Adaptive two-stage Kalman filter for x-ray pulsar navigation

2021 ◽  
Author(s):  
Qiang Xu ◽  
Xiaohu Fan ◽  
Bangping Ding ◽  
Liguo Xu ◽  
Ning Liu
Keyword(s):  
Kalman Filter ◽  
Two Stage ◽  
X Ray ◽  
Pulsar Navigation

X-ray pulsar navigation precision analysis considering orbit propagation error effects

2016 ◽  
Author(s):  
Heng Shi ◽  
Kai Xiong ◽  
Chunling Wei ◽  
Lei Wang ◽  
Zhiwu Mei
Keyword(s):  
Precision Analysis ◽  
Orbit Propagation ◽  
X Ray ◽  
Pulsar Navigation

scholarly journals Aircraft Inertial Measurement Unit Fault Diagnosis Based on Optimal Two-Stage UKF

2018 ◽  
Vol 36 (5) ◽  
pp. 933-941
Author(s):  
Qizhi He ◽  
Weiguo Zhang ◽  
Degang Huang ◽  
Huakun Chen ◽  
Jinglong Liu
Keyword(s):  
Kalman Filter ◽  
Fault Diagnosis ◽  
Nonlinear System ◽  
Inertial Measurement Unit ◽  
Unscented Kalman Filter ◽  
Optimal Estimation ◽  
Measurement Unit ◽  
Two Stage ◽  
Inertial Measurement ◽  
System States

Optimal two stage Kalman filter (OTSKF) is able to obtain optimal estimation of system states and bias for linear system which contains random bias. Unscented Kalman filter (UKF) is a conventional nonlinear filtering method which utilizes Sigmas point sampling and unscented transformation technology realizes propagation of state means and covariances through nonlinear system. Aircraft is a typical complicate nonlinear system, this paper treats the faults of Inertial Measurement Unit (IMU) as random bias, established a filtering model which contains faults of IMU. Hybird the two stage filtering technique and UKF, this paper proposed an optimal two stage unscented Kalman filter (OTSUKF) algorithm which is suitable for fault diagnosis of IMU, realized optimal estimation of system states and faults identification of IMU via proposed innovative designing method of filtering model and the algorithm was validated that it is robust to wind disterbance via real flight data and it is also validated that proposed OTSUKF is optimal in the existance of wind disturbance via comparing with the existance iterated optimal two stage extended kalman filter (IOTSEKF) method.

scholarly journals Aircraft Inertial Measurement Unit Fault Diagnosis Based on Adaptive Two-Stage UKF

2020 ◽  
Vol 38 (4) ◽  
pp. 806-813
Author(s):  
Qizhi He ◽  
Weiguo Zhang ◽  
Xiaoxiong Liu ◽  
Weinan Li
Keyword(s):  
Kalman Filter ◽  
Random Walk ◽  
Fault Diagnosis ◽  
Inertial Measurement Unit ◽  
Unscented Kalman Filter ◽  
Random Walk Model ◽  
Measurement Unit ◽  
Actual Situation ◽  
Two Stage ◽  
Inertial Measurement

In the case of nonlinear systems with random bias, the Optimal Two-Stage Unscented Kalman Filter (OTSUKF) can obtain the optimal estimation of system state and bias. But it requires random bias to be accurately modeled, while it is always very difficult in actual situation because the aircraft is a typical nonlinear system. In this paper, the faults of the Inertial Measurement Unit (IMU) are treated as a random bias, and the random walk model is used to describe the fault. The accuracy of the random walk model depends on the degree of matching between the covariance of the random walk model and the actual situation. For the IMU fault diagnosis method based on OTSUKF, the covariance of the random walk model is assigned with a constant matrix, and the value of the matrix is initialized empirically. It is very difficult to select a matching matrix in practical applications. For this problem, in this paper, the covariance matrix of the random walk model is adaptively adjusted online based on the innovation covariance matching technique, and an adaptive Two-Stage Unscented Kalman Filter (ATSUKF) is proposed to solve the fault diagnosis problem of the IMU. The simulation experiment compares the IMU fault diagnosis performance of OTSUKF and ATSUKF, and verifies the effectiveness of the proposed adaptive method.

Chirped-beam two-stage free-electron laser for high-power femtosecond x-ray pulse generation

2002 ◽  
Vol 19 (8) ◽  
pp. 1782 ◽  
Author(s):  
Carl B. Schroeder ◽  
Claudio Pellegrini ◽  
Sven Reiche ◽  
John Arthur ◽  
Paul Emma
Keyword(s):  
High Power ◽  
Free Electron ◽  
Free Electron Laser ◽  
Pulse Generation ◽  
Two Stage ◽  
X Ray

Flash x‐ray tube for diffraction studies on a two‐stage light‐gas gun

1980 ◽  
Vol 51 (6) ◽  
pp. 741-749 ◽  
Author(s):  
Quintin Johnson ◽  
A. C. Mitchell ◽  
Ian D. Smith
Keyword(s):  
Two Stage ◽  
X Ray ◽  
Gas Gun

Error analysis of initial phase estimation for X-ray pulsar navigation system

2021 ◽  
pp. 2150287
Author(s):  
Wei Li ◽  
Ning-Juan Ruan ◽  
Xun Liu ◽  
Feng Yan
Keyword(s):  
Navigation System ◽  
Initial Phase ◽  
Estimation Error ◽  
Nonlinear Least Squares ◽  
Great Promise ◽  
Phase Estimation ◽  
Time Of Arrival ◽  
Pulse Time ◽  
X Ray ◽  
Pulsar Navigation

In this paper, a nonlinear least squares estimator based on the extending cost function is derived, and its performance is analyzed in a Monte-Carlo simulation. Numerical results show that estimation error of the pulse time of arrival satisfies the normal distribution, the relation between the variance and the number of X-ray photon obtained by our simulation is compared with the analytical model. In addition, the effect of time bin size on the statically behavior of estimation error is also studied. This work holds great promise for designing the parameters of X-ray camera adopted in the pulsar navigation system.

Two-stage SASE FEL as Fully Coherent X-ray Laser

1998 ◽  
pp. II-65-II-66
Author(s):  
J. Feldhaus ◽  
E.L. Saldin ◽  
J.R. Schneider ◽  
E.A. Schneidmiller ◽  
M.V. Yurkov
Keyword(s):  
Two Stage ◽  
X Ray ◽  
Sase Fel
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