Download or read book The Autonomous Underwater Vehicle Emergency Localization System written by Ronald S. Lewis and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an inherent risk of loss that accompanies any operations of Autonomous Underwater Vehicle (AUV) technology. This complexity and risk are increased for AUV missions that are conducted beneath ice and in harsh environmental conditions (i.e. extreme cold, compromised visibility, etc.). Risk-based methodologies have been developed to quantify the risk of loss for specific AUV platforms prior to deployments. Their goal is to identify and mitigate where possible the significant contributors (technical or otherwise) to the overall risk of a specific operation. Not surprisingly, there is an abundant amount of literature related to successful AUV missions; however, there has been very little published work related to AUV loss. Specifically, this author is not aware of any examples of a developed procedure to employ during an AUV loss event to date, much less specific algorithms developed to locate a missing AUV. This is a subset of the AUV tracking or positioning that is rarely given specific treatment. The motivating problem is based on the loss event of an AUV during polar operations. For example, (i) the vehicle might navigate outside of its predefined spatial area through some fault or error, or, (ii) its mission involves over-the-horizon operations, i.e. beyond the range of standard acoustical tracking technologies. In either circumstance, at the end of its pre-programmed mission, the AUV fails to return to the base station. Such an eventuality defines the need for reliable, long-range acoustic tracking capability that is able to coarsely localize the AUV and subsequently enable communications and/or recovery of the AUV. The thesis describes a novel approach for an acoustic positioning system for AUV localization in harsh environments with non-standard acoustic challenges that can be implemented using only basic acoustic technology, a basic single-beacon, singlehydrophone (SBSH) system. Inversive geometric techniques are applied for source localization of a one-way traveling, asynchronous acoustic signal. This differs from the usual methods of spherical, two-way direct flight measurement based on time of arrival (TOA), or hyperbolic, one-way time difference of arrival (TDOA) target tracking for transmission based on a purely Euclidean geometry. This is a novel approach to the problem of localizing an AUV. A second method of solving the non-linear system of equations that arise from the problem using the SBSH approach is derived. Both methods, the novel Apollonian inversion geometry localization (AIGL) and the non linear system localization (NLSL), are evaluated in simulation and using live field data. It will be shown that the novel algorithm performs comparable to the standard method of solving the nonlinear systems resulting from a SBSH approach. Furthermore, in certain situations it improves the localization result.
Download or read book Autonomous Underwater Vehicles written by Jing Yan and published by Springer Nature. This book was released on 2021-11-01 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous underwater vehicles (AUVs) are emerging as a promising solution to help us explore and understand the ocean. The global market for AUVs is predicted to grow from 638 million dollars in 2020 to 1,638 million dollars by 2025 – a compound annual growth rate of 20.8 percent. To make AUVs suitable for a wider range of application-specific missions, it is necessary to deploy multiple AUVs to cooperatively perform the localization, tracking and formation tasks. However, weak underwater acoustic communication and the model uncertainty of AUVs make achieving this challenging. This book presents cutting-edge results regarding localization, tracking and formation for AUVs, highlighting the latest research on commonly encountered AUV systems. It also showcases several joint localization and tracking solutions for AUVs. Lastly, it discusses future research directions and provides guidance on the design of future localization, tracking and formation schemes for AUVs. Representing a substantial contribution to nonlinear system theory, robotic control theory, and underwater acoustic communication system, this book will appeal to university researchers, scientists, engineers, and graduate students in control theory and control engineering who wish to learn about the core principles, methods, algorithms, and applications of AUVs. Moreover, the practical localization, tracking and formation schemes presented provide guidance on exploring the ocean. The book is intended for those with an understanding of nonlinear system theory, robotic control theory, and underwater acoustic communication systems.
Download or read book A Novel Localization System for Experimental Autonomous Underwater Vehicles written by Russell Walter Morin and published by . This book was released on 2010 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Localization is a classic and complex problem in the field of mobile robotics. It becomes particularly challenging in an aqueous environment because currents within the water can move the robot. A novel localization module and corresponding localization algorithm for experimental autonomous underwater vehicles is presented. Unlike other available positioning systems which require fixed hardware beacons, this custom built module relies only on information available from sensors on-board the vehicle and knowledge of its bounded domain. This allows the user to save valuable time which would otherwise be devoted to the setup and calibration of a beacon or sensor network. The module uses three orthogonal ultrasonic transducers to measure distances to the tank boundaries. Using the measured tri-axial orientation of the vehicle, the algorithm analytically determines the robot's position within the domain in absolute coordinates. Certain vehicle states do not allow the position to be completely resolved by the algorithm alone. In this case, state estimation is used to estimate the robot position until its state is no longer indeterminate. The modular design of this system makes it ideal for application on underwater vehicles which operate in a bounded environment for research purposes. An experimental version of the module was constructed and tested in the WPI swimming pool and showed successful localization under normal conditions.
Download or read book Cooperative Localization for Autonomous Underwater Vehicles written by Alexander Bahr and published by . This book was released on 2009 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-localization of an underwater vehicle is particularly challenging due to the absence of Global Positioning System (GPS) reception or features at known positions that could otherwise have been used for position computation. Thus Autonomous Underwater Vehicle (AUV) applications typically require the pre-deployment of a set of beacons.This thesis examines the scenario in which the members of a, group of AUVs exchange navigation information with one another so as to improve their individual position estimates. We describe how the underwater environment poses unique challenges to vehicle navigation not encountered in other environments in which robots operate and how cooperation can improve the performance of self-localization. As intra-vehicle communication is crucial to cooperation, we also address the constraints of the communication channel and the effect that these constraints have on the design of cooperation strategies. The classical approaches to underwater self-localization of a single vehicle, as well as more recently developed techniques are presented. We then examine how methods used for cooperating land-vehicles can be transferred to the underwater domain. An algorithm for distributed self-localization, which is designed to take the specific characteristics of the environment into account, is proposed. We also address how correlated position estimates of cooperating vehicles can lead to overconfidence in individual position estimates. Finally, key to any successful cooperative navigation strategy is the incorporation of the relative positioning between vehicles. The performance of localization algorithms with different geometries is analyzed and a distributed algorithm for the dynamic positioning of vehicles, which serve as dedicated navigation beacons for a fleet of AUVs, is proposed.
Download or read book Development and Testing of Navigation Algorithms for Autonomous Underwater Vehicles written by Francesco Fanelli and published by Springer. This book was released on 2019-04-16 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on pose estimation algorithms for Autonomous Underwater Vehicles (AUVs). After introducing readers to the state of the art, it describes a joint endeavor involving attitude and position estimation, and details the development of a nonlinear attitude observer that employs inertial and magnetic field data and is suitable for underwater use. In turn, it shows how the estimated attitude constitutes an essential type of input for UKF-based position estimators that combine position, depth, and velocity measurements. The book discusses the possibility of including real-time estimates of sea currents in the developed estimators, and highlights simulations that combine real-world navigation data and experimental test campaigns to evaluate the performance of the resulting solutions. In addition to proposing novel algorithms for estimating the attitudes and positions of AUVs using low-cost sensors and taking into account magnetic disturbances and ocean currents, the book provides readers with extensive information and a source of inspiration for the further development and testing of navigation algorithms for AUVs.
Download or read book Underwater Vehicle Localization Using Range Measurements written by Georgios Papadopoulos and published by . This book was released on 2010 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates the problem of cooperative navigation of autonomous marine vehicles using range-only acoustic measurements. We consider the use of a single maneuvering autonomous surface vehicle (ASV) to aid the navigation of one or more submerged autonomous underwater vehicles (AUVs), using acoustic range measurements combined with position measurements for the ASV when data packets are transmitted. The AUV combines the data from the surface vehicle with its proprioceptive sensor measurements to compute its trajectory. We present an experimental demonstration of this approach, using an extended Kalman filter (EKF) for state estimation. We analyze the observability properties of the cooperative ASV/AUV localization problem and present experimental results comparing several different state estimators. Using the weak observability theorem for nonlinear systems, we demonstrate that this cooperative localization problem is best attacked using nonlinear least squares (NLS) optimization. We investigate the convergence of NLS applied to the cooperative ASV/AUV localization problem. Though we show that the localization problem is non-convex, we propose an algorithm that under certain assumptions (the accumulative dead reckoning variance is much bigger than the variance of the range measurements, and that range measurement errors are bounded) achieves convergence by choosing initial conditions that lie in convex areas. We present experimental results for this approach and compare it to alternative state estimators, demonstrating superior performance.
Download or read book Underwater Acoustic Localization written by Navinda Kottege and published by LAP Lambert Academic Publishing. This book was released on 2011-04 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advancement of the field of underwater robotics, the amount of autonomy embodied in the vehicles themselves have considerably increased while making it possible to build and deploy swarms of small autonomous underwater vehicles (AUVs). Apart from the many environmental and mechanical challenges encountered in the underwater domain, the swarming paradigm demands the need for each vehicle to be aware of the positions of at least its near neighbours. The Serafina AUV project which was initiated with the goal of developing swarming technology for the small and highly agile Serafina class AUVs requires a localization system which could cope with the dynamic and fast changing vehicle configurations while being small, reliable, robust, and energy efficient and not dependent on pre-deployed acoustic beacons. The acoustical relative localisation system proposed here uses hyperbolic and spherical localization concepts and provides each vehicle with the azimuth, range and heading of its near neighbors.
Download or read book Undersea Vehicles and National Needs written by Committee on Undersea Vehicles and National Needs and published by National Academies Press. This book was released on 1996-12-03 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: The United States faces decisions requiring information about the oceans in vastly expanded scales of time and space and from oceanic sectors not accessible with the suite of tools now used by scientists and engineers. Advances in guidance and control, communications, sensors, and other technologies for undersea vehicles can provide an opportunity to understand the oceans' influence on the energy and chemical balance that sustains humankind and to manage and deliver resources from and beneath the sea. This book assesses the state of undersea vehicle technology and opportunities for vehicle applications in science and industry. It provides guidance about vehicle subsystem development priorities and describes how national research can be focused most effectively.
Download or read book Doppler based Localization for Mobile Autonomous Underwater Vehicles written by William Somers and published by . This book was released on 2011 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel algorithm for localization of Autonomous Underwater Vehicles (AUVs) operating in under-the-ice environments is proposed along with a mathematical analysis for the same. The objective is to accurately predict the position of a mobile AUV via cooperation with neighboring vehicles by utilizing a Doppler-based approach. Current existing localization techniques require either an anchor or surfacing AUV to acquire a GPS fix or rely on a system of expensive and difficult to deploy hardware. Our Doppler-based approach is based on observed Doppler shifts, which are measured opportunistically from ongoing communications between AUVs. These observed Doppler shifts can be used to project the subsequent positions of the AUV and limit the internal uncertainty associated with traditional localization techniques. An AUV's internal uncertainty is the uncertainty in the position of a mobile vehicle as estimated by itself, e.g., via localization techniques. In addition, this Doppler-based approach has minimal network overhead when compared to traditional localization techniques and does not require synchronization between AUVs. The main focus of this thesis is to quantify (via simulations) the solution behavior as well as its sensitivity to possible sources of errors.
Download or read book Long Range Gravity Aided Autonomous Underwater Vehicle Navigation written by Franz Heubach and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous underwater vehicles (AUV) are a mobile platform for underwater sensing, an environment relatively unexplored. Georeferencing measurements is difficult due to the challenge of AUV localization. The rapid attenuation of radio frequencies underwater restricts AUVs from using the global position system (GPS), the above-water solution to localization. Underwater localization relies on dead-reckoning, the integration of vehicle inertia measurements to arrive at a position estimate. However, the dead-reckoned position error is unbounded. This error can be bounded using a source of position feedback. Terrain aided navigation (TAN) - using georeferenced geophysical terrain maps can provide that feedback. TAN shows significant promise as a method for long-range, passive underwater AUV navigation, especially gravity-aided navigation (GAN). This thesis presents a TAN algorithm that uses a gravity gradiometer and gravity gradient maps to successfully limit dead-reckoning error by a factor of 25 over a 500 km long AUV mission, with a localization accuracy of 1 km. The TAN algorithm exploits the correlation between terrain and the gravity anomaly to use a global database of bathymetry maps (GEBCO) with 400 m resolution. The mission was simulated in the AUV navigation testbed (ANT), a collection of tooling developed during this thesis to accelerate research in TAN. Among the contributions made by the ANT, is a inertial navigation system (INS) that emulates the uncertainty characteristics of a commercial navigation grade INS (Kearfott Seanav) \textemdash~to simulate dead-reckoning error growth. Parts of the ANT have been released to the research community as open-source, and are being used by researchers in the Intelligent Systems Laboratory (ISL) at Dalhousie University.
Download or read book Cooperative Localization for Autonomous Underwater Vehicles in Strong Ocean Currents written by Zhuoyuan Song and published by . This book was released on 2014 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unavailability of GPS (global positioning system) for underwater navigation has created significant challenges for operation and localization of autonomous underwater vehicles (AUVs). This is more pronounced in dynamic ocean flows where significant background flows exist. In this thesis, a collaborative underwater localization hierarchy is introduced to improve the cooperative performance of a small AUV swarm by utilizing vehicles with bounded localization error as moving references in the presence of dominating background flows. Initially represented in probability theory, the problem is then decomposed into a cooperative localization problem and a dynamic simultaneous localization and mapping problem with moving features. To address the incomplete covariance updating issue, which arises when directly applying the extended Kalman filter in fully distributed systems, the modified extended Kalman filter (MEKF) is proposed and a MEKF based algorithm is discussed in detail. A particle filter based algorithm is implemented for comparative purposes due to its advantages in modeling multimodal non-Gaussian distributions. However, it is shown that the particle filter requires greater computational effort than the MEKF when the number of vehicles is small. Both proposed algorithms are verified in three-dimensional background flow simulations. The divergent behavior of localization error, which appears when using solely cooperative localization, is avoided through the implementation of either the MEKF algorithm or the particle algorithm. Significant decreases in localization error are subsequently observed.
Download or read book Design and Implementation of a Localization System for Underwater Drones Incorporating Machine Learning written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Autonomous Underwater Vehicle (AUV) is a class of robot, designed to explore and navigate underwater environments. AUVs are used in underwater surveying and inspection as they are capable of operating at extreme depths without risk to human life. Long-duration missions require accurate localization to facilitate underwater navigation, in the deep ocean environment (> 200 meter depth) localization is a significant challenge. This thesis proposes a machine learning model to provide velocity pseudo measurements to an EKF to improve position estimates without relying on external references. The proposed system is built on the Robot Operating System (ROS) and was validated in simulation and on a real-world AUV created for this research. The results showed that in simulation the AUV was capable of localizing itself to an error of 0.477% of distance traveled for the simulation and 9.13% for the real-world AUV.
Download or read book Navigation and Localization of an Autonomous Underwater Vehicle Fleet for Magnetic Field Measurements written by Jordan Stringfield and published by . This book was released on 2012 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Underwater Robots written by Gianluca Antonelli and published by Springer. This book was released on 2013-11-21 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the state of the art in underwater robotics experiments of dynamic control of an underwater vehicle. The author presents experimental results on motion control and fault tolerance to thrusters’ faults with the autonomous vehicle ODIN. This second substantially improved and expanded edition new features are presented dealing with fault-tolerant control and coordinated control of autonomous underwater vehicles.
Download or read book Incorporation of GPS INS Into Small Autonomous Underwater Vehicle Navigation written by and published by . This book was released on 1992 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Navigation of an Autonomous Underwater Vehicle (AUV) is a problem that has not been adequately solved. Although the inclusion of the Global Positioning System (GPS) into AUV navigation has been briefly examined before, this possibility is explored further in this thesis. GPS and Inertial Measurement System (INS) based navigation package offers many advantages for AUV navigation especially for transits and precise object location in shallow water. This thesis provides background information on GPS and INS as they pertain to small AUV employment. Other required components are also examined as they pertain to small AUV employment. The use of the GPS/INS navigation package for AUV transits and precise object location work is presented. Two designs with specified components are developed. A GPS receiver was tested for AUV employment suitability. These test results are presented and analyzed. Autonomous underwater vehicles, Global positioning system, Inertial measurement system.
Download or read book Slam Based Navigation System for an Autonomous Underwater Vehicle written by Oduetse Matsebe and published by . This book was released on 2011 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the development and implementation of a Simultaneous Localization and Mapping (SLAM) system for an Autonomous Underwater Vehicle (AUV) using Mechanically Scanned Imaging Sonar (MSIS) to extract corner features.
Download or read book A Cooperative Architecture to Localize Targets for Underwater Vehicles written by Assia Belbachir and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underwater target localization using several autonomous underwater vehicles(AUVs) is a challenging issue. A systematic and exhaustive coverage strategy is not efficient in term of exploration time: it can be improved by making the AUVs share their information and cooperate to optimize their motions. Communication points are required to make underwater vehicles exchange information: for that purpose the system involves one autonomous surface vehicle (ASV), which helps the AUVs to re-localize and to exchange data, and two AUVs that adapt their strategy according to gathered information, while satisfying the associated communication constraints. Each AUV is endowed with a sensor that estimates its distance with respect to targets, and cooperates with others to explore an area with the help of an ASV. To provide the required autonomy for these vehicles, we built upon an existing system with additional components, which provides an embedded planning and execution control framework. Simulation results are carried out to evaluate the proposed architecture and adaptive exploration strategy.
