• International Journal of Precision Engineering and Manufacturing
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• 제6권2호
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• pp.61-71
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• 2005

The study reported deals with investigating the feasibility of control strategy for a serial rigid link manipulator that applies impulsive torques at the joints. The strategy is illustrated for a planar three rigid link manipulator. An impulse-based concept which uses successive torque impulses on rigid link as the controller for motion correction was introduced. This control strategy was tested over the entire trajectory to demonstrate that the tracking error could be reduced effectively. The best condition for minimizing the tracking error with the least impulse input at each joint is investigated by considering one design and one operating parameter. The first was the damping in the system, and the second was the sampling time during operation. The results show that this approach can provide useful guidance for the design and control of robot manipulators that require minimum impulse feedback for accurate tracking.

• 한국정보전자통신기술학회논문지
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• 제9권1호
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• pp.109-113
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• 2016

사물 통신과 멀티미디어 협동 작업 환경의 필요성을 기술하고, 그 기반 하에 사물 통신 기반 화이트보드에서의 오류 처리에 대해서 제안하였다. 본 정보의 수집 및 활용 관계가 사람 대 사람에서 사람 대 사물의 관계, 사물 대 사물의 관계로 변화되어 사물 간 상호 정보 교환 및 제어 시스템을 통해 사물이 자율적으로 관리하는 형태로 진화되고 있다. 본 논문은 사물형 지능 통신 기반의 멀티미디어 공동 작업 환경을 위한 화이트보드와 오류 제어에 대해서 기술한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.34.2-34
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• 2001

There are many control methods guaranteeing the robustness of systems. Among them, H$\infty$ control, sliding mode control and disturbance observer have been used widely. Especially, disturbance observer(DOB) is one of the most popular methods because it is easy to apply and the cost to pay is low due to its simplicity. Conventional DOB utilizes output signal as a feedback signal. But in Optical Disk Drive(ODD) systems, the Position Error Signal(PES) is the only available one. So conventional DOB is not applicable. If we use error signal in stead of output signal, another form of DOB is made. We call it as Error based Disturbance Observer(EDOB). We show in this paper the difference between two systems, namely conventional DOB system and the EDOB system, and also show the effectiveness of EDOB through experiment.

• 제어로봇시스템학회논문지
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• 제6권12호
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• pp.1053-1060
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• 2000

In this paper, a discrete-time variable structure control method using recursively defined switching function and a decoupled variable structure disturbance compensator is used to achieve high performance circular motion control of a CNC machining center. The discrete-time variable structure control with the decoupled disturbance compensator method developed in this paper uses a recursive switching function defined as the sum of the current tracking error vector and the previous value of the switching function multiplied by a positive constant less than one. This recursive switching function provides much improved performance compared to the method that uses a switching function defined only as a linear combination of the current tracking error. Enhancements in tracking performance are demonstrated in the circular motion control using a CNC milling machine.

• 대한기계학회논문집A
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• 제20권2호
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• pp.399-407
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• 1996

A fuzzy learning algorithm to get the optimal fuzzy rules is presented in this paper. The algorithm introduces a reference model to generate a desired output and a performance index funtion instead of the performance index table. The performance index funtion is a cost function based on the error and error-rate between the reference and plant output. The cost function is minimized by a gradient method and the control input is also updated. In this case, the control rules which generate the desired response can be obtained by changing the portion of the error-rate in the cost funtion. In SISO(Single-Input Single- Output)plant, only by the learning delay, it is possible to experss the plant model and to get the desired control rules. In the long run, this algorithm gives us the good control rules with a minimal amount of prior informaiton about the environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.435-437
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• 1998

In this productive system, it needs to control the each axis motion harmoniously to perform accurately for the manufacturing, transporting and printing. Independent Axis Control usually used for this objection. However, if Independent Axis Control mismatched the parameter of each axis system or in the case of free curve tracking or the case of high speed control, there would be big contour error so that cannot achieve control objection. As a result, there is Contour Control method suggested to supply for this defect. This paper carried modeling of biaxial system and implemented Independent Axis Control & Contouring Control on straight line, circular, and coner path by simulation and experiment. If feedrate increased, contour error growed. In consequence, according to this factor, we introduced contouring controller, so we could find the fact that contour error was reduced more than that of independent axis control about each path.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.244-246
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• 1998

Robust control for DC motor is needed according to the highest precision of industrial automation. However when a motor control system with PID controller has an effect of load disturbance, it is very difficult to guarantee the robustness of control system. As a compensation method solving this problem, in this paper, PID-supervision hybrid control method for motor control system is presented. If the PID control system (without the supervisory controller) is stable in the sense that the error is inside the constraint set, the supervisory control is idle. If the error hits the boundary of the constraint, the supervisory controller begins operation to force the error back to the constraint set. We prove that the PID-supervision hybrid control system is globally stable in the sense that the error is guaranteed to be within the tolerance limits specified by the system designer.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.345-350
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• 1993

This paper presents an on-line feedback error learning control algorithm for a magnetic levitation system. It will be shown that even in the case of abrupt changes of the system parameters and disturbanes, the control performance is still very satisfactory.

• 대한전자공학회논문지TC
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• 제37권2호
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• pp.91-97
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• 2000

본 논문에서는 Feedforward 선형화기 시스템에서 error sensor loop 부분에 적용할 수 있는 새로운 형태의 제어 회로를 제안하였다. 이 제어 회로를 error sensor loop에 적용하였을때 11dB의 입력 전력의 변화 범위에서 안정적으로 동작하였으며, 주 신호가 3차 IM 신호보다 작은 전력 레벨인 -40dB 이상의 감쇄를 갖도록 제어할 수 있었다. 이때 세기 제어 회로에 있어서 제어 오차는 0.05~0.12dB이며, 위상 제어 회로의 제어 오차는 0.016 "이내의 값을 가진다. 이러한 실험 결과를 토대로 입력 전력의 변화, 동작 온도의 변화, 습도, 및 주변 환경의 변화등에 의한 고출력 증폭기의 비선형 특성의 변화를 정밀하게 보상할 수 있음을 이론적으로 검증하였다.

• International Journal of Control, Automation, and Systems
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• 제3권4호
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• pp.612-619
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• 2005

A robust adaptive speed sensorless induction motor direct torque control (DTC) using a neural network (NN) is presented in this paper. The inherent lumped uncertainties of the induction motor DTC system such as parametric uncertainty, external load disturbance and unmodeled dynamics are approximated by the NN. An additional robust control term is introduced to compensate for the reconstruction error. A control law and adaptive laws for the weights in the NN, as well as the bounding constant of the lumped uncertainties are established so that the whole closed-loop system is stable in the sense of Lyapunov. The effect of the speed estimation error is analyzed, and the stability proof of the control system is also proved. Experimental results as well as computer simulations are presented to show the validity and efficiency of the proposed system.