scholarly journals DESIGN AND VALIDATION OF A SURFACE PROFILING APPARATUS FOR AGRICULTURAL TERRAIN ROUGHNESS MEASUREMENTS

2019 ◽  
Vol 59 (3) ◽  
pp. 169-180 ◽  
Author(s):  
Jianguo Yan ◽  
Chunguang Wang ◽  
Shengshi Xie ◽  
Lijuan Wang
Keyword(s):  
Global Navigation Satellite Systems ◽  
Sensor Data ◽  
Measurement Unit ◽  
Full Description ◽  
Ongoing Research ◽  
Satellite Systems ◽  
Surface Profiling ◽  
Laser Sensors ◽  
Global Navigation Satellite ◽  
Flat Section

How to accurately and efficiently measure the profiles of the terrain on which agricultural machines operate has been an ongoing research topic. In this study, a surface profiling apparatus (profiler) was developed to measure agricultural terrain profiles along parallel tracks. The profiler is mainly composed of sensor frames, an RTK-GNSS system (Real Time Kinematics-Global Navigation Satellite Systems), laser sensors, an Inertial Measurement Unit (IMU) sensor and a data acquisition system. Along with a full description of how the terrain profiles were produced, a methodology to compensate for the tractor motion was included in the sensor data analysis. In field profiling validation, two trapezoidal bumps with known dimensions were used to assess the ability of the terrain profiler to reproduce the vertical profiles of the bumps, resulting in root mean square error (RMSE) of 3.6-4.7 mm and 4.5-5.1 mm with profiling speeds of 1.02 and 2.56 km/h, respectively. In addition, a validation test was also conducted on an asphalt road by profiling a flat road with the measuring wheels of the profiler rolling on the flat section but with the tractor wheels driving over a trapezoidal bump to excite the tractor pitch and roll motion. The measured profiles then also exhibited a flat road, which showed the ability of the profiler to remove the tractor motion from the profiling measurements.

Multi-Sensor Integrated Navigation in Urban and Indoor Environments

2018 ◽  
pp. 397-442 ◽  
Author(s):  
Mohamed Atia
Keyword(s):  
Sensor Fusion ◽  
Global Navigation Satellite Systems ◽  
Measurement Unit ◽  
Indoor Environments ◽  
Integrated Navigation ◽  
Satellite Systems ◽  
Tightly Coupled ◽  
Sensor Processing ◽  
Global Navigation Satellite ◽  
Dense Urban Environment

The art of multi-sensor processing, or “sensor-fusion,” is the ability to optimally infer state information from multiple noisy streams of data. One major application area where sensor fusion is commonly used is navigation technology. While global navigation satellite systems (GNSS) can provide centimeter-level location accuracy worldwide, they suffer from signal availability problems in dense urban environment and they hardly work indoors. While several alternative backups have been proposed, so far, no single sensor or technology can provide the desirable precise localization in such environments under reasonable costs and affordable infrastructures. Therefore, to navigate through these complex areas, combining sensors is beneficial. Common sensors used to augment/replace GNSS in complex environments include inertial measurement unit (IMU), range sensors, and vision sensors. This chapter discusses the design and implementation of tightly coupled sensor fusion of GNSS, IMU, and light detection and ranging (LiDAR) measurements to navigate in complex urban and indoor environments.

scholarly journals Motorway Measurement Campaign to Support R&D Activities in the Field of Automated Driving Technologies

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2169
Author(s):  
Viktor Tihanyi ◽  
Tamás Tettamanti ◽  
Mihály Csonthó ◽  
Arno Eichberger ◽  
Dániel Ficzere ◽  
...  
Keyword(s):  
Ground Truth ◽  
Global Navigation Satellite Systems ◽  
Sensor Data ◽  
Automated Driving ◽  
High Definition ◽  
Data Set ◽  
Measurement Campaign ◽  
Satellite Systems ◽  
Road Geometry ◽  
Global Navigation Satellite

A spectacular measurement campaign was carried out on a real-world motorway stretch of Hungary with the participation of international industrial and academic partners. The measurement resulted in vehicle based and infrastructure based sensor data that will be extremely useful for future automotive R&D activities due to the available ground truth for static and dynamic content. The aim of the measurement campaign was twofold. On the one hand, road geometry was mapped with high precision in order to build Ultra High Definition (UHD) map of the test road. On the other hand, the vehicles—equipped with differential Global Navigation Satellite Systems (GNSS) for ground truth localization—carried out special test scenarios while collecting detailed data using different sensors. All of the test runs were recorded by both vehicles and infrastructure. The paper also showcases application examples to demonstrate the viability of the collected data having access to the ground truth labeling. This data set may support a large variety of solutions, for the test and validation of different kinds of approaches and techniques. As a complementary task, the available 5G network was monitored and tested under different radio conditions to investigate the latency results for different measurement scenarios. A part of the measured data has been shared openly, such that interested automotive and academic parties may use it for their own purposes.

scholarly journals UAVS ENHANCED NAVIGATION IN OUTDOOR GNSS DENIED ENVIRONMENT USING UWB AND MONOCULAR CAMERA SYSTEMS

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 665-672 ◽  
Author(s):  
S. Zahran ◽  
A. Masiero ◽  
M. M. Mostafa ◽  
A. M. Moussa ◽  
A. Vettore ◽  
...  
Keyword(s):  
Navigation System ◽  
Low Cost ◽  
Global Navigation Satellite Systems ◽  
Ultra Wideband ◽  
Measurement Unit ◽  
Satellite Systems ◽  
Monocular Camera ◽  
Camera Systems ◽  
Global Navigation Satellite ◽  
The Cost

<p><strong>Abstract.</strong> The demand for small Unmanned Aerial Vehicles (UAVs) is massively increasing these days, due to the wide variety of applications utilizing such vehicles to perform tasks that may be dangerous or just to save time, effort, or cost. Small UAVs navigation system mainly depends on the integration between Global Navigation Satellite Systems (GNSS) and Inertial Measurement Unit (INS) to estimate the Positions, Velocities, and Attitudes (PVT) of the vehicle. Without GNSS such UAVs cannot navigate for long periods of time depending on INS alone, as the low-cost INS typically exhibits massive accumulation of errors during GNSS absence. Given the importance of ensuring full operability of the UAVs even during GNSS signals unavailability, other sensors must be used to bound the INS errors and enhance the navigation system performance. This paper proposes an enhanced UAV navigation system based on integration between monocular camera, Ultra-Wideband (UWB) system, and INS. In addition to using variable EKF weighting scheme. The paper also investigates this integration in the case of low density of UWB anchors, to reduce the cost required for such UWB system infrastructure. A GoPro Camera and UWB rover were attached to the belly of a quadcopter, an on the shelf commercial drone (3DR Solo), during the experimental flight. The velocity of the vehicle is estimated with Optical Flow (OF) from camera successive images, while the range measurements between the UWB rover and the stationary UWB anchors, which were distributed on the field, were used to estimate UAV position.</p>

scholarly journals Motorway Measurement Campaign to Support R&D Activities in the Field of Automated Driving Technologies

2021 ◽  
Author(s):  
Viktor Tihanyi ◽  
Tettamanti Tamás ◽  
Mihály Csonthó ◽  
Arno Eichberger ◽  
Dániel Ficzere ◽  
...  
Keyword(s):  
Ground Truth ◽  
Global Navigation Satellite Systems ◽  
Added Value ◽  
Sensor Data ◽  
Automated Driving ◽  
High Definition ◽  
Measurement Campaign ◽  
Satellite Systems ◽  
Road Geometry ◽  
Global Navigation Satellite

The paper presents the measurement campaign carried out on a real-world motorway stretch of Hungary with the participation of both industrial and academic partners from Austria and Hungary. The measurement included vehicle based as well as infrastructure based sensor data. The obtained results will be extremely useful for future automotive R&amp;amp;D activities due to the available ground truth for static and dynamic content. The aim of the measurement campaign was twofold. On the one hand, road geometry was mapped with high precision in order to build Ultra High Definition (UHD) map of the test road. On the other hand, the vehicles - equipped with differential Global Navigation Satellite Systems (GNSS) for ground truth localization - carried out special test scenarios while collecting detailed data using different sensors. All test runs were recorded by both vehicles and infrastructure. As a complementary task, the available 5G network was monitored and tested. The paper also showcases application examples based on the measurement campaign data, in which the added value of having access to the ground truth labeling and the created UHD map of the motorway section becomes apparent. In order to present our work transparently, a part of the measured data have been shared openly such that interested automotive as well as academic parties may use it for their own purposes.

Hydrogeophysical Survey of Groundwater Development at Okada Community Ovia North – East L.G.A. Edo State

2018 ◽  
Vol 2 (1) ◽  
pp. 39-45
Author(s):  
M. O. Ehigiator
Keyword(s):  
Global Navigation Satellite Systems ◽  
Geophysical Investigation ◽  
Satellite Systems ◽  
North East ◽  
Long Time ◽  
Electrical Sounding ◽  
Edo State ◽  
Global Navigation Satellite ◽  
Water Problems ◽  
Aquifer Unit

Geophysical investigation was conducted at Okada community in ovia North Local Govertment area of Edo state to determine the prospect of aquifer zone. The Petrozenith PZ-02 Terrameter, one of the Electrical Resistivity Equipment was used to conduct a Vertical Electrical Sounding (VES) in the study area. The Garmin Etrex 10 Global Navigation satellite systems (GNSS) was used to acquire Geodetic coordinates of point where VES observations were made. This research was carried out as a pre-drilling Hydro-geophysical survey conducted for the purpose of surveying and studying the proposed water borehole site at Okada Community that has suffered acute water problems for a very long time. There have been series of boreholes drilled in the studied area but all are dry wells. This survey was conducted to investigate the subsurface complexity of the sites in respect of lithology and to recommend the total drill depth based on the prospective aquifer unit so identified. Result of interpretation suggests that the area is underlain with substantive aquiferous formation but at a depth not exceeding 121.60 m (398.95 ft), which is the lower aquifer unit. The value of elevation at point of observation referenced to mean sea level is 94 m.

scholarly journals Forty-three years of absolute gravity observations of the Fennoscandian postglacial rebound in Finland

2021 ◽  
Vol 95 (2) ◽  
Author(s):  
Mirjam Bilker-Koivula ◽  
Jaakko Mäkinen ◽  
Hannu Ruotsalainen ◽  
Jyri Näränen ◽  
Timo Saari
Keyword(s):  
Gravity Data ◽  
Gravity Change ◽  
Global Navigation Satellite Systems ◽  
Absolute Gravity ◽  
Data Sets ◽  
Postglacial Rebound ◽  
Land Uplift ◽  
Satellite Systems ◽  
Gravity Measurements ◽  
Global Navigation Satellite

AbstractPostglacial rebound in Fennoscandia causes striking trends in gravity measurements of the area. We present time series of absolute gravity data collected between 1976 and 2019 on 12 stations in Finland with different types of instruments. First, we determine the trends at each station and analyse the effect of the instrument types. We estimate, for example, an offset of 6.8 μgal for the JILAg-5 instrument with respect to the FG5-type instruments. Applying the offsets in the trend analysis strengthens the trends being in good agreement with the NKG2016LU_gdot model of gravity change. Trends of seven stations were found robust and were used to analyse the stabilization of the trends in time and to determine the relationship between gravity change rates and land uplift rates as measured with global navigation satellite systems (GNSS) as well as from the NKG2016LU_abs land uplift model. Trends calculated from combined and offset-corrected measurements of JILAg-5- and FG5-type instruments stabilized in 15 to 20 years and at some stations even faster. The trends of FG5-type instrument data alone stabilized generally within 10 years. The ratio between gravity change rates and vertical rates from different data sets yields values between − 0.206 ± 0.017 and − 0.227 ± 0.024 µGal/mm and axis intercept values between 0.248 ± 0.089 and 0.335 ± 0.136 µGal/yr. These values are larger than previous estimates for Fennoscandia.

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