• Title/Summary/Keyword: decouple method

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DECOUPLING OF MULTI-INPUT MULTI-OUTPYT TWO DIMENSIONAL SYSTEMS

  • Kawakami, Atsushi
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.1130-1134
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    • 1990
  • In this paper, we propose a mthod to decouple the multi-input multi-output two-dimensional system. Then, we analyze the realization dimension of the feedback, feedforward given to decouple. Moreover, we consider the possibility of the reduction of the dynamical dimension needed to decouple. Besides, in order to stabilize the decoupled two-dimensional system, we suggest a method to assign the poles of each entry of the transfer function matrix to the desired positions.

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Fringe-Order Determination Method in White-Light Phase-Shifting Interferometry for the Compensation of the Phase Delay and the Suppression of Excessive Phase Unwrapping

  • Kim, SeongRyong;Kim, JungHwan;Pahk, HeuiJae
    • Journal of the Optical Society of Korea
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    • v.17 no.5
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    • pp.415-422
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    • 2013
  • White-light phase-shifting interferometry (WLPSI) is widely recognized as a standard method to measure shapes with high resolution over a long distance. In practical applications, WLPSI, however, is associated with some degree of ambiguity of its phase, which occurs due to a phase delay, which is the offset between the phase of the fringes and the fringe envelope peak position. In this paper, a new algorithm is proposed for the determination of a fringe order suitable for samples in which the phase delay mainly occurs due to noise, diffraction and a steep angle. The concepts of the decouple factor and the connectivity are introduced and a method for calculating the decouple factor and the connectivity is developed. With the phase-unwrapping procedure which considers these values, it is demonstrated that our algorithm determines the correct fringe order. To verify the performance of the algorithm, a simulation was performed with the virtual step height under noise. Some specimens such as step height standard and a column spacer with a steep angle are also measured with a Mirau interference microscope, after which the algorithm is shown to be effective and robust.

ANALYSIS OF SOME PROJECTION METHODS FOR THE INCOMPRESSIBLE FLUIDS WITH MICROSTRUCTURE

  • Jiang, Yao-Lin;Yang, Yun-Bo
    • Journal of the Korean Mathematical Society
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    • v.55 no.2
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    • pp.471-506
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    • 2018
  • In this article, some projection methods (or fractional-step methods) are proposed and analyzed for the micropolar Navier-Stokes equations (MNSE). These methods allow us to decouple the MNSE system into two sub-problems at each timestep, one is the linear and angular velocities system, the other is the pressure system. Both first-order and second-order projection methods are considered. For the classical first-order projection scheme, the stability and error estimates for the linear and angular velocities and the pressure are established rigorously. In addition, a modified first-order projection scheme which leads to some improved error estimates is also proposed and analyzed. We also present the second-order projection method which is unconditionally stable. Ample numerical experiments are performed to confirm the theoretical predictions and demonstrate the efficiency of the methods.

Idle Vibration Development Procedure of 4WD SUV (SUV차량의 Idle 성능 개발)

  • 최승우;이남영
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.120-124
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    • 2003
  • NVH issue at idle condition is one of the major concerns of Passenger and Commercial Vehicle including Sports Utility Vehicle Especially steering wheel vibration at idle condition is a very complex problem and affected by firing frequency of the engine, stiffness of a steering wheel system and the body to which the steering wheel system is attached. To avoid vibration mode coupling between each system of a vehicle, experimental and analytical method has been used at the pre-prototype stage. The resonance frequency of the body and the frame has been decoupled by CAE and the resonance frequency of steering wheel system has been set in between the 1st bending frequency of body and frame. These Results has been used as design guidelines tot the prototype drawing stage. The experimental verification of tile modified pre-prototype vehicle shows good results of the vibration mode decouple. Modal test of prototype vehicle also confirms the vibration mode decouple between each system.

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Decoupling Control of Levitation and Thrust Motion of The Transverse Flux Linear Induction Motor Using DC-biased Multi Phase Inputs (DC 편의된 다상 입력을 이용한 횡자속 선형 유도 전동기의 부상/추진 독립제어)

  • Jung, Kwang-Suk;Huh, Jin-Hyuk;Baek, Yoon-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.11
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    • pp.1733-1740
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    • 2004
  • In the transverse flux linear induction motor(TFLIM) with the general secondary composed of conductor and back-yoke, there exists a magnetized force into the normal direction or the air-gap direction of the thrust motion as well as the thrust force. Therefore, the various methodologies have been tried to use the normal force by the two independent control variables of the multi-phase input. But, as the force depends inevitably and strongly on the thrust force, it is essential to decouple both forces for two control index. In this paper, we suggest a novel approach capable of compensating the couple between both forces and the control index by using the DC-biased multi-phase input, and then realizing the independent control of TFLIM.

Analysis of Stress Intensity Factors for Circular arc Cracks by Boundary Element Method (경계요소법에 의한 아크균열의 응력확대계수 해석)

  • 백열선;이장규;우창기
    • Journal of the Korean Society of Safety
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    • v.14 no.4
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    • pp.28-36
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    • 1999
  • In this paper, A circular arc crackered plate in biaxially stretched sheets was investigated in the boundary element method. The applications of fracture mechanics have traditionally concentrated on crack problems under an mode I, straight crack. However, many service failures occur from growth of cracks subjected to mixed mode loadings. A rectangular plate with arc crack or slanted central crack, under biaxial tensile loading, was treated analytically and also solved numerically. The Results from BEM applying different loading conditions, crack length (a/W), arc angle($\alpha$) are presented and discussed. The stress intensity factors are evaluated by the techniques of the J-integral. The decomposition method, used to decouple the stress intensity factors in mixed mode problems, is implemented by a considering a small circular contour path around each crack tip. The BIE method was successfully applied to a circular arc crackerd plate problem, also slanted centre cracked plate under mixed mode.

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Determination of Camera System Orientation and Translation in Cartesian Coordinate (직교 좌표에서 카메라 시스템의 방향과 위치 결정)

  • 이용중
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.04a
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    • pp.109-114
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    • 2000
  • A new method for the determination of camera system rotation and translation from in 3-D space using recursive least square method is presented in this paper. With this method, the calculation of the equation is found by a linear algorithm. Where the equation are either given or be obtained by solving five or more point correspondences. Good results can be obtained in the presence if more than the eight point. A main advantage of this new method is that it decouple rotation and translation, and then reduces computation. With respect to error in the solution point number in the input image data, adding one more feature correspondence to required minimum number improves the solution accuracy drastically. However, further increase in the number of feature correspondence improve the solution accuracy only slowly. The algorithm proposed by this paper is used to make camera system rotation and translation easy to recognize even when camera system attached at end effecter of six degrees of freedom industrial robot manipulator are applied industrial field.

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Analysis for Noise on PCB due to External Electromagnetic-Wave Penetration (외부 전자파에 의해 발생하는 PCB 상의 노이즈 해석)

  • Han, Seung-Moon;Hwang, Sun-Mook;Huh, Chang-Su;Seo, Yu-Jin;Choi, Jin-Su
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.1416-1417
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    • 2008
  • External electromagnetic penetration occurs hazard effects on electronic and electrical systems. complementary full wave analysis method need much of analysis time, memory. But BLT method need less time, memory. BLT method need to decouple the system into each volumes and surfaces for setting tubes and junctions. When 1 V/m impulsive EMP noise penetrates into PCB strip line(w=2mm, L=6cm), ringing wave appears at each loads attached in strip-line. Its frequency is 91.8MHz.

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Design Sensitivity Analysis and Topology Optimization of Piezoelectric Crystal Resonators (압전 수정진동자의 설계민감도 해석과 위상 최적설계)

  • Ha Youn-Doh;Cho Seon-Ho;Jung Sang-Sub
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.335-342
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    • 2005
  • Using higher order Mindlin plates and piezoelectric materials, eigenvalue problems are considered. Since piezoelectric crystal resonators produce a proper amount of electric signal for a thickness-shear frequency, the objective is to decouple the thickness-shear mode from the others. Design variables are the bulk material densities corresponding to the mass of masking plates for electrodes. The design sensitivity expressions for the thickness-shear frequency and mode shape vector are derived using direct differentiation method(DDM). Using the developed design sensitivity analysis (DSA) method, we formulate a topology optimization problem whose objective function is to maximize the thickness-shear component of strain energy density at the thickness-shear mode. Constraints are the allowable volume and area of masking plate. Numerical examples show that the optimal design yields an improved mode shape and thickness-shear energy.

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LCC Optimization for Reinforced Concrete Structures under Seismic Hazards

  • Park, Soon-Kyu
    • KCI Concrete Journal
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    • v.13 no.2
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    • pp.26-32
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    • 2001
  • A simple expected damage cost model is developed and a systematic approach to evaluate the economic effects of seismic hazards to reinforced concrete structures is presented. An expected damage cost function during a specific lifetime is modeled by a Poisson's process with uniform continuous cash flow assumption. It is possible that the proposed method can decouple the damage cost effect from random earthquake events. Thus, expected damage cost function can be formulated as a combination of three independent terms; a present worth factor of Poisson's process, a damage cost interpolation function and a mean occurrence rate of earthquake intensity. The validity of the proposed method is demonstrated by a comparative study of LCC evaluations with the previous study.

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