• Title/Summary/Keyword: nonlinear experiments

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The FEM Analysis of Membrane for LNG Storage Tank (LNG 저장탱크용 멤브레인 개발을 위한 유한요소해석)

  • Oh B.T.;Hong S.H.;Yoon I.S.;Kim Y.K.;Seo H.S.
    • Journal of the Korean Institute of Gas
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    • v.6 no.4 s.18
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    • pp.47-52
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    • 2002
  • Analytical studies have been performed to investigate the strength of the membrane and the reaction force at the anchor point. Using nonlinear FEM code and experiments, the stress analysis of the corrugated membrane related the cryogenic liquid pressure and thermal loading is performed to ensure the stability and fatigue strength of the membrane. This paper reports on the FEM results of membrane.

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Nonlinear Finite Element Analysis of Precast Pier Coping (프리캐스트 교각 코핑부의 비선형 유한요소해석)

  • Cheon, Ju-Hyoun;Kim, Tae-Hoon;Kim, Young-Jin;Shin, Hyun-Mock
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.153-154
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    • 2010
  • For completing an fully optimized and prefabricated substructure system of bridge, developing pier of precast segment PSC which equip the connection structure of shear resistance and precast foundation are conducted previously. Specimens of coping of bridge were developed and customized, and experiments were performed. The result of the experiment through the result from a reliable non-linear analysis program (RCAHEST) were compared and analyzed and evaluated the stability and ultimate behavior of coping of precast pier.

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Adaptive Robust Control for Robot Manipulator with the Uncertain Bound Estimation and Implementation (불확실성의 경계를 추정하는 로봇 매니퓰레이터의 적응견실제어기 설계 및 실험)

  • 한명철;하인철
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.4
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    • pp.312-316
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    • 2004
  • In this paper, it is presented an adaptive robust control system to implement real-time control of a robot manipulator. There are Quantitative or qualitative differences between a real robot manipulator and a robot modeling. In order to compensate these differences, uncertain factors are added to a robot modeling. The uncertain factors come from imperfect knowledge of system parameters, payload change, friction, external disturbance, etc. Also, uncertainty is often nonlinear and time-varying. In the proceeding work, we proposed a class of robust control of a robot manipulator and provided the stability analysis. In the work, we propose a class of adaptive robust control of robot manipulator with bound estimation. Through experiments, the proposed adaptive robust control scheme is proved to be an efficient control technique for real-time control of a robot system using DSP.

Dynamic decoupling and load desensitization of direct-drive robots by current feedback

  • Kim, Young-Tark;Asada, Haruhiko
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10b
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    • pp.1014-1017
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    • 1988
  • Direct-drive robots have excellent features including no backlash, small friction, and high mechanical stiffness. However, dynamic coupling among joints as well as nonlinear effects become more prominent than traditional robots with reducers. Another critical issue is that the robot becomes more sensitive to the change of load. In this paper, we develop a simple current feedback scheme for reducing the influence of dynamic coupling and load sensitivity on the direct-drive robots. The method is implemented on a 2 d.o.f. planar direct-drive robot. Then the validity of the method is demonstrated through experiments.

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Fuzzy rule-based assembly algorithm for precision parts mating (퍼지규칙을 이용한 정밀부품 결합을 위한 조립알고리즘)

  • 박용길;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.693-698
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    • 1991
  • This paper describes a fuzzy rule-based assembly algorithm for precision parts mating, The difficulties in devising reliable assembly strategies result from the complexity of the assembly process and the uncertainty such as imperfect knowledge of the parts being assembled as well as the limitations of the devices performing the assembly. To cope with above problems, we propose an assembly algorithm utilizing fuzzy set theory. The presented method allows us to represent the uncertainty by using fuzzy membership function and treat nonlinear sapping from measured force/torque to corrective motions using rules. Finally, the performance of this method is evaluated through a series of experiments. Experimental results show that the proposed method can be effectively used for chamferless and precision parts mating.

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3-D position estimation for eye-in-hand robot vision

  • Jang, Won;Kim, Kyung-Jin;Chung, Myung-Jin;ZeungnamBien
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10b
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    • pp.832-836
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    • 1988
  • "Motion Stereo" is quite useful for visual guidance of the robot, but most range finding algorithms of motion stereo have suffered from poor accuracy due to the quantization noise and measurement error. In this paper, 3-D position estimation and refinement scheme is proposed, and its performance is discussed. The main concept of the approach is to consider the entire frame sequence at the same time rather than to consider the sequence as a pair of images. The experiments using real images have been performed under following conditions : hand-held camera, static object. The result demonstrate that the proposed nonlinear least-square estimation scheme provides reliable and fairly accurate 3-D position information for vision-based position control of robot. of robot.

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Decoupled Controller Design of an Autonomous Underwater Vehicle and Performance Test Results (수중운동체에 대한 비연성 제어기 설계 및 성능 평가)

  • Hyun, Chul
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.9
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    • pp.768-773
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    • 2013
  • In this paper, decoupled course, depth and roll controller design for an Autonomous Underwater Vehicle (AUV) and its performance test results are presented. Control system design is done using the PD control scheme based on a mathematical model of the AUV. Details of system implementation are given and the results of simulations and experiments using the prototype vehicle model are discussed. The designed controller was successfully applied to the nonlinear and coupled system under non-ideal actuator conditions.

Interpolation on data with multiple attributes by a neural network

  • Azumi, Hiroshi;Hiraoka, Kazuyuki;Mishima, Taketoshi
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.814-817
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    • 2002
  • High-dimensional data with two or more attributes are considered. A typical example of such data is face images of various individuals and expressions. In these cases, collecting a complete data set is often difficult since the number of combinations can be large. In the present study, we propose a method to interpolate data of missing combinations from other data. If this becomes possible, robust recognition of multiple attributes is expectable. The key of this subject is appropriate extraction of the similarity that the face images of same individual or same expression have. Bilinear model [1]has been proposed as a solution of this subjcet. However, experiments on application of bilinear model to classification of face images resulted in low performance [2]. In order to overcome the limit of bilinear model, in this research, a nonlinear model on a neural network is adopted and usefulness of this model is experimentally confirmed.

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Characteristics of Finite Difference Methods for the Shallow Water Equation (천수방정식의 유한차분 특성)

  • Lee, Kil Seong;Kang, Ju Whan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.1
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    • pp.41-52
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    • 1989
  • Numerical characteristics for the shallow water equation are analyzed with ADI, Hansen, Heaps, Richtmyer and MacCormack schemes. Stability, CPU time and accuracy are investigated for the linear model which has analytic solutions and circulation is simulated for the nonlinear model. The results show that ADI method has some defects in CPU time and accuracy for the computation of velocity. But ADI method simulates circulation well and has the largest stability region. Richtmyer scheme is the best among the other explicit schemes. Effective viscosity term is found to be essential for numerical experiments of the shallow water equation.

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A Study on Temperature Process Control of Electric Furnace (전기로 온도공정제어에 관한 연구)

  • 오진석;김윤식;오세준;최순만;신명철
    • Journal of Advanced Marine Engineering and Technology
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    • v.21 no.3
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    • pp.311-318
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    • 1997
  • In this paper, a controller with monitoring functions is proposed for controlling temperature of an electric furnace system. The controller includes holding and ramp control functions, and the control program for the temperature process monitor of the electric furnace. For this purpose, the implementation and performance of auto tuning algorithms in a computer¬based controller is studied in relation to control of a nonlinear electric furnace system which is characterized with large time delay. The communicator of a control and detection signals, between the controller and the electric furnace is implemented by an I/O data card. Experiments for the practical electric furnace are performed to illustrate the performance of the proposed controller.

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