• 제어로봇시스템학회논문지
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• 제5권5호
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• pp.630-639
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• 1999

To achieve fast loading and unloading of containers from a container ship, quick suppression of the remaining sway motion of the container at the end of each trolley stroke is crucial. Due to the pendulum motion of the container and disturbances like sind, residual sway always exists at the end of trolley movement. In this paper, the sway-control problem of a container crane is investigated. A two-stage control is proposed. The first stage is a time optimal controlfor the purpose of fast trolley traveling. The second stage is a nonlinear control for the quick suppression of residual sway, which starts right after the first stage while lowering the container. The nonlinear control is investigated in the perspective of controlling an underatuated mechanical system, which combines partial feedback linearization to account for the known nonlinearities as much as possible, and variable structure control to account for the unmodeled dynamics and disturbances. Simulation and experimental results are provided.

• 제어로봇시스템학회논문지
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• 제15권10호
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• pp.988-993
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• 2009

In this paper, we deal with a tracking gain-up controller design problem to control effectively the shake of tracking actuator after a track seek. A minimum tracking gain-up open-loop gain can be calculated by estimating the shake of tracking actuator and a desired transient specification is considered to diminish effectively the shake of actuator. A tracking gain-up controller is designed by considering a robust $H_{\infty}$ control problem with a regional stability constraint. The proposed tracking gain-up controller design method is applied to the track-following system of a DVD recording device and is evaluated through the experimental results.

• 대한기계학회논문집
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• 제19권2호
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• pp.519-526
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• 1995

Experiments have been performed to test the analytical tools developed concurrently for the motion-related unsteady pressure in annular passages. The outer cylindrical body was oscillated by a shaker in either rocking motion about a hinge-point or lateral translation motion. In the equilibrium configuration the two bodies are either concentric or eccentric, in the plane of oscillation or normal to it. The unsteady pressure generated by the oscillatory motion with low amplitudes (displacement/radius) was measured on wall of the fixed inner cylinder at various axial and azimuthal locations. The unsteady pressure were compared with theoretical predictions, and agreement was found to be within 10%. Experiments have been shown that the effect of flow velocity on the unsteady pressure is minimal and the pressure increases more or less with oscillatory motion, for low flow velocities (Re = 2 900).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.112-117
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• 1997

This paper presents a GA(Genetic Algorithms)-Optical control strategy for the control of the swing motion and the transverse position of the overhead crane. The overhead crane system is defined uncertain due to unknown system parameters such as payload and trolly mass. To control the overhead crane. the GA-Optimal control scheme is suggested. which transfers a trolly to a desired place as fast as possible and minimizes the swing of the payload during the transfer. The genetic algorithms are applied to fine digital optimal feedback gains. A computer simulation demonstrate the performance of the proposed the GA-digital optimal controller for the overhead crane.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.720-725
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• 1997

This paper is to study the wind effect of the large scale gantry crane. It is used to control the sway of gantry crane in the loadingiunloading job of containers. I'hls is very important in the automated container terminal because the sway of handling equipments in pard is caused by thc l~nexpected disturbance such as wind and dynamic inertia by deriving force. This study shows the process of the modelling simulation of the wind effect of the sway motion of the gantry crane. Pro-Engineer, ANSYS and DAD'; ~ rr . used for 3D solid modelling and dynamic simulation. Though this study did not use the real parameters. the ; cwl ~ shows the trend of the wind effect is very large in the large scale crane and should be considered in design of the large scale gantry crane. In future, if the study is done by using the real parameters, the result is much more ~ise!'ul for dynamic control and design of gantry crane.

• 대한기계학회논문집A
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• 제33권11호
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• pp.1288-1293
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• 2009

This paper discusses about modeling method to simulate a nonlinear behavior like sliding or rocking of two stacked body system under earthquake condition. A double body system design can be an option to reduce seismic response of a component in comparison to a single body system for free standing structures. Therefore, according to the priority of components, the structure is to be designed by proper ratio of partition in their height for improvement of seismic capability and structural integrity. Nonlinear modeling and analysis using simple rigid body and dynamic system has been performed to check the trend in such cases. As a result, one of the two bodies can be chosen to reduce the seismic response from energy absorption of the other one by appropriate application of friction ratios not only in slip-slip condition but in slip-rock condition.

• 한국광학회지
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• 제8권5호
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• pp.362-365
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• 1997

Mach-Zehnder형 외부 광 변조기나 Homodyne 검출기 같은 간섭계 원리를 이용한 장치에서 최대 또는 최소의 광 출력을 유지하도록 두 입력 광 사이의 위상 차를 제어하는 새로운 방법을 제시하였다. 이 방법은 Steepest Descent 알고리즘의 변형된 형태로 Delta Modulation 이론으로 성능을 해석할 수 있다. 이 방법은 기존의 흔들림(dithering) 방법을 적용하기 어려운 저속 펄스가 사용되는 간섭계 장치에도 사용할 수 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제24권6호
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• pp.53-60
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• 2000

In this paper, we design a GA-fuzzy controller for position control and anti-swing at the destination point. A genetic algorithm is used to complement the demerits such as the difficulty of the component selection of the fuzzy controller, namely, scaling factors, membership functions and control rules. Lagrange equation is used to represent the motion equation of trolley and load in order to obtain mathematical modelling. Simulation results show that the proposed control technique is superior to a conventional optimal control in destination point moving and modification.

• 자동차안전학회지
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• 제7권2호
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• pp.19-24
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• 2015

Ferritic Nitro Carburizing (FNC) cast iron brake discs is known to improve corrosion resistance and brake creep groan noise as well as prevent corrosion-induced pulsation. But, it is necessary to treat honing machining on braking surface to avoid grinding noise during braking.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.144-149
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• 1994

반도체 산업계에 있어서 IC 등을 주류로 하는 마이크로칩의 생산성 및 성능이 현저히 성장하여 많은 경제효과를 가져오고 있다. 이와함께 전자부품에 사용되어지는 취성재료의 종류 및 그양도 점점 증가하는 추세이다. 이러한 취성재료의 절단에는 초극박의 다이야몬드 브레이드가 널리 사용되어지고 있다. 실리콘웨이퍼와 같은 취성재료의 다이싱가공에서 문제가 되고있는것은 칩핑과 사행현상의 발생이다. 사행현상의 원인으로서는 브레이드축면의 비대칭성,절삭날의 둔화,숫돌축과 이송방향의 위치결정오차,후렌지 단면의 흔들림등을 들수 있다. 그러나, 사행의 발생영역과 사행이 계속되는 이유에 대해서는 전혀 검토되어진바 없는것이 현실이다. 본 연구에서는 다이싱가공시의 사행현상에 주목해서 사행현상의 발생영역을 명확하게 함과 동시에 AE 센서를 이용하여 인프로세서로 사행현상의 검출방법을 개발하는 것을 목적으로 한다.