A New Kalman-Type Approach for Satellites Attitude Determination

2014 ◽  
Vol 555 ◽  
pp. 57-65
Author(s):  
Adrian Mihail Stoica
Keyword(s):  
Attitude Determination ◽  
Measurement Unit ◽  
Hybrid Filter ◽  
Space Applications ◽  
Satellite Attitude ◽  
Time Component ◽  
Linearized Model ◽  
Numerical Case Study

This paper presents a Kalman type method for attitude determination of satellites. It is shown that the linearized model describing the satellite kinematics may be expressed as a stochastic system corrupted with both additive and multiplicative white noise. For this class of stochastic models a hybrid Kalman filter is used to estimate the quaternion expressing the satellite attitude and the bias of the inertial measurement unit. By contrast with the classical Kalman filters, the hybrid filter used in this paper includes a continuous-time and a discrete-time component. The advantage is that it may provide a time varying estimation of the states between the sampling moments which usually are sparse in space applications. The theoretical developments is illustrated via a numerical case study.

scholarly journals APPLICATION OF VEHICLE DYNAMIC MODELING IN UAVS FOR PRECISE DETERMINATION OF EXTERIOR ORIENTATION

2016 ◽  
Vol XLI-B3 ◽  
pp. 827-831 ◽  
Author(s):  
M. Khaghani ◽  
J. Skaloud
Keyword(s):  
Navigation System ◽  
Carrier Phase ◽  
Attitude Determination ◽  
Measurement Unit ◽  
Main Process ◽  
Vehicle Dynamic ◽  
Exterior Orientation ◽  
Sensor Orientation ◽  
Imaging Results

Advances in unmanned aerial vehicles (UAV) and especially micro aerial vehicle (MAV) technology together with increasing quality and decreasing price of imaging devices have resulted in growing use of MAVs in photogrammetry. The practicality of MAV mapping is seriously enhanced with the ability to determine parameters of exterior orientation (EO) with sufficient accuracy, in both absolute and relative senses (change of attitude between successive images). While differential carrier phase GNSS satisfies cm-level positioning accuracy, precise attitude determination is essential for both direct sensor orientation (DiSO) and integrated sensor orientation (ISO) in corridor mapping or in block configuration imaging over surfaces with low texture. Limited cost, size, and weight of MAVs represent limitations on quality of onboard navigation sensors and puts emphasis on exploiting full capacity of available resources. Typically short flying times (10-30 minutes) also limit the possibility of estimating and/or correcting factors such as sensor misalignment and poor attitude initialization of inertial navigation system (INS). This research aims at increasing the accuracy of attitude determination in both absolute and relative senses with no extra sensors onboard. In comparison to classical INS/GNSS setup, novel approach is presented here to integrated state estimation, in which vehicle dynamic model (VDM) is used as the main process model. Such system benefits from available information from autopilot and physical properties of the platform in enhancing performance of determination of trajectory and parameters of exterior orientation consequently. The navigation system employs a differential carrier phase GNSS receiver and a micro electro-mechanical system (MEMS) grade inertial measurement unit (IMU), together with MAV control input from autopilot. Monte-Carlo simulation has been performed on trajectories for typical corridor mapping and block imaging. Results reveal considerable reduction in attitude errors with respect to conventional INS/GNSS system, in both absolute and relative senses. This eventually translates into higher redundancy and accuracy for photogrammetry applications.

Modeling of Accurate Variable Slope Angles in Open-Pit Mine Design Using Spline Interpolation / Modelowanie Zmiennego Kąta Nachylenia Stoku W Projektowaniu Kopalni Odkrywkowych Za Pomocą Interpolacji Funkcjami Sklejającymi (Metodą Spline’Ów)

2012 ◽  
Vol 57 (4) ◽  
pp. 921-932 ◽  
Author(s):  
Masoud Soleymani Shishvan ◽  
Javad Sattarvand
Keyword(s):  
Interpolation Method ◽  
Spline Interpolation ◽  
Slope Angle ◽  
Linear Interpolation ◽  
Open Pit ◽  
Cubic Form ◽  
The Given ◽  
Numerical Case Study

Abstract In this paper a new method of modeling variable slope angles has been presented based on the spline interpolation method. Slope angle modeling and defining precedency of the blocks are the vital parts of almost any open pit optimization algorithm. Traditionally heuristic patterns such as 1:5 or 1:9 have been used to generate slope angles. Cone template based models were later employed in developing variable slope angles. They normally use a linear interpolation process for determination of slope angles between the given directions which leads to sharp and non-realistic pits. The other elliptical alternatives suffer from having limitations in defining slope angles in non-geographical directions. The method is capable to consider any number of slope angles in any desired direction as well as creating quite accurate and realistic pit shapes. Three major types of the spline interpolation including cubic, quadratic and cardinal are tested, however, the cubic form is preferred due to more realistic outcomes. Main steps of the method are described through a numerical case study.

Survey Boat Attitude Determination with GPS/IMU Systems

2001 ◽  
Vol 54 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Reha Metin Alkan ◽  
Orhan Baykal
Keyword(s):  
Carrier Phase ◽  
Inertial Measurement Unit ◽  
Attitude Determination ◽  
Measurement Unit ◽  
Phase Measurements ◽  
Inertial Measurement ◽  
The Third ◽  
Hydrographic Surveying ◽  
Echo Sounder

Any vehicle such as a vessel or aeroplane has three attitude parameters. These are most commonly defined as pitch, roll and heading from true north. In hydrographic surveying, determination of these parameters is essential for the correction of multi-beam echo sounder measurements. In the study on which this paper is based, two of the three parameters, the pitch and roll angles, were measured with an inexpensive IMU (Inertial Measurement Unit) device. The third was calculated from GPS carrier phase measurements that were collected from two antennas on the boat. The GPS antennas depart from the vertical when they are subject to pitch and roll effects. In this case, the coordinates derived from GPS will be erroneous. Thus, if heading is to be calculated accurately, the horizontal coordinates have to be corrected for pitch and roll. This paper defines an algorithm for the purpose that enables pitch and roll angles to be measured with an accuracy of about 0·003 arcdeg and headings computed with an accuracy of about 0·010 arcdeg.

scholarly journals APPLICATION OF VEHICLE DYNAMIC MODELING IN UAVS FOR PRECISE DETERMINATION OF EXTERIOR ORIENTATION

2016 ◽  
Vol XLI-B3 ◽  
pp. 827-831 ◽  
Author(s):  
M. Khaghani ◽  
J. Skaloud
Keyword(s):  
Navigation System ◽  
Carrier Phase ◽  
Attitude Determination ◽  
Measurement Unit ◽  
Main Process ◽  
Vehicle Dynamic ◽  
Exterior Orientation ◽  
Sensor Orientation ◽  
Imaging Results

Advances in unmanned aerial vehicles (UAV) and especially micro aerial vehicle (MAV) technology together with increasing quality and decreasing price of imaging devices have resulted in growing use of MAVs in photogrammetry. The practicality of MAV mapping is seriously enhanced with the ability to determine parameters of exterior orientation (EO) with sufficient accuracy, in both absolute and relative senses (change of attitude between successive images). While differential carrier phase GNSS satisfies cm-level positioning accuracy, precise attitude determination is essential for both direct sensor orientation (DiSO) and integrated sensor orientation (ISO) in corridor mapping or in block configuration imaging over surfaces with low texture. Limited cost, size, and weight of MAVs represent limitations on quality of onboard navigation sensors and puts emphasis on exploiting full capacity of available resources. Typically short flying times (10-30 minutes) also limit the possibility of estimating and/or correcting factors such as sensor misalignment and poor attitude initialization of inertial navigation system (INS). This research aims at increasing the accuracy of attitude determination in both absolute and relative senses with no extra sensors onboard. In comparison to classical INS/GNSS setup, novel approach is presented here to integrated state estimation, in which vehicle dynamic model (VDM) is used as the main process model. Such system benefits from available information from autopilot and physical properties of the platform in enhancing performance of determination of trajectory and parameters of exterior orientation consequently. The navigation system employs a differential carrier phase GNSS receiver and a micro electro-mechanical system (MEMS) grade inertial measurement unit (IMU), together with MAV control input from autopilot. Monte-Carlo simulation has been performed on trajectories for typical corridor mapping and block imaging. Results reveal considerable reduction in attitude errors with respect to conventional INS/GNSS system, in both absolute and relative senses. This eventually translates into higher redundancy and accuracy for photogrammetry applications.

The Research of Micro-Satellite Attitude Determination Based on Predictive Filter

2011 ◽  
Vol 110-116 ◽  
pp. 5413-5419 ◽  
Author(s):  
Lu Cao ◽  
Wei Wei Yang ◽  
Xiao Qian Chen ◽  
Yi Yong Huang
Keyword(s):  
Angular Velocity ◽  
Attitude Determination ◽  
High Reliability ◽  
Measurement Model ◽  
Model Errors ◽  
Predicting Model ◽  
Satellite Attitude ◽  
One Step ◽  
Simulation Results

— An extended predictive filter is presented for attitude determination of Micro-satellite based on the basic theory of predictive filter. This algorithm enhances the precision of kinematics equation, accurately estimates satellite attitude angle and angular velocity using measurement vectors from magnetometer and sun sensors by predicting model errors and angular velocity errors one step ahead. In addition, a new measurement model is derived about angular velocity, which improved the efficiency of the use of measurement vectors. Simulation results show both the high reliability and precision of this method.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

The Calculation of Turbulent Diffusion Coefficients in Aquatic Ecosystems

2019 ◽  
Vol 70 (11) ◽  
pp. 3903-3907
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Transport Equation ◽  
Turbulent Diffusion ◽  
Diffusion Coefficients ◽  
Aquatic Ecosystems ◽  
Specific Area ◽  
Left Bank ◽  
The Right ◽  
Prut River

The paper deals with the issues related to the pollution of aquatic ecosystems. The influence of turbulence on the transport and dispersion of pollutants in the mentioned systems, as well as the calculation of the turbulent diffusion coefficients are studied. A case study on the determination of turbulent diffusion coefficients for some sectors of the Prut River is presented. A new method is proposed for the determination of the turbulent diffusion coefficients in the pollutant transport equation for specific sectors of a river, according to the associated number of P�clet, calculated for each specific area: the left bank, the right bank and the middle of the river.

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