• Title/Summary/Keyword: tip position control

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Tip position control of translational 1-link flexible arm with tip mass (Tip mass를 갖는 병진운동 1-링크 탄성암 선단의 위치제어)

  • 이영춘;방두열;이성철
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.1036-1041
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    • 1993
  • The tip of the flexible robot arm has to be controlled by the active control reducing vibration because it has residual vibration after getting to desired position. This paper presents an end-point position control of a 1-link flexible robot arm having tip mass by the PID control algorithm. The system is composed of a flexible arm with tip mass, dc servomotor and ballscrew mechanism under translational motion. The feedback signal composed of the tip displacement measured by laser sensor, estimated velocity and acceleration is used to control the base motion. Theoretical results are obtained by applying the Laplace transform and the numerical inversion method to the governing equations. After the flexible robot arm reaches to. the desired position, the residual vibration is controlled by the PID algorithm. This paper gives the simulation and experimental results of end-point responses according to changing tip-mass and arm length. And this algorithm shows good effects of reducing the residual vibration. Approximately, theoretical response is in good agreement with experimental one.

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Tip Position Control of a Flexible Cantilever Based on Kalman Estimation Using an Accelerometer (가속도계를 이용한 칼만 추정 기반의 유연 외팔보의 종단 제어)

  • Kim, Gook-Hwan;Lee, Soon-Geul
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.5
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    • pp.591-598
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    • 2011
  • Tip position control of a flexible cantilever is difficult due to the non-minimum phase dynamics that result from the finite propagating speed of a mechanical wave along the cantilever. In this paper, we propose a method for the tip position control using a light and cheap accelerometer that does not bring any significant change to the dynamics of the cantilever system. The linear system identification model of the flexible cantilever is obtained with measurements by a laser displacement sensor. A Kalman estimator is designed with this model and calculates the estimated tip position with the acceleration data of the accelerometer that is attached on the tip of the cantilever. To verify reliability of the estimator, the estimated tip position is used to the feedback control system that uses a fuzzy logic controller. The control results are compared with those of the fuzzy control system where the real tip position is measured by a laser displacement sensor. Also, the performance of the estimator with the accelerometer is presented and discussed.

Tip Position Control of Flexible Robot Manipulators Using 2-DOF Controller with Sliding Mode (슬라이딩 모드를 가진 2-자유도 제어기를 이용한 유연한 로봇 조작기의 끝점 위치 제어)

  • 신효필;이종광;강이석
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.6
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    • pp.471-477
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    • 2000
  • The position control accuracy of a robot arm is significantly deteriorated when a long arm robot is operated at a high speed. In this case, the robot arm must be modeled as a flexible structure, not a rigid one, and its control system should be designed with its elastic modes taken into account. In this paper, the tip position control scheme of a one-link flexible manipulator using 2-DOF controller with sliding mode is presented. The robot consists of a flexible arm manufactured with a thin aluminium plate, an AC servo motor with a harmonic drive for speed reduction, an optical encoder and a CCD camera as a vision sensor for on-line measuring the tip deflection of the flexible m. Simulation and experimental results of the flexible manipulator with a proposed controller are provided to show the effectiveness of the controller.

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Fuzzy Algorithm에 의한 1-링크 탄성 로보트 Arm 선단의 위치제어

  • 양길태;이영춘;이성철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.10a
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    • pp.149-153
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    • 2001
  • This paper presents an end-point control of 1-link flexible arm tip-mass by using fuzzy position control algorithm. The arm is mounted on a translational mechanism driven by a ballscrew, whose rotation is controlled by a DC servomotor. Tip position is controlled so that it follows a desired position. Feedback signal is composed of both tip displacement error and change of error. This paper gives tip responses according to the variations of tip-mass and beam length, and the effects of reducing the residual vibrations occurring at the end-point. In the case of the residual vibrations of tip displacement, fuzzy control has better results than the PD-control.

A Study on the Bucket Tip's Position Control for the Intelligent Excavation System (지능형 굴삭 시스템의 버킷 끝단 위치제어에 관한 연구)

  • Kim, K.Y.;Jang, D.S.;Ahn, H.S.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.5 no.4
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    • pp.32-37
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    • 2008
  • For the bucket tip position control of the excavator, a traditional hydraulic excavator system was exchanged into an electro-hydraulic one. EPPR valves are attached to the traditional MCV and hydraulic joysticks are replaced by electronic ones to develop the electro-hydraulic system. To control the electronic pump with a good performance, the control logic for the pump is deduced from the AMESim simulation and the experimental method on the test bench. To get a good position control performance of the excavator bucket tip, PI+AntiWindup controller is selected as a position controller. The experimental results showed the good controllability for the electro-hydraulic excavator system on the test bench.

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Tip Position Control of a Robot Manipulator using Visual Markers (영상표식 기반의 로봇 매니퓰레이터 끝점 위치 제어)

  • Lim, Sei-Jun;Lim, Hyun;Lee, Young-Sam
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.9
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    • pp.883-890
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    • 2010
  • This paper proposes tip position control system which uses a visual marker to determine the tip position of a robot manipulator. The main idea of this paper is to introduce visual marker for the tracking control of a robot manipulator. Existing researches utilize stationary markers to get pattern information from them. Unlike existing researches, we introduce visual markers to get the coordinates of them in addition to their pattern information. Markers need not be stationary and the extracted coordinate of markers are used as a reference trajectory for the tracking control of a robot manipulator. To build the proposed control scheme, we first obtain intrinsic parameters through camera calibration and evaluate their validity. Secondly, we present a procedure to obtain the relative coordinate of a visual marker with respect to a camera. Thirdly, we derive the equation for the kinematics of the SCORBOTER 4pc manipulator which we use for control of manipulator. Also, we provide a flow diagram of entire visual marker tracking system. The feasibility of the proposed scheme will be demonstrated through real experiments.

A Study on Position Recognition of Bucket Tip for Excavator (굴삭기의 버킷 끝단 위치인식에 관한 연구)

  • Kim, Jae Hoon;Bae, Jong Ho;Jung, Woo Yong
    • Journal of Drive and Control
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    • v.13 no.1
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    • pp.49-53
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    • 2016
  • The accurate calculation of bucket tip position has a large influence on showing the motion of an excavator on the display device of the excavator and controlling the excavator automatically. It is generally known that Inertial Measurement Unit (IMU) sensors are more accurate than accelerometer-based sensors while the boom, arm or bucket moves because additional forces beyond gravity add additional acceleration to the sensors. To prove the accuracy difference between the two types of sensors, a position recognition system using an accelerometer-based sensor and an IMU sensor is implemented on the excavator. The experimental results show that the system using the IMU sensor significantly reduces the position recognition error while bucket moves and additional force beyond gravity exists.

Tip Position Control of Flexible Manipulator Using Disturbance Estimator (외란 추정기를 이용한 유연 매니퓰레이터의 선단 위치제어)

  • 김상열;최승복
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11a
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    • pp.219-224
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    • 2001
  • An accurate tip position control of a single-link flexible manipulator subjected to torque disturbance is achieved by utilizing so called sliding mode controller with disturbance estimation (SMCDE). After formulating the governing equation of motion in the state 1pace representation, a stable sliding surface is designed via the LQR method. The SMCDE is then synthesized by integrating equivalent sliding mode controller with the disturbance estimator which is featured by an integrated average value of the imposed disturbance over a certain sampling period. The regulating tip motion of the flexible manipulator is evaluated by employing the proposed SMCDE.

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Experimental Evaluation of Neural Network Based Controllers for Tracking the Tip Position of Flexible-Link (신경회로망을 이용한 유연한 관절의 선단위치 tracking 제어기에 관한 실험적 평가)

  • 최부귀;이형기;박양수
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.6
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    • pp.738-746
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    • 1998
  • This paper presents a neural network-based adaptive controller for a single flexible-link. The control for feedback-error loaming of neural network is designed by using the re-definition approach. The neural network controllers are implemented on an single flexible-link experimental test-bed. The tip response is significantly improved and the vibrations of the flexible modes are damped very fast. Experimental and simulation results are presented of the proposed tip position tracking controllers over the conventional PD-type, passive controllers.

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Tip vibration control of a single-link flexible robot arm under translational motion

  • Lee, Seong-Cheol;Cheong, Hoon;Chonan, Seiji;Inooka, Hikaru
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10b
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    • pp.607-612
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    • 1992
  • This paper presents a tip position control of a single-link flexible arm with a payload by using closed loop control. The shifting problem of the arm from the initial position to desired position is considered by the variation of the displacement gain $G_{p}$ and velocity gain $G_{v}$. The system is composed of a flexible arm with payload, DC servomotor, and a ballscrew mechanism. The flexible arm is mounted on a mobile stage driven by a servomotor and ballscrew. As a result, the increase of the displacement and velocity gain respectively comes to the reduction of tip vibration. Theoretical results are approximately in good agreement with those obtained experimentally.y.y.

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