Comparison of the Ensemble Kalman filter with the Unscented Kalman filter : application to the construction of a road embankment
Comparison of the Ensemble Kalman filter with the Unscented Kalman filter : application to the construction of a road embankment
复制标题
集成卡尔曼滤波器与无迹卡尔曼滤波器的比较:在路堤施工中的应用
DOI:
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发表时间:
2008
期刊:
影响因子:
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通讯作者:
S. Nishimura
中科院分区:
文献类型:
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作者:
A. Hommels;A. Murakami;S. Nishimura
The Extended Kalman Filter (EKF) has been used in the field of geomechanics for nonlinear state space estimation (Murakami, 1991). However a couple of alternative approaches have emerged over the last few years, namely the Ensemble Kalman filter (EnKF) and the Unscented Kalman filter (UKF). The EnKF was designed to resolve two major problems related to the use of EKF. The first problem relates to the use of an approximate closure scheme in the EKF (first order Taylor expansion). The second problem relates to the huge computational requirements associated with the storage and forward integration of the error covariance matrix P. In the Ensemble Kalman filter, an ensemble of possible state vectors, which are randomly generated using a Monte Carlo approach, represents the statistical properties of the state vector. The EnKF algorithm does not require a tangent linear model, which is required for the EKF, and is very easy to implement. The UKF claims a higher accuracy and robustness for non-linear models than the EKF. Instead of linearizing the functions as is done in the EKF, the UKF uses a set of points and propagates this set through the actual non-linear function. These points are chosen such that their mean, covariance and possibly also higher order moments match the Gaussian random variable. The mean and the covariance can be recalculated from the propagated points, yielding more accurate results compared to the ordinary function linearization. The performance of the EnKF compared to the UKF will be shown in a conceptual nonlinear case study, based on the construction of a road embankment.