• Title/Summary/Keyword: least-square

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Least Mean Square Estimator for Motor Frequency Measurement Based on Linear Hall Sensor (선형 홀센서 기반의 모터 회전속도 측정을 위한 평균 최소 자승 추정기)

  • Choi, Ga-Hyoung;Ra, Won-Sang;Kwak, Ki-Seok;Yoon, Tae-Sung;Park, Jin-Bae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.5
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    • pp.866-874
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    • 2008
  • Motor frequency can be measured by a hall sensor. Among the many hall sensors, a linear type hall sensor is good at high accuracy frequency measuring problem. However, in general, this linear type hall sensor has DC offset which can vary along sensor's operating voltage change. Therefore, In motor frequency measurement problem using the linear hall sensor, it needs an estimator that can estimate frequency and DC offset simultaneously. In this paper, we propose the least mean square estimator to estimate motor frequency. To verify its performance, we compare the LMS estimator with a commercial analog tachometer. Experimental results shows the proposed LMS estimator works well in varying frequency and stationary DC offset.

Numerical analysis of free surface flow s using least square/level-set method (최소자승법과 Level-set 방법을 이 용한 자유표면 유동의 수치해석)

  • Choi, Hyoung-G.
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.565-567
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    • 2008
  • In the present study, a least square/level set based two-phase flow code has been developed using finite element discretization, which can be utilized for the analysis of a free surface flow problem in a complex geometry. Since the finite element method is employed for the spatial discretization of governing equations, an unstructured mesh can be naturally adopted for the level set simulation of a bubble-in-liquid flow without an additional load for the code development except that solution methods of the hyperbolic type redistancing and advection equations of the level set function should be devised in order to give a bounded solution on the unstructured mesh. For the discretization of hyperbolic type redistancing and advection equations, least square method is adopted. From the numerical experiments of the present study, it is shown that the proposed method is both robust and accurate.

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A High Speed Distance Relaying Algorithm Based on a Least Square Error Method (최소자승법을 이용한 고속 거리계전 알고리즘)

  • Gang, Sang-Hui;Gwon, Tae-Won
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.7
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    • pp.855-862
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    • 1999
  • A high speed digital distance relaying algorithm based on a least square error method is proposed. To obtain stable phasor values very quickly, first, a lowpass filter which has very short transient period and no overshoot is presented. Secondly, the least square error method having the data window of 3 samples is used by applying a FIR filter which removes the DC-offset component in current relaying signals. Test results show that the proposed distance relaying algorithm detects most of internal faults within a half cycle after faults in a 154[kV] overhead transmission line system.

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Research on Noise Reduction Algorithm Based on Combination of LMS Filter and Spectral Subtraction

  • Cao, Danyang;Chen, Zhixin;Gao, Xue
    • Journal of Information Processing Systems
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    • v.15 no.4
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    • pp.748-764
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    • 2019
  • In order to deal with the filtering delay problem of least mean square adaptive filter noise reduction algorithm and music noise problem of spectral subtraction algorithm during the speech signal processing, we combine these two algorithms and propose one novel noise reduction method, showing a strong performance on par or even better than state of the art methods. We first use the least mean square algorithm to reduce the average intensity of noise, and then add spectral subtraction algorithm to reduce remaining noise again. Experiments prove that using the spectral subtraction again after the least mean square adaptive filter algorithm overcomes shortcomings which come from the former two algorithms. Also the novel method increases the signal-to-noise ratio of original speech data and improves the final noise reduction performance.

An Efficient QCLS Positioning Method Using Weight Estimation for TDOA Measurements (TDOA 측정치를 이용한 가중치 추정방식의 QCLS 측위 방법)

  • Kim, Dong-Hyouk;Song, Seung-Hun,;Park, Kyoung-Soon;Sung, Tae-Kyung
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.4 s.316
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    • pp.1-7
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    • 2007
  • When the sensor geometry is poor, the user position estimate obtained by of GN (Gauss-Newton) method is often diverged in radio navigation. In other to avoid divergence problem QCLS (Quadratic Correction Least Square) method using TDOA (Time Difference of Arrival) measurements is introduced, but the estimation error is somewhat large. This paper presents the modified QCLS method using weighted least square. Since the weighting matrix is influenced by the unknown user position, two-step approach is employed in the proposed method. The weighting matrix is estimated in the first step using least square, and then find user position is obtained using weighted least square. Simulation results show that the performance of the proposed method is superior to the conventional QCLS all over the workspace.

Robust Modal Parameter Idnentification Using Total Least Square Method (전최소자승법을 이용한 강인한 모드매개변수)

  • Jeong, Weui-Bong;Kim, Jun-Yeop;Kim, Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.3
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    • pp.843-849
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    • 1996
  • The least square estimation is used frequently in experimental modal analysis techinque to eliminate noise signals. However, identified modal parameters are sometimes inaccurate, since the least squre estimation is sensitive to noise. In this paper, a new total least squre estimation, which is robust to noise signals, is developed and applied to experimental modal analysis technique such as Prony method and Circle Fit method. Several simulated results show that the proposed method is robuster to noise than conventional method.

A New Circular Curve Fitting of Articulated Manipulators Using Least Squares (Least Square를 이용한 수직다관절 Manipulator의 새로운 원호 경로 보간 방법)

  • 정원지;이춘만;김대영;서영교;홍형표
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.4
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    • pp.17-22
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    • 2003
  • This paper presents a new circular curve fitting approach of articulated manipulators, based on least square. The approach aims at gaining the interpolation of circle from n data points, under the condition that the fitted circle should pass both a starting point and an ending point. First a spherical fitting should be performed, using least squares. Then the circular curve fitting can be resulted from the intersection of the fitted sphere and the plane obtained from 3 points, i. e., a starting point, an ending point and the center of a sphere. The proposed algorithms are shown to be efficient by using MATLAB-based simulation.

Analysis of Partial Least Square Regression on Textural Data from Back Extrusion Test for Commercial Instant Noodles (시중 즉석 조리 면의 Back Extrusion 텍스처 데이터에 대한 Partial Least Square Regression 분석)

  • Kim, Su kyoung;Lee, Seung Ju
    • Food Engineering Progress
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    • v.14 no.1
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    • pp.75-79
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    • 2010
  • Partial least square regression (PLSR) was executed on curve data of force-deformation from back extrusion test and sensory data for commercial instant noodles. Sensory attributes considered were hardness (A), springiness (B), roughness (C), adhesiveness to teeth (D), and thickness (E). Eight and two kinds of fried and non-fried instant noodles respectively were used in the tests. Changes in weighted regression coefficients were characterized as three stages: compaction, yielding, and extrusion. Correlation coefficients appeared in the order of E>D>A>B>C, root mean square error of prediction D>C>E>B>A, and relative ability of prediction D>C>E>B>A. Overall, 'D' was the best in the correlation and prediction. 'A' with poor prediction ability but high correlation was considered good when determining the order of magnitude.

Adaptive Feedback Interference Cancellation Algorithm Using Correlations for Adaptive Interference Cancellation System (적응 간섭 제거 시스템을 위한 상관도를 적용한 적응적 궤환 간섭 제거 알고리즘)

  • Han, Yong-Sik;Yang, Woon-Geun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.4
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    • pp.427-432
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    • 2010
  • To reduce the outage probability and to increase the transmission capacity, the importance of repeaters in cellular systems is increasing. But a RF(Radio Frequency) repeater has a problem that the output of the transmit antenna is partially feedback to the receive antenna, which is feedback interference. In this paper, we proposed adaptive Sign-Sign LMS(Least Mean Square) algorithm using correlations for the performance enhancement of RF repeater. The weight vector is updated by using sign of input signal and error signal to the least squared error of the conventional algorithms. When compared with the conventional method, the proposed canceller achieves the maximum 10 dB performance gain in terms of the MSE(Mean Square Error).

Interference Cancellation System in Repeater Using Adaptive algorithm with step sizes (스텝사이즈에 따른 적응 알고리즘을 이용한 간섭제거 중계기)

  • Han, Yong-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.5
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    • pp.549-554
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    • 2014
  • In the paper, we propose a new Signed LMS(Least Mean Square) algorithm for ICS(Interference Cancellation System). The proposed Signed LMS algorithm improved performances by adjusting step size values. At the convergence of 1000 iteration state, the MSE(Mean Square Error) performance of the proposed Signed LMS algorithm with step size of 0.067 is about 3 ~ 18 dB better than the conventional LMS, CMA algorithm. And the proposed Signed LMS algorithm requires 500 ~ 4000 less iterations than the and LMS and CMA algorithms at MSE of -25dB.