• Title/Summary/Keyword: Recursive Least Squares

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FIR System Identification Method Using Collaboration Between RLS (Recursive Least Squares) and RTLS (Recursive Total Least Squares) (RLS (Recursive Least Squares)와 RTLS (Recursive Total Least Squares)의 결합을 이용한 새로운 FIR 시스템 인식 방법)

  • Lim, Jun-Seok;Pyeon, Yong-Gook
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.6
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    • pp.374-380
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    • 2010
  • It is known that the problem of FIR filtering with noisy input and output data can be solved by a total least squares (TLS) estimation. It is also known that the performance of the TLS estimation is very sensitive to the ratio between the variances of the input and output noises. In this paper, we propose a convex combination algorithm between the ordinary recursive LS based TLS (RTLS) and the ordinary recursive LS (RLS). This combined algorithm is robust to the noise variance ratio and has almost the same complexity as the RTLS. Simulation results show that the proposed algorithm performs near TLS in noise variance ratio ${\gamma}{\approx}1$ and that it outperforms TLS and LS in the rage of 2 < $\gamma$ < 20. Consequently, the practical workability of the TLS method applied to noisy data has been significantly broadened.

Adaptive System Identification Using an Efficient Recursive Total Least Squares Algorithm

  • Choi, Nakjin;Lim, Jun-Seok;Song, Joon-Il;Sung, Koeng-Mo
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.3E
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    • pp.93-100
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    • 2003
  • We present a recursive total least squares (RTLS) algorithm for adaptive system identification. So far, recursive least squares (RLS) has been successfully applied in solving adaptive system identification problem. But, when input data contain additive noise, the results from RLS could be biased. Such biased results can be avoided by using the recursive total least squares (RTLS) algorithm. The RTLS algorithm described in this paper gives better performance than RLS algorithm over a wide range of SNRs and involves approximately the same computational complexity of O(N²).

A Coupled Recursive Total Least Squares-Based Online Parameter Estimation for PMSM

  • Wang, Yangding;Xu, Shen;Huang, Hai;Guo, Yiping;Jin, Hai
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2344-2353
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    • 2018
  • A coupled recursive total least squares (CRTLS) algorithm is proposed for parameter estimation of permanent magnet synchronous machines (PMSMs). TLS considers the errors of both input variables and output ones, and thus achieves more accurate estimates than standard least squares method does. The proposed algorithm consists of two recursive total least squares (RTLS) algorithms for the d-axis subsystem and q-axis subsystem respectively. The incremental singular value decomposition (SVD) for the RTLS obtained by an approximate calculation with less computation. The performance of the CRTLS is demonstrated by simulation and experimental results.

An Efficient Recursive Total Least Squares Algorithm for Training Multilayer Feedforward Neural Networks

  • Choi Nakjin;Lim Jun-Seok;Sung Koeng-Mo
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.527-530
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    • 2004
  • We present a recursive total least squares (RTLS) algorithm for multilayer feedforward neural networks. So far, recursive least squares (RLS) has been successfully applied to training multilayer feedforward neural networks. But, when input data contain additive noise, the results from RLS could be biased. Such biased results can be avoided by using the recursive total least squares (RTLS) algorithm. The RTLS algorithm described in this paper gives better performance than RLS algorithm over a wide range of SNRs and involves approximately the same computational complexity of $O(N^{2})$.

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Real-time Projectile Motion Trajectory Estimation Considering Air Resistance of Obliquely Thrown Object Using Recursive Least Squares Estimation (비스듬히 던진 물체의 공기저항을 고려한 재귀 최소 자승법 기반 실시간 포물선 운동 궤적 추정)

  • Jeong, Sangyoon;Chwa, Dongkyoung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.3
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    • pp.427-432
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    • 2018
  • This paper uses a recursive least squares method to estimate the projectile motion trajectory of an object in real time. The equations of motion of the object are obtained considering the air resistance which occurs in the actual experiment environment. Because these equations consider air resistance, parameter estimation of nonlinear terms is required. However, nonlinear recursive least squares estimation is not suitable for estimating trajectory of projectile in that it requires a lot of computation time. Therefore, parameter estimation for real-time trajectory prediction is performed by recursive least square estimation after using Taylor series expansion to approximate nonlinear terms to polynomials. The proposed method is verified through experiments by using VICON Bonita motion capture system which can get three dimensional coordinates of projectile. The results indicate that proposed method is more accurate than linear Kalman filter method based on the equations of motion of projectile that does not consider air resistance.

Adaptive Inverse Modelling of Noisy System by Total Least Squares (완전최소자승법을 이용한 잡음환경하에서 시스템의 적응 역 모델링)

  • 황재섭
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1991.06a
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    • pp.23-27
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    • 1991
  • RLS(Recursive Least Squares)나 LMS(Least mean square)등은 알고리듬 고유의 성질상 잡음이 섞인 시스템에 있어서는 올바른 역 모델링을 할 수 없다. 따라서, 잡음의 영향을 받지않는 견실한(robust) 모델 추정 알고리듬이 필요하다. 본 논문에서는 잡음환경하에 있는 시스템을역 모델링하는데 있어서, 잡음의 영향을 줄이기위해 완전최소자승법을 도입하고 기존의 최소자승법과 비교 실험하였다. 그리고, 이 방법의 적응 알고리듬을 제안하였으며, RLS(Recursive least squares)와 그 성능을 비교하여 타당성을 검토하였다.

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A study on robust recursive total least squares algorithm based on iterative Wiener filter method (반복형 위너 필터 방법에 기반한 재귀적 완전 최소 자승 알고리즘의 견실화 연구)

  • Lim, Jun Seok
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.3
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    • pp.213-218
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    • 2021
  • It is known that total least-squares method shows better estimation performance than least-squares method when noise is present at the input and output at the same time. When total least squares method is applied to data with time series characteristics, Recursive Total Least Squares (RTS) algorithm has been proposed to improve the real-time performance. However, RTLS has numerical instability in calculating the inverse matrix. In this paper, we propose an algorithm for reducing numerical instability as well as having similar convergence to RTLS. For this algorithm, we propose a new RTLS using Iterative Wiener Filter (IWF). Through the simulation, it is shown that the convergence of the proposed algorithm is similar to that of the RTLS, and the numerical robustness is superior to the RTLS.

QR-Decomposition based Adaptive Bbilinear Lattice Algorithms (QR 분해법을 이용한 적응 쌍선형 격자 알고리듬)

  • 안봉만;황지원;백흥기
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.10
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    • pp.32-43
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    • 1994
  • This paper presents new QRD-based recursive least squares algorithms for bilinear lattice filter. Bilinear recursive least square lattice algorithms are derived by using the QR decomposition for minimization covariance matrix of predication error by applying Givens rotation to the bilinear recursive least squares lattics algorithms. The proposed algorithms are applied to the bilinear system identification to evaluate the performance of algoithms. Computer simulations show that the convergence properties of the proposed algorithms are superior to that of the algorithms proposed by Baik when signal includes the measurement noise.

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Least-squares Lattice Laguerre Smoother

  • Kim, Dong-Kyoo;Park, Poo-Gyeon
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1189-1191
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    • 2005
  • This paper introduces the least-squares order-recursive lattice (LSORL) Laguerre smoother that has order-recursive smoothing structure based on the Laguerre signal representation. The LSORL Laguerre smoother gives excellent performance for a channel equalization problem with smaller order of tap-weights than its counterpart algorithm based on the transversal filter structure. Simulation results show that the LSORL Laguerre smoother gives better performance than the LSORL transversal smoother.

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A New Recursive Least-Squares Algorithm based on Matrix Pseudo Inverses (ICCAS 2003)

  • Quan, Zhonghua;Han, Soo-Hee;Kwon, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.927-931
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    • 2003
  • In this paper, a new Recursive Least-Squares(RLS) algorithm based on matrix pseudo-inverses is presented. The aim is to use the proposed new RLS algorithm for not only the over-determined but also the under-determined estimation problem. Compared with previous results, e.g., Jie Zhou et al., the derivation of the proposed recursive form is much easier, and the recursion form is also much simpler. Furthermore, it is shown by simulations that the proposed RLS algorithm is more efficient and numerically stable than the existing algorithms.

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