• Title/Summary/Keyword: Recursive estimation

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Design of self-tuning controller utilizing neural network (신경회로망기법을 이용한 자기동조제어기 설계)

  • 구영모;이윤섭;김대종;임은빈;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.399-401
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    • 1989
  • Utilizing an interconnected set of neuron-like elements, the present study is to provide a method of parameter estimation for a second order linear time invariant system of self-tuning controller. The result from the proposed method is evaluated by comparing with those obtained by the recursive least square (RLS) identification algorithm and extended recursive least square (ERLS) algorithm, and it shows that, although the smoothness of system performance is still to be improved, the effectiveness of shorter computing time is demonstrated which may be of considerable value to real time computing.

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System Identification of a Small Unmanned Rotorcraft (소형 무인 헬리콥터의 시스템 식별)

  • Ryu, Seong-Sook;Song, Yong-Kyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.1
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    • pp.44-53
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    • 2009
  • In this paper, Recursive Least Squares (RLS) and Fourier Transform Regression (FTR) methods for estimating stability and control derivatives of small unmanned helicopter are evaluated together with MMLE technique. Flight data simulated by using a commercial small-scale helicopter model are exploited to estimate the parameters with accuracies for hover and cruise modes. The performances of the system identification methods are also compared by analyzing the responses of the reconstructed systems using estimated derivatives.

Monitoring System Design for Estimating Lateral Velocity and Sideslip Angle (감지시스템을 통한 차량의 횡 속도 및 슬립각 추정)

  • Han, Sang-Oh;Huh, Kun-Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.1
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    • pp.51-57
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    • 2011
  • Information of the lateral velocity and the sideslip angle in a vehicle is very useful in many active vehicle safety applications such as yaw stability control and rollover prevention. Because cost-effective sensors to measure the lateral velocity and the sideslip angle are not available, reliable algorithms to estimation them are necessary. In this paper, a sliding mode observer is designed to estimate the lateral velocity. The side slip angle is estimated using the recursive least square with the disturbance observer and the pseudo integral. The estimated parameters from the combined estimation method are updated recursively to minimize the discrepancy between the model and the physical plant, and any possible effects caused by disturbances. The performance of the proposed monitoring system is evaluated through simulations and experiments.

Estimation of Electrical Loads Patterns by Usage in the Urban Railway Station by RNN (RNN을 활용한 도시철도 역사 부하 패턴 추정)

  • Park, Jong-young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.11
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    • pp.1536-1541
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    • 2018
  • For effective electricity consumption in urban railway station such as peak load shaving, it is important to know each electrical load pattern by various usage. The total electricity consumption in the urban railway substation is already measured in Korea, but the electricity consumption for each usage is not measured. The author proposed the deep learning method to estimate the electrical load pattern for each usage in the urban railway substation with public data such as weather data. GRU (gated recurrent unit), a variation on the LSTM (long short-term memory), was used, which aims to solve the vanishing gradient problem of standard a RNN (recursive neural networks). The optimal model was found and the estimation results with that were assessed.

Multiprocess Dynamic Survival Models with Numbers of Deaths

  • Joo Yong Shim;Joong Kweon Sohn;Sang Gil Kang
    • Journal of the Korean Statistical Society
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    • v.25 no.4
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    • pp.567-576
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    • 1996
  • The multiprocess dynamic survival model is proposed for the application of the regression model on the analysis of survival data with time-varying effects of covariates : where the survival data consists of numbers of deaths at certain time-points. The algorithm for the recursive estimation of a time-varying parameter vector is suggested. Also the algorithm of forecasting of numbers of deaths of each group in the next time interval based on the information gathered until the end of current time interval is suggested.

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The Fault Location Estimation Algorithm in Transmission Line Using a Recursive Least Square Error Method (순환형 최소자승법을 이용한 송전선로의 고장점 추정 알고리즘)

  • Yoon, C.D.;Lee, J.J.;Jung, H.S.;Shin, M.C.;Choi, S.Y.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.203-205
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    • 2002
  • This paper presents the fault location estimation algorithm in transmission line using a recursive least square error method (RLSE). To minimize the computational burden of the digital relay a RLSE approach is used. Computer simulation results of the RLSE algorithm seem promising, indicating that it should be considered for further testing and evaluation.

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Inertia and Coefficient of Friction Estimation of Electric Motor using Recursive Least-Mean-Square Method (순환 최소자승법을 이용한 전동기 관성과 마찰계수 추정)

  • Kim, Ji-Hye;Choi, Jong-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.2
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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.

Blind Signal Processing for Wireless Sensor Networks

  • Kim, Namyong;Byun, Hyung-Gi
    • Journal of Sensor Science and Technology
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    • v.23 no.3
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    • pp.158-164
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    • 2014
  • In indoor sensor networks equalization algorithms based on the minimization of Euclidean distance (MED) for the distributions of constant modulus error (CME) have yielded superior performance in compensating for signal distortions induced from optical fiber links, wireless-links and for impulsive noise problems. One main drawback of MED-CME algorithms is a heavy computational burden hindering its implementation. In this paper, a recursive gradient estimation for weight updates of the MED-CME algorithm is proposed for reducing the operations $O(N^2)$ of the conventional MED-CME to O(N) at each iteration time for N data-block size. From the simulation results of the proposed recursive method producing exactly the same results as the conventional method, the proposed estimation method can be considered to be a reliable candidate for implementation of efficient receivers in indoor sensor networks.

Residual Synchronization Error Elimination in OFDM Baseband Receivers

  • Hu, Xingbo;Huang, Yumei;Hong, Zhiliang
    • ETRI Journal
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    • v.29 no.5
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    • pp.596-606
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    • 2007
  • It is well known that an OFDM receiver is vulnerable to synchronization errors. Despite fine estimations used in the initial acquisition, there are still residual synchronization errors. Though these errors are very small, they severely degrade the bit error rate (BER) performance. In this paper, we propose a residual error elimination scheme for the digital OFDM baseband receiver aiming to improve the overall BER performance. Three improvements on existing schemes are made: a pilot-aided recursive algorithm for joint estimation of the residual carrier frequency and sampling time offsets; a delay-based timing error correction technique, which smoothly adjusts the incoming data stream without resampling disturbance; and a decision-directed channel gain update algorithm based on recursive least-squares criterion, which offers faster convergence and smaller error than the least-mean-squares algorithms. Simulation results show that the proposed scheme works well in the multipath channel, and its performance is close to that of an OFDM system with perfect synchronization parameters.

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Mixture Filtering Approaches to Blind Equalization Based on Estimation of Time-Varying and Multi-Path Channels

  • Lim, Jaechan
    • Journal of Communications and Networks
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    • v.18 no.1
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    • pp.8-18
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    • 2016
  • In this paper, we propose a number of blind equalization approaches for time-varying andmulti-path channels. The approaches employ cost reference particle filter (CRPF) as the symbol estimator, and additionally employ either least mean squares algorithm, recursive least squares algorithm, or $H{\infty}$ filter (HF) as a channel estimator such that they are jointly employed for the strategy of "Rao-Blackwellization," or equally called "mixture filtering." The novel feature of the proposed approaches is that the blind equalization is performed based on direct channel estimation with unknown noise statistics of the received signals and channel state system while the channel is not directly estimated in the conventional method, and the noise information if known in similar Kalman mixture filtering approach. Simulation results show that the proposed approaches estimate the transmitted symbols and time-varying channel very effectively, and outperform the previously proposed approach which requires the noise information in its application.