Investigation of Alternative Parameters for Immunity-based UAV Navigation in GNSS-denied Environment

2020 ◽  
Vol 09 (01) ◽  
pp. 65-72
Author(s):  
Mohanad Alnuaimi ◽  
Mario G. Perhinschi
Keyword(s):  
Autonomous Navigation ◽  
Dead Reckoning ◽  
Global Navigation Satellite Systems ◽  
External Information ◽  
Artificial Immune ◽  
Tracking Errors ◽  
Satellite Systems ◽  
Vehicle Position ◽  
Global Navigation Satellite ◽  
Uav Navigation

This paper is focused on analyzing effects of several significant parameters on the performance of an immunity-inspired methodology for autonomous navigation of unmanned air vehicles when measurements from global navigation satellite systems (GNSS) or similar current sources, including external information of opportunity, are not available. An artificial immune system (AIS) provides corrections to a dead reckoning algorithm for adequate estimates of vehicle position and velocity. Parameter effects are assessed and analyzed through simulation in terms of trajectory tracking errors during autonomous flight.

scholarly journals Practical Modeling of GNSS for Autonomous Vehicles in Urban Environments

Sensors ◽  
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.

Astronomical Vessel Position Determination Utilizing the Optical Super Wide Angle Lens Camera

2014 ◽  
Vol 67 (4) ◽  
pp. 633-649 ◽  
Author(s):  
Chong-hui Li ◽  
Yong Zheng ◽  
Chao Zhang ◽  
Yu-Lei Yuan ◽  
Yue-Yong Lian ◽  
...  
Keyword(s):  
Autonomous Navigation ◽  
Estimation Method ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Celestial Navigation ◽  
Wide Angle Lens ◽  
Celestial Bodies ◽  
Determination System ◽  
Fisheye Camera ◽  
Global Navigation Satellite

Celestial navigation is an important type of autonomous navigation technology which could be used as an alternative to Global Navigation Satellite Systems (GNSS) when a vessel is at sea. After several centuries of development, a variety of astronomical vessel position (AVP) determination methods have been invented, but the basic concepts of these methods are all based on angular observations with a device such as a sextant, which has disadvantages including low accuracy, manual operation, and a limited period of observation. This paper proposes a new method that utilises a fisheye camera to image the celestial bodies and horizon simultaneously. Then, we calculate the obliquity of the fisheye camera's principal optical axis according to the image coordinates of the horizon. Next, we calculate the altitude of the celestial bodies according to the image coordinates of the celestial bodies and the obliquity. Finally, the AVP is determined by the altitudes according to the robust estimation method. Experimental results indicate that this method not only could realize automation and miniaturization of the AVP determination system, but could also greatly improve the efficiency of celestial navigation.

Dynamic GNSS Mission Planning Using DTM for Precise Navigation of Autonomous Vehicles

2016 ◽  
Vol 70 (3) ◽  
pp. 483-504 ◽  
Author(s):  
Aleksander Nowak
Keyword(s):  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Digital Terrain Model ◽  
Dead Reckoning ◽  
Urban Environments ◽  
Mission Planning ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Terrain Model ◽  
Global Navigation Satellite

Nowadays, the most widely used method for estimating location of autonomous vehicles in real time is the use of Global Navigation Satellite Systems (GNSS). However, positioning in urban environments using GNSS is hampered by poor satellite geometry due to signal obstruction created by both man-made and natural features of the urban environment. The presence of obstacles is the reason for the decreased number of observed satellites as well as uncertainty of GNSS positioning. It is possible that in some sections of the vehicle route there might not be enough satellites necessary to fix position. It is common to use software for static GNSS measurement campaign planning, but it is often only able to predict satellite visibility at one point. This article presents a proposal for dynamic GNSS mission planning using a Digital Terrain Model (DTM) and dead reckoning. The methodology and sample results of numerical experiments are also described. They clearly show that proper dynamic GNSS mission planning is necessary in order to complete a task by an autonomous vehicle in an obstructed environment.

scholarly journals Problems of creating autonomous navigation systems on geophysical fields

2021 ◽  
Vol 310 ◽  
pp. 03008
Author(s):  
Vyacheslav Fateev ◽  
Dmitrii Bobrov ◽  
Murat Murzabekov ◽  
Ruslan Davlatov
Keyword(s):  
Autonomous Navigation ◽  
Global Navigation Satellite Systems ◽  
Navigation Systems ◽  
Integrated Navigation ◽  
Geophysical Fields ◽  
Satellite Systems ◽  
Integrated Navigation System ◽  
New Methods ◽  
The Stability ◽  
Global Navigation Satellite

Global navigation satellite systems, which provide high accuracy of navigation, in certain conditions (in tunnels, in closed rooms, in conditions of interference, etc.) have restrictions on their use. In this regard, in order to ensure “seamless” navigation in any conditions of the situation, it becomes necessary to develop new methods and means to increase the stability of navigation definitions. The article is devoted to the consideration of the problems of creating an integrated navigation system using measurements of the parameters of the Earth’s gravitational and magnetic fields. Requirements for meters of parameters of geophysical fields and navigation charts are considered, a number of new navigation meters, new methods and means of preparing navigation charts are proposed. The ways of development of relativistic geodesy and the possibility of using the achievements of gravitational-wave astronomy in gravimetry are considered.

scholarly journals GNSS/LiDAR-Based Navigation of an Aerial Robot in Sparse Forests

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4061 ◽  
Author(s):  
Antonio C. B. Chiella ◽  
Henrique N. Machado ◽  
Bruno O. S. Teixeira ◽  
Guilherme A. S. Pereira
Keyword(s):  
Autonomous Navigation ◽  
Unscented Kalman Filter ◽  
Unmanned Vehicles ◽  
Global Navigation Satellite Systems ◽  
Fusion Algorithm ◽  
Forest Environment ◽  
Satellite Systems ◽  
Aerial Robot ◽  
Robust Adaptive ◽  
Global Navigation Satellite

Autonomous navigation of unmanned vehicles in forests is a challenging task. In such environments, due to the canopies of the trees, information from Global Navigation Satellite Systems (GNSS) can be degraded or even unavailable. Also, because of the large number of obstacles, a previous detailed map of the environment is not practical. In this paper, we solve the complete navigation problem of an aerial robot in a sparse forest, where there is enough space for the flight and the GNSS signals can be sporadically detected. For localization, we propose a state estimator that merges information from GNSS, Attitude and Heading Reference Systems (AHRS), and odometry based on Light Detection and Ranging (LiDAR) sensors. In our LiDAR-based odometry solution, the trunks of the trees are used in a feature-based scan matching algorithm to estimate the relative movement of the vehicle. Our method employs a robust adaptive fusion algorithm based on the unscented Kalman filter. For motion control, we adopt a strategy that integrates a vector field, used to impose the main direction of the movement for the robot, with an optimal probabilistic planner, which is responsible for obstacle avoidance. Experiments with a quadrotor equipped with a planar LiDAR in an actual forest environment is used to illustrate the effectiveness of our approach.

scholarly journals Accuracy Benchmark of Galileo and EGNOS for Inland Waterways

2020 ◽  
Author(s):  
G Yayla ◽  
S Van Baelen ◽  
G Peeters
Keyword(s):  
Sensor Fusion ◽  
Autonomous Navigation ◽  
Global Navigation Satellite Systems ◽  
Navigation Systems ◽  
Inland Waterways ◽  
Satellite Systems ◽  
Coordinate Measurement ◽  
Measurement Units ◽  
Satellite Navigation Systems ◽  
Global Navigation Satellite

While Global Navigation Satellite Systems (GNSS) serve as a fundamental positioning technology for autonomous ships in Inland Waterways (IWW), in order to compensate for unexpected signal outages from constellations due to structures such as bridges and high buildings, it is not uncommon to use a sensor fusion setup with GNSS and Inertial Measurement Units (IMU)/Inertial Navigation Systems (INS). However, the accuracy of this fusion relies on the accuracy of the main localization technology itself. In Europe, Galileo and the European Geostationary Navigation Overlay Service (EGNOS) are two satellite navigation systems under civil control and they provide European users with independent access to a reliable positioning satellite signal, claiming better accuracy than what is offered by other accessible systems. Therefore, considering the potential utilization of these systems for autonomous navigation, in this paper, we discuss the results of a case study for benchmarking the accuracy of Galileo and EGNOS in IWW. We used a Coordinate Measurement Machine (CMM) and a sub-cm Real-Time Kinematic (RTK) service which is available in Flanders to quantify the benchmark reference. The results with and without sensor fusion show that Galileo has a better horizontal accuracy profile than standalone Global Positioning System (GPS), and its augmentation with EGNOS is likely to provide European IWW users more accurate positioning levels in the future.

A Differential Measurement Method for Solving the Ephemeris Observability Issues in Autonomous Navigation

2015 ◽  
Vol 68 (6) ◽  
pp. 1133-1140 ◽  
Author(s):  
Shilong Liao ◽  
Zhaoxiang Qi ◽  
Zhenghong Tang
Keyword(s):  
Autonomous Navigation ◽  
Measurement Method ◽  
Global Navigation Satellite Systems ◽  
Differential Measurement ◽  
Positioning Systems ◽  
Satellite Systems ◽  
Navigation Function ◽  
Satellite Links ◽  
Global Navigation Satellite ◽  
First Time

The autonomous navigation of navigation and positioning systems such as the Global Positioning System (GPS) and other Global Navigation Satellite Systems (GNSS) was motivated to improve accuracy and survivability of the navigation function for 180 days without ground contact. These improvements are accomplished by establishing inter-satellite links in the constellation for pseudo-range observations and communications between satellites. But observability issues arise for both ephemeris and clock since the pseudo-range describes only the relative distance between satellites. A differential measurement method is proposed to measure the rotation of the constellation as a whole for the first time. The feasibility of the proposed method is verified by simulations.

scholarly journals Selected Issues and Constraints of Image Matching in Terrain-Aided Navigation: A Comparative Study

2020 ◽  
Author(s):  
Piotr Turek ◽  
Stanisław Grzywiński ◽  
Witold Bużantowicz
Keyword(s):  
Navigation System ◽  
Operating Conditions ◽  
Global Navigation Satellite Systems ◽  
Reference Image ◽  
Satellite Systems ◽  
Performance Effectiveness ◽  
Reference Images ◽  
Global Navigation Satellite ◽  
Navigational Systems ◽  
Uav Navigation

The sensitivity of global navigation satellite systems to disruptions precludes their use in conditions of armed conflict with an opponent possessing comparable technical capabilities. In military unmanned aerial vehicles (UAVs) the aim is to obtain navigational data to determine the location and correction of flight routes by means of other types of navigational systems. To correct the position of an UAV relative to a given trajectory, the systems that associate reference terrain maps with image information can be used. Over the last dozen or so years, new, effective algorithms for matching digital images have been developed. The results of their performance effectiveness are based on images that are fragments taken from source files, and therefore their qualitatively identical counterparts exist in the reference images. However, the differences between the reference image stored in the memory of navigation system and the image recorded by the sensor can be significant. In this paper modern methods of image registration and matching to UAV position refinement are compared, and adaptation of available methods to the operating conditions of the UAV navigation system is discussed.

scholarly journals ENHANCED UAV NAVIGATION USING HALL-MAGNETIC AND AIR-MASS FLOW SENSORS IN INDOOR ENVIRONMENT

2019 ◽  
Vol IV-2/W5 ◽  
pp. 187-194 ◽  
Author(s):  
S. Zahran ◽  
A. Moussa ◽  
N. El-Sheimy
Keyword(s):  
Mass Flow ◽  
Navigation System ◽  
System Performance ◽  
Low Cost ◽  
Dead Reckoning ◽  
Global Navigation Satellite Systems ◽  
Flow Sensors ◽  
Air Mass ◽  
Satellite Systems ◽  
Global Navigation Satellite

<p><strong>Abstract.</strong> The use of Unmanned Aerial Vehicles (UAVs) in many commercial and emergency applications has the potential to dramatically alter several industries, and, in the process, change our attitudes regarding their impact on our daily lives activities. The navigation system of these UAVs mainly depends on the integration between the Global Navigation Satellite Systems (GNSS) and Inertial Navigation System (INS) to estimate the positions, velocities, and attitudes (PVT) of the UAVs. However, GNSS signals are not always available everywhere and therefore during GNSS signal outages, the navigation system performance will deteriorate rapidly especially when using low-cost INS. Additional aiding sensors are required, during GNSS signal outages, to bound the INS errors and enhance the navigation system performance. This paper proposes the utilization of two sensors (Hall-magnetic and Air-Mass flow sensors) to act as flying odometer by estimating the UAV forward velocity. The estimated velocity is then integrated with INS through Extended Kalman Filter (EKF) to enhance the navigation solution estimation. A real experiment was carried out with the 3DR quadcopter while the proposed system is attached on the top of the quadcopter. The results showed great enhancement in the navigation system performance with more than 98% improvement when compared to the free running INS solution (dead-reckoning).</p>

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