• 대한의용생체공학회:의공학회지
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• 제23권3호
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• pp.207-216
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• 2002

본 논문은 가상 자전거 시스템을 이용한 자세균형 훈련의 정량적 평가에 대한 연구이다. 본 연구의 실험은 20명의 정상 성인을 대상으로 하여 자세균형에 미치는 요인들을 분석하였다 측정 파라메터로서 주행시간. 주행속력. 주행경로 이탈의 횟수. 압력중심, 그리고 체중이동에 대한 변수들을 추출하여 정량적으로 평가하였다 또한, 균형훈련의 효과를 향상시키기 위해, 체중이동에 따른 시각적 피드백 정보의 유용성을 분석하였다 실험결과. 반복훈련결과. 체중이동 분포의 visual feedback 정보를 제시했을때 COP의 총길이가 줄어들어 동요도가 줄고 체중이동값이 50 %에 가까워져 자세제어 및 조절능력이 향상됨을 알 수 있었다. 따라서 가상 자전거 시스템은 효율적인 자세균형 재활 훈련 장비로서 효과가 있음을 확인하였으며 분석방법은 재활훈련 분야에서 널리 활용될 수 있는 가능성을 보여 주었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.71-76
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• 2010

This paper presents the feasibility for improving the ride quality of railway vehicle equipped with semi-active suspension system using magnetorheological(MR) fluid damper. In order to achieve this goal, a fifteen degree of freedom of railway vehicle model, which includes a car body, bogie frame and wheel-set is proposed to represent lateral, yaw and roll motions. The MR damper system is incorporated with the governing equation of motion of the railway vehicle which includes secondary suspension. To illustrate the effectiveness of the controlled MR dampers on railway vehicle secondary suspension system, the sky-hook control law using the velocity feedback is adopted. Computer simulation for performance evaluation is performed using Matlab. Various control performances are demonstrated under external excitation which is the creep force between wheel and rail.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 추계학술대회 논문집
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• pp.69-70
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• 2013

By using differential force between left and right wheel, lateral motion can be controlled known as Direct Yaw-moment Control (DYC). In previous researches, DYC control is proposed to increase the stability of the vehicle, but maneuverability has not been discussed sufficiently. The car handling condition which is called the index parameter of maneuverability is dependent on the vehicle velocity and steering angle. To achieve the desired vehicle's cornering path, the car handling condition must be considered sufficiently. In this paper, the novel DYC method is proposed which gives the car handling condition regardless of the longitudinal speed. The proposed controller is based on the PI controller to feedback the curvature parameter. The controlled system shows the advantages of DYC regarding to the reference trajectory by the dual motor system. With respect to the uncontrolled model, the effectiveness of the proposed method is validated by numerical examples.

• Journal of Advanced Marine Engineering and Technology
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• 제17권1호
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• pp.26-32
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• 1993

The loads exerted on electro-hydraulic servo system are classified into inertial, viscous, and spring load. The additional load called disturbances is also exerted on system but is generally not modeled. To deal with these kinds of loads, it is necessary to maintain the continuous signal transfer, so we can construct compensator to satisfy control specifications using feedback signal such as displacement, velocity, acceleration and pressure known as state variables. In case of controlling the speed of hydraulic motor, we must keep up robust performance for the various loads and disturbances acted on the system. However, the load flow rate in the valve is characterized by nonlinearity so that traditional theory of linear control could not be expected to give the desired performance. In this paper, it is shown that speed controller of hydraulic motor gives a good command following and disturbance rejection performance by applying sliding mode theory as a way of robust control to the nonlinearity, variation of loads and disturbances.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.488-493
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• 2005

In gun stabilization systems, the torque comes from the unbalance mass of gun and the base acceleration is an important source of disturbance which degrades stabilization performance. Fatigue of gear train is another important factor affecting structural safety problems. In this paper, a feedback control gain is designed by optimal control weighting to difference between motor and gun velocity, and a feedforward controller using FXLMS algorithm is adopted to investigate those problems. Experimental results show that the feedforward compensator based on FXLMS can reduce the disturbance effects. The directional convergence property according to initial conditions of the FXLMS is also shown through experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.23-25
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• 2005

This paper is devoted to the passivity based control in bilateral teleoperation for varying time delay. Toimprove the stability and task performance, master and slave in bilateral teleoperation must be coupled via the network through which the force and velocity are communicated. However, time delay existing in the transmission channel is a long standing impediment to bilateral control and can destabilize the system, even if the system is stable without time delay, In this paper, we investigate how the varying time delay affects the advanced teleoperation stability and results in an out-of-control status. A new approach based on passivity control has been bilaterally designed for both the master and slave sites and the simulation result will verify that our approach is better and effective for passive bilateral teleoperation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.153.1-153
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• 2001

This paper describes a development of rehabilitation training system for the postural balance control. A new rehabilitation training system, designated as a virtual cycling system, was developed to improve postural balance control by combining virtual reality technology with an unfixed bicycle. In this experiment, 20 normal adults were tested to investigate the influencing parameters of postural balance control. In order to evaluate the usefulness and the training effects of the system, several parameters Including path deviation, cycling velocity, cycling time, center of pressure, and head movement were evaluated and analyzed quantitatively. Also, to improve the effect of balance training, the visual feedback information related to the subject´s weight shift was ...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.181.6-181
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• 2001

This paper describes a development of rehabilitation training system for the postural balance control. A new rehabilitation training system, designated as a virtual cycling system, was developed to improve postural balance control by combining virtual reality technology with an unfixed bicycle. In this experiment, 20 normal adults were tested to investigate the influencing parameters of postural balance control. In order to evaluate the usefulness and the training effects of the system, several parameters including path deviation, cycling velocity, cycling time, center of pressure, and head movement were evaluated and analyzed quantitatively. Also, to improve the effect of balance training, the visual feedback information related to the subject's weight shift was assessed to identify whether it was useful. It could be also known ...

• 대한기계학회논문집
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• 제11권5호
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• pp.781-788
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• 1987

본 연구에서는 제어대상으로 설정된 유압서어보 시스템은 비선형 시스템이므 로, 실제로 측정한 상태변수와 관측기에서 추정한 상태변수를 비교하여 이들이 서로 일치하는 것을 보임으로써 관측기에서 추정한 다른 상태변수들에 대한 신뢰도를 높일 수 있다. 따라서 본논문에서는 전차수 관측기를 사용한 경우에 대하여 고찰한다.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.40-45
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• 2008

This paper presents a linear positioning system and its control algorithm design with nano accuracy/resolution. The basic linear stage structure is driven by an ultrasonic motor and its displacement feedback is detected by a LDGI (Laser Diffraction Grating Interferometer), which can achieve nanometer resolution. Due to the friction driving property of the ultrasonic motor, the driving situation differs in various ranges along the travel. Experiments have been carried out in order to observe and realize the phenomena of the three main driving modes: AC mode (for mm motion), Gate mode (for ${\mu}m$ motion), and DC mode (for nm motion). A proposed FCMAC (Fuzzy Cerebella Model Articulation Controller) control algorithm is implemented for manipulating and predicting the velocity variation during the motion of each mode respectively. The PCbased integral positioning system is built up with a NI DAQ Device by a BCB (Borland $C^{++}$ Builder) program to accomplish the purpose of an intelligent nanopositioning control.