High Precision Outdoor and Indoor Reference State Estimation for Testing Autonomous Vehicles

A current trend in automotive research is autonomous driving. For the proper testing and validation of automated driving functions a reference vehicle state is required. Global Navigation Satellite Systems (GNSS) are useful in the automation of the vehicles because of their practicality and accuracy. However, there are situations where the satellite signal is absent or unusable. This research work presents a methodology that addresses those situations, thus largely reducing the dependency of Inertial Navigation Systems (INSs) on the SatNav. The proposed methodology includes (1) a standstill recognition based on machine learning, (2) a detailed mathematical description of the horizontation of inertial measurements, (3) sensor fusion by means of statistical filtering, (4) an outlier detection for correction data, (5) a drift detector, and (6) a novel LiDAR-based Positioning Method (LbPM) for indoor navigation. The robustness and accuracy of the methodology are validated with a state-of-the-art INS with Real-Time Kinematic (RTK) correction data. The results obtained show a great improvement in the accuracy of vehicle state estimation under adverse driving conditions, such as when the correction data is corrupted, when there are extended periods with no correction data and in the case of drifting. The proposed LbPM method achieves an accuracy closely resembling that of a system with RTK.

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ASSESSMENT OF CAR COLLABORATIVE POSITIONING WITH UWB AND VISION

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliii-b1-2021-221-2021 ◽

2021 ◽

Vol XLIII-B1-2021 ◽

pp. 221-227

Author(s):

A. Masiero ◽

C. Toth ◽

J. Gabela ◽

G. Retscher

Keyword(s):

Autonomous Driving ◽

Global Navigation Satellite Systems ◽

Navigation Systems ◽

Common People ◽

Positioning Systems ◽

Satellite Systems ◽

Vehicle To Vehicle ◽

The Absolute ◽

Global Navigation Satellite ◽

Consumer Devices

Abstract. During the last decades the role of positioning and navigation systems is drastically changed in the everyday life of common people, influencing people behavior even multiple times each day. One of the most common applications of this kind of systems is that of terrestrial vehicle navigation: the use of GPS in the automotive navigation sector started thirty years ago, and, nowadays, it commonly assists drivers in reaching most of their non-standard destinations. Despite the popularity of global navigation satellite systems (GNSS), their usability is quite limited in certain working conditions, such as in urban canyons, in tunnels and indoors. While the latter case is typically not particularly interesting for the automotive sector, the first two scenarios represent important cases of interest for automotive navigation. In addition to the market request for increasing the usability of navigation systems on consumer devices, the recent increasing eagerness for autonomous driving is also attracting a lot of researchers’ attention on the development of alternative positioning systems, able to compensate for the unavailability or unreliability of GNSS. In accordance with the motivations mentioned above, this paper focuses on the development of a positioning system based on collaborative positioning between vehicles with UltraWide-Band devices and vision. To be more specific, this work focuses on assessing the performance of the developed system in successfully accomplishing three tasks, associated to different levels of gathered information: 1) assessing distance between vehicles, 2) determining the vehicle relative positions, 3) estimating the absolute car positions. The obtained results show that a) UWB can be reliably used (error of few decimeters error) to assess distances when vehicles are relatively close to each other (e.g. less than 40 m), b) the combination of UWB and vision allows to obtain good results in the computation of relative positions between vehicles, c) UWB-based collaborative positioning can be used for determining the absolute vehicle positions if a sufficient number of UWB range measurements can be ensured (sub-meter error for vehicles connected with a static UWB infrastructure, whereas error at meter level for those exploiting only vehicle-to-vehicle UWB communications).

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Global reliance on GPS creates new risks

Emerald Expert Briefings ◽

10.1108/oxan-db241765 ◽

2019 ◽

Keyword(s):

Power Distribution ◽

Autonomous Vehicles ◽

Critical Infrastructure ◽

Organised Crime ◽

Global Navigation Satellite Systems ◽

Economic Losses ◽

Navigation Systems ◽

Content Type ◽

Satellite Systems ◽

Global Navigation Satellite

Subject Reliance on GPS. Significance Critical infrastructure, essential services and entire industries have become dependent on global navigation satellite systems (GNSSs). This dependence has emerged in an unplanned and unanticipated manner. GNSSs are vulnerable to disruption, with a risk of serious economic losses, loss of life and threats to national security. Impacts Reliance on GNSS will rise in established industries, notably finance, power distribution, agriculture and transportation. GNSS will be vital to the successful development of emerging industries such as autonomous vehicles, drones and new space systems. Demand will grow for high-quality GNSS receivers and software, and for backup systems such as ground-based radio navigation systems. Rising dependence on GNSS will incentivise efforts by national militaries and organised crime to exploit vulnerabilities. The greatest vulnerabilities may emerge in poorer countries where finances are more constrained and regulation is likely to be weaker.

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Robust TOA-Based UAS Navigation under Model Mismatch in GNSS-Denied Harsh Environments

Remote Sensing ◽

10.3390/rs12182928 ◽

2020 ◽

Vol 12 (18) ◽

pp. 2928

Author(s):

Jan Mortier ◽

Gaël Pagès ◽

Jordi Vilà-Valls

Keyword(s):

Intelligent Transportation Systems ◽

Autonomous Systems ◽

Real Life ◽

Transportation Systems ◽

Urban Environments ◽

Global Navigation Satellite Systems ◽

Ultra Wideband ◽

Time Of Arrival ◽

Navigation Systems ◽

Satellite Systems

Global Navigation Satellite Systems (GNSS) is the technology of choice for outdoor positioning purposes but has many limitations when used in safety-critical applications such Intelligent Transportation Systems (ITS) and Unmanned Autonomous Systems (UAS). Namely, its performance clearly degrades in harsh propagation conditions and is not reliable due to possible attacks or interference. Moreover, GNSS signals may not be available in the so-called GNSS-denied environments, such as deep urban canyons or indoors, and standard GNSS architectures do not provide the precision needed in ITS. Among the different alternatives, cellular signals (LTE/5G) may provide coverage in constrained urban environments and Ultra-Wideband (UWB) ranging is a promising solution to achieve high positioning accuracy. The key points impacting any time-of-arrival (TOA)-based navigation system are (i) the transmitters’ geometry, (ii) a perfectly known transmitters’ position, and (iii) the environment. In this contribution, we analyze the performance loss of alternative TOA-based navigation systems in real-life applications where we may have both transmitters’ position mismatch, harsh propagation environments, and GNSS-denied conditions. In addition, we propose new robust filtering methods able to cope with both effects up to a certain extent. Illustrative results in realistic scenarios are provided to support the discussion and show the performance improvement brought by the new methodologies with respect to the state-of-the-art.

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Practical Modeling of GNSS for Autonomous Vehicles in Urban Environments

Sensors ◽

10.3390/s19194236 ◽

2019 ◽

Vol 19 (19) ◽

pp. 4236

Author(s):

Woosik Lee ◽

Hyojoo Cho ◽

Seungho Hyeong ◽

Woojin Chung

Keyword(s):

Motion Estimation ◽

Autonomous Vehicles ◽

Autonomous Navigation ◽

Urban Environments ◽

Global Navigation Satellite Systems ◽

Navigation Satellite ◽

Key Technology ◽

Satellite Systems ◽

Agricultural Robots ◽

Global Navigation Satellite

Autonomous navigation technology is used in various applications, such as agricultural robots and autonomous vehicles. The key technology for autonomous navigation is ego-motion estimation, which uses various sensors. Wheel encoders and global navigation satellite systems (GNSSs) are widely used in localization for autonomous vehicles, and there are a few quantitative strategies for handling the information obtained through their sensors. In many cases, the modeling of uncertainty and sensor fusion depends on the experience of the researchers. In this study, we address the problem of quantitatively modeling uncertainty in the accumulated GNSS and in wheel encoder data accumulated in anonymous urban environments, collected using vehicles. We also address the problem of utilizing that data in ego-motion estimation. There are seven factors that determine the magnitude of the uncertainty of a GNSS sensor. Because it is impossible to measure each of these factors, in this study, the uncertainty of the GNSS sensor is expressed through three variables, and the exact uncertainty is calculated. Using the proposed method, the uncertainty of the sensor is quantitatively modeled and robust localization is performed in a real environment. The approach is validated through experiments in urban environments.

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Assessment of the Implementation of GNSS into Gliding

MAD - Magazine of Aviation Development ◽

10.14311/mad.2017.04.01 ◽

2017 ◽

Vol 5 (4) ◽

pp. 6

Author(s):

Tomáš Kubáč ◽

Jakub Hospodka

Keyword(s):

Global Navigation Satellite Systems ◽

Navigation Satellite ◽

Navigation Systems ◽

Satellite Systems ◽

Global Navigation ◽

Global Navigation Satellite ◽

Global Navigation Systems ◽

Usage Preference ◽

Selection Of ◽

Wide Usage

Global navigation satellite systems are increasingly part of our lives and many industries including aviation. Glider flying is no exception in this trend. Global navigation satellite systems were part of gliding since the early 1990s. First as official recording devices for simple evidence of sporting performances, then as navigation systems, anti-collision systems and emergency location transmitters. Development of recording application was initiated and supported by International Gliding Commission of World Air Sports Federation in way of certifications for flight recorders. The use of navigation and other modern instruments in gliders has brought many benefits but also risks. However, the advantages outweigh the disadvantages and these systems are now integral part of gliding. With this wide usage of global navigation satellite systems devices, there is great many possibilities how and in which way one can use these systems. Pilots must orient themselves in varied selection of products, which they can use to choose one solution, that fits him. Therefore, to find out how and if pilots use these devices, we created questionnaire survey among 143 Czech glider pilots. We found out, that 84% of them are using global navigation satellite systems devices for official record of flight and for navigation as well. More than half of pilots is using free, not built-in devices. Most common devices are mobile phones up to 5 inches of screen diagonal in combination with approved flight recorder without display. If pilots use mobile device for navigation, 52% of them is using one with Windows Mobile operating system, 33% use Android. Navigational software on these mobile devices is then almost tied between SeeYou Mobile, XCSoar and LK8000. Knowledge about usage preference of global navigation systems devices should help pilots with selection and overall orientation in subject.

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Seamless Vehicle Positioning by Lidar-GNSS Integration: Standalone and Multi-Epoch Scenarios

Remote Sensing ◽

10.3390/rs13224525 ◽

2021 ◽

Vol 13 (22) ◽

pp. 4525

Author(s):

Junjie Zhang ◽

Kourosh Khoshelham ◽

Amir Khodabandeh

Keyword(s):

Autonomous Driving ◽

Measurement Model ◽

Urban Environments ◽

Global Navigation Satellite Systems ◽

High Definition ◽

Satellite Systems ◽

The Road ◽

Gnss Receivers ◽

Vehicle Positioning ◽

Global Navigation Satellite

Accurate and seamless vehicle positioning is fundamental for autonomous driving tasks in urban environments, requiring the provision of high-end measuring devices. Light Detection and Ranging (lidar) sensors, together with Global Navigation Satellite Systems (GNSS) receivers, are therefore commonly found onboard modern vehicles. In this paper, we propose an integration of lidar and GNSS code measurements at the observation level via a mixed measurement model. An Extended Kalman-Filter (EKF) is implemented to capture the dynamic of the vehicle movement, and thus, to incorporate the vehicle velocity parameters into the measurement model. The lidar positioning component is realized using point cloud registration through a deep neural network, which is aided by a high definition (HD) map comprising accurately georeferenced scans of the road environments. Experiments conducted in a densely built-up environment show that, by exploiting the abundant measurements of GNSS and high accuracy of lidar, the proposed vehicle positioning approach can maintain centimeter-to meter-level accuracy for the entirety of the driving duration in urban canyons.

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Co-location of SLR and GNSS techniques onboard Galileo and GLONASS satellites

10.5194/egusphere-egu21-7142 ◽

2021 ◽

Author(s):

Grzegorz Bury ◽

Krzysztof Sośnica ◽

Radosław Zajdel ◽

Dariusz Strugarek ◽

Urs Hugentobler

Keyword(s):

Orbital Plane ◽

Terrestrial Reference Frame ◽

Global Navigation Satellite Systems ◽

Navigation Systems ◽

Local Ties ◽

Satellite Systems ◽

The Impact ◽

Space Ties ◽

Gnss Observations

All satellites of the Galileo and GLONASS navigation systems are equipped with laser retroreflector arrays for Satellite Laser Ranging (SLR). SLR observations to Global Navigation Satellite Systems (GNSS) provide the co-location of two space geodetic techniques onboard navigation satellites.SLR observations, which are typically used for the validation of the microwave-GNSS orbits, can now contribute to the determination of the combined SLR+GNSS orbits of the navigation satellites. SLR measurements are especially helpful for periods when the elevation of the Sun above the orbital plane (&#946;&#160;angle) is the highest. The quality of Galileo-IOV orbits calculated using combined SLR+GNSS observations improves from 36 to 30 mm for &#946;>&#8201;60&#176; as compared to the microwave-only solution.&#160;Co-location of two space techniques allows for the determination of the linkage between SLR and GNSS techniques in space. Based on the so-called space ties, it is possible to determine the 3D vector between the ground-based co-located SLR and GNSS stations and compare it with the local ties which are determined using the ground measurements. The agreement between local ties derived from co-location in space and ground measurements is at the level of 1 mm in terms of the long-term median values for the co-located station in Zimmerwald, Switzerland.We also revise the approach for handling the SLR range biases which constitute one of the main error sources for the SLR measurements. The updated SLR range biases consider now the impact of not only of SLR-to-GNSS observations but also the SLR observations to LAGEOS and the microwave GNSS measurements. The updated SLR range biases improve the agreement between space ties and local ties from 34 mm to 23&#160;mm for the co-located station in Wettzell, Germany.Co-location of SLR and GNSS techniques onboard navigation satellites allows for the realization of the terrestrial reference frame in space, onboard Galileo and GLONASS satellites, independently from the ground measurements. It may also deliver independent information on the local tie values with full variance-covariance data for each day with common measurements or can contribute to the control of the ground measurements as long as both GNSS and SLR-to-GNSS observations are available.

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Research on Accuracy of a Boat Position Determination Using GNSS Techniques in Kinematic Mode

Proccedings of 10th International Conference "Environmental Engineering" ◽

10.3846/enviro.2017.239 ◽

2017 ◽

Author(s):

Zbigniew Siejka

Keyword(s):

Research Work ◽

Precise Determination ◽

Global Navigation Satellite Systems ◽

Floating Platform ◽

Satellite Systems ◽

Depth Measurement ◽

Satellite Positioning ◽

Global Navigation Satellite ◽

Hydroacoustic Survey

The main aim of this work is research on the use of satellite positioning GNSS – RTK / RTN techniques to estimate the trajectory of a hydrographic boat. Modern hydrographic boat is the carrier of advanced bathymetry system, integral with GNSS positioning techniques. The key elements of the correct execution of the hydroacoustic survey are two elements: the height of the water surface and precise determination of the position in the moment of performing depth measurement. Integrated Bathymetric System (ZSB) is installed on a floating platform which is in constant motion. To obtain correct results of the hydroacoustic survey, it is necessary to know the precise (3D) position of the platform. In this paper the author presented his own research on the precise determination of accurate and reliable trajectory of a boat. The proposed method uses Real Time Kinematic (RTK) techniques of satellite positioning GNSS (Global Navigation Satellite Systems). The article presents examples of the results obtained during the research work at the largest Polish river.

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Assessment of the Cutting Performance of a Robot Mower Using Custom Built Software

Agronomy ◽

10.3390/agronomy9050230 ◽

2019 ◽

Vol 9 (5) ◽

pp. 230 ◽

Cited By ~ 4

Author(s):

Luisa Martelloni ◽

Marco Fontanelli ◽

Stefano Pieri ◽

Christian Frasconi ◽

Lisa Caturegli ◽

...

Keyword(s):

Autonomous Vehicles ◽

Global Navigation Satellite Systems ◽

Forward Speed ◽

Satellite Systems ◽

Different Shapes ◽

Global Navigation Satellite ◽

High Level ◽

Short Time ◽

Gnss Data ◽

Collection And Management

Before the introduction of positioning technologies in agriculture practices such as global navigation satellite systems (GNSS), data collection and management were time-consuming and labor-intensive tasks. Today, due to the introduction of advanced technologies, precise information on the performance of agricultural machines, and smaller autonomous vehicles such as robot mowers, can be collected in a relatively short time. The aim of this work was to track the performance of a robot mower in various turfgrass areas of an equal number of square meters but with four different shapes by using real-time kinematic (RTK)-GNSS devices, and to easily extract data by a custom built software capable of calculating the distance travelled by the robot mower, the forward speed, the cutting area, and the number of intersections of the trajectories. These data were then analyzed in order to provide useful functioning information for manufacturers, entrepreneurs, and practitioners. The path planning of the robot mower was random and the turfgrass area for each of the four shapes was 135 m2 without obstacles. The distance travelled by the robot mower, the mean forward speed, and the intersections of the trajectories were affected by the interaction between the time of cutting and the shape of the turfgrass. For all the different shapes, the whole turfgrass area was completely cut after two hours of mowing. The cutting efficiency decreased by increasing the time, as a consequence of the increase in overlaps. After 75 minutes of cutting, the efficiency was about 35% in all the turfgrass areas shapes, thus indicating a high level of overlapping.

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Time-Sensitive Network (TSN) Experiment in Sensor-Based Integrated Environment for Autonomous Driving

Sensors ◽

10.3390/s19051111 ◽

2019 ◽

Vol 19 (5) ◽

pp. 1111 ◽

Cited By ~ 5

Author(s):

Juho Lee ◽

Sungkwon Park

Keyword(s):

Communication Networks ◽

Autonomous Vehicles ◽

Performance Test ◽

Autonomous Driving ◽

Navigation Systems ◽

Data Traffic ◽

Control Units ◽

Band Size ◽

Integrated Environment ◽

Vehicle Network

Recently, large amounts of data traffic from various sensors and image and navigation systems within vehicles are generated for autonomous driving. Broadband communication networks within vehicles have become necessary. New autonomous Ethernet networks are being considered as alternatives. The Ethernet-based in-vehicle network has been standardized in the IEEE 802.1 time-sensitive network (TSN) group since 2006. The Ethernet TSN will be revised and integrated into a subsequent version of IEEE 802.1Q-2018 published in 2018 when various new TSN-related standards are being newly revised and published. A TSN integrated environment simulator is developed in this paper to implement the main functions of the TSN standards that are being developed. This effort would minimize the performance gaps that can occur when the functions of these standards operate in an integrated environment. As part of this purpose, we analyzed the simulator to verify that the traffic for autonomous driving satisfies the TSN transmission requirements in the in-vehicle network (IVN) and the preemption (which is one of the main TSN functions) and reduces the overall End-to-End delay. An optimal guard band size for the preemption was also found for autonomous vehicles in our work. Finally, an IVN model for autonomous vehicles was designed and the performance test was conducted by configuring the traffic to be used for various sensors and electronic control units (ECUs).

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