• Transactions on Control, Automation and Systems Engineering
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• 제4권2호
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• pp.169-175
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• 2002

A sliding mode control of spacecraft attitude tracking with actuator, especially reaction wheel, is presented. The sliding mode controller is derived based on quaternion parameterization for the kinematic equations of motion. The reaction wheel dynamic equations represented by wheel input voltage are presented. The input voltage to wheel is calculated from the sliding mode controller and reaction wheel dynamics. The global asymptotic stability is shown using a Lyapunov analysis. In addition the robustness analysis is performed for nonlinear system with parameter variations and disturbances. It is shown that the controller ensures control objectives for the spacecraft with reaction wheels.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.92.1-92
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• 2001

Sliding mode control of spacecraft attitude tracking with actuator, especially reaction wheel, is presented. The sliding mode controller is derived based on quaternion parameterization for the kinematic equations of motion. The reaction wheel dynamic equations represented by wheel input voltage are presented. The input voltage to wheel is calculated from the sliding mode controller and reaction wheel dynamics. The global asymptotic stability is shown using a Lyapunov analysis. In addition the robustness analysis is taken for nonlinear system with parameter variations and disturbances. It is shown that the controller ensures control objectives for the spacecraft with reaction wheels.

• 분석과학
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• 제19권3호
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• pp.203-210
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• 2006

Octopole reaction cell inductively coupled plasma mass spectrometer (ORC-ICP-MS)를 이용하여 우유 분말시료 중 극미량의 셀레늄(Se)을 정량하였다. 반응가스로 $H_2$를 사용함으로써 극미량 측정에서 발생되는 다원자 이온 종들과 공존 원소에 의해 발생되는 분자들의 방해를 현저하게 제거하였다. Normal mode에 비해서 $H_2$ cell gas mode는 정확성과 정밀성을 크게 향상시켰으며, 우유 표준시료의 보증 값에 비해 정량한 결과는 평균 102.7%로 약간 높게 나타났고, 5회 정량한 값에 대한 상대표준편차는 7.6%이었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.233-236
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• 2004

In this paper, a new sensorless vibration control scheme is proposed for a flexible manipulator system. A robust sliding mode controller incorporating with a ‘reaction moment observer’ used for the estimation of the reaction moment reciprocally acting on flexible arm and hub inertia is introduced to achieve desired control target. The rigid body dynamics of the single-link flexible manipulator is simply considered in the design of the sliding mode controller. Then, the reaction moment is estimated by the proposed reaction moment observer to suppress the residual vibration of the flexible arm. The performance of the proposed control scheme is verified by computer simulation and experiment.

• 공업화학
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• 제9권7호
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• pp.1004-1010
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• 1998

Single-jet 반회분식 결정화 반응기에서 동력투입량, 반응물의 주입시간 및 주입방법등 반응조건의 변화가 란타늄 옥살레이트 결정입자의 반응성 결정화에 미치는 영향에 대해 실험적으로 조사하였다. 란타늄 옥살레이트 결정입자의 크기분포는 반응조건에 관계없이 monomodal 형태의 크기분포를 나타내었으나 평균결정크기는 반응조건에 크게 영향을 받았다. 동력투입량이 증가할수록, 반응물의 주입속도가 빠를수록, 란타늄 옥살레이트의 결정입자크기는 감소하였으나 상대적 유도시간은 증가하였다. 반응물의 주입방법에 있어서 옥살산 용액이 주입되는 경우보다 염화란타늄 용액이 주입되는 경우에 결정입자는 크게 나타났으며 상대적 유도시간은 감소하였다. 그리고 결정입자의 형태는 모두 침상형으로 반응조건의 변화에 크게 영향을 받지 않았다.

• 한국소음진동공학회논문집
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• 제15권2호
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• pp.169-175
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• 2005

In this paper, a novel vibration control scheme for a single-link flexible manipulator system without using a vibration feedback sensor is proposed. In order to achieve the vibration information of the flexible link, a reaction moment estimator based on the dynamic characteristics of the flexible manipulator is proposed. While the manipulator is maneuvering the reaction moment is reciprocally acting on the flexible link and the hub inertia due to the vibration of the link. A sliding mode controller based on the equivalent rigid body dynamics corresponding to the proposed flexible manipulator is then augmented with the reaction moment estimator to realize a decentralized control system. The reaction moment estimator is implemented via the first order low pass filter. The performance of the proposed control scheme is verified by computer simulation and experiment.

• ETRI Journal
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• 제33권1호
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• pp.121-124
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• 2011

Digital harmonics, which may reduce the radio frequency sensitivity of a system, can be coupled with an antenna in a mobile handset. This letter presents a decoupling method for increasing the isolation between digital harmonics on a flexible printed circuit board (FPCB) and an antenna in terms of the ground mode current and the concept of reaction. We model the signal and ground lines in an FPCB as a loop circuit exciting a ground mode current and demonstrate a simple but efficient decoupling method for reducing the excited ground mode current.

• Journal of Advanced Marine Engineering and Technology
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• 제39권5호
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• pp.554-562
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• 2015

This paper describes an analysis of an architecture and control system of a firefighting cannon manipulator (FCM) composed of two joint axes and one water-shooting actuator. Because the orienting FCM motion is disturbed by the reaction force from water shooting, the water shooting force has been modeled for robust control. The dynamics model of the manipulator has been set up including the external force of water-shooting reaction on the manipulator. A PD Controller and Sliding Mode Controller have been designed and their performance been tested through simulation to track a desired trajectory under the disturbance of a water-shooting reaction. The simulation shows that the performance of the Sliding Mode Controller is better than that of the PD controller.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.205-212
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• 2006

Three-dimensional numerical study was carried out for the investigation of the detonation wave structures propagating in tubes. Fluid dynamics equations and conservation equation of reaction progress variable were analyzed by a MUSCL-type TVD scheme and four stage Runge-Kutta time integration. Chemical reaction was modeled by using a simplified one-step irreversible kinetics model. The variable gas properties between unburned and burned states were considered by using variable specific heat ratio formulation. The unsteady computational results in three-dimension show the detailed mechanisms of rectangular and diagonal mode of detonation wave instabilities resulting same cell length but different cell width in smoked-foil record. The results for the small reaction constant shows the spinning mode of three-dimensional detonation wave dynamics, which was rarely observed in the previous numerical simulation of the detonation waves.

• 한국항공우주학회지
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• 제41권2호
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• pp.98-106
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• 2013

본 논문에서는 슬라이딩 모드 제어와 간단한 적응 법칙을 이용하여 반작용 휠 고장에 대한 고장 허용 제어 법칙을 제안한다. 위성의 동역학식에 시스템 파라미터 오차와 고장 불확실성을 고려하여 자세 제어 법칙을 설계하였다. 고장은 구동기 고장인 반작용 휠 고장만을 고려하였으며, 반작용 휠 고장은 곱 형태로 반영된다. 제안된 자세 제어 법칙은 르야프노프 안정성 이론을 통해 안정성을 확인하였고, 수치 시뮬레이션을 통하여 기존의 슬라이딩 모드 제어기와 비교하였으며 위성의 자세 각속도가 안정화되지 않은 경우 제안된 적응 슬라이딩 자세 제어기가 고장에 더욱 빠른 응답 속도를 갖는 것을 확인하였다.