• 한국정밀공학회지
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• 제9권4호
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• pp.136-146
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• 1992

This paper provides the end-point positioning of a single-link flexible robot arm by inverse dynamics. The system is composed of a flexible arm, the mobile ballscrew stage as an arm base, a DC servomotor as an actuator, and a computer. Actuator voltages required for the model of a flexible arm to follow a given tip trajectory are formulated on the basis of the Bermoullie-Euler beam theory and solved by applying the Laplace transform method, and computed by the numerical inversion method proposed by Weeks. The mobile stage as the arm base is shifted so that the end-point follows the desired trajectories. Then the trajectory of end-point is measured by the laser displacement sensor. Here, two kinds of functions are chosen for the given tip trajectories. One is what is called the bang-bang acceleration profile and the other is the Gaussian velocity profile.

• 대한전기학회논문지
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• 제38권9호
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• pp.753-760
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• 1989

A method is suggested to design a stochastic observer which can be used as a state estimator for the optimal control of a one link flexible manipulator. This stochastic observer is derived from unifying the two concepts of reduced-state deterministic observer theory and optimal Kalman filtering theory. In estimating state variables for the optimal control, instead of using the two different state estimators for the deterministic system with noise free measurements and stochastic system with noise measurements, only one stochastic observer is designed which is to be used in both systems commonly. Through the simulation, it has been shown that the flexible system with the stochastic observer is similar in characteristics to the flexible system assuming that all states can be measured.

• Journal of Advanced Marine Engineering and Technology
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• 제23권2호
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• pp.227-235
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• 1999

In this paper a vibration control fo a one-link flexible beam is considered. At first a state-space model for a flexible beam is derived by using the assumed-modes approach. Based on this model the transfer function between the applied torque and the tip deflection fo the beam is presented because it is convenient to apply our method. In general there exist some control difference due to flexibility of the beam so we adop a forward-passive controller to reduce these phenomena. And a complex dual-input describing function compensator is used to control the tip deflection. The stabiltiy and the performance of the closed-loop system are analyzed. Finally the validity of the derived model and the effectiveness of proposed controller are confirmed throuth simula-tions and experiments.

• 한국정밀공학회지
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• 제18권12호
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• pp.66-72
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• 2001

In this paper, by using pseudo-inverse matrix of the spatial redundant flexible manipulators, a position control method and its effect in vibration suppression was presented. Vibration suppression control was developed using lumped mass spring model of the flexible manipulators. With 2 elastic links and 7 rotory joint manipulator ADAM, (1)position control for no redundancy, and (2)position control for one redundant DOF(degree of freedom) were tested. The objective of this experiment is to show the effect of position control, using pseudo-inverse matrix. toward the improvement of operation, and at the same time, to reduce the vibration of the link and the magnitude of the joint torque.

• 한국소음진동공학회논문집
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• 제22권10호
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• pp.949-958
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• 2012

Position tracking control of a link of a slave manipulator which needed to track the corresponding link of a master manipulator was addressed in this paper. Since driving torque from motor is transmitted through a set of flexible cable to link, the motion control system is modeled by a two-mass model connected with elastic coupling which has finite stiffness. Relative vibration of two-mass resonant system is a serious problem to operate manipulator. This paper proposed sliding mode control to reduce resonant vibration and fine position tracking control. Also, a pseudo-sliding mode control which uses a saturation function instead of a signum function was discussed and showed that the pseudo-sliding mode control can improve disturbance regulation performance as well as guarantees fine command tracking without chattering which is an inherent drawback of basic sliding mode control. In addition, a disturbance observer based sliding mode control has been suggested to improve disturbance regulation performance. The feasibility of the proposed control design was verified along with some simulation results.

• 한국통신학회논문지
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• 제14권2호
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• pp.155-163
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• 1989

단일 링크 유연성 로보트 팔의 제어를 위해서 가정 모드 방법으로 유도된 동 특성 모델링에 QUADRATIC-최적제어 이론을 적용하였다. 이 제어 기법에 대한 제어 루우프 구성에는 모든 상태값의 피이트 백을 필요로 하지만 유연성 팔에 있어서 모드형태의 시 종속 변화율은 직접 출력으로부터 피이드백 될수 없기 때문에 최적 제어기를 실현하기 위해서는 상태 추정기의 도입이 필요하게 된다. 특히 시스템에 외란이나 측정에 노이즈가 발생할 때는 확률 추정 방법을 적용해서 상태를 추정해야 하는데 이를 위해서 칼만 필터를 사용하였다. 상태 추정기를 이용한 유연성 메니퓨레이터 팔의 시스템 모델을 모든 상태 값이 직접 측정될 수 있다고 가정한 유연성 시스템 모델과 시뮤레이션을 통해서 비교하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.630-632
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• 2018

장거리 (50 fiber spans ${\times}$ 80 km) 전송 링크의 융통적 구성을 위해 단일 모드 광섬유 (SMF; single mode fiber)의 길이와 중계 구간 당 잉여 분산 (RDPS; residual dispersion per span)이 랜덤하게 분포하는 링크에서 광 위상 공액과 결합된 분산 제어 (DM; dispersion management)를 통한 왜곡된 WDM 채널의 보상 특성을 살펴보았다.

• Journal of Power Electronics
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• 제19권2호
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• pp.560-568
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• 2019

This paper studies the inherent relationship between currents and zero-sequence components. Then a precise algorithm is proposed to calculate the injected zero-sequence component to control the DC-Link neutral-point voltage balance, which can result in a more efficient and flexible neutral point voltage balance with a desirable performance. In addition, it is shown that carried-based PWM with the calculated zero-sequence component scheme can be equivalent to space-vector pulse-width modulation (SVPWM). Based on the proposed method, the optimal zero-sequence component of the feasible modulation indices is analyzed. In addition, the unbalanced load limitation of the DC-Link neutral-point voltage balance control is also revealed. Simulation and experimental results are shown to verify the validity and practicality of the proposed algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.8-13
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• 1998

A tracking controller is presented for RLFJ(rigid link flexible joint) robot manipulators with only position measurements. The controller is developed based on the integrator backstepping design method and on the two observers: the first is simple linear form observer for the filtered link velocity errors and the other for the actuator velocities. The proposed controller achieves exponential tracking of link positions and velocities while keeping all internal signals bounded. It also guarantees exponential convergence of the estimated signals to their actual ones. Finally, simulation results are included to demonstrate the tracking performance.

• 동력기계공학회지
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• 제7권1호
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• pp.34-41
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• 2003

A method is presented for generating the path which significantly reduces residual vibration of a flexible robot manipulator and applying control theory to track the desired path. The desired path is optimally designed so that the system completes the required move with minimum residual vibration. A closed loop control theory is applied to track the planned path in the case of load variation. Specifically, it is desired that the optimally designed path has a better trajectory tracking capabilities during the residual vibration over the cycloidal path, in various cases of load. Perturbation adaptive control is used as closed loop control scheme. A planar two link manipulator is used to evaluate this method.