Title
Some Relations Between Extended and Unscented Kalman Filters
Abstract
The unscented Kalman filter (UKF) has become a popular alternative to the extended Kalman filter (EKF) during the last decade. UKF propagates the so called sigma points by function evaluations using the unscented transformation (UT), and this is at first glance very different from the standard EKF algorithm which is based on a linearized model. The claimed advantages with UKF are that it propagates the first two moments of the posterior distribution and that it does not require gradients of the system model. We point out several less known links between EKF and UKF in terms of two conceptually different implementations of the Kalman filter: the standard one based on the discrete Riccati equation, and one based on a formula on conditional expectations that does not involve an explicit Riccati equation. First, it is shown that the sigma point function evaluations can be used in the classical EKF rather than an explicitly linearized model. Second, a less cited version of the EKF based on a second-order Taylor expansion is shown to be quite closely related to UKF. The different algorithms and results are illustrated with examples inspired by core observation models in target tracking and sensor network applications.
Year
DOI
Venue
2012
10.1109/TSP.2011.2172431
IEEE Transactions on Signal Processing
Keywords
Field
DocType
different algorithm,classical ekf,core observation model,standard ekf algorithm,system model,conceptually different implementation,extended kalman filter,kalman filter,unscented kalman filter,linearized model,unscented kalman filters,control engineering,second order,covariance matrix,conditional expectation,riccati equation,sensor network,linear model,taylor series,transformations,taylor expansion,posterior distribution,system modeling,kalman filters
Mathematical optimization,Extended Kalman filter,Control theory,Kalman filter,Unscented transform,Posterior probability,Riccati equation,Covariance matrix,Invariant extended Kalman filter,Mathematics,Taylor series
Journal
Volume
Issue
ISSN
60
2
1053-587X
Citations 
PageRank 
References 
58
2.89
7
Authors
2
Name
Order
Citations
PageRank
Fredrik Gustafsson12287281.33
Gustaf Hendeby221621.37