• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1076-1078
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• 1999

In this paper, pseudomeasurements have decided using real-time measurements and forecasting data in order to reduce the difference between accuracy of real-time measurements and pseudomeasurements. A decided pseudomeasurement by means of the presented method can look for estimated solution as compared to conventional pseudomeasurement because there is no difference between accuracy of measurements. The simulations are carried out for test systems and corresponding results are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2423-2425
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• 2004

Mobility of an indoor wheeled robot is affected by adhesion force that is related to various floor conditions. When the adhesion force between driving wheels and the floor decreases suddenly, the robot has slip state. First of all, this paper models adhesion characteristics and slip in wheeled robot. Secondly, the paper proposes estimation method of adhesion force coefficient(AFC) according to slip velocity. In order to overcome this slip problem, optimal slip velocity must be decided for stable movement of wheeled robot. The paper proposes an anti-slip control system based on an ordinary disturbance observer, that is, the re-adhesion control is achieved by reducing the driving torque enough to give maximum adhesion force coefficient. fuzzy logic controller(FLC) is petty useful with slip through that compare fuzzy with PI control for the controller performance. These procedure is implemented using a Pioneer 2-DXE parameter.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.65.2-65
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• 2002

This paper is concerned with the accurate position control of a rodless pneumatic cylinder using On/Off solenoid valve. A novel Intelligent Modified Pulse Width Modulation(MPWM) is newly proposed. The control performance of this pneumatic cylinder depends on the external loads. To overcome this problem , switching of control parameter using artificial neural network is newly proposed, which estimates external loads on rodless pneumatic cylinder using this training neural network. As an underlying controller, a state feedback controller using position, velocity and acceleration is applied in the switching control the system. The effectiveness of the proposed control algorithms are demonstrated...on/off solenoid valve, load estimation, MPWM, Artificial neural network.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.893-898
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• 2003

Coulomb friction is an important factor for precise position tracking control systems. The control systems with friction causes the steady state error because of being sensitive to the change of system condition and highly nonlinear characteristics. To overcome these problems, we use an estimation scheme of Coulomb friction to experiment for it's compensating. The estimated factor for Coulomb friction is used as a feed-forward compensator to improve the tracking performance of ball-screw systems. The tracking performance was improved by compensating the estimated friction torque in the feed-forward term. And, the sliding mode control which is derived from the Lyapunov stability theorem is applied for robust stability and reducing chattering. The experimental results show that the sliding mode controller with adaptive friction compensator has a good tracking performance compared with the friction uncompensated controller.

• Computers and Concrete
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• 제5권1호
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• pp.37-60
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• 2008

Structural health monitoring of existing infrastructure is currently an important field of research, where elaborate experimental programs and advanced analytical methods are used in identifying the current state of health of critical and important structures. The paper outlines two methods of system identification of beam-like reinforced concrete structures representing bridges, through static measurements, in a distributed damage scenario. The first one is similar to the stiffness method, re-cast and the second one to flexibility method. A least square error (LSE) based solution method is used for the estimation of flexural rigidities and damages of simply supported, cantilever and propped cantilever beam from the measured deformation values. The performance of both methods in the presence of measurement errors is demonstrated. An experiment on an un-symmetrically damaged simply supported reinforced concrete beam is used to validate the developed method. A method for damage prognosis is demonstrated using a generalized, indeterminate, propped cantilever beam.

• 제어로봇시스템학회논문지
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• 제7권6호
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• pp.471-476
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• 2001

This paper presents a state observer for nonlinear systems using approximate observer from. It is shown that if a nonlinear system is approximately error linearizable, then there exists a local nonlinear observer whose estimation error converges exponentially to zero. Since the proposed method relaxes strong geometric conditions of previous works, it improves the existing results for nonlinear observer design. Finally, some example is given to show the effectiveness of this scheme.

• Transactions on Control, Automation and Systems Engineering
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• 제2권4호
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• pp.235-243
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• 2000

The probabilistic data association filter(PDAF) is known to provide better tracking performance than the standard Kalman filter(KF) in a cluttered environment. In this paper, the stability of the PDAF of Fortmann et al[7], in the presence of uncertainties with regard to the origin of measurement, is investigated. The modified Riccati equation derived by approximating two random terms with their expectations is used to prove the stability of the PDAF. A new Lyapunov function based approach, which is different from the quantitative evaluation of Li and Bar-Shalom[7], is pursued. With the assumption that the system and observation noises are bounded, specific tracking error bounds are established.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.2081-2082
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• 2008

본 논문에서는 전기공사의 표준 공사원가 산정기준인 전기부문 표준품셈 체계개편이 2002-2004년까지 있었던 바, 동 체계개편 과정에서의 문제점 보완과 신규 제정 품셈에 대한 현황을 분석하고 공사원가에 미치는 영향 및 품셈 제.개정 과정에서의 문제점 등을 분석하여 합리적이고 객관적인 공사원가 산정기준을 만드는데 기여하고자 체계개편 내용과 동 내용을 적용한 2006년 이후 최근 2년간의 제 개정 현황을 비교하여 종합적으로 분석 표준품셈 제.개정의 합리적 개선방안을 제시하고자 한다.

• 한국콘텐츠학회논문지
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• 제6권2호
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• pp.9-16
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• 2006

본 논문은 광대역 무선 통신망의 물리계층 OFDMA시스템 구조에서 멀티미디어 패킷 서비스의 효율적인 처리를 위한 스케줄링 알고리즘을 제안한다. 스케줄링 알고리즘은 무선 채널 상태 정보 추정을 이용하고 클래스 및 우선권 정책 기반 전송 순위 결정과 이에 의한 전송률 할당을 한다. 그 결과로 제안된 스케줄링 알고리즘은 실시간 서비스에 대해선 최대 트래픽 처리량과 jitter의 최소화를 만족하고 비실시간 서비스에 대해 공평한 트래픽 처리를 수행한다. 제안 된 스케줄링 알고리즘은 기존의 라운드 로빈 스케줄링 방식과 시뮬레이션을 통한 비교를 통해서 보다 우수한 성능을 보인다.

• 전력전자학회논문지
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• 제5권6호
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• pp.592-600
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• 2000

본 논문은 직류측 센서만을 갖는 3상 PWM 정류기의 새로운 제어기법을 제안한다. 제어가 내부의 모텔전류와 시스템 전류의 편차를 영으로 제어하여 상전압의 크기와 위상을 추정하고 스위칭 상태와 직류링크전류로부터 상전류를 재구성한다. 제안한 상전압 빛 상전류 센서리스 기법을 PWM 정류기 시스템에 적용한 실험을 통하여 그 타당성을 검증하였다.