• Title/Summary/Keyword: Rotational Motion Mode1

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Deployment or Retraction of Beam with Large Rotational Motion (대각 선회하는 보의 전개 및 수납)

  • 김상원;김지환
    • Journal of KSNVE
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    • v.11 no.1
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    • pp.111-117
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    • 2001
  • Present work deals with a study on the deployment or retraction of cantilever beam that includes the rigid-body motion of large displacement of beam through the translational and rotational motions in 2-dimensional plane. The equations of motion are derived with respect to non-Cartesian coordinate system. In the formulation of equations of motion, shear deformations and geometrically non-linear effect are included. An assumed mode method is applied and numerical convergence characteristics are studied also. Types of motion of the moving beam are assumed to be classified as‘slow’or‘fast’motion, and the dynamic characteristics are investigated.

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Hybrid Position/Force Control of a 3-D Rehabilitation Robot System for Upper Extremities (상지 재활을 위한 3-D 로봇 시스템의 혼합 위치/힘 제어)

  • Lee, Soo-Han;Shin, Kyu-Hyeon
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.5
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    • pp.599-605
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    • 2011
  • A 3-D rehabilitation robot system is developed. The robot system is for the rehabilitation of upper extremities, especially the shoulder and elbow joints, and has 3-D workspace for occupational therapy to recover physical functions in activities of daily living(ADL). The rehabilitation robot system has 1 DOF in horizontal rotational motion and 2 DOF in vertical rotational motion, where all actuators are set on the ground. Parallelogram linkage mechanisms lower the equivalent inertia of the control elements as well as control forces. Also the mechanisms have high mechanical rigidity for the end effector and the handle. In this paper, a hybrid position/force controller is used for controlling positions and forces simultaneously The controller is tuned according to the robot posture. The active motion modes for rehabilitation program consist of active-resisted motion mode and active-free motion mode. The results of the experiments show that the proposed motion modes provide the intended forces effectively.

Development of a 3-D Rehabilitation Robot System for Upper Extremities (상지 재활을 위한 3-D 로봇 시스템의 개발)

  • Shin, Kyu-Hyeon;Lee, Soo-Han
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.4
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    • pp.64-71
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    • 2009
  • A 3-D rehabilitation robot system is developed in this paper. The robot system is for the rehabilitation of upper extremities, especially the shoulder and elbow joints, and has 3-D workspace for enabling occupational therapy to recover physical functions in activities of daily living(ADL). The rehabilitation robot system, which is driven by actuators, has 1 DOF in horizontal rotational motion and 2 DOF in vertical rotational motion, where all actuators are set on the ground. Parallelogram linkage mechanisms lower the equivalent inertia of the control elements as well as control forces. Also the mechanisms have high mechanical rigidity for the end effector and the handle. Passive motion mode experiments have been performed to evaluate the proposed robot system. The results of the experiments show and excellent performance in simulating spasticity of patients.

Motion of a System with Varying Damping Subject to Harmonic Force - Analytical Analysis (변화하는 감쇠를 갖는 계가 조화력을 받을 때의 운동 - 이론적 해석)

  • Park, O-Cheol;Lee, Gun-Myung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.898-902
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    • 2006
  • The motion of a system composed of a plate, constant springs and varying dampers is considered when the system is subject to harmonic force. Letting the frequencies of harmonic force and damper variation ${\Large f}_1\;and\;{\Large f}_2$ respectively, the displacement at the center of the plate has the strongest component at frequency ${\Large f}_1$. The angular displacement of the plate has strong components at ${\Large f}_1-{\Large f}_2$ and the natural frequency of the rotational mode of the system. If these two frequencies coincide, the plate oscillates with almost single frequency and a large amplitude. Part of these simulation results are proved analytically.

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Motion of a System with Varying Stiffness/Damping Subject to Harmonic Force (변화하는 강성/감쇠를 갖는 계가 조화력을 받을 때의 운동)

  • Lee, Gun-Myung;Park, O-Cheol
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.9 s.114
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    • pp.958-963
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    • 2006
  • The motion of a system composed of a plate, constant springs and varying dampers is considered when the system is subject to harmonic force. Letting the frequencies of harmonic force and damper variation $f_1\;and\;f_2$, respectively, the displacement at the center of the plate has the strongest component at frequency $f_1$. The angular displacement of the plate has strong components at $f_1-f_2$ and the natural frequency of the rotational mode of the system. If these two frequencies coincide, the plate oscillates with almost single frequency and a large amplitude. These results can be applied to development of a moment shaker with low frequencies.

Dynamic Modeling and Repulsive Force Control of Medical Hpatic Master (의료용 햅틱 마스터의 동적 모델링과 힘 반향 제어)

  • Oh, Jong-Seok;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.3
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    • pp.284-290
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    • 2012
  • In this research, a new type of haptic master device using electrorheological(ER) fluid for minimally invasive surgery(MIS) is devised and control performance of the proposed haptic master is evaluated. The proposed haptic master consists of ER bi-directional clutch/brake for 2 DOF rotational motion(X, Y) using gimbal structure and ER brake on the gripper for 1 DOF rotational motion (Z). Using Bingham characteristic of ER fluid and geometrical constraints, principal design variables of the haptic master are determined. Then, the generation of torque of the proposed master is experimentally evaluated as a function of applied field of voltage. A sliding mode controller which is robust to uncertainties is then designed and empirically realized. It has been demonstrated via experiment that the proposed haptic master associated with the controller can be effectively applied to MIS in real field conditions.

Molecular Vibrational Study of the Allosteric Effect in 2,2'-Bipyridyl Crown Ether (분자진동방법을 사용한 2, 2'-Bipyridyl Crown Ether 의 다른자리 입체성 효과에 관한 연구)

  • Wan Kyu Kim;Soon Ryang Chung
    • Journal of the Korean Chemical Society
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    • v.29 no.3
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    • pp.205-212
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    • 1985
  • By using the Mass-Weighted-Cartesian coordinate method, the allosteric effect of 2,2'-bipyridyl crown(4) ether is studied. The vibrational modes of 235, 234, 188, and 178cm$^{-1}$ belong to the pore opening motion of crown ether and those of 168, 104, and 67cm$^{-1}$ belong to the rotational vibration motion of bipyridyl. Especially the mode appearing at 178cm$^{-1}$ shows a large allosteric effect by activation of the allosteric site.

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Physicians' Requirement Analysis Based Design of the Master Device Mechanism for Teleoperated Interventional Robotic System (원격 중재시술용 마스터장치에 대한 의료진 요구분석 및 이를 반영한 메커니즘 설계)

  • Woo, Hyun Soo;Cho, Jang Ho;Lee, Hyuk Jin
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.8
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    • pp.603-609
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    • 2016
  • This paper presents an optimally designed master device mechanism for teleoperated interventional robotic system. The interventional procedures using the teleoperated robotic system and the physicians' requirements are summarized. The master device should implement 5-DOF motion including 2-DOF translational motion for the entry position control, 2-DOF rotational motion for the orientation control, and 1- DOF translational motion for needle insertion. The handle assembly includes a 1-DOF translational mechanism for needle insertion and buttons for operation mode selection. The mechanisms for the 2-DOF translational motion and the 2-DOF rotational motion are designed using motors and brakes based on the various mechanisms to satisfy all the above requirements, respectively. Absolute position sensors are adopted to implement automatic initial positioning and orientation matching at the first step of needle insertion.

Free vibration analysis of tall buildings with outrigger-belt truss system

  • Malekinejad, Mohsen;Rahgozar, Reza
    • Earthquakes and Structures
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    • v.2 no.1
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    • pp.89-107
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    • 2011
  • In this paper a simple mathematical model is presented for estimating the natural frequencies and corresponding mode shapes of a tall building with outrigger-belt truss system. For this purposes an equivalent continuum system is analyzed in which a tall building structure is replaced by an idealized cantilever continuum beam representing the structural characteristics. The equivalent system is comprised of a cantilever shear beam in parallel to a cantilever flexural beam that is constrained by a rotational spring at outrigger-belt truss location. The mathematical modeling and the derivation of the equation of motion are given for the cantilevers with identically paralleled and rotational spring. The equation of motion and the associated boundary conditions are analytically obtained by using Hamilton's variational principle. After obtaining non-trivial solution of the eigensystem, the resulting is used to determine the natural frequencies and associated mode shapes of free vibration analysis. A numerical example for a 40 story tall building has been solved with proposed method and finite element method. The results of the proposed mathematical model have good adaptation with those obtained from finite element analysis. Proposed model is practically suitable for quick evaluations during the preliminary design stages.

Vibration Analysis of a BEBTS(Built-in Eccentric Bearing-Torsional Spring) Type ABTU(Automatic Belt Tension Unit) (편심 베어링 - 비틀림 스프링 내장형 자동벨트 긴장장치의 진동해석)

  • Choe, Yeong-Hyu;An, Yeong-Deok;Jeong, Won-Ji
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.3
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    • pp.95-100
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    • 2002
  • Built-in Eccentric Bearing-Torsional Spring (BEBTS) type Automatic Belt Tension Unit (ABTU) is one of typical belt tension units. The BEBTS type ABTU system frequently experiences torsional vibration about its pivot due to the variation of belt tension. However, it is very difficult to analyze the rotational (or torsional) vibration of the ABTU because the exciting moment varies according to the change of belt tension. To get over this difficulty, in this paper. the ABTU was simplified as 1-DOF translational motion model in the tangential direction. Its equation of motion was derived and solved. The time history and frequency responses were computed and examined for three of BEBTS type ABTUs which are made by different manufacturers but the tame kind.