Precise Attitude Determination of Ship Based on Star Sensor

2013 ◽  
Vol 380-384 ◽  
pp. 995-1002 ◽  
Author(s):  
Bing Liu ◽  
Feng Chen ◽  
Tong Shuang Zhang ◽  
Dean Zhong ◽  
Lei Yang ◽  
...  
Keyword(s):  
Engineering Design ◽  
High Precision ◽  
Attitude Determination ◽  
Measured Data ◽  
Star Sensor ◽  
Single Star

This paper analyses the attitude measured model and presents the attitude determination algorithm of space TT&C ship (space tracking, telemetry, and command ship) based on single star sensor. Considering lower precision of rolling angel for single star sensor, we proposed an algorithm by integrating attitude determination and redundancy measure to obtain high precision ship attitude data. Aiming at the circumstance of space TT&C ship, the factors that influence the precision of attitude measured data such as the number of star, atmosphere refraction correct and installation elevation are analyzed, which this can provide valuable references to the engineering design for star sensor used on space TT&C ship.

Precise attitude determination of ship based on star sensor

2012 ◽  
Author(s):  
Bing Liu ◽  
Feng Chen ◽  
Tongshuang Zhang ◽  
Dean Zhong ◽  
Lei Yang ◽  
...  
Keyword(s):  
Attitude Determination ◽  
Star Sensor

scholarly journals Design of an Extended Interacting Multiple Models Adaptive Estimator for Attitude Determination of a Stereoimagery Satellite

2011 ◽  
Vol 2011 ◽  
pp. 1-19 ◽  
Author(s):  
Hossein Bolandi ◽  
Farhad Fani Saberi ◽  
Amir Mehrjardi Eslami
Keyword(s):  
Attitude Determination ◽  
Estimation Error ◽  
Attitude Estimation ◽  
Estimation Accuracy ◽  
Multiple Models ◽  
Uniform Motion ◽  
Star Sensor ◽  
Adaptive Estimator ◽  
Motion Mode

We will design an extended interacting multiple models adaptive estimator (EIMMAE) for attitude determination of a stereoimagery satellite. This algorithm is based on interacting multiple models (IMM) extended kalman filters (EKF) using star sensor and gyroscope data. In this method, the motion of satellite during stereoimaging manoeuvres is partitioned into two different modes: “manoeuvring motion” mode and “uniform motion” mode. The proposed algorithm will select the suitable Kalman filter structure to estimate gyro errors accurately in order to maintain the peak attitude estimation error less enough at the beginning of manoeuvres while the satellite is in “manoeuvring motion” mode and then will select the suitable star sensor measurement noise level at the end of manoeuvres while the satellite is in “uniform motion” mode to reduce attitude estimation errors. It will be shown that using the proposed algorithm, the attitude estimation accuracy of stereoimagery satellite will be increased considerably. The effectiveness of the proposed algorithm will be examined and compared with the previous proposed methods through numerical simulations.

On effects of non-systematic reflections on weak-beam images of partial dislocations

1991 ◽  
Vol 49 ◽  
pp. 688-689
Author(s):  
K. Z. Botros ◽  
S. S. Sheinin
Keyword(s):  
High Precision ◽  
Stacking Fault ◽  
Important Application ◽  
Stacking Fault Energy ◽  
Sharp Peak ◽  
Weak Beam ◽  
Partial Dislocations ◽  
Deviation Parameter ◽  
Beam Diffraction

The main features of weak beam images of dislocations were first described by Cockayne et al. using calculations of intensity profiles based on the kinematical and two beam dynamical theories. The feature of weak beam images which is of particular interest in this investigation is that intensity profiles exhibit a sharp peak located at a position very close to the position of the dislocation in the crystal. This property of weak beam images of dislocations has an important application in the determination of stacking fault energy of crystals. This can easily be done since the separation of the partial dislocations bounding a stacking fault ribbon can be measured with high precision, assuming of course that the weak beam relationship between the positions of the image and the dislocation is valid. In order to carry out measurements such as these in practice the specimen must be tilted to "good" weak beam diffraction conditions, which implies utilizing high values of the deviation parameter Sg.

Comparative assessment of informational content of the equations of F.P. Hadlock and the computer program of V.N. Demidov in determination of term of gestation and fetal weight in the III trimester of gestation

2017 ◽  
Author(s):  
E.A. Derkach , O.I. Guseva
Keyword(s):  
Computer Program ◽  
High Precision ◽  
Gestational Age ◽  
Computer Programs ◽  
Comparative Assessment ◽  
Fetal Weight ◽  
Informational Content ◽  
Third Trimester ◽  
The Third

Objectives: to compare the accuracy of equations F.P. Hadlock and computer programs by V.N. Demidov in determining gestational age and fetal weight in the third trimester of gestation. Materials: 328 patients in terms 36–42 weeks of gestation are examined. Ultrasonography was performed in 0–5 days prior to childbirth. Results: it is established that the average mistake in determination of term of pregnancy when using the equation of F.P. Hadlock made 12,5 days, the computer program of V.N. Demidov – 4,4 days (distinction 2,8 times). The mistake within 4 days, when using the equation of F.P. Hadlock has met on average in 23,1 % of observations, the computer program of V.N. Demidov — 65,9 % (difference in 2,9 times). The mistake more than 10 days, took place respectively in 51,7 and 8,2 % (distinction by 6,3 times). At a comparative assessment of size of a mistake in determination of fetal mass it is established that when using the equation of F.P. Hadlock it has averaged 281,0 g, at application of the computer program of V.N. Demidov — 182,5 g (distinction of 54 %). The small mistake in the mass of a fetus which isn't exceeding 200 g at application of the equation of F.P. Hadlock has met in 48,1 % of cases and the computer program of V.N. Demidov — 64,0 % (distinction of 33,1 %). The mistake exceeding 500 g has been stated in 18 % (F.P. Hadlock) and 4,3 % (V.N. Demidov) respectively (distinction 4,2 times). Conclusions: the computer program of V.N. Demidov has high precision in determination of term of a gestation and mass of a fetus in the III pregnancy.

scholarly journals Determination of electron backscattering coefficient of beryllium by a high-precision Monte Carlo simulation

2021 ◽  
Vol 26 ◽  
pp. 100862
Author(s):  
Abrar Hussain ◽  
Lihao Yang ◽  
Shifeng Mao ◽  
Bo Da ◽  
Károly Tőkési ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
High Precision ◽  
Backscattering Coefficient ◽  
Electron Backscattering

Multi-spacecraft collaborative attitude determination of space tumbling target with experimental verification

2021 ◽  
Vol 185 ◽  
pp. 1-13
Author(s):  
Di Zhao ◽  
Chong Sun ◽  
Zhanxia Zhu ◽  
Wenya Wan ◽  
Zixuan Zheng ◽  
...  
Keyword(s):  
Experimental Verification ◽  
Attitude Determination ◽  
Tumbling Target

The Determination of the Three-Point Support Design of Machine Tool Based on iSIGHT

2014 ◽  
Vol 607 ◽  
pp. 342-345
Author(s):  
Sheng Hui Zhao ◽  
Xiao Chuang Zhu ◽  
Da Wei Zhang
Keyword(s):  
Machine Tool ◽  
High Precision ◽  
Multidisciplinary Optimization ◽  
Joint Surface ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Support Design ◽  
Optimal Position ◽  
Point Support

In order to meet the requirements of high-precision machine tool, it has been an important factor to select an appropriate way to support the bed. By building a multidisciplinary optimization (MDO) process based on iSIGHT, this article select the deformation difference of the guides and the deformation difference of the joint surface between column and bed of the machine tool as the objective functions, and then conduct a multi-objective optimization (MOO) of the positional parameters of the three-point support. Eventually the optimization result is given and the optimal position of the three-point support is determined.

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