Sequential Covariance Intersection Fusion Kalman Filter for Multiple Time-delay
Sensor Network Systems with Colored Noises
Jun Wang, Tianmeng Shang, Yuan Gao
*
, Chenjian Ran, Yinlong Huo, Gang Hao, Yun Li
Department of Automation, Heilongjiang University, Harbin 150080
E-mail: gaoyuan_hlju@163.com
Abstract: This paper is concerned with the fusion estimation problem for multi-sensor discrete time-invariant linear systems
with multiple time delays and colored measurement noise. In order to transform those systems into systems with correlated white
noise, a system transformation method is introduced. A sequential covariance intersection (SCI) fusion Kalman filter is given
based on the local optimal recursive Kalman filter in the linear minimum variance sense, which avoids the calculation of the
cross covariance matrices between local sensors. It is proved that the presented fused Kalman filter has higher accuracy than
those local filters. The simulation result reveals that the actual accuracy of the SCI fusion Kalman filter approximates to
distributed fusion Kalman filter weighted by matrices, and based on the covariance ellipse, the geometric interpretation with
respect to accuracy relation of the local and the fused Kalman filter is shown.
Key Words: Multi time delays, Colored measurement noises, SCI fusion, Cross covariance
1 Introduction
As a result of sustaining development in signal processing
and communication networks, state estimation for
time-delay systems is widely applied [1]. Because of the
aging of the components, the lack of sensitivity and delays
in information transmission, time-delay phenomenon is
inevitable. One of the typical methods to handle those
systems with time delays is the system augmentation method
in conjunction with standard Kalman filtering [2]. However,
it is known that the augmented Kalman filtering approach is
computationally expensive, especially when the dimension
of the system is high and the measurement lags are large [3].
Another method is the measurement transformation
approach [4], by which the system with time delays can be
transformed into an equivalent one without measurement
delay. Although it reduces the computational cost largely, it
also needs big memory space [5].
The multi-sensor data fusion has received great attention
in recent years. Its aim is to combine the local estimators
obtained from each sensor in order to obtain a better fused
estimator [6]. The basic fusion methods are the centralized
and the distributed fusion methods, depending on whether
raw data are used directly for fusion or not [7]. The former
can give the globally optimal state estimation by directly
combining local measurement data to obtain an augmented
measurement equation, but its disadvantage is creating a
larger computational burden. The latter includes the
distributed state fusion and the distributed measurement
fusion methods [6, 8]. It is common knowledge that
computing the optimal fuser requires the cross covariance
matrices among local Kalman filters. However, in many
*
This work is supported by National Nature Science Foundation under
Grant 61503125 and 61203121, National Science Foundation of
Heilongjiang Province (QC 2013C062), Reserve Leader Fund of Leading
Talent Echelon of Heilongjiang Province, “Modern Sensing Technology”
High College Innovation Team (2012TD007), Science Foundation of
Distinguished Young Scholars of Heilongjiang university, Open Fund of
Key Laboratory of Electronics Engineering, College of Heilongjiang
Province.
application situations, these cross covariance matrices are
unknown or their computation is quite complex [9]. In order
to reduce the complexity and computational burden, the
covariance intersection (CI) fusion method has been
presented [10]. For multisensor fusion problems, a
sequential covariance intersection (SCI) fusion Kalman
filter is presented based on the two-sensor CI fusion Kalman
filters [6].
In this paper, for multi-sensor multiple time-delay
systems with colored measurement noiseˈ using SCI fusion
method, a fused filter is obtained, where the cross
covariance matrices among the local Kalman estimators are
avoided when the weight coefficients are calculated [11].
The advantages of the SCI fusion Kalman filter are that it
has consistency and the computational burden can be
reduced significantly. It is proved that its accuracy is higher
than that of each local Kalman filter, and is lower than that
of the optimal Kalman filter weighted by matrices with
known cross covariance matrices.
2 Problem Formulation
Consider the multi-sensor discrete time-invariant linear
stochastic control system with multiple time delays and
colored measurement noises
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Proceedings of the 36th Chinese Control Conference
Jul
26-28, 2017, Dalian, China
5282