Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  SDCM
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
This paper presents a modified algorithm for determining the positioning accuracy of a UAV based on a joint GPS/EGNOS+GPS/SDCM (Global Positioning System/European Geostationary Navigation Overlay Service+Global Positioning System/ System for Differential Corrections and Monitoring) solution. Firstly, the average weighted model for determining the position of the UAV (Unmanned Aerial Vehicle) was developed. The algorithm takes into account the coordinates from the individual GPS/EGNOS and GPS/SDCM solution as well as correction coefficients that are a function of the inverse of the ionospheric VTEC (Vertical TEC) delay. Next the accuracy term was estimated in the form of the position errors and RMS (Root Mean Square) errors. Finally the Kalman filter algorithm was used for improved the position errors and RMS errors. The developed algorithm is concerned with determining the positioning accuracy of the UAV for BLh (B-Latitude, L-Longitude, h-ellipsoidal height) ellipsoidal coordinates. The algorithm was tested on kinematic GPS/SBAS (Global Positioning System/Satellite Based Augmentation System) data recorded by a GNSS (Global Navigation Satellite System) receiver placed on a DJI Matrice 300RTK type unmanned platform. As part of the research test, two flights of the UAV were performed on 16 March 2022 in Olsztyn. In the first flight, the proposed algorithm enabled an increase in UAV positioning accuracy from 4% to 57% after Kalman filter process. In the second flight, on the other hand, UAV positioning accuracy was increased from 6% to 42%. The developed algorithm enabled an increase in UAV positioning accuracy and was successfully tested in two independent flight experiments. Ultimately, further research is planned to modify the algorithm with other correction coefficients.
EN
The article shows the results of a study on the determination of SBAS satellite positioning integrity parameters as a HPL and VPL protection levels. To this end, a modified algorithm was developed to determine the HPL and VPL protection levels from a common aircraft position navigation solution based on EGNOS and SDCM augmentation systems. The developed mathematical scheme was verified on real GNSS kinematic data recorded by two onboard Septentrio AsterRx2i and Trimble Alloy receivers installed on a Diamond DA 20-C aircraft. Based on the conducted tests, it was found that the HPL parameter does not exceed 12.24 m, while respectively the VPL does not exceed 18.01 m. In addition, in the course of the study it was found that the proposed EGNOS+SDCM solution improves the HPL/VPL integrity determination in relation to the EGNOS solution by 8÷66%. The mathematical scheme used in the study was also applied to designation the HPL/VPL terms for the UAV platform. The obtained results of the HPL/VPL values for the positioning of the aircraft and the UAV platform show a high efficiency of the developed algorithm for improving the integrity parameter.
EN
SBAS systems are applied in precise positioning of UAV. The paper presents the results of studies on the improvement of UAV positioning with the use of the EGNOS+SDCM solutions. In particular, the article focuses on the application of the model of totaling the SBAS positioning accuracy to improve the accuracy of determining the coordinates of UAVs during the realisation of a test flight. The developed algorithm takes into account the position errors determined from the EGNOS and SDCM solutions. as well as the linear coefficients that are used in the linear combination model. The research was based on data from GPS observations and SBAS corrections from the AsteRx-m2 UAS receiver installed on a Tailsitter platform. The tests were conducted in September 2020 in northern Poland. The application of the proposed algorithm that sums up the positioning accuracy of EGNOS and SDCM allowed for the improvement of the accuracy of determining the position of the UAV by 82-87% in comparison to the application of either only EGNOS or SDCM. Apart from that, another important result of the application of the proposed algorithm was the reduction of outlier positioning errors that reduced the accuracy of the positioning of UAV when a single SBAS solution (EGNOS or SDCM) was used. The study also presents the effectiveness of the proposed algorithm in terms of calculating the accuracy of EGNOS+SDCM positioning for the weighted average model. The developed algorithm may be used in research conducted on other SBAS supporting systems.
EN
This paper presents an algorithm for determining the precision parameter for aircraft position coordinates based on a combined GPS/EGNOS and GPS/SDCM solution. The proposed algorithm uses a weighted average model that combines a single GPS/EGNOS and GPS/SDCM position navigation solution to determine the resulting aircraft coordinates. The weighted mean model include the linear coefficients as a function of: the inverse of the number of tracked GPS satellites for which EGNOS and SDCM corrections have been generated, and the inverse of the geometric coefficient of the PDOP (Position Dilution of Precision). The corrections between the single GPS/EGNOS and GPS/SDCM solution to the aircraft's resultant coordinates are then calculated on this basis. Finally, the standard deviation for the aircraft resultant BLh (B-Latitude, L-Longitude, h-ellipsoidal height) coordinates is calculated as a measure of precision. The research experiment used recorded on-board GPS+SBAS data from two GNSS receivers mounted on a Diamond DA 20-C1 aircraft. The test flight was carried out on the Olsztyn-Suwałki-Olsztyn route. The calculations of aircraft position based on GPS/EGNOS and GPS/SDCM solution were performed in the RTKLIB v.2.4.3 program in the RTKPOST module. Next, aircraft resultant coordinates and standard deviations were computed in Scilab v.6.0.0 software package. Based on the tests performed, it was found that for the Trimble Alloy receiver, the standard deviation values for the ellipsoidal coordinates BLh of the aircraft do not exceed 1.77 m. However, for the Septentrio AsterRx2i receiver, the values of standard deviations for the aircraft's ellipsoidal BLh coordinates do not exceed 5.04 m. The use of linear coefficients as the inverse of the number of tracked GPS satellites with SBAS corrections in the GPS/EGNOS+GPS/SDCM positioning model resulted in a reduction in standard deviations of approximately 50-51% relative to the solution with linear coefficients calculated as the inverse of the PDOP parameter. In paper, the standard deviation was also obtained using arithmetic mean model. However the values of standard deviation from weighted mean model are lower than arithmetic mean model.
EN
The article presents a modified scheme of determining the accuracy parameter of SBAS (Satellite Based Augmentation System) positioning with use of two supporting systems: EGNOS (European Geostationary Navigation Overlay Service) and SDCM (System of Differential Correction and Monitoring). The proposed scheme is based on the weighted mean model, which combines single solutions of EGNOS and SDCM positions in order to calculate the accuracy of positioning of the aerial vehicle. The applied algorithm has been tested in a flight experiment conducted in 2020 in north-eastern Poland. The phase of approach to landing of a Diamond DA 20-C1 aircraft at the EPOD airport (European Poland Olsztyn Dajtki) was subjected to numerical analysis. The Septentrio AsterRx2i geodesic receiver was installed on board of the aircraft to collect and record GPS (Global Positioning System) observations to calculate the navigation position of the aircraft. In addition, the EGNOS and SDCM corrections in the “*.ems” format were downloaded from the real time server data. The computations were realized in RTKPOST library of the RTKLIB v.2.4.3 software and also in SciLab application. Based on the conducted research, it was found that the accuracy of aircraft positioning from the EGNOS+SDCM solution ranged from -1.63 m to +3.35 m for the ellipsoidal coordinates BLh. Additionally, the accuracy of determination of the ellipsoidal height h was 1÷28% higher in the weighted mean model than in the arithmetic mean model. On the other hand, the accuracy of determination of the ellipsoidal height h was 1÷28% higher in the weighted mean model than for the single EGNOS solution. Additionally, the weighted mean model reduced the resultant error of the position RMS-3D by 1÷13% in comparison to the arithmetic mean model. The mathematical model used in this study proved to be effective in the analysis of the accuracy of SBAS positioning in aerial navigation.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.