• 대한기계학회논문집A
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• 제26권9호
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• pp.1795-1805
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• 2002

A position controller which can achieve a specified dynamic performance irrespective of the different operating position of the pneumatic cylinder is proposed. The position controller developed in this paper is composed of a nonlinear compensator and a disturbance observer. The nonlinear compensator which feeds back position, velocity and acceleration is derived from the nonlinear dominating equations of the position control system to compensate for variation of dynamic characteristics of a pneumatic cylinder according to the change of the operating position. The disturbance observer including a simplified linear model is designed to reduce the effect of model discrepancy in the low frequency range which cannot be suppressed by the nonlinear compensator. The results of the experiments show that the position control performance maintains a designed performance regardless of the variations of an operating position of the pneumatic cylinder.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.913-916
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• 1990

In this paper, attempts have been made to control AC synchronous servo motor used as actuators of joints of the FARA robot with high dynamic performance and precise positioning. The AC synchronous servo motors used in FARA robots have resolves as position sensors. Resolver to digital converters are used in order to obtain the information of rotor speed and position from resolver outputs. The proposed joint position control system consists of four speed controller and one position controller. Analog methods are used in the position controller, while digital methods are used in the position controller. For precise position control, PID control algorithm and interpolation functions are executed in two 16 bit microprocessors with sampling rate 2ms. Experimental results show that the proposed joint position control system can be effectively applied to industrial robots in order to obtain high dynamic performance and precise positioning. The proposed joint position control system is being used in the control of FARA robots of Samsung Electronics.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.228-232
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• 2004

This paper is to identify the position of random disturbance on flexible dynamic system, and the position of the piezo ceramic actuator 0 minimize tip response. Correlation of the output signals from each parts on flexible system is used to identify the position of random disturbance. Except the correlation with an output signal from the position of random disturbance, other correlations have time delay. This is a base idea to identify the position on this study.

• 한국응용과학기술학회지
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• 제38권4호
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• pp.1107-1116
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• 2021

이 연구의 목적은 8주간의 플라이오메트릭 훈련이 대학 태권도 시범단의 순발력, 동적 평형성 및 관절 위치감각에 미치는 영향을 분석하고자 하였다. 태권도 시범 전공 대학생 20명을 훈련군 10명, 통제군 10명으로 분류한 후 운동군은 주 3회, 60분, 8주간 플라이오메트릭 훈련을 하였다. 측정 변인은 제자리높이뛰기, 제자리멀리뛰기, 배근력, 동적 평형성 및 관절 위치감각으로 사전 사후 측정하였다. 연구 결과, 제자리높이뛰기와 멀리뛰기 및 배근력에서 유의한 운동의 효과가 있었다(p<.05). 동적 평형성은 후방 바깥쪽과(p<.01) 후방 안쪽에서(p<.05) 유의한 운동의 효과가 있었다. 관절 위치감각은 왼발 15°와(p<.01) 45°에서는(p<.05) 운동군에서 유의한 효과가 있었다. 이상의 결과 8주간의 플라이오메트릭 훈련은 태권도 시범선수의 순발력과 동적 평형성 및 관절 위치감각에 긍정적인 영향을 미치는 것으로 나타났다.

• Journal of Power Electronics
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• 제4권1호
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• pp.28-38
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• 2004

In this paper, the position control of a detuned indirect field oriented control (IFOC) induction motor drive is studied. A proposed Simple-Neuro-Controllers (SNCs) are designed and analyzed to achieve high-dynamic performance both in the position command tracking and load regulation characteristics for robotic applications. The proposed SNCs are trained on-line based on the back propagation algorithm with a modified error function. Four SNCs are developed for position, speed and ｄ-ｑ axes stator currents respectively. Also, a synchronous proportional plus integral-derivative (PI-D) two-degree-of-freedom (2DOF) position controller and PI-D speed controller are designed for an ideal IFOC induction motor drive with the desired dynamic response. The performance of the proposed SNCs and synchronous PI-D 2DOF position controllers for detuned field oriented induction motor servo drive is investigated. Simulation results show that the proposed SNCs controllers provide high-performance dynamic characteristics which are robust with regard to motor parameter variations and external load disturbance. Furthermore, comparing the SNC position controller with the synchronous PI-D 2DOF position controller demonstrates the superiority of the proposed SNCs controllers due to attain a robust control performance for IFOC induction motor servo drive system.

• 제어로봇시스템학회논문지
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• 제15권10호
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• pp.1029-1038
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• 2009

This paper proposes a gain switching algorithm for joint position control of a hydraulic humanoid robot. Accurate position control of the lower body is one of the basic requirements for robust balance and walking control. Joint position control is more difficult for hydraulic robots than it is for electric robots because of an absence of reduction gear and better back-drivability of hydraulic joints. Backdrivability causes external forces and torques to have a large effect on the position of the joints. External ground reaction forces therefore prevent a simple proportional-derivative (PD) controller from realizing accurate and fast joint position control. We propose a state feedback controller for joint position control of the lower body, define three modes of state feedback gains, and switch the gains according to the Zero Moment Point (ZMP) and linear interpolation. Dynamic equations of hydraulic actuators were experimentally derived and applied to a robot simulator. Finally, the performance of the algorithm is evaluated with dynamic simulations.

• Transactions on Control, Automation and Systems Engineering
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• 제4권4호
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• pp.296-304
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• 2002

A position tracking control schemes on the precise mechanical system in presence of nonlinear dynamic friction is proposed. A nonlinear dynamic friction is regarded as the bristle friction model to compensate effects of friction. The conventional sliding mode controller often has been used as a non-model-based friction controller, but it has a poor tracking performance in high-precision position tracking application since it completely cannot compensate the friction effect below a certain precision level. Thus to improve the precise position tracking performance, we propose the sliding mode control method combined with the friction-model-based observer having tunable structure of the transient response. Then this control scheme has a good transient response as well as the high precise tracking performance compared with the conventional sliding mode control without observer and the control system with similar type of observer. The experiments on the bali-screw drive table with the nonlinear dynamic friction show the feasibility of the proposed control scheme.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2012년도 춘계학술대회
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• pp.401-402
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• 2012

해양 자원의 개발이 연안에서 심해로 이동하면서 해양플랜트 건조도 또한 심해라는 특수한 상황에서 운용될 수 있도록 건조되고 있다. 여러 가지 운용 시스템 중 Dynamic Positioning(DP) 시스템은 해상에서 해양 구조물을 일정기간동안 원하는 위치를 유지 시켜주는 시스템으로써 다양한 선박 및 해양플랜트에서 사용되고 있다. 이러한 DP 시스템은 기본적으로 GPS를 이용하여 해상에서 그 위치를 유지하고 있지만 그 외에도 다양한 Position Reference 시스템이 사용되고 있다. 이에 본 논문에서는 DP 시스템의 기본적인 원리와 DP Class 구분 그리고 DP 시스템에 사용되는 다양한 Position Reference 시스템에 대해서 개략적으로 다루고자 한다.

• 조형예술학연구
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• 제2권
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• pp.239-293
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• 2000

The paper aims to study how to describe the rigorous position on which semantic elements are laid, within the visual space. This purpose is, first of all, for the construction of visual syntactical semantics of the visual space. For this aim, the preliminary research begins with some definitions on : 1) visual space, visual design, visual syntactical semantic meaning, 2) position, sequence of position, 2-dim. sequence of position, and 3) 2-dim. numerical series of position, harmonious dynamic values. Here, The main issue is to define the position in general. To solve this problem, the researcher surveyed the positions on which the sets of pixemes are set up. The results are as follows ; 1. As far as the positions in visual space are concerned, they are the possible locations permitted in the visual patches. They are not the factual but the possible positions. 2.The position value that the sequential point has is not arithmetical but harmonious-dynamic, for it is not permitted for its own sake, but for the person, that is to say, for the viewer's visual perception. 3. The harmonious-dynamic value of positional sequence can be composed of the 2-dimensional successive numerical series which is, in turn, composed of the primordial 3 values x0, $\mu0$, y0. Here, the $\mu0$ is the harmonious mean value of x0 and y0. The x0 and y0 are, therefore, of the mutual dynamic relationship. 4. From this, the 2-dim general $\Delta-TABLE$ of the numerical series of position in visual design could be acquired through development of the primordial 3 values into the $X_i,\;Y_i$, orbit values.

• Journal of Information Processing Systems
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• 제11권4호
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• pp.538-555
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• 2015

Event detection based on using features from a static grid can give poor results from the viewpoint of two main aspects: the position of the camera and the position of the event that is occurring in the scene. The former causes problems when training and test events are at different distances from the camera to the actual position of the event. The latter can be a source of problems when training events take place in any position in the scene, and the test events take place in a position different from the training events. Both issues degrade the accuracy of the static grid method. Therefore, this work proposes a method called a dynamic grid for event detection, which can tackle both aspects of the problem. In our experiment, we used the dynamic grid method to detect four types of event patterns: implosion, explosion, two-way, and one-way using a Multimedia Analysis and Discovery (MAD) pedestrian dataset. The experimental results show that the proposed method can detect the four types of event patterns with high accuracy. Additionally, the performance of the proposed method is better than the static grid method and the proposed method achieves higher accuracy than the previous method regarding the aforementioned aspects.