• Industrial Engineering and Management Systems
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• 제9권3호
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• pp.262-274
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• 2010

This article investigates how to adaptively predict the time-varying metrology delay that could realistically occur in the semiconductor manufacturing practice. Metrology delays pose a great challenge for the existing run-to-run (R2R) controllers, driving the process output significantly away from target if not adequately predicted. First, the expected asymptotic double exponentially weighted moving average (DEWMA) control output, by using the EWMA and recursive least squares (RLS) prediction methods, is derived. It has been found that the relationships between the expected control output and target in both estimation methods are parallel, and six cases are addressed. Within the context of time-varying metrology delay, this paper presents a modified recursive least squares-linear trend (RLS-LT) controller, in combination with runs test. Simulated single input-single output (SISO) R2R processes subject to various time-varying metrology delay scenarios are used as a testbed to evaluate the proposed algorithms. The simulation results indicate that the modified RLS-LT controller can yield the process output more accurately on target with smaller mean squared error (MSE) than the original RLSLT controller that only deals with constant metrology delays.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권4호
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• pp.129-136
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• 2002

This paper presents a $H_{\infty}$ robust controller with parameter estimation in polynomial approach. For good performance of a uncertain system, the parameters are estimated by RLS algorithm. The controller minimizes the sum of $H_{\infty}$ norm between sensitivity function and complementary sensitivity function by employing the Youla parameterization and polynomial approach at the same time. A numerical example and its simulation results are given to show the validity of the proposed controller.

• 전기학회논문지
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• 제56권2호
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• pp.311-316
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• 2007

This paper proposes the algorithm which estimates moment of the inertia and friction coefficient of friction for high performance speed control of electric motor. The proposed algorithm finds the moment of inertia and friction coefficient of friction by observing the speed error signal generated by the speed observer and using Recursive Least-Mean-Square method(RLS). By feedbacking the estimated inertia and estimated coefficient of friction to speed controller and full order speed observer, then the errors of the inertia and coefficient of friction and speed due to the inaccurate initial value are decreased. Inertia and coefficient of friction converge to the actual value within several times of speed changing. Simulation and actual experiment results are given to demonstrate the effectiveness of the proposed parameter estimator.

• 한국통신학회논문지
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• 제22권7호
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• pp.1468-1476
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• 1997

상태축약심볼열추정(RSSE: Reduced State Sequence Estimation) 수신기는 비터비 복호기와 채널 추정기로 구성된다. 이동통신과 같이 채널이 변하는 환경에서는 적응 채널추정기(adaptive channel estimator)로 채널의 변화를 계속적으로 추정해야 한다. 일반적으로 사용되는 채널 추정기는 임시결정된 비터비 복호기의 출력을 사용하여 채널을 추정 하는데, 비터비 복호기에서 잘못된 결정을 내릴 경우 이로 인해 오류전파(error propagation)가 발생할 수있다. 본 논문에서는 좀더 정확한 채널 추정과 오류전파를 막기 위해 경로 메모리를 사용하는 새로운 채널추정기를 사용한다. 이 채널 추정기는 비터비 복호기의 여러 경로중에서 가장 작은 경로를 선택하여 그 경로상의 신호를 이용하여 채널 추정을 행한다. 그리고 채널 추정기의 적응 알고리듬으로서 LMS(Least Mean Square)알고리듬과 Recursive Least Square(RLS) 알고리듬을 사용하여 비교한다. 실험 결과를 통해 제안된 채널 추정기를 사용하는 RSSE 수신기가 기존의 채널 추정기를 사용하는 RSSE 수신기에 비해 더 나은 성능을 나타내는 것을 볼 수있으며, 페이딩이 존재하는 이동통신 환경에서는 LMS 알고리듬이 적합하지 않음을 알 수있다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 추계학술대회 논문집
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• pp.200-201
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• 2013

This paper investigates a new approach for Li-Ion battery state-of-charge (SOC) estimation using sliding mode observer (SMO) technique including parameters aging compensation via recursive least squares (RLS). The main advantages of this approach would be low computational load, easiness of implementation along with the robustness of the method for internal battery model parameters estimation. The proposed algorithm was first tested on a set of acquired battery data using implementation in Simulink and later developed as C-code module for firmware application.

• 한국음향학회지
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• 제29권6호
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• pp.374-380
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• 2010

잡음이 섞인 입출력 신호를 갖는 시스템 인식 문제는 완전 최소 자승법 (Total Least Squares (TLS))으로 알려져 있다. 완전 최소 자승법의 성능은 입력 신호 부가 잡음 파워와 출력 신호 부가 잡음간의 분산비에 매우 민감하다. 본 논문에서는 TLS의 성능 향상을 위해서 LS (Least Squares)와의 결합을 제안한다. 그 한 형태로 재차적인 TLS (Recursive TLS)와 재차적인 LS (Recursive Least Squares)간의 결합 알고리즘을 제안한다. 이 결합은 잡음간 분산비에 강인한 결과를 낳았다. 모의실험을 통해 얻은 결과로부터 입력 신호에 신호대 잡음비가 5dB를 유지히는 잡음을 부가할 경우 입력 잡음과출력 잡음의 비 $\gamma$가 약 20 정도까지로 적용 범위가 확대되는 결과를 얻었다. 따라서 제안된 결합 방법이 기존의 TLS의 적용 범위를 넓힐 수 있음을 알 수 있다.

• Journal of Power Electronics
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• 제9권4호
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• pp.654-666
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• 2009

Direct torque control (DTC) of induction machines (IM) is a well-known strategy of these drives control which has a fast dynamic and a good tracking response. In this paper a nonlinear DTC of speed sensorless IM drives is presented which is based on input-output feedback linearization control theory. The IM model includes iron losses using a speed dependent shunt resistance which is determined through some effective experiments. A stator flux vector is estimated through a simple integrator based on stator voltage equations in the stationary frame. A novel method is introduced for DC offset compensation which is a major problem of AC machines, especially at low speeds. Rotor speed is also determined using a rotor flux sliding-mode (SM) observer which is capable of rotor flux space vector and rotor speed simultaneous estimation. In addition, stator and rotor resistances are estimated using a simple but effective recursive least squares (RLS) method combined with the so-called SM observer. The proposed control idea is experimentally implemented in real time using a FPGA board synchronized with a personal computer (PC). Simulation and experimental results are presented to show the capability and validity of the proposed control method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.877-881
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• 2007

Recently, noise map is used widely by synthetic estimation method for noise reduction. For correct manufacture of noise map, selection of suitable noise prediction method is important. This study compares XPS31-133 with CRTN, RLS90 which are widely used by foreign commercial noise maps.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.559-562
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• 2011

본 연구에서, 우리는 상호신호 간 간섭 및 부가적인 백색 가우시안 잡음이 존재하는 디지털 펄스폭 변조 시퀀스에 대하여 추정하는 적응 최우 추정 채널로써 회귀 최소 자승 알고리듬을 유도였으며 회귀 최소 자승 알고리듬은 기존의 최소자승 알고리듬보다 수렴특성이 더 좋음을 알 수 있었다.

• 제어로봇시스템학회논문지
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• 제22권8호
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• pp.650-655
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• 2016

In this paper, a novel RLS-based DOB (Recursive Least Squares Disturbance Observer) scheme is proposed to improve the performance of DOB for nominal model identification. A nominal model can be generally assumed to be a second order system in the form of a proper transfer function of an ARMA (Autoregressive Moving Average) model. The RLS algorithm for the model identification is proposed in association with DOB. Experimental studies of the balancing control of a one-wheel robot are conducted to demonstrate the feasibility of the proposed method. The performances between the conventional DOB scheme and the proposed scheme are compared.