scholarly journals Integrated navigation approaches of vehicle aided by the strapdown celestial angles

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142093200 ◽  
Author(s):  
Hongmei Chen ◽  
Hongbo Gao ◽  
Huijuan Zhang
Keyword(s):  
Coordinate System ◽  
Bayesian Method ◽  
Azimuth Angle ◽  
Integrated Navigation ◽  
Inertial Coordinate System ◽  
Rapid Variability ◽  
Navigation Data ◽  
Geographic Coordinate System ◽  
Attitude Alignment ◽  
Data Dropouts

The integrated navigation method based on star sensor celestial angles (altitude angle and azimuth angle) is proposed to serve the need for rapidly responsive, reliable, and precise of a hypersonic vehicle under a sophisticated environment. An integrated navigation algorithm suitable for large azimuth misalignment is established under launching point inertial coordinate and local geographical coordinate system based on altitude angle and azimuth angles. Meanwhile, a Bayesian method for data dropouts aided by the strapdown celestial angles is presented for the rapid variability in the celestial star angle with active galaxies. A nonlinear Bayesian filter is applied to implement the simulation on account of the nonlinear feature of the state and measurement equations. The simulation results showed that the Bayesian method for integrated navigation data dropouts could be accomplished by altitude angle and azimuth angle aiding in both launching point inertial coordinate and local geographical coordinate systems, which converge to 1′ in 10 s. The method indicated that the integrated navigation significant errors derived from initial localization and initial attitude alignment could be modified by the strapdown inertial navigation system (SINS) supported by the star sensor’s celestial angle in the local geographic coordinate system in the early launch stage. For the seconds of the flight phase, the integrated navigation aided by celestial angles in the launching point inertial coordinate system was guaranteed for the feasibility and validity. During the flight, the feasibility and validity of integrated navigation were guaranteed aided by celestial angles in launching point inertial coordinate system.

scholarly journals A new result under weak and non-relativistic approximation from general theory of relativity

2021 ◽  
Author(s):  
Abhijit Samanta
Keyword(s):  
Field Equation ◽  
Energy Density ◽  
General Theory ◽  
Force Field ◽  
Coordinate System ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
Inertial Coordinate System ◽  
Relativistic Approximation ◽  
Moving Particle

Abstract We have derived a metric field equation in the locally inertial coordinate system from Einstein's field equation considering the energy density of the moving particle with the approximations that the force field under which the particle is moving is weak and the velocity of the particle is non-relativistic. We study the motion of different microscopic systems using this metric equation and compared the results with the experimentally measured values and we find that the results are identical.

scholarly journals Approximate Inertial Coordinate System Selections for Rotation Problems - The Gravitational Field of the Celestial Body Higher than the Object Being Rotated

2015 ◽  
Vol 8 (1) ◽  
pp. 102
Author(s):  
Zifeng Li
Keyword(s):  
Gravitational Field ◽  
Coordinate System ◽  
Celestial Body ◽  
Angular Speed ◽  
Calculation Error ◽  
Cartesian Coordinate System ◽  
Inertial Coordinate System ◽  
The Earth ◽  
The Galaxy ◽  
Cartesian Coordinate

<p class="1Body">Selection of the coordinate system is essential for rotation problems. Otherwise, mistakes may occur due to inaccurate measurement of angular speed. Approximate inertial coordinate system selections for rotation problems should be the gravitational field of the celestial body higher than the object being rotated: (1) the Earth fixed Cartesian coordinate system for normal rotation problem; (2) heliocentric - geocentric Cartesian coordinate system for satellites orbiting the Earth; (3) the Galaxy Heart - heliocentric Cartesian coordinates for Earth's rotation around the Sun. In astrophysics, mass calculation error and angular velocity measurement error lead to a black hole conjecture.</p>

scholarly journals Complex Geodynamical Investigations in the Area of the USSR Academy of Sciences Central Astronomical Observatory at Pulkovo

1990 ◽  
Vol 141 ◽  
pp. 72-72
Author(s):  
V. K. Abalakin ◽  
V. I. Bogdanov ◽  
Yu.D. Boulanger ◽  
V. A. Naumov
Keyword(s):  
Coordinate System ◽  
Ussr Academy ◽  
Astronomical Observatory ◽  
Coordinate Systems ◽  
Inertial Coordinate System ◽  
Gravitation Field ◽  
Practical Applications ◽  
Star Catalogue ◽  
Academy Of Sciences

For astronomical, geodetical and geodynamical investigations as well as for practical applications the inertial coordinate system is widely used which is based on the Fundamental Star Catalogue FK5 together with local coordinate systems in observation stations on the Earth's surface which are intrinsically connected with the geometry of the gravitation field.

scholarly journals The Availability Of Automatic Identification System (AIS) Based On Latency Position Reports In The Gulf Of Gdansk

2014 ◽  
Vol 21 (1) ◽  
pp. 59-74 ◽  
Author(s):  
Krzysztof Jaskólski
Keyword(s):  
Global Scale ◽  
Digital Data ◽  
Automatic Identification ◽  
Identification System ◽  
Navigation Systems ◽  
Integrated Navigation ◽  
Gulf Of Gdańsk ◽  
Integrated Navigation System ◽  
Navigation Data ◽  
Gulf Of Gdansk

AbstractThe problem of determining geographic position considered only in terms of measurement error, seems to be solved on a global scale. In view of the above, from the nineties, the operational characteristics of radio-navigation systems are equally important. The integrated navigation system operate in a multi-sensor environment and it is important to determinate a temporal validity of data to make it usable in data fusion process. In the age of digital data processing, the requirements for continuity, availability, reliability and integrity information are already grown. This article analyses the problem of time stamp discrepancies of dynamic position reports. For this purpose, the statistical summary of Latency Position Reports has been presented. The navigation data recordings were conducted during 30 days of March 2014 from 19 vessels located in area of Gulf of Gdansk. On the base of Latency Position Reports it is possible to designate the availability of AIS system.

Real-time Accurate Runway Detection based on Airborne Multi-sensors Fusion

2017 ◽  
Vol 67 (5) ◽  
pp. 542 ◽  
Author(s):  
Lei Zhang ◽  
Yue Cheng ◽  
Zhengjun Zhai
Keyword(s):  
Coordinate System ◽  
Real Time ◽  
Recognition Rate ◽  
Region Of Interest ◽  
Flight Simulation ◽  
Hierarchical Architecture ◽  
Projection Model ◽  
Line Segments ◽  
Navigation Data ◽  
Sensors Fusion

<p>Existing methods of runway detection are more focused on image processing for remote sensing images based on computer vision techniques. However, these algorithms are too complicated and time-consuming to meet the demand for real-time airborne application. This paper proposes a novel runway detection method based on airborne multi-sensors data fusion which works in a coarse-to-fine hierarchical architecture. At the coarse layer, a vision projection model from world coordinate system to image coordinate system is built by fusing airborne navigation data and forward-looking sensing images, then a runway region of interest (ROI) is extracted from a whole image by the model. Furthermore, EDLines which is a real-time line segments detector is applied to extract straight line segments from ROI at the fine layer, and fragmented line segments generated by EDLines are linked into two long runway lines. Finally, some unique runway features (e.g. vanishing point and runway direction) are used to recognise airport runway. The proposed method is tested on an image dataset provided by a flight simulation system. The experimental results show that the method has advantages in terms of speed, recognition rate and false alarm rate.</p>

Justification of kinematic scheme small of the manipulator forestry machines

2015 ◽  
Vol 5 (3) ◽  
pp. 234-239
Author(s):  
Платонова ◽  
Marina Platonova ◽  
Драпалюк ◽  
Mikhail Drapalyuk ◽  
Платонов ◽  
...  
Keyword(s):  
Coordinate System ◽  
Reference System ◽  
Coordinate Systems ◽  
Kinematic Scheme ◽  
Inertial Coordinate System ◽  
Generalized Coordinates ◽  
Right Hand ◽  
The Absolute ◽  
Orthogonal Coordinate Systems ◽  
Base Machine

This article discusses the the selection and justification of the reference system and of the generalized coordinates for the kinematic scheme developed by of the manipulator taking into account these factors. The absolute (inertial) coordinate system associated with the center of the support member (eg turntable), joins the arm to the base machine and the subsequent coordinate system formed in accordance with the rules. On the whole, to describe the position of the investigated little detail of the manipulator in the space of generalized coordinates must be four and five right-hand orthogonal coordinate systems.

Dealing with Observation Outages within Navigation Data using Gaussian Process Regression

2014 ◽  
Vol 67 (4) ◽  
pp. 603-615 ◽  
Author(s):  
Hongmei Chen ◽  
Xianghong Cheng ◽  
Haipeng Wang ◽  
Xu Han
Keyword(s):  
Kalman Filter ◽  
Theoretical Analysis ◽  
Gaussian Process ◽  
Inertial Navigation System ◽  
Dynamic Models ◽  
Gaussian Process Regression ◽  
Parametric Model ◽  
Integrated Navigation ◽  
Data Set ◽  
Navigation Data

Gaussian process regression (GPR) is used in a Spare-grid Quadrature Kalman filter (SGQKF) for Strap-down Inertial Navigation System (SINS)/odometer integrated navigation to bridge uncertain observation outages and maintain an estimate of the evolving SINS biases. The SGQKF uses nonlinearized dynamic models with complex stochastic nonlinearities so the performance degrades significantly during observation outages owing to the uncertainties and noise. The GPR calculates the residual output after factoring in the contributions of the parametric model that is used as a nonlinear SINS error predictor integrated into the SGQKF. The sensor measurements and SINS output deviations from the odometer are collected in a data set during observation availability. The GPR is then applied to predict SINS deviations from the odometer and then the predicted SINS deviations are fed to the SGQKF as an actual update to estimate all SINS biases during observation outages. We demonstrate our method's effectiveness in bridging uncertain observation outages in simulations and in real road tests. The results agree with the theoretical analysis, which demonstrate that SGQKF using GPR can maintain an estimate of the evolving SINS biases during signal outages.

Sign in / Sign up

Export Citation Format

Share Document