• Title/Summary/Keyword: Sway Length

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Fuzzy Nonlinear Adaptive Control of Overhead Cranes for Anti-Sway Trajectory Tracking and High-Speed Hoisting Motion (고속 권상운동과 흔들림억제 궤적추종을 위한 천정주행 크레인의 퍼지 비선형 적응제어)

  • Park, Mun-Soo;Chwa, Dong-Kyoung;Hong, Suk-Kyo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.5
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    • pp.582-590
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    • 2007
  • Nonlinear adaptive control of overhead cranes is investigated for anti-sway trajectory tracking with high-speed hoisting motion. The sway dynamics of two dimensional underactuated overhead cranes is heavily coupled with the trolley acceleration, hoisting rope length, and the hoisting velocity which is an obstacle in the design of decoupling control based anti-sway trajectory tracking control law To cope with this obstacle. we propose a fuzzy nonlinear adaptive anti-sway trajectory tracking control law guaranteeing the uniform ultimate boundedness of the sway dynamics even in the presence of uncertainties in such a way that it cancels the effect of the trolley acceleration and hoisting velocity on the sway dynamics. In particular. system uncertainties, including system parameter uncertainty unmodelled dynamics, and external disturbances, are compensated in an adaptive manner by utilizing fuzzy uncertainty observers. Accordingly, the ultimate bound of the tracking errors and the sway angle decrease to zero when the fuzzy approximation errors decrease to zero. Finally, numerical simulations are performed to confirm the effectiveness of the proposed scheme.

Anti-sway Control for Crane System Using Two Degree of Freedom Servo Controller (2자유도 서보제어기를 이용한 크레인의 Anti-sway 제어)

  • 이진우;여태경;김환성;김상봉
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.555-558
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    • 1995
  • In designing the anti-sway controller for crane system in the industrial field, one of the basic problem is to keep the stability of system, even if the mathematical model of the plant is not exact and disturbance exists. Form this point of view, a two-degree-of-freedom(2DOF) servo controller effact to the system in which the integral compensation is effctive only when a modeling error and/or a disturbance input exist. In this paper, the change of load weight and variation of wire rope length considered as the structured uncertainty, and design the 2DOF servo contorller using independently the informations of reference signal and control output with both feedforward and feedback. The effectivenss is proved through the results for the anti-sway system in the system with the position control of trolley.

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Investigation of postural sway characteristics of patients after total hip replacement (인공 고관절시술자환자의 중심동요 특성에 관한 연구)

  • 강창수;신승헌;민병우
    • Journal of the Ergonomics Society of Korea
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    • v.14 no.2
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    • pp.87-104
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    • 1995
  • This research investigates the possibility of using the postural sway of patients as a reference for measruing the progress of the disease and healing of patients who received total hip replacement; the progress of the disease by X-ray pictures, the pain felt by the patients, and the difficulties encountered in moving the joints. The measurements on the force platform were taken during a 25 second period standing on both feet and during a 5 second period standing on one foot with both eyes open. The result of the research showed that the trace and area of the overall length of postural sway was a good indicator which represented the healing progress of the patients who received total hip replacement, and the weakening of the muscles and the recovery process for 3 or 4 month after receiving the operation, which did not appear on X-ray pictures, were exhibited on the postural sway. Finally, standing on a single foot represented the healing progress much better than standing on both feet.

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Position Control of the Trolley and Spreader Using Pole-placement Method (극점배치기법을 이용한 트롤리 및 스프레더의 위치제어)

  • Lee, Tae-Young;Kim, Myun-Hee;Choi, Won-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.2
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    • pp.165-172
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    • 1999
  • Crane operation for transporting heavy loads causes swinging motion at the loads. This sway causes the suspension ropes to leave their grooves and leads to possibility of serious damages. Generally crane is operated by expert's knowledge. Therefore, a satisfactory control method to supress object sway during transport is indispensible. The dynamic behavior of the crane shows nonlinear characteristics. when the length of the rope is changed the crane is time varying system and the design of anti-sway controller is very difficult. In this paper, the nonlinear dynamic model for the industrial overhead crane is derived. and the feedback gain matrix based on the pole-placement method is proposed to supress the swing motion and control the position of the crane. The performance of the controller for the crane model is simulated on the personal computer.

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The effect of whole body vibration training on postural sway in patients with spinal cord injury: a pilot study

  • Asakawa, Yasuyoshi;Lee, Myung-Mo;Song, Chang-Ho
    • Physical Therapy Rehabilitation Science
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    • v.2 no.2
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    • pp.70-74
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    • 2013
  • Objective: The aim of this study was to determine the impact of the application of whole body vibration training (WBV) on the balance ability of patients with an American Spinal Injury Association (ASIA) type C or D spinal cord injury. Design: Randomized controlled trial. Methods: Twelve patients with spinal cord injury were enrolled in this study. The participants were randomized to an experimental group (n=6) or control group (n=6). The subjects in the experimental group received WBV exercise and the control group received the sham exercise without vibration. The vibrations were adjusted vertically to the patient at a 30 Hz frequency and 3 mm amplitude. The whole body vibration lasted for 16 minutes in total including 5-minutes warm-up and cool-down at the beginning and end of the program, respectively. The static sitting balance ability was assessed by measuring the postural sway while sitting on the force plate with the eyes opened or closed. Postural sway length was measured for 30 seconds with a self-selected comfortable position. Results: In the static balance test, the anterio-posterior, medio-lateral, and total postural sway length with the eyes open and closed was improved significantly before and after the intervention in the experimental group (p<0.05). The experimental group showed significantly more improvement than the control group (p<0.05). Conclusions: Our results demonstrated that WBV training has a positive effect on improving static sitting balance and enhanced control of postural sway in patients with an ASIA-C or D type spinal cord injury.

Anti-Sway Control System Design for the Container Crane

  • An, Sang-Back;Kim, Young-Bok;Kang, Gi-Bong;Zhai, Guisheng
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1404-1409
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    • 2003
  • The sway control problem of the pendulum motion of the container crane hanging on the trolley, which transports containers from the container ship to the truck, is considered in this paper. In the container crane control problem, the main issue is to suppress the residual swing motion of the container at the end of the acceleration, deceleration or the case of that the unexpected disturbance input exists. For this problem, in general, the trolley motion control strategy is introduced and applied to real plants. In this paper, we suggest a new type of swing motion control system for a crane system in which a small auxiliary mass is installed on the spreader. The actuator reacting against the auxiliary mass applies inertial control forces to the spreader of the container crane to reduce the swing motion in the desired manner. In this paper, we consider that the length of the rope varies is we design the anti-sway control system based on LMI(linear matrix inequality) approach. And, it will be shown that the proposed control strategy is useful and it can be easily applicable to the real world. So, in this study, we investigate usefulness of the proposed anti-sway system and evaluate system performance from simulation and experimental studies.

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Sway Control of a Container Crane ( Part I ) : Modeling, Control Strategy, Error Feedback Control Via Reference Velocity Profiles (컨테이너 크레인의 흔들림 제어 ( Part I ) : 모델링, 제어전략, 기준선도를 통한 오차 피이드백 제어)

  • Hong, Keum-Shik;Sohn, Sung-Chull;Lee, Man-Hyung
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.1
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    • pp.23-31
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    • 1997
  • The sway control problem of pendulum motion of a container hanging on a Portainer Crane, which transports containers from a container ship to trucks, is considered in the paper. The equations of motion are obtained through the Lagrange mechanics and simplified for control purposes. Considering that the fast traveling of trolley and no residual swing motion of the container at the end of acceleration and deceleration are crucial for quick transportation, several velocity patterns of trolley movement including the time-optimal control are investigated. Incorporating the change of rope length, a reference swing trajectory is introduced in the control loop and the error signal between the reference sway angle and the measured sway angle is feedbacked. Proposed control strategy is shown to be robust to disturbances like winds and initial sway motion.

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Anti-sway and Position 3D Control of the Nonlinear Crane System using Fuzzy Algorithm

  • Lee, Tae-Young;Lee, Sang-Ryong
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.1
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    • pp.66-75
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    • 2002
  • The crane operation used fur transporting heavy loads causes a swinging motion with the loads due to the crane\`s acceleration and deceleration. This sway causes the suspension ropes to leave their grooves and can cause serious damage. Ideally, the purpose of a crane system is to transport loads to a goal position as soon as possible without any oscillation of the rope. Currently, cranes are generally operated based on expert knowledge alone, accordingly, the development of a satisfactory control method that can efficiently suppress object sway during transport is essential. The dynamic behavior of a crane shows nonlinear characteristics. When the length of the rope is changed, a crane becomes a time-varying system thus the design of an anti-sway controller is very difficult. In this paper, a nonlinear dynamic model is derived for an industrial overhead crane whose girder, trolley, and hoister move simultaneously. Furthermore, a fuzzy logic controller, based on expert experiments during acceleration, constant velocity, deceleration, and stop position periods is proposed to suppress the swing motion and control the position of the crane. Computer simulation is then used to test the performance of the fuzzy controller with the nonlinear crane model.

Correlation Analysis between Postural Sway and Kinematics Variables of Putter Head during Golf Putting (골프 퍼팅 시 자세 흔들림과 퍼터 헤드의 운동학적 변인 간 상관성 분석)

  • Lee, Jae-Woo;Kwon, Moon-Seok;Park, Jun-Sung;Lim, Young-Tae
    • Korean Journal of Applied Biomechanics
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    • v.30 no.3
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    • pp.217-223
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    • 2020
  • Objective: The purpose of this study was to analyze the effect of postural sway on the kinematic variables of the putter head during golf putting and to provide information to the importance of postural sway control in the putting stroke for novice golfers. Method: The center of pressure (CoP) and Kinematics variables of the putter head were calculated during 2 m flat golf putting using 8 motion capture cameras (250 Hz) and 2 force plate (1,000 Hz). SPSS 24.0 was used to perform Pearson's correlation coefficient and simple regression analysis, and the statistically significance level was set to .05. Results: As a result of analyzing the correlation between CoP variables and the putter head rotation angle, the CoP moving length, CoP moving range (ML direction), and CoP moving velocity (ML direction) showed a positive correlation with the putter head rotation angle (yaw axis) and were statistically significant. Conclusion: Therefore, In order to perform the accurate putting stroke maintaining the ball's directionality, it is determined that it is important to control posture sway in the ML directions by minimizing the movement and velocity of the CoP.

Anti-sway and 3D position Control of the Nonlinear Crane System using Fuzzy Algorithm (퍼지 알고리즘을 이용한 비선형 크레인 시스템의 진동방지 및 3차원 위치제어)

  • Lee, Tae-Young;Lee, Sang-Ryong
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.8
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    • pp.193-202
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    • 1999
  • Crane operation for transporting heavy loads causes swinging motion at the loads due to crane's acceleration and deceleration. This sway causes the suspension ropes to leave their grooves and leads to possibility of serious damages. So, this swing of the objects is a serious problem and the goal of crane system is transporting to a goal position as soon as possible without the oscillation of the rope. Generally crane is operated by expert's knowledge. Therefore, a satisfactory control method to supress object sway during transport is indispensible. The dynamic behavior of the crane shows nonlinear characteristics. when the length of the rope is changed the crane is time varying system and the design of anti-sway controller is very difficult. In this paper, the nonlinear dynamic model for the industrial overhead crane whose girder, trolley and hoister move simultaneously is derived. and the Fuzzy logic controller based on the expert experiments during acceleration, constant velocity, deceleration and stop position period is proposed to supress the swing motion and control the position of the crane. The performance of the fuzzy controller for the nonlinear crane model is simulated on the personal computer.

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