• 한국생산제조학회지
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• 제21권1호
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• pp.161-166
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• 2012

Intravenous (IV) injection is widely used to supply Ringer solution directly into a vein in hospital. Generally, a passive injection method has been used, which causes the inconsistent flow rate of fluid and inappropriate control of injection time by a patient. It leads to an unnecessary nurse's overwork and decrement of IV injection's effect. To solve these problems, flow control infusion pumps have been developed. But because of relatively heavy weight and high price, its usage has been limited. In the present study, a new automatic IV injection system is developed. It is installed with a small pressing mechanism driven by a small electric motor to regulate the flow rate by pressing tube. Proportional integral derivative (PID) feedback control algorithm is applied to control the electric motor. The system is smaller in size and uses lower power than the existing commercial product. The newly developed system is also installed with networking capability, which enables monitoring the status of several automatic IV injection system at the same time.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.416-419
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• 2009

The widely used control theory based design of PI family controllers fails to perform satisfactorily under-parameter variation, nonlinear or load disturbance. In high performance applications, it is useful to automatically extract the complex relation that represent the drive behaviour. The use of loaming through example algorithms can be a powerful tool for automatic modelling variable speed drives. They can automatically extract a functional relationship representative of the drive behavior. These methods present some advantages over the classical ones since they do not rely on the precise knowledge of mathematical models and parameters. The paper proposes high performance speed and current control of synchronous reluctance motor(SynRM) drive using adaptive loaming mechanism-fuzzy neural network (ALM-FNN) and fuzzy logic control(FLC) controller. The proposed controller is developed to ensure accurate speed and current control of SynRM drive under system disturbances and estimation of speed using artificial neural network(ANN) controller. Also, this paper proposes the analysis results to verify the effectiveness of the ALM-FNN and ANN controller.

• 제어로봇시스템학회논문지
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• 제10권11호
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• pp.1044-1051
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• 2004

This paper described a novel locomotion interface that can generate infinite floor for various surface, named as virtual walking machine. This interface allows users to participate in a life-like walking experience in virtual environments, which include various terrains such as plains, slopes and stair ground surfaces. The interface is composed of two three-DOF (X, Y, Yaw) planar devices and two four-DOF (Pitch, Roll, Z, and relative rotation) footpads. The planar devices are driven by AC servomotors for generating fast motions, while the footpad devices are driven by pneumatic actuators for continuous support of human weight. To simulate natural human walking, the locomotion interface design specification are acquired based on gait analysis and each mechanism is optimally designed and manufactured to satisfy the given requirements. The designed locomotion interface allows natural walking(step: 0.8m, height: 20cm, load capability: 100kg, slope:30deg) for various terrains.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.963-968
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• 2003

The continuous process systems usually consists of various components: driven rollers. idle rolls, load-cell and so on. Even a simple fault in a single component in the line may cause a catastrophic damage on the final products. Therefore it is absolutely necessary to diagnosis the components of the continuous systems. In this paper, an adaptive eccentricity compensation method is presented. And a new diagnosis method for transverse roll shape defects on rolling process is developed. The new method was induced from analyzing the rolling mechanism by using rolling force model, tension model, Hitchcock's equation, and measured delivery thickness of materials etc. Computer simulation results also show that the proposed diagnosis methods is very effective in the diagnosis of 3-D roll shape

• 전자공학회논문지A
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• 제32A권4호
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• pp.32-39
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• 1995

In this paper, a timer thresholds tuning algorithm is proposed, satisfying the required response time for traffic with time-critical applications and asynchronous traffic in FDDI network. Under light and medium load, priorities and timer thresholds play a minor role for medium access control. In these cases all quenes are served exhaustively with a ver high service probability and the packet loss probability approaches almost zero. Under overload condition, however, the performance of the FDDI Network is completely determined by the selection of the timer thresholds. The timer thresholds tuned by mathematical results is confirmed by simulation results using SIMAN/UNIX package. The allocation of guaranteed bandwidth can be controlled easily by tuning the timer thresholds according to the proposed rules.

• Journal of Advanced Marine Engineering and Technology
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• 제33권5호
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• pp.713-720
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• 2009

Numerous applications of position controlling devices using servoing technique and transmission of energy through belt drives are practiced in the industry. Belt drive is a simple, lightweight, low cost power transmission system. Belt drives provide freedom to position the motor relative to the load and this phenomenon enables reduction of the robot arm inertia. It also facilitates quick response when employed in robotics. In this paper, precision positioning of a belt driven mechanism using a feed-forward compensator under maximum acceleration and velocity constraints is proposed. The proposed method plans the desired trajectory and modifies it to compensate delay dynamics and vibration. Being an offline method, the proposed method could be easily and effectively adopted to the existing systems without any modification of the hardware setup. The effectiveness of the proposed method is demonstrated through computer simulation and experimental results.

• 대한전기학회논문지
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• 제38권11호
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• pp.888-895
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• 1989

A novel model reference adaptive control (MRAC) scheme for electrical servo drives is proposed, in which the control input is synthesized without any parameter identification mechanism and a PI controller is inserted ahead of the plant to reduce the steady state chattering. The proposed scheme is shown to be asymptotically stable in the case where the load torque disturbance satisfies a certan condition. An application to a permanent magnet synchronous motor drive shows that the output error between the plant and the reference model tends to zero and the chattering is greatly reduced.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.472-475
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• 2003

Electric Power Steering (EPS) mechanism has become widely equipped in passenger vehicle due to the environmental consciousness and higher fuel efficiency. This paper describes the development of co-simulation technique and simulation integration technique of EPS control system with dynamic vehicle model. A full vehicle model interacted with EPS control algorithm is concurrently simulated on a single bump road condition. Dynamic responses of vehicle chassis and steering system resulting from road surface impact are evaluated and compared with proving ground experimental data. The comparisons will show reasonable agreement on tie-rod load. rack displacement, handle-wheel torque and tire center acceleration. This developed simulation capability can be used for EPS performance evaluation and calibration as well as for vehicle handling performance integration and synthesis.

• 한국산학기술학회논문지
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• 제19권1호
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• pp.644-653
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• 2018

최근 기후변화로 인한 집중호우, 태풍 등의 영향으로 산사태가 빈번히 발생하고 있다. 산사태를 예방할 수 있는 효율적인 방법은 사방사업이다. 이러한 사방사업의 효율성을 높이기 위해서는 산지에서 유출되는 토사량에 대한 정량적 측정이 필요하다. 본 연구에서는 산지계류에 Load-cell 센서를 설치하고, 분동테스트를 통하여 계류에서의 적용성과 재하 형태에 따른 출력값을 비교하였다. 개별 및 복합 하중시험을 실시한 결과, Site 1에서 평균 0.4kgf, Site 2에서 평균 0.6kgf 차이로 재하 형태의 영향은 낮게 나타났다. 또한 측정값의 정확도를 높이기 위해 하중계수를 산정하였다. 하중계수를 Load-cell 측정 값에 적용하여 보정한 결과, 두 사이트에서 출력율이 각각 14.8%p, 24.6%p 상승하여 기준값에 근사하게 산정되었다. Load-cell 센서는 수위, 강우 등과 함께 시계열 분석을 통하여 산지 토사유출량을 정량적으로 산정할 수 있었다. 모니터링이 장기간 이루어진다면 산림유역에 대한 토사유출 매커니즘 구명에도 활용할 수 있을 것이다. 또한 Load-cell과 같은 센서를 산지 계곡에 적용함으로써 계측센서 등 관련분야 산업 발전에 기여할 수 있을 것으로 기대된다.

• 전력전자학회논문지
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• 제22권6호
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• pp.517-526
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• 2017

In this paper, we propose an LLC resonant converter that operates over a wide controllable output voltage ($50V_{DC}$ to $800V_{DC}$) and shows high efficiency characteristics under all load conditions and output voltages. Two 3.3kW prototypes are designed for an experimental comparison between the variable frequency control (control scheme 1) and the variable input voltage($V_{IN}$) control (control scheme 2) mechanisms. The experimental results show that the variable input control mechanism demonstrates high efficiency under all loads and output voltages.