Download or read book Acoustic Underwater Navigation of the Phoenix Autonomous Underwater Vehicle Using the Divetracker System written by Arthur W. Scrivener and published by . This book was released on 1996-03-01 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous Underwater Vehicles (AUVs) require a navigation system in order to conduct useful functions. This research was an experimental investigation of the commercial DiveTracker underwater acoustic navigation system used onboard the NPS Phoenix AUV. Tests conducted with the DiveTracker system proved that the system could be used successfully in AUV navigation while submerged and revealed that more precise positioning could be obtained through postconditioning of the DiveTracker output ranges, rather than prefiltering.

Download or read book Control Systems Architecture Navigation and Communication Research Using the NPS Phoenix Underwater Vehicle written by and published by . This book was released on 2005 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: While there has always been a need to determine the global position of an underwater vehicle, in some missions involving search, mapping, and intervention with objects, navigation to local area landmarks is more appropriate and precise. All aspects of autonomous search have been of interest to us for some time now, and we have recently developed and extended our robot control system architecture using Prolog as a rule based mission specification language to drive vehicle missions involving motion around targets of interest. In particular, we have studied the use of onboard scanning sonar to perform local area navigation. Additionally, we have installed a new low cost short / long baseline acoustic communications / navigation system called DiveTracker, and are developing filtering software that would combine inputs from several sources having different update rates and levels of precision to produce high update rate navigational information with the precision afforded by the low update rate reference. Also, the DiveTracker system affords a low cost acoustic communications system that can be used for low rate message sending and retrieval from autonomous vehicles.

Download or read book Analysis of the Divetracker Acoustical Navigation System for the NPS AUV written by Jerome Zinni and published by . This book was released on 1996-03-01 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous Underwater Vehicles (AUVs) require an accurate navigation system for operating in mine fields located in the near suff zone very shallow water. This research project examined the precision, performance characteristics, and reliability of a low cost, commercially produced, acoustical navigation system called 'DiveTracker'. The DiveTracker acoustical navigation system provides both an acoustical short baseline operator and the AUV with position data on a 1 hertz update rate. Experiments conducted on the DiveTracker system included static and dynamic tests which examined the system's ability to accurately measure distances and track a moving AUV under water.

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 An Underwater Vehicle Navigation System Using Acoustic and Inertial Sensors written by Khalid M. Alzahrani and published by . This book was released on 2018 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unmanned Underwater Vehicles (UUVs) have become an essential tool for different underwater tasks. Compared with other unmanned systems, the navigation and localization for UUVs are particularly challenging due to the unavailability of Global Positioning System (GPS) signals underwater and the complexity of the unstable environment. Alternative methods such as acoustic positioning systems, Inertial Navigation Systems (INS), and the geophysical navigation approach are used for UUV navigation. Acoustic positioning systems utilize the characteristics of acoustic signals that have a lower absorption rate and a more extended propagation distance than electromagnetic signals underwater. The significant disadvantage of the INS is the "drift," the unbounded error growth over time in the outputs. This thesis is aimed to study and test a combined UUV navigation system that fuses measurements from the INS, Doppler Velocity Log (DVL), and Short Baseline (SBL) acoustic positioning system to reduce the drift. Two Kalman filters are used to do the fusion: the Extended Kalman Filter (EKF) and the Unscented Kalman Filter (UKF). After conducting the experiments and simulation, the results illustrated the INS/SBL fusion navigation approach was able to reduce the drift problems in the INS. Moreover, UKF showed a better performance than the EKF in the INS.

Download or read book Simultaneous Navigation of Autonomous Underwater Vehicles Using an Acoustic Sensor written by Bradley N. Baker and published by . This book was released on 2005 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Virtual Long Baseline VLBL Autonomous Underwater Vehicle Navigation Using a Single Transponder written by Cara Elizabeth Grupe LaPointe and published by . This book was released on 2006 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic long baseline (LBL) navigation systems are often used for precision underwater vehicle navigation. LBL systems triangulate the position of the vehicle by calculating the range between the vehicle and multiple transponders with known locations. A typical LBL system incorporates between two and twelve acoustic transponders. The vehicle interrogates the beacons acoustically, calculates the range to each beacon based on the roundtrip travel time of the signal, and uses the range data from two or more of the acoustic transponders at any point in time to determine its position. However, for accurate underwater navigation, the location of each deployed transponder in the array must be precisely surveyed prior to conducting autonomous vehicle operations. Surveying the location of the transponders is a costly and time-consuming process, especially in cases where underwater vehicles are used in mapping operations covering a number of different locations in succession. During these extended mapping operations, the transponders need to be deployed, surveyed, and retrieved in each location, adding significant time and, consequently, significant cost to any operation.

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 97 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 Acoustic Navigation for the Autonomous Underwater Vehicle Remote Environmental Measuring UnitS written by Thomas Friedrich Fulton and published by . This book was released on 2000 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Docking the Ocean Explorer Autonomous Underwater Vehicle Using a Low Cost Acoustic Positioning System and a Fuzzy Logic Guidance Algorithm written by David Kronen and published by . This book was released on 1997 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Contributions to Automated Realtime Underwater Navigation written by Michael Jordan Stanway and published by . This book was released on 2012 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents three separate-but related-contributions to the art of underwater navigation. These methods may be used in postprocessing with a human in the loop, but the overarching goal is to enhance vehicle autonomy, so the emphasis is on automated approaches that can be used in realtime. The three research threads are: i) in situ navigation sensor alignment, ii) dead reckoning through the water column, and iii) model-driven delayed measurement fusion. Contributions to each of these areas have been demonstrated in simulation, with laboratory data, or in the field-some have been demonstrated in all three arenas. The solution to the in situ navigation sensor alignment problem is an asymptotically stable adaptive identifier formulated using rotors in Geometric Algebra. This identifier is applied to precisely estimate the unknown alignment between a gyrocompass and Doppler velocity log, with the goal of improving realtime dead reckoning navigation. Laboratory and field results show the identifier performs comparably to previously reported methods using rotation matrices, providing an alignment estimate that reduces the position residuals between dead reckoning and an external acoustic positioning system. The Geometric Algebra formulation also encourages a straightforward interpretation of the identifier as a proportional feedback regulator on the observable output error. Future applications of the identifier may include alignment between inertial, visual, and acoustic sensors. The ability to link the Global Positioning System at the surface to precision dead reckoning near the seafloor might enable new kinds of missions for autonomous underwater vehicles. This research introduces a method for dead reckoning through the water column using water current profile data collected by an onboard acoustic Doppler current profiler. Overlapping relative current profiles provide information to simultaneously estimate the vehicle velocity and local ocean current-the vehicle velocity is then integrated to estimate position. The method is applied to field data using online bin average, weighted least squares, and recursive least squares implementations. This demonstrates an autonomous navigation link between the surface and the seafloor without any dependence on a ship or external acoustic tracking systems. Finally, in many state estimation applications, delayed measurements present an interesting challenge. Underwater navigation is a particularly compelling case because of the relatively long delays inherent in all available position measurements. This research develops a flexible, model-driven approach to delayed measurement fusion in realtime Kalman filters. Using a priori estimates of delayed measurements as augmented states minimizes the computational cost of the delay treatment. Managing the augmented states with time-varying conditional process and measurement models ensures the approach works within the proven Kalman filter framework-without altering the filter structure or requiring any ad-hoc adjustments. The end result is a mathematically principled treatment of the delay that leads to more consistent estimates with lower error and uncertainty. Field results from dead reckoning aided by acoustic positioning systems demonstrate the applicability of this approach to real-world problems in underwater navigation.

Download or read book Absolute Positioning of an Autonomous Underwater Vehicle Using GPS and Coustic Measurements written by Neil Harvey Kussat and published by . This book was released on 2004 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Virtual Ocean Framework for Environmentally Adaptive Embedded Acoustic Navigation on Autonomous Underwater Vehicles written by Bhatt. EeShan C. and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous underwater vehicles (AUVs) are an increasingly capable robotic platform, with embedded acoustic sensing to facilitate navigation, communication, and collaboration. The global positioning system (GPS), ubiquitous for air- and terrestrial-based drones, cannot position a submerged AUV. Current methods for acoustic underwater navigation employ a deterministic sound speed to convert recorded travel time into range. In acoustically complex propagation environments, however, accurate navigation is predicated on how the sound speed structure affects propagation. The Arctic's Beaufort Gyre provides an excellent case study for this relationship via the Beaufort Lens, a recently observed influx of warm Pacific water that forms a widespread yet variable sound speed lens throughout the gyre. At short ranges, the lens intensifies multipath propagation and creates a dramatic shadow zone, deteriorating acoustic communication and navigation performance. The Arctic also poses the additional operational challenge of an ice-covered, GPSdenied environment. This dissertation demonstrates a framework for a physics-based, model-aided, real-time conversion of recorded travel time into range--the first of its kind--which was essential to the successful AUV deployment and recovery in the Beaufort Sea, in March 2020. There are three nominal steps. First, we investigate the spatio-temporal variability of the Beaufort Lens. Second, we design a human-in-the-loop graphical decision-making framework to encode desired sound speed profile information into a lightweight, digital acoustic message for onboard navigation and communication. Lastly, we embed a stochastic, ray-based prediction of the group velocity as a function of extrapolated source and receiver locations. This framework is further validated by transmissions among GPS-aided modem buoys and improved upon to rival GPS accuracy and surpass GPS precision. The Arctic is one of the most sensitive regions to climate change, and ^as warmer surface temperatures and shrinking sea ice extent continue to deviate from historical conditions, the region will become more accessible and navigable. Underwater robotic platforms to monitor these environmental changes, along with the inevitable rise in human traffic related to trade, fishing, tourism, and military activity, are paramount to coupling national security with international climate security.

Download or read book Sequential Long Baseline Navigation for REMUS An Autonomous Underwater Vehicle written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many of the problems of operating an AUV (autonomous underwater vehicle) can be reduced to one of navigation: How accurately do you know where you are? Navigational precision determines the ability to follow truck lines, the ability to map a target to world coordinates, and ultimately, even determines the areas where you ore willing to operate the vehicle. This paper presents the technique used for long baseline acoustic navigation by REMUS (Remote Environmental Measuring Units), a low cost AUV developed by the Oceanographic Systems Laboratory (OSL) of the Woods Hole Oceanographic Institution. Adopting the traditional long base line approach to this vehicle presents a complex problem because it must be low power, low cost and small in size, and in addition must work in a shallow water environment. The REMUS system uses a single data acquisition system and DSP to interrogate and receive multiple transponders in a sequential manner. It uses spread spectrum technology which reduces the impact of multi-path in the shallow water environment. A moored pair of acoustic transponders whose coordinates are determined using differential or P-code GPS allow the vehicle to navigate in world coordinates. The DSP minimizes the hardware requirements, thus lowering the associated hardware cost, size, and complexity. This paper describes the techniques used and provides results of this system using frequencies in the 20-30 khz band, giving a range of up to 1500 meters in water 4 meters deep, and also 10-15 khz band, giving a range of up to 7000 meters in waters 14 meters deep.

Download or read book Autonomous Underwater Vehicles written by Nuno Cruz and published by BoD – Books on Demand. This book was released on 2011-10-21 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous Underwater Vehicles (AUVs) are remarkable machines that revolutionized the process of gathering ocean data. Their major breakthroughs resulted from successful developments of complementary technologies to overcome the challenges associated with autonomous operation in harsh environments. Most of these advances aimed at reaching new application scenarios and decreasing the cost of ocean data collection, by reducing ship time and automating the process of data gathering with accurate geo location. With the present capabilities, some novel paradigms are already being employed to further exploit the on board intelligence, by making decisions on line based on real time interpretation of sensor data. This book collects a set of self contained chapters covering different aspects of AUV technology and applications in more detail than is commonly found in journal and conference papers. They are divided into three main sections, addressing innovative vehicle design, navigation and control techniques, and mission preparation and analysis. The progress conveyed in these chapters is inspiring, providing glimpses into what might be the future for vehicle technology and applications.

Download or read book Cooperative Acoustic Navigation Scheme for Heterogenous Autonomous Underwater Vehicles written by Xianbo Xiang and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Cooperative Acoustic Navigation Scheme for Heterogenous Autonomous Underwater Vehicles.

Download or read book Autonomous Underwater Vehicle Navigation written by and published by . This book was released on 2008 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report considers the vehicle navigation problem for an autonomous underwater vehicle with six degrees of freedom. We approach this problem using an error state formulation of the Kalman filter. Integration of the vehicle's high-rate inertial measurement unit's accelerometers and gyros allow time propagation while other sensors provide measurement corrections. The low-rate aiding sensors include a Doppler velocity log, an acoustic long baseline system that provides round-trip travel times from known locations, a pressure sensor for aiding depth, and an attitude sensor. Measurements correct the filter independently as they arrive, and as such, the filter is not dependent on the arrival of any particular measurement. The navigation system can estimate critical bias parameters that improve performance. The result is a robust navigation system. Simulation and experimental results are provided.