scholarly journals Performance Improvement of Inertial Navigation System by Using Magnetometer with Vehicle Dynamic Constraints

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Daehee Won ◽  
Jongsun Ahn ◽  
Sangkyung Sung ◽  
Moonbeom Heo ◽  
Sung-Hyuck Im ◽  
...  
Keyword(s):  
Magnetic Measurements ◽  
Inertial Sensor ◽  
Inertial Navigation ◽  
Nonholonomic Constraints ◽  
Satellite System ◽  
Indoor Navigation ◽  
Ground Vehicles ◽  
Dynamic Constraints ◽  
Global Navigation Satellite ◽  
Inertial Measurements

A navigation algorithm is proposed to increase the inertial navigation performance of a ground vehicle using magnetic measurements and dynamic constraints. The navigation solutions are estimated based on inertial measurements such as acceleration and angular velocity measurements. To improve the inertial navigation performance, a three-axis magnetometer is used to provide the heading angle, and nonholonomic constraints (NHCs) are introduced to increase the correlation between the velocity and the attitude equation. The NHCs provide a velocity feedback to the attitude, which makes the navigation solution more robust. Additionally, an acceleration-based roll and pitch estimation is applied to decrease the drift when the acceleration is within certain boundaries. The magnetometer and NHCs are combined with an extended Kalman filter. An experimental test was conducted to verify the proposed method, and a comprehensive analysis of the performance in terms of the position, velocity, and attitude showed that the navigation performance could be improved by using the magnetometer and NHCs. Moreover, the proposed method could improve the estimation performance for the position, velocity, and attitude without any additional hardware except an inertial sensor and magnetometer. Therefore, this method would be effective for ground vehicles, indoor navigation, mobile robots, vehicle navigation in urban canyons, or navigation in any global navigation satellite system-denied environment.

scholarly journals Measurements and Accuracy Evaluation of a Strapdown Marine Gravimeter Based on Inertial Navigation

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3902 ◽  
Author(s):  
Wei Wang ◽  
Jinyao Gao ◽  
Dongming Li ◽  
Tao Zhang ◽  
Xiaowen Luo ◽  
...  
Keyword(s):  
Coupling Effect ◽  
Inertial Navigation ◽  
Satellite System ◽  
Gravity Survey ◽  
Accuracy Evaluation ◽  
Earth’S Gravity Field ◽  
Marine Gravity ◽  
Global Navigation Satellite ◽  
Measuring Unit ◽  
Rough Sea

The strapdown gravimetry system uses the combination of an Inertial Measuring Unit (IMU) and a Global Navigation Satellite System (GNSS) to measure the Earth’s gravity field. Due to limited accuracies of IMU and GNSS, early strapdown gravimetry systems were more often used in airborne surveys, but less used in marine surveys. We developed a strapdown inertial navigation system (SINS), the Sea-Air Gravimeter-2Marine (SAG-2M), using novel IMU components, whose accuracy was further improved with the application of Precise Point Positioning (PPP) and enhanced algorithm, making it possible to be used in marine gravity survey. The testing results of the SAG-2M were compared to those of the Lacoste and Romberg S-129 gravimeter on the same ship in the South China Sea basin. The cruise lasted for 50 days, during which 134 effective gravity profiles were measured, resulting in 174 crossover points. The results showed that, for the SAG-2M, the root mean square (RMS) crossover points were 1.35 mGal before difference adjustment and 0.69 mGal after difference adjustment; for the S-129 gravimeter, they were 5.62 mGal and 0.95 mGal, correspondingly. In calm sea conditions, the results of the two systems were relatively consistent at all wavelengths. However, in rough sea conditions, since the SAG-2M was not affected by the cross-coupling effect, its data demonstrated less high-frequency jump. A physical platform adopted in SAG-2M can further make the transition data effective when the ship is turning around. Therefore, SAG-2M was able to improve the proportion of valid data and the efficiency of data post-processing for measurements taken during the cruise. The testing results indicate that in terms of accuracy and efficiency in the marine gravity survey, SAG-2M is better than S-129. In addition, as the miniaturization and precision of inertial components are developing continuously, SAG-2M also shows great potential in miniaturization.

scholarly journals Automatic Mapping of Center Line of Railway Tracks using Global Navigation Satellite System, Inertial Measurement Unit and Laser Scanner

2020 ◽  
Vol 12 (3) ◽  
pp. 411 ◽  
Author(s):  
Sangeetha Shankar ◽  
Michael Roth ◽  
Lucas Andreas Schubert ◽  
Judith Anne Verstegen
Keyword(s):  
Laser Scanner ◽  
Satellite System ◽  
Sensor Data ◽  
Measurement Unit ◽  
Center Line ◽  
Railway Tracks ◽  
Combination Of Methods ◽  
Global Navigation Satellite ◽  
Inertial Measurements ◽  
Gnss Data

Up-to-date geodatasets on railway infrastructure are valuable resources for the field of transportation. This paper investigates three methods for mapping the center lines of railway tracks using heterogeneous sensor data: (i) conditional selection of satellite navigation (GNSS) data, (ii) a combination of inertial measurements (IMU data) and GNSS data in a Kalman filtering and smoothing framework and (iii) extraction of center lines from laser scanner data. Several combinations of the methods are compared with a focus on mapping in tree-covered areas. The center lines of the railway tracks are extracted by applying these methods to a test dataset collected by a road-rail vehicle. The guard rails in the test area were also extracted during the center line detection process. The combination of methods (i) and (ii) gave the best result for the track on which the measurement vehicle had moved, mapping almost 100% of the track. The combination of methods (ii) and (iii) and the combination of all three methods gave the best result for the other parallel tracks, mapping between 25% and 80%. The mean perpendicular distance of the mapped center lines from the reference data was 1.49 meters.

scholarly journals A Multilevel Architecture for Autonomous UAVs

Drones ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 55
Author(s):  
Luca Bigazzi ◽  
Michele Basso ◽  
Enrico Boni ◽  
Giacomo Innocenti ◽  
Massimiliano Pieraccini
Keyword(s):  
Additional Data ◽  
Communication Protocol ◽  
Inertial Sensor ◽  
Satellite System ◽  
Streaming Video ◽  
Radio Receiver ◽  
Flight Operations ◽  
Global Navigation Satellite ◽  
Computer Board

In this paper, a multilevel architecture able to interface an on-board computer with a generic UAV flight controller and its radio receiver is proposed. The computer board exploits the same standard communication protocol of UAV flight controllers and can easily access additional data, such as: (i) inertial sensor measurements coming from a multi-sensor board; (ii) global navigation satellite system (GNSS) coordinates; (iii) streaming video from one or more cameras; and (iv) operator commands from the remote control. In specific operating scenarios, the proposed platform is able to act as a “cyber pilot” which replaces the role of a human UAV operator, thus simplifying the development of complex tasks such as those based on computer vision and artificial intelligence (AI) algorithms which are typically employed in autonomous flight operations.

scholarly journals Semi-tightly coupled integration of multi-GNSS PPP and S-VINS for precise positioning in GNSS-challenged environments

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Xingxing Li ◽  
Xuanbin Wang ◽  
Jianchi Liao ◽  
Xin Li ◽  
Shengyu Li ◽  
...  
Keyword(s):  
Global Navigation Satellite System ◽  
Inertial Navigation ◽  
Satellite System ◽  
Navigation Satellite ◽  
Navigation Systems ◽  
Tight Coupling ◽  
Positioning Accuracy ◽  
3D Positioning ◽  
Global Navigation ◽  
Global Navigation Satellite

AbstractBecause of its high-precision, low-cost and easy-operation, Precise Point Positioning (PPP) becomes a potential and attractive positioning technique that can be applied to self-driving cars and drones. However, the reliability and availability of PPP will be significantly degraded in the extremely difficult conditions where Global Navigation Satellite System (GNSS) signals are blocked frequently. Inertial Navigation System (INS) has been integrated with GNSS to ameliorate such situations in the last decades. Recently, the Visual-Inertial Navigation Systems (VINS) with favorable complementary characteristics is demonstrated to realize a more stable and accurate local position estimation than the INS-only. Nevertheless, the system still must rely on the global positions to eliminate the accumulated errors. In this contribution, we present a semi-tight coupling framework of multi-GNSS PPP and Stereo VINS (S-VINS), which achieves the bidirectional location transfer and sharing in two separate navigation systems. In our approach, the local positions, produced by S-VINS are integrated with multi-GNSS PPP through a graph-optimization based method. Furthermore, the accurate forecast positions with S-VINS are fed back to assist PPP in GNSS-challenged environments. The statistical analysis of a GNSS outage simulation test shows that the S-VINS mode can effectively suppress the degradation of positioning accuracy compared with the INS-only mode. We also carried out a vehicle-borne experiment collecting multi-sensor data in a GNSS-challenged environment. For the complex driving environment, the PPP positioning capability is significantly improved with the aiding of S-VINS. The 3D positioning accuracy is improved by 49.0% for Global Positioning System (GPS), 40.3% for GPS + GLOANSS (Global Navigation Satellite System), 45.6% for GPS + BDS (BeiDou navigation satellite System), and 51.2% for GPS + GLONASS + BDS. On this basis, the solution with the semi-tight coupling scheme of multi-GNSS PPP/S-VINS achieves the improvements of 41.8–60.6% in 3D positioning accuracy compared with the multi-GNSS PPP/INS solutions.

scholarly journals Evaluation on Nonholonomic Constraints and Rauch–Tung–Striebel Filter-Enhanced UWB/INS Integration

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Zhouzheng Gao ◽  
Lin Chen ◽  
Yu Min ◽  
Jie Lv ◽  
You Li
Keyword(s):  
Three Dimensional ◽  
Nonholonomic Constraints ◽  
Satellite System ◽  
Least Square ◽  
Precise Positioning ◽  
Global Navigation Satellite ◽  
Navigation Accuracy ◽  
The Impact ◽  
The Mathematical Model ◽  
Better Than

Precise and seamless positioning is becoming a basic requirement for the Internet of Things (IoT). However, there is a gap for precise positioning in Global Navigation Satellite System- (GNSS-) denied indoor areas. Thus, a multisensor integration system based on ultrawide-band (UWB), inertial navigation system (INS), nonholonomic constraints (NHCs), and Rauch–Tung–Striebel (RTS) smoother is proposed. In this system, the UWB performs as the major precise positioning system, while the INS bridges the UWB-degraded and UWB-denied periods. Meanwhile, the NHC restrains the drifts of INS, while the RTS smoother further upgrades the navigation accuracy. The contributions of this article are as follows. First, it presents the robust least square- (RLS-) based UWB positioning. The proposed method is effective in mitigating the impact of the effect of non-line-of-sight (NLOS), which is one of the most significant error sources for UWB positioning. Second, it derives the mathematical model of the UWB/INS/NHC/RTS integration, which is new compared to the existing approaches. Results illustrate that the proposed system can provide centimeter-level positioning accuracy, millimeter-level velocimetry accuracy, and accuracy of better than 0.05 and 0.15 degrees for horizontal and vertical attitude angles, respectively. Even in the scenario with short-term UWB outages (30 s), simulation results show that the three-dimensional position still can be better than 20 cm. Such accuracy values reach the state-of-the-art for indoor positioning using UWB and INS.

scholarly journals IOT ENABLED INDOOR NAVIGATION SYSTEM DESIGN FOR EMERGENCIES

2019 ◽  
Vol XLII-4/W12 ◽  
pp. 61-64
Author(s):  
A. Duru ◽  
I. R. Karas
Keyword(s):  
System Design ◽  
Navigation System ◽  
Signal Propagation ◽  
Satellite System ◽  
Indoor Positioning ◽  
Indoor Navigation ◽  
Positioning Accuracy ◽  
Indoor Navigation System ◽  
Global Navigation Satellite ◽  
High Building

<p><strong>Abstract.</strong> Global Navigation Satellite System is widely accepted and it has good positioning accuracy for outdoor applications. However, it does not provide sufficient positioning accuracy for inside of buildings. Signals are attenuated inside of buildings or dense high building areas because various materials between satellites and receiver create interference to the signal propagation. Thus, indoor positioning technologies have emerged to cover the problem. In this paper, indoor positioning technologies have been investigated and UWB based indoor positioning technology has been chosen between them. In addition to indoor positioning, accelerometer and Wi-Fi connection has been added to the system for mobility. The accelerometer detects emergency cases and alerts relatives of an intended person by using web service. Hereby, remote navigation system design is presented for first aid of the user. The system can detect emergencies, especially falls using the accelerometer and it can locate patients anywhere in the world. The designed system showed that it is possible to detect emergencies and transfer to the web with a 24.17&amp;thinsp;cm average positioning error. Also, it is an assuring system for future remote positioning applications.</p>

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