• Title/Summary/Keyword: 파라미터 추정 오차

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Modeling and Parameter estimation of Antilock Braking System (최소자승법에 의한 ABS(Antilock Braking System)의 모델링 및 파라미터 평가)

  • Song, Chang-Sub;Rho, Hyoung-Woo
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.4
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    • pp.87-92
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    • 2002
  • By using the signal error test, model structure of total antilock braking system consisting of electromagnetic system and hydraulic system is determined as 9th order system. For determining parameters of the ABS, using time discrete model of parametric method, parameters in time discrete model are searched by least square method. By bilinear transform, we have found the model of ABS in s domain. Afterward, experimental output data is compared with simulated output data by MATLAB haying identified parameter. As the result, experimental data is agreed with simulated data very well.

Modeling and Parameter Estimation of Solenoid Valve in Automatic Transmission by the Least Square Method (최소자승법에 의한 A/T용 솔레노이드 밸브의 모델링 및 파라미터 평가)

  • 노형우;박상훈;송창섭
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.10
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    • pp.98-104
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    • 2003
  • Model structure of solenoid valve in the automatic transmission is determined as 5th order system by the signal error test. For determining parameter of the solenoid valve, parameters in time discrete model are searched by the least square method. By bilinear transform, we have found the model of solenoid valve in s domain. Afterward, experimental output data is compared with simulated output data by MATLAB having identified parameter. As the result, experimental data is agreed with simulated data very well.

A State Observer for MINO Nonlinear Systems (다입력 다출력 비선형 시스템의 상태 관측기 설계)

  • Lee, Sung-Ryul
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.5
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    • pp.8-12
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    • 2008
  • In this paper, the robust state observer for nonlinear systems with unknown disturbance is proposed. The proposed method has an advantage in that it can reduce the effect of disturbance on estimation error of observer up to a specified level. Therefore, our design a roach can deal with a larger class of uncertain nonlinear system than the existing methods. The sufficient conditions on the existence of robust observer are characterized by well grown linear matrix inequality. Finally, an illustrative example is given to verify the proposed design scheme.

An Approach of Ultra-Precision Positioning System using Adaptive Fuzzy-Kalman Filter Observer (적응형 퍼지-칼만 필터 기반의 초정밀 위치 결정 시스템 제어)

  • Choi, In-Sung;Choi, Seung-Ok;You, Kwan-Ho
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.221-222
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    • 2007
  • 본 논문에서는 초정밀 위치 결정 시스템에서 보다 정확한 제어를 위한 새로운 제어기를 설계한다. 외란을 고려한 시스템의 경우, 환경이 달라질 때마다 측정 노이즈를 정확하게 알아내기란 쉽지 않다. 따라서 측정 장치의 정확성을 나타낼 수 있도록 칼만 필터추정기와 퍼지 이론을 이용하여 정확한 측정 오차값을 구한다. 이때, 파라미터 불확실성과 의란에 강인한 제어를 위해 슬라이딩 모드 제어기와 LQ 최적 제어기가 적용된다. 최종적으로, 제안된 제어기와 시간 최적 제어기의 성능비교를 통하여 보다 강인하고 안정된 성능개선을 증명한다.

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Establishment of Correspondent points and Sampling Period Needed to Estimate Object Motion Parameters (운동물체의 파라미터 추정에 필요한 대응점과 샘플링주기의 설정)

  • Jung, Nam-Chae;Moon, Yong-Sun;Park, Jong-An
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.5
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    • pp.26-35
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    • 1997
  • This paper deals with establishing correspondent points of feature pints and sampling period when we estimate object motion parameters from image information of freely moving objects in space of gravity-free state. Replacing the inertial coordinate system with the camera coordinate system which is equipped within a space robot, it is investigated to be able to analyze a problem of correspond points from image information, and to obtain sequence of angular velocity $\omega$ which determine a motion of object by means of computer simulation. And if a sampling period ${\Delta}t$ is shortened, the relative errors of angular velocity are increased because the relative errors against moving distance of feature points are increased by quantization. In reverse, if a sampling period ${\Delta}t$ is lengthened too much, the relative error are likewise increased because a sampling period is long for angular velocity to be approximated, and we confirmed the precision that grows according to ascending of resolution.

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A Study on the Flux Estimation Simulator Application for the Induction Motor Speed Control (속도제어를 위한 유도전동기 자속추정 시뮬레이터 적용에 관한 연구)

  • Hwang, Lark-Hoon;Na, Seung-Kwon;Choi, Gi-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.3
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    • pp.1289-1301
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    • 2011
  • In this paper, flux estimation method at the Induction motor is applied to stability flux estimate of possibility in overall speed domain. angle operation has voltage and current and speed information using the Induction motor direct control method. Induction motor direct control is material to flux information. Exact flux estimation method to using current model flux estimator of low-speed domain and voltage model flux estimator of high-speed domain. Speed and current and flux controller using PI controller. And error of integral requital for add to Anti-Windup PI controller. Verified to performance of Current model Flux controller and voltage model flux controller using Matlab / Simulink. Analysis has parameter influence of direct vector control and indirect vector control at the Induction motor vector control. So, verified to minute control. Analyzed to simulation result and proof to validity of presented algorithm.

A Study on Establishment of the Helicopter Initial Design Model Using the Modified Weight Estimation Equations (수정된 추정식을 적용한 헬리콥터 초기 설계 모델 정립에 관한 연구)

  • Kim, Seung Bum;Choi, Jong Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.3
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    • pp.213-223
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    • 2015
  • The helicopter initial design model was established by using the latest weight estimation equations based on the Tishchenko's methodology through the study existing initial design tools. The sequential decomposition method is used to reduce analysis time in the sizing. Empirical parameters of the weight estimation equation were also extracted from numerical and regression analysis for a helicopter database. Design input and output values were compared with the RISPECT design tool. Finally, comparison of the re-design resulting for several existing helicopters was presented and showed the good agreement within less than 5% in the weight estimation and main rotor sizing. Established initial design model was proved to be effectively used as initial design tool.

Parameter Estimation of Recurrent Neural Networks Using A Unscented Kalman Filter Training Algorithm and Its Applications to Nonlinear Channel Equalization (언센티드 칼만필터 훈련 알고리즘에 의한 순환신경망의 파라미터 추정 및 비선형 채널 등화에의 응용)

  • Kwon Oh-Shin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.5
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    • pp.552-559
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    • 2005
  • Recurrent neural networks(RNNs) trained with gradient based such as real time recurrent learning(RTRL) has a drawback of slor convergence rate. This algorithm also needs the derivative calculation which is not trivialized in error back propagation process. In this paper a derivative free Kalman filter, so called the unscented Kalman filter(UKF), for training a fully connected RNN is presented in a state space formulation of the system. A derivative free Kalman filler learning algorithm makes the RNN have fast convergence speed and good tracking performance without the derivative computation. Through experiments of nonlinear channel equalization, performance of the RNNs with a derivative free Kalman filter teaming algorithm is evaluated.

PRELIMINARY STUDY ON THE PLATE MOTION IN KOREAN PENINSULA WITH NEW KOREAN VLBI ARRAY (우주측지 VLBI를 이용한 한반도 지각판 운동 예비 연구)

  • Kwak, Young-Hee;Sasao, Tetsuo;Cho, Jung-Ho
    • Journal of Astronomy and Space Sciences
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    • v.23 no.4
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    • pp.345-354
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    • 2006
  • Korean Peninsula has been postulated to be on the Eurasian plate(EU). On the other hand, recent seismological works and GPS researches suggest that it is on a separate plate called the Amurian plate (AM). However, the GPS results we inconsistent with each other beyond the estimated statistical errors. Moreover, the estimated plate motion parameter, which we obtained from the velocity data of six Korean GPS stations, was not well agreeing with any existing results. Therefore, independent measurements are required to distinguish those results. In near future, we will have 4 VLBI stations in Korea. This compact Korean VLBI array is capable of achieving good determination of the plate motion parameters if it is located on stable sites. We estimated the precision of the AM motion parameters with the Korean VLBT array. The results showed that the Korean VLBI array would verify the existence of the AM, as far as the observation precision of 0.2-0.5mm/yr for station velocities is achieved. Therefore, new Korean geodetic VLBI array can contribute to crustal deformation studies in East Asia.

The Design of Target Tracking System Using FBFE Based on VEGA (VEGA 기반 FBFE을 이용한 표적 추적 시스템 설계)

  • 이범직;주영훈;박진배
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.4
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    • pp.359-365
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    • 2001
  • In this paper, we propose the design methodology of target tracking system using fuzzy basis function expansion(FBFE) based on virus evolutionary genetic algorithm (VEGA). In general, the objective of target tracking is to estimate the future trajectory of the target based on the past position of the target obtained from the sensor. In the conventional and mathematical nonlinear filtering method such as extended Kalman filter(EKF), the performance of the system may be deteriorated in highly nonlinear situation. To resolve these problems of nonlinear filtering technique, by appling artificial intelligent technique to the tracking control of moving targets, we combine the advantages of both traditional and intelligent control technique. In the proposed method, after composing training datum from the parameters of extended Kalman filter, by combining FDFE, which has the strong ability for the approximation, with VEGA, which prevent GA from converging prematurely in the case of lack of genetic diversity of population, and by idenLifying the parameters and rule numbers of fuzzy basis function simultaneously, we can reduce the tracking error of EKF. Finally, the proposed method is applied to three dimensional tracking problem, and the simulation results shows that the tracking performance is improved by the proposed method.

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