• Title/Summary/Keyword: recursive system

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Windowed Quaternion Estimator For Gyroless Spacecraft Attitude Determination

  • Kim, Injung
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.167.5-167
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    • 2001
  • Single point attitude determination method provides an optimal attitude minimizing the Wahba loss function. However, for the insufficient number of measurement vectors, the conventional single point methods has no unique solution. Thus, we introduce the sequential method to and an optimal attitude minimizing the windowed loss function. In this paper, this function is de ned as the sum of square errors for all measurement vectors within the axed sliding window. For simple implementation, the proposed algorithm is rewritten as a recursive form. Moreover, the covariance matrix is derived and expressed as a recursive form. Finally, we apply this algorithm to the attitude determination system with three LOS measurement sensors.

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Real-time recursive identification of unknown linear systems (미지의 선형 시스템에 대한 실시감 회귀 모델링)

  • 최수일;김병국
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.548-553
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    • 1992
  • In this paper and recursive version of orthogonal ARMA identification algorithm is proposed. The basic algorithm is based on Gram-Schmidt orthogonalization of automatically selected basis functions from specified function space, but does not require explicit creation of orthogonal functions. By using two dimensional autocorrelations and crosscorrelations of input and output with constant data length, identification algorithm is extended to cope slowly time-varying or order-varying delayed system.

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On-Line Identification Algorithm of Unknown Linear Systems (미지의 선형 시스템에 대한 On-Line 모델링 알고리즘)

  • 최수일;김병국
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.4
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    • pp.48-54
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    • 1994
  • A recursive on-line algorithm with orthogonal ARMA identification is proposed for linear systems with unkonwn time delay, order, and parameters. The algorithm is based on the Gram-Schmidt orthogonalization of basis functions, and extendedto recursive form by using two dimensional autocorrelations and crosscorrelations of input and output with constant data length. The proposed algorith can cope with slowly time-varying or order-varying delayed system. Various simulations reveal the performance of the algorithm.

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RECURSIVE TWO-LEVEL ILU PRECONDITIONER FOR NONSYMMETRIC M-MATRICES

  • Guessous, N.;Souhar, O.
    • Journal of applied mathematics & informatics
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    • v.16 no.1_2
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    • pp.19-35
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    • 2004
  • We develop in this paper some preconditioners for sparse non-symmetric M-matrices, which combine a recursive two-level block I LU factorization with multigrid method, we compare these preconditioners on matrices arising from discretized convection-diffusion equations using up-wind finite difference schemes and multigrid orderings, some comparison theorems and experiment results are demonstrated.

A New Algorithm for Recursive Short-term Load Forecasting (순환형식에 의한 기분거좌상측 알고리)

  • Young-Moon Park;Sung-Chul Oh
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.32 no.5
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    • pp.183-188
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    • 1983
  • This paper deals with short-term load forecasting. The load model is represented by the state variable form to exploit the Kalman filter technique. The load model is derived from Taylor series expansion and remainder term is considered as noise term. In order to solve recursive filter form, among various algorithm of solving Kalman filter, this paper uses exponential data weighting technique. This paper also deals with the asymptotic stability of filter. Case studies are carried out for the hourly power demand forecasting of the Korea electrical system.

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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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The Efficient Implementation of DGPS System with Low Cost GPS modules Using a Recursive Least Squares Lattice Filtering Method (RLSLF 방식을 적용하여 저가의 GPS 모듈로 구성된 DGPS 시스템의 효율적인 구현)

  • 이창복;주세철;김기두;김영범
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.10
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    • pp.1338-1346
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    • 1995
  • In this paper, we suggest the implementation of a DGPS system using two low cost commercial C/A code GPS modules and modems and its efficient operational techniques to provide DGPS service which guarantees the position accuracy of better than 10 meters for more users. The proposed DGPS system can be implemented easil at low cost because it needs a GPS module and a modem for each reference station and user. The reference station makes plans of the receiving schedule from the satellite set at each period and then provides the correction data for various satellite sets in a period. The main contribution of this paper is that users can utilize the correction data continuously and efficiently through the recursive least squares lattice filtering method. Experimental results show the position accuracy of better than 10 meters using the suggested DGPS system in almost real time.

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A Study on the Parameters Estimation of Electro-Hydraulic Servo Systems Using RMSM (RLSM 방법을 이용한 전기 유압 서보 시스템의 파라미터 추정에 관한 연구)

  • Kim, Byeong-Woo;Hur, Jin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1510-1514
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    • 2011
  • In this paper, linear discrete model of the electro-hydraulic servo system are made for parameters estimation. The parameters of electro-hydraulic servo system are estimated using the recursive least square method. Persistent excitation conditions are studied in order to estimate parameters of electro-hydraulic servo system to real values and parameters estimation affections are studied due to the forgetting factors variation. As the results, An parameter estimation method has been synthesized for minimizing the error between reference and error.

A Recursive Algorithm for Generating the Equations of Motion of Spatial Mechanical Systems with Application to the Five-Point Suspension

  • Attia, Hazem-Ali
    • Journal of Mechanical Science and Technology
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    • v.18 no.4
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    • pp.550-559
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    • 2004
  • In this paper, a recursive formulation for generating the equations of motion of spatial mechanical systems is presented. The rigid bodies are replaced by a dynamically equivalent constrained system of particles which avoids introducing any rotational coordinates. For the open-chain system, the equations of motion are generated recursively along the serial chains using the concepts of linear and angular momenta Closed-chain systems are transformed to open-chain systems by cutting suitable kinematic joints and introducing cut-joint constraints. The formulation is used to carry out the dynamic analysis of multi-link five-point suspension. The results of the simulation demonstrate the generality and simplicity of the proposed dynamic formulation.

A FLUID TRANSIENT ANALYSIS FOR THE PROPELLANT FLOW WITH AN UNSTEADY FRICTION IN A MONOPROPELLANT PROPULSION SYSTEM (단일추진제 추진시스템의 비정상 마찰을 고려한 과도기유체 해석)

  • Chae Jong-Won
    • Journal of computational fluids engineering
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    • v.11 no.1 s.32
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    • pp.43-51
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    • 2006
  • A fluid transient analysis on the Koreasat 1 & 2 pipeline system is conducted through numerical parametric studies in which unsteady friction results are compared with quasi-steady friction results and show relatively accurate prediction of the response curve with the unsteady friction. The code developed and used in this analysis has finished verification through comparing with the original Zielke model, the full and recursive convolution model and quasi-steady model as a reference. The unsteady friction is calculated by the recursive convolution Zielke model in which a complete evolution history of velocity field is no longer required so that it makes the fluid transient analysis on the complicated system possible. The results show that the application of quasi-steady friction to model cannot predict the entire response curve properly except the first peak amplitude but the application of unsteady friction to model can predict reasonably the response curve, therefore it is to know the characteristics of the propulsion system.