the low-pass snb-band and several band-pass snb-bands. For the low-pass snb-band, the fnsion method is based on the regional energy. For the band-pass snbbands, the fnsion method is based on the local standard deviation. Finally, the fnsed image will be obtained by the inverse NSCT. The resnlt proves that, compared with the similar research methods, the performance of the proposed method is better. © 2016 IEEE.


Ji X.,Nanhang Jincheng College
Proceedings - 2016 8th International Conference on Intelligent Human-Machine Systems and Cybernetics, IHMSC 2016 | Year: 2016

In this paper, a novel image fusion method of infrared image and SAR image is proposed combining Shearlet transform and sparse representation to avoid the disadvantages of Wavelet transform. The registered images are decomposed by the shearlet transform to obtain the low frequency subband and a series of high frequency subbands. The low frequency subband with lower sparseness is disposed with sparse representation, construct over complete dictionary, solve sparse coefficient over the trained dictionary, and choose the low frequency coefficients with the larger energy fusion rule. And the rule of gradient absolute value maximization is applied to the high frequency subbands. Then the fusion image is obtained by the inverse Shearlet transform. Experimental results show that the proposed method can retain good visual quality and objective evaluation index, and performs some related fusion approaches. © 2016 IEEE.


Zhao C.,Nanhang Jincheng College | Chen S.,Jiangsu University | Wang J.,Jiangsu University
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2015

The objective of this research was to supply theoretical bases for design and optimization of stiffness and damping parameters of active suspension system based on LQG control. Taking linear and nonlinear half car models with 4-degrees of freedom (DOF) as research examples respectively, influences of the above two parameters on active suspension system were analyzed through theoretical derivation and numerical simulation. Theoretical derivation about the linear model showed that the Ricatti Equation's solution of the active suspension system based on LQG had nothing to do with stiffness and damping parameters. Result came as that the time domain response of the active suspension system had nothing to do with stiffness and damping parameters. Numerical simulation about the linear model revealed that each integral force made up with stiffness force, damping one and active control one were independent of the other and invariable when stiffness and damping parameters were changed, and the global damping characteristics of the active control obviously became negative from positive with its parallel damping parameter increasing. As for the nonlinear car model in general, three steps, including linearizing the control system, designing LQG controller for the linearized control system, and de-linearizing in control implement, were executed to achieve the LQG controller for the nonlinear active suspension system. The design process showed that the integral forces were not influenced by stiffness and damping parameters, because their force actions were counteracted in the above linearizing and de-linearizing steps. Thus, the above results about the linear active suspension system were also true when the active suspension system was with nonlinear stiffness and damping characteristics. © 2015, Chinese Society of Agricultural Machinery. All right reserved.


Hufenqiao,NANHANG JINCHENG COLLEGE | Bin J.,Nanjing University of Aeronautics and Astronautics
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011 - Proceedings | Year: 2011

This paper considers the problem of actuator fault diagnosis for a class of systems with two kinds of uncertaintiesunstructured uncertainty and structured one. To detect the unknown fault signals, the observer is designed for a system augmented by a dynamical model of the fault signals. It is well-known that sliding mode observers designed for systems with matched uncertainty require an upper bound to be known exactly. To remove this requirement, a novel sliding mode observer is proposed. The novelty lies in the mechanism introduced to update the sliding mode observer gain for counteracting uncertainty. As a result, the knowledge of its upper bound is not required. It is proved that the observer can guarantee the state estimation error convergent asymptotically. Finally, a simulation study of an aircraft system is presented to show the effectiveness of the proposed scheme. © 2011 IEEE.


Sun J.,Nanjing University of Aeronautics and Astronautics | You Y.,Nanjing University of Aeronautics and Astronautics | Li Y.,Nanjing University of Aeronautics and Astronautics | Yang X.,Nanjing University of Aeronautics and Astronautics | Suin J.,Nanhang Jincheng College
2016 IEEE International Conference on Mechatronics and Automation, IEEE ICMA 2016 | Year: 2016

The on-line identification of the moment of inertia is researched, in order to improve the performance of servo system. The identification of the moment of inertia based on the recursive forgetting factor least squares(RFFLS), gradient descent (GDM)and model reference adaptive (MRA)methods is designed respectively. And the advantages and disadvantages of the three methods are summarized. The factors affecting the identification accuracy of the algorithm and convergence time are studied by simulation experiment. In physical experiment, the estimated values of RFFLS and GDM converge faster, but they have obviously oscillation. The estimated value of MRA converges slowly, but it has little oscillation. The estimated errors in steady state of RFFLS, GMD and MRA are 11%,24%and 10%. In order to reduce the estimated errors, the friction obtained by friction model is applied to the identification of the moment of inertia. The effectiveness of this method is demonstrated by experimental results. © 2016 IEEE.


Yin J.,Nanhang Jincheng College | Yin J.,Nanjing University of Aeronautics and Astronautics | Luo F.,Nanjing University of Aeronautics and Astronautics
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2014

To solve the problem that the motion time calculated from acceleration and deceleration control before interpolation control in CNC system, on the basis of continuous time velocity profiles and the principles of displacement equivalent transformation, an algorithm for the generation of periodic discrete velocity profiles was proposed, whose motion time fited into an integral number of interpolation periods. The feedrate computational formulae for each interpolation period of different acceleration and deceleration phases were deduced in detail in cases where both start speed and end speed were any desired positive real number. The proposed method did not need variant interpolation periods and it was easy to apply in traditional servo motion control system. The interpolation instance shows it is able to generate such velocity profile that the constant speed is strictly equal to instruction speed and guarantees the velocity at the segment terminal to be the specified speed. In addition, it has high motion efficiency and interpolation accuracy. ©, 2014, China Mechanical Engineering Magazine Office. All right reserved.


Luo F.,Nanjing University of Aeronautics and Astronautics | You Y.,Nanjing University of Aeronautics and Astronautics | Yin J.,Nanhang Jincheng College
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2012

The first or the second order Taylor expansion is an usual approach for NURBS curve iterative interpolation. The approach always resulted in chord errors and consequent feedrate fluctuation and motion impact. Therefore, after analyzing the three reasons that cause Taylor-expansion-based interpolation errors, an improved approach was proposed to deriving accurate interpolation points by means of search neighborhood determination and binary interpolation search based on the first Taylor expansion. The proposed approach made full use of both origin accuracy of the first Taylor expansion and the local linear characteristics of NURBS curve. The interpolation test shows the average relative displacement error is decreased to 6.46×10 -11. Moreover, the search times are no more than three in every interpolation period. Thus, feedrate fluctuation is greatly suppressed and high speed and high stability machining is realized.


Li H.,Nanjing University of Aeronautics and Astronautics | Zhou J.,Nanjing University of Aeronautics and Astronautics | Tan J.,Nanhang Jincheng College | Wang F.,Nanjing University of Aeronautics and Astronautics
Shuju Caiji Yu Chuli/Journal of Data Acquisition and Processing | Year: 2014

A multi-objective particle swarm optimization (MOPSO) with an initial non-inferior solution from maximizing directivities of conformal antenna array is proposed to get Pareto optimal solutions for desired multi-beam and low sidelobes. The proposed algorithm first uses multi-objective decomposition strategy to get a non-inferior solution by the weighted linear combination of multiple single-beam optimal solution. Then, the local search strategy based on the particle space and target space constraints at the same time in MOPSO is designed to achieve optimization of multi-beam and sidelobes. Results indicate that the approach can effectively get Pareto optimal solutions for multi-beam forming with low sidelobes of the satellite conformal array antenna.


Lu R.,Nanjing University of Aeronautics and Astronautics | Lu R.,Nanhang Jincheng College | Li N.,Nanjing University of Aeronautics and Astronautics
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2016

In this paper we study closed-loop supply chain models for an electronic product which is featured with a short life-cycle and price depending on rand demand. We focus on the manufacturer's choice of two take-back channel structures in retailer competing settings: the manufacturer collects the used products directly and the retailers collect the used products for the manufacturer. We characterize and compare the retailers' sale price and profit of the manufacturer under the two take-back channel structures, and get the manufacturer's optimal take-back channel selection. We also develop some extensions to the model. We find that if the collection rate is exogenous, then the retailers are the effective undertakers of the product collection activity for the manufacturer, and the competitive interaction between the retailers do not affect the manufacturer's reverse channel structure selection. This result is generally robust no matter whether the quantity of collected used products is a fraction of the retailers' order quantity from the manufacturer or sales quantity in the regular season and no matter whether the salvage value of the unsold products is zero or not. We also find that if the collection rate is endogenous, then the reverse channel structure with retailer collecting is better to the manufacturer only if the retailers collect all their ordered products. © 2016, Editorial Board of Journal of Systems Engineering Society of China. All right reserved.

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