• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.25-28
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• 1987

Design procedure of adaptive controller with variable load condition is present and applied to velocity control of small, permanent magnet DC servo motor. The state feedback control scheme is adopted and Recursive Least Squares algorithm is used for parameter estimation. In order to reduce the time consuming. In the procedure of adaptation-gain tuning of state feedback controller, approximate curve fitting technique is applied to the relations between load condition and poles of the system, load condition and feedback gains. With this method, fast adaptation can be accomplished. It is shown that this procedure can be applied not only to variable load condition but also to variation of other system constants, for example variation of resistance and inductance etc.. Simulation results is present for both cases - variable inertia load, variable motor resistance to verify performance improvements. This design procedure produces an adaptive con troller which is feasible for implementation with microprocessor by reducing calculation time.

• 대한전기학회논문지
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• 제39권11호
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• pp.1207-1218
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• 1990

The lack of persistent excitation (PE) can be the reason of freezing in the recursive least square estimators and the covariance windup in the exponential weighted least square estimators. We present a theoretical analysis of these phenomena and a simple method to check the exciting condition in real time. Using these results and under some conditions such as slowly time varying Plant and a tracking problem for set point, a robust self-tuning regulators without PE is proposed. In this algorithm, when PE is not satisfied, only plant gain is estimated, and then the system parameters are corrected by it. It is shown that the gain adaptive scheme makes the robustness to be improved against modeling error, off-set, and correlated noise etc, by the results of analysis and simulations.

• 전기의세계
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• 제49권9호
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• pp.9-16
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• 2000

A receding horizon $H_{\infty}$ predictive control method is derived by solving a min-max problem in non-recursive forms. The min-max cost index is converted to a quadratic form which for systems with input saturation can be minimized using QP. Through the use of closed-loop prediction the prediction of states the use of closed-loop prediction the prediction of states in the presence of disturbances are made non-conservative and it become possible to get a tighter $H_{\infty}$ norm bound. Stability conditions and $H_{\infty}$ norm bounds on disturbance rejection are obtained in infinite horizon sence. Polyhedral types of feasible sets for sets and disturbances are adopted to deal with the input constraints. The weight selection procedures are given in terms of LMIs and the algorithm is formulated so that it can be solved via QP. This work is a modified version of an earlier work which was based on ellipsoidal type feasible sets[15].

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.409-413
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• 1997

In linear motor positioning systems, nonlinearitys such as friction and cogging exist. These inner system with compliance may cause the steady state error and oscillation. So it is necessary to consider these elements for precision positioning control. In this paper, a nonlinear model of a linear motor positioning system including the friction, cogging and compliance is proposed. The parameters of the proposed model are identified by recursive least-squares method. The validity of the proposed model is confirmed by computer simulation.

• 전자공학회논문지A
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• 제32A권2호
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• pp.130-139
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• 1995

A hierarchical placement system based on routing region assignment has been developed to increase the probability of routing completion after placement. While most of the existing placement systems attempt to reduce the cell density at the portions where routing density is high, our method is distinguished in that specific routing regions are allocated to secure complete routing where the routing density is greater than the routing capacity. Hierarchy is vuilt by clustering and recursive paritioning, and the initial placement obtained by partitioning at each level is improved by using the region refinement algorithm. After placement at each hierarchical level, global routing is performed and fouting regions are assigned, if routing density is greater than routing capacity, to be considered at the next level of placement. the proposed algorithm has been implemented and applied to place several industrical gate-array circuits. A couple of circuits which cannot be routed by using conventional placement techniques can be completely routed by using our new placement technique with routing region assignment.

• 대한전자공학회논문지
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• 제25권2호
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• pp.211-219
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• 1988

In this paper effective block matching algorithms are proposed to find the motion vector. There are two approaches to the estimation of the motion vector in MCC (motion compensated coding), i.e.pel(pixel element) recursive algorithm and block matching algorithm. The search algorithm in this paper is based on the block matching method. The advantage of this algorithm is the reduction of the computation time. In order to reduce the computation time, three mathods are proposed in this paper. These new algorithms are faster than other methods. Compared with the three step algorithm by Koga et al., the average ratio of the computational savings obtained from the proposed algorithm is about 3-4.

• 한국컴퓨터정보학회논문지
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• 제4권4호
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• pp.94-100
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• 1999

본 논문은 흡필드 모델의 실수연산을 고속으로 수행할 수 있는 디지털 신경회로망의 구현에 관한 연구이다. 흡필드 모델［1］-［8］의 연산과정은 행렬-벡터의 연산으로 기술 할 수 있으며, 이 연산과정은 순환, 반복적으로 이루어지므로 어레이프로세서 구조로 설계하기에 적합하다. 또한, Look-up-Table(연산표)에 의하여 비선형 함수를 출력함으로써, 고속의 실수 연산을 수행할 수 있도록 설계하였다. 본 논문에서 제안한 방법은 현재 개발된 VLSI기술로 실현 가능하기 때문에 실제 신경회로망의 응용분야에 이용될 수 있을 것으로 기대된다.

• 대한기계학회논문집
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• 제12권1호
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• pp.163-172
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• 1988

본 논문에서는 GAC방법을 이용하여 공작기계의 안내면오차를 수치제어 공작기계가 가지고 있는 가공조건의 조절 능력을 이용하여 가공오차를 보상제어 함으로써 규명(identification)할 수 있는 방법을 제시한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.301-303
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• 2008

Tuning of the speed controller in the linear servo applications needs the accurate information of a mover mass including a load mass. Therefore this paper proposes the mass estimation method of a permanent magnet linear synchronous motor(PMLSM) applied at the vertical axis by using the recursive Least-Squares estimation algorithm. First, this paper derives the deterministic autoregressive moving average(DARMA) model of the mechanical dynamic system used at the vertical axis. Results obtained by the Matlab/Simulink simulation show that the mass of a PMLSM applied at the vertical axis can be accurately estimated both at no-load and at load.

• 대한의용생체공학회:의공학회지
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• 제17권1호
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• pp.99-108
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• 1996

Diverse digital filters have been designed previously to eliminate powerline(AC) interference in the electrocardiouam. This paper describes filtering methods which have been developed recursive notch, adaptive, IEF(Incremental Estimation Filter) and proposes a new AIEF(Advanced Incremental Estimation Filter) method. The performances of these filters are compared on artificial signals as well as actual ECG signals with the aid of validated CSE(Common Standards for Quantitative Electrocardiowaphy). AC interference in this database is shown to exhibit two qualities especially relevant to filter design : considerable deviations from a nominal 60Hz frequency and substantial noise at higher harmonics.