Effects of Initial Attitude Estimation Errors on Loosely Coupled Smartphone GPS/IMU Integration System

Park, Kwansik; Kim, Woohyun; Seo, Jiwon

doi:10.23919/iccas50221.2020.9268364

Cited by 19 publications

(4 citation statements)

References 18 publications

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“…systems for both indoor and outdoor applications [17], [18], [19], [20], [21], [22], [23]. Other commonly-used sensors for navigation include vision sensors [24], [25], [26], [27], [28], [29], ultrasonic sensors [30], [31], [32], [33], lidar [34], [35], [36], [37], and ultra-wide band (UWB) radar [38], [39], [40], [41], [42], [43].…”

Section: Introductionmentioning

confidence: 99%

Low-Cost GNSS Simulators With Wireless Clock Synchronization for Indoor Positioning

Kim

Seo

2023

IEEE Access

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In regions where global navigation satellite systems (GNSS) signals are unavailable, such as underground areas and tunnels, GNSS simulators can be deployed for transmitting simulated GNSS signals. Then, a GNSS receiver in the simulator coverage outputs the position based on the received GNSS signals (e.g., Global Positioning System (GPS) L1 signals in this study) transmitted by the corresponding simulator. This approach provides periodic position updates to GNSS users while deploying a small number of simulators without modifying the hardware and software of user receivers. However, the simulator clock should be synchronized to the GNSS satellite clock to generate almost identical signals to the live-sky GNSS signals, which is necessary for seamless indoor and outdoor positioning handover. The conventional clock synchronization method based on the wired connection between each simulator and an outdoor GNSS antenna causes practical difficulty and increases the cost of deploying the simulators. This study proposes a wireless clock synchronization method based on a private time server and time delay calibration. Additionally, we derived the constraints for determining the optimal simulator coverage and separation between adjacent simulators. The positioning performance of the proposed GPS simulator-based indoor positioning system was demonstrated in the underground testbed for a driving vehicle with a GPS receiver and a pedestrian with a smartphone. The average position errors were 3.7 m for the vehicle and 9.6 m for the pedestrian during the field tests with successful indoor and outdoor positioning handovers. Since those errors are within the coverage of each deployed simulator, it is confirmed that the proposed system with wireless clock synchronization can effectively provide periodic position updates to users where live-sky GNSS signals are unavailable.INDEX TERMS Indoor navigation, GNSS simulators, clock synchronization, network time protocol (NTP).

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Section: Introductionmentioning

confidence: 99%

Low-Cost GNSS Simulators With Wireless Clock Synchronization for Indoor Positioning

Kim

Seo

2023

IEEE Access

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“…Global navigation satellite systems (GNSSs), particularly the global positioning system (GPS) of the United States of America, play an essential role in various aspects of our lives [1]- [19]. Recently, as autonomous vehicles, such as unmanned aerial vehicles (UAVs), have emerged, the use of GNSS has increased further [20]- [34].…”

Section: Introductionmentioning

confidence: 99%

Machine Learning-Based GPS Multipath Detection Method Using Dual Antennas

Kim,

Byun,

Park

2022

Preprint

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In urban areas, global navigation satellite system (GNSS) signals are often reflected or blocked by buildings, thus resulting in large positioning errors. In this study, we proposed a machine learning approach for global positioning system (GPS) multipath detection that uses dual antennas. A machine learning model that could classify GPS signal reception conditions was trained with several GPS measurements selected as suggested features. We applied five features for machine learning, including a feature obtained from the dual antennas, and evaluated the classification performance of the model, after applying four machine learning algorithms: gradient boosting decision tree (GBDT), random forest, decision tree, and K-nearest neighbor (KNN). It was found that a classification accuracy of 82%-96% was achieved when the test data set was collected at the same locations as those of the training data set. However, when the test data set was collected at locations different from those of the training data, a classification accuracy of 44%-77% was obtained.

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“…In order to obtain positioning, navigation, and timing (PNT) information [1][2][3][4][5][6][7][8][9][10], the demand for global navigation satellite systems (GNSSs), in particular the global positioning system (GPS) [11][12][13][14][15][16], is increasing in various applications such as ground vehicles, air/marine transport, unmanned aerial vehicles (UAVs), and robots [17][18][19][20][21][22][23][24][25][26][27]. Thanks to multi-constellation and multi-frequency GNSS technology, the positioning accuracy and availability significantly improved [28,29].…”

Section: Introductionmentioning

confidence: 99%

GPS Multipath Detection Based on Carrier-to-Noise-Density Ratio Measurements from a Dual-Polarized Antenna

Kim¹,

Lee²,

Park³

2021

Preprint

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In this study, the global positioning system (GPS) multipath detection was performed based on the carrier-tonoise-density ratio, C/N 0 , measured through a dual-polarized antenna. As the right hand circular polarization (RHCP) antenna is sensitive to the signals directly received from the GPS, and the left hand circular polarization (LHCP) antenna is sensitive to the singly reflected signals, the C/N 0 difference between the RHCP and LHCP measurements is used for multipath detection. Once we collected the GPS signals in a low multipath location, we calculated the C/N 0 difference to obtain a threshold value that can be used to detect the multipath GPS signal received from another location. The results were validated through a ray-tracing simulation.

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Effects of Initial Attitude Estimation Errors on Loosely Coupled Smartphone GPS/IMU Integration System

Cited by 19 publications

References 18 publications

Low-Cost GNSS Simulators With Wireless Clock Synchronization for Indoor Positioning

Low-Cost GNSS Simulators With Wireless Clock Synchronization for Indoor Positioning

Machine Learning-Based GPS Multipath Detection Method Using Dual Antennas

GPS Multipath Detection Based on Carrier-to-Noise-Density Ratio Measurements from a Dual-Polarized Antenna

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