• Title/Summary/Keyword: recursive least square method

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A Study on the Camera Calibration Algorithm of Robot Vision Using Cartesian Coordinates

  • Lee, Yong-Joong
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.6
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    • pp.98-104
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    • 2002
  • In this study, we have developed an algorithm by attaching a camera at the end-effector of industrial six-axis robot in order to determine position and orientation of the camera system from cartesian coordinates. Cartesian coordinate as a starting point to evaluate for suggested algorithm, it was easy to confront increase of orientation vector for a linear line point that connects two points from coordinate space applied by recursive least square method which includes previous data result and new data result according to increase of image point. Therefore, when the camera attached to the end-effector has been applied to production location, with a calibration mask that has more than eight points arranged, this simulation approved that it is possible to determine position and orientation of cartesian coordinates of camera system even without a special measuring equipment.

A UDU decomposition based recursive total least square method (UDU 행렬분해법을 이용한 재귀적 TLS 알고리즘)

  • Lim Jun-seok;Choi Nakjin;Sung KoengMo
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.547-550
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    • 2004
  • 본 논문은 시스템 인식에서 RLS의 성능을 높이기 위한 한 방법으로 UDU 행렬 분해법을 바탕으로 한 recursive total least squares (RTLS) algorithm을 제안한다. 기존의 RTLS는 Power Method에 의거해서 recursive하게 만든 형태이어서 RLS와 거의 같은 구조이다. 그러나 본 논문에서는 일반적인 Power Method가 rank-1 update를 이용하기 때문에 ill-condition에 빠질 가능성이 높은 점을 감안하여, UDU 행렬 분해법을 사용한 RTLS방법을 제안하고, 그를 시스템 인식에 적용한다.

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Online Identification of Li-ion Battery's Internal Resistance based on a Recursive Least Squares Method to Prevent Overvoltage/Undervoltage (리튬이온 배터리의 과전압/저전압을 막기 위한 회기 최소 자승법 기반의 실시간 내부 저항 추정방법)

  • Kim, Woo-Yong;Lee, Pyeong-Yeon;Kim, Jonghoon;Kim, Kyung-Soo
    • Proceedings of the KIPE Conference
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    • 2018.07a
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    • pp.237-239
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    • 2018
  • This paper proposes an on-line estimation algorithm of internal resistance of Li-ion battery based on the recursive least squares method to prevent the overvoltage and undervoltage casing degradation of life cycle of battery. An equivalent circuit model with single time constant is adopted, and under assumptions that the terminal voltage, current and SOC are measured accurately, the discrete time based nonlinear equation of the model can be converted to the linear equation which can be applied to recursive least squares method. Since the coefficients of the discrete time linear equation can be expressed by the parameters of the equivalent circuit model, it is shown that an internal resistance (Ri) can be estimated in real time using the least square method.

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New Motor Parameter Estimation Method of Surface-mounted Permanent Magnet Motors (표면 부착형 영구자석 전동기의 새로운 상수 추정 방법)

  • Lee, Dong-Myung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.517-522
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    • 2019
  • This paper proposes a new motor parameter estimation method. Because the proposed method is based on difference equations, it does not affect the error in the voltage magnitude so called dead-time effect. Information on the motor constant may be needed to improve the motor control performance. For example, a control technique called DTC (Direct Torque Control) requires a motor constant when calculating the torque and flux magnitude. As another example, in the case of predictive control, information on the motor parameters is required to generate voltage references. Because the constant of the motor fluctuates according to the driving environment, it is essential to estimate the correct motor constant because the control performance is degraded when incorrect motor information is used. In the proposed scheme, the motor constant estimated based on the voltage difference equation is obtained using the RLS (Recursive Least Square) technique. The RLS algorithm is applied to obtain the value through an iterative calculation so that the estimation performance is robust to noise. The simulation results carried out with surface mounted permanent magnet motors confirmed the validity of the proposed method.

An Experimental Study on Realtime Estimation of a Nominal Model for a Disturbance Observer: Recursive Least Squares Approach (실시간 공칭 모델 추정 외란관측기에 관한 실험 연구: 재귀최소자승법)

  • Lee, Sang-Deok;Jung, Seul
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.8
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    • pp.650-655
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    • 2016
  • In this paper, a novel RLS-based DOB (Recursive Least Squares Disturbance Observer) scheme is proposed to improve the performance of DOB for nominal model identification. A nominal model can be generally assumed to be a second order system in the form of a proper transfer function of an ARMA (Autoregressive Moving Average) model. The RLS algorithm for the model identification is proposed in association with DOB. Experimental studies of the balancing control of a one-wheel robot are conducted to demonstrate the feasibility of the proposed method. The performances between the conventional DOB scheme and the proposed scheme are compared.

Design of Incremental FCM-based Recursive RBF Neural Networks Pattern Classifier for Big Data Processing (빅 데이터 처리를 위한 증분형 FCM 기반 순환 RBF Neural Networks 패턴 분류기 설계)

  • Lee, Seung-Cheol;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.6
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    • pp.1070-1079
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    • 2016
  • In this paper, the design of recursive radial basis function neural networks based on incremental fuzzy c-means is introduced for processing the big data. Radial basis function neural networks consist of condition, conclusion and inference phase. Gaussian function is generally used as the activation function of the condition phase, but in this study, incremental fuzzy clustering is considered for the activation function of radial basis function neural networks, which could effectively do big data processing. In the conclusion phase, the connection weights of networks are given as the linear function. And then the connection weights are calculated by recursive least square estimation. In the inference phase, a final output is obtained by fuzzy inference method. Machine Learning datasets are employed to demonstrate the superiority of the proposed classifier, and their results are described from the viewpoint of the algorithm complexity and performance index.

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.

A Controlled Neural Networks of Nonlinear Modeling with Adaptive Construction in Various Conditions (다변 환경 적응형 비선형 모델링 제어 신경망)

  • Kim, Jong-Man;Sin, Dong-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1234-1238
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    • 2004
  • A Controlled neural networks are proposed in order to measure nonlinear environments in adaptive and in realtime. The structure of it is similar to recurrent neural networks: a delayed output as the input and a delayed error between tile output of plant and neural networks as a bias input. In addition, we compute the desired value of hidden layer by an optimal method instead of transfering desired values by backpropagation and each weights are updated by RLS(Recursive Least Square). Consequently, this neural networks are not sensitive to initial weights and a learning rate, and have a faster convergence rate than conventional neural networks. This new neural networks is Error Estimated Neural Networks. We can estimate nonlinear models in realtime by the proposed networks and control nonlinear models. To show the performance of this one, we have various experiments. And this controller call prove effectively to be control in the environments of various systems.

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Nonlinear Neural Networks for Vehicle Modeling Control Algorithm based on 7-Depth Sensor Measurements (7자유도 센서차량모델 제어를 위한 비선형신경망)

  • Kim, Jong-Man;Kim, Won-Sop;Sin, Dong-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.525-526
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    • 2008
  • For measuring nonlinear Vehicle Modeling based on 7-Depth Sensor, the neural networks are proposed m adaptive and in realtime. The structure of it is similar to recurrent neural networks; a delayed output as the input and a delayed error between the output of plant and neural networks as a bias input. In addition, we compute the desired value of hidden layer by an optimal method instead of transfering desired values by backpropagation and each weights are updated by RLS(Recursive Least Square). Consequently, this neural networks are not sensitive to initial weights and a learning rate, and have a faster convergence rate than conventional neural networks. This new neural networks is Error Estimated Neural Networks. We can estimate nonlinear models in realtime by the proposed networks and control nonlinear models.

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Design of Speed Controller for Induction Motor With Inertia Variation (관성 변동을 갖는 유도전동기 속도 제어기 설계)

  • 신은철;김종선;공병구;유지윤;박내식;이준호
    • The Transactions of the Korean Institute of Power Electronics
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    • v.6 no.5
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    • pp.446-452
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    • 2001
  • In this paper, a novel design method of variable motor inertia in Induction motor drive system is proposed. The inertia of a load and a motor are estimated by using RLS (Recursive Least Square) algorithm. The speed controller is designed by Kharitonov theory of motor. The effectiveness of the proposed scheme is verified with simulation and experiment results.

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