Download or read book Advances in Autonomous Underwater Vehicle Based Passive Bottom Loss Estimation by Processing of Marine Ambient Noise written by and published by . This book was released on 2015 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate modeling of acoustic propagation in the ocean waveguide is important to SONAR-performance prediction, and requires, particularly in shallow water environments, characterizing the bottom reflection loss with a precision that databank-based modeling cannot achieve. Recent advances in the technology of autonomous underwater vehicles (AUV) make it possible to envision a survey system for seabed characterization composed of a short array mounted on a small AUV. The bottom power reflection coefficient (and the related reflection loss) can be estimated passively by beamforming the naturally occurring marine ambient-noise acoustic field recorded by a vertical line array of hydrophones. However, the reduced array lengths required by small AUV deployment can hinder the process, due to the inherently poor angular resolution. In this dissertation, original data-processing techniques are presented which, by introducing into the processing chain knowledge derived from physics, can improve the performance of short arrays in this particular task. Particularly, the analysis of a model of the ambient-noise spatial coherence function leads to the development of a new proof of the result at the basis of the bottom reflection-loss estimation technique. The proof highlights some shortcomings inherent in the beamforming operation so far used in this technique. A different algorithm is then proposed, which removes the problem achieving improved performance. Furthermore, another technique is presented that uses data from higher frequencies to estimate the noise spatial coherence function at a lower frequency, for sensor spacing values beyond the physical length of the array. By "synthesizing" a longer array, the angular resolution of the bottom-loss estimate can be improved, often making use of data at frequencies above the array design frequency, otherwise not utilized for beamforming. The proposed algorithms are demonstrated both in simulation and on real data acquired during several experimental campaigns.

Download or read book Technology and Applications of Autonomous Underwater Vehicles written by Gwyn Griffiths and published by CRC Press. This book was released on 2002-11-28 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oceans are a hostile environment, and gathering information on deep-sea life and the seabed is incredibly difficult. Autonomous underwater vehicles are robot submarines that are revolutionizing the way in which researchers and industry obtain data. Advances in technology have resulted in capable vehicles that have made new discoveries on how th

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 Underwater Vehicle Control and Communication Systems Based on Machine Learning Techniques written by Tien Anh Tran and published by CRC Press. This book was released on 2023-12-04 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of intelligent transportation systems, especially autonomous underwater vehicles, has become significant in marine engineering, with an aim to enhance energy efficiency management and communication systems. This book covers different aspects of optimization of autonomous underwater vehicles and their propulsion systems via machine learning techniques. It further analyses hydrodynamic characteristics including the study of experimental investigation combined with hydrodynamic characteristics backed by MATLAB® codes and simulation study results. Features: Covers utilization of machine learning techniques with a focus on marine science and ocean engineering. Details effect of the intelligent transportation system (ITS) into the sustainable environment and ecology system. Evaluates performance of particle swarm intelligence-based optimization techniques. Reviews propulsion performance of the remote-controlled vehicles based on machine learning techniques. Includes MATLAB® examples and simulation study results. This book is aimed at graduate students and researchers in marine engineering and technology, computer science, and control system engineering.

Download or read book Autonomous Underwater Vehicles written by Cynthia Mitchell and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gravity-gradient and magnetic-gradient inversion equations are combined to estimate the orientation and distance of an underwater object. The CKF algorithm based on EMMAF algorithm and Spherical-Radial is proposed and is applied to the fault diagnosis of slaver AUV in multi AUV collaborative positioning system. Simulation results are used to analyze the advantages and disadvantages of the three algorithms. This book looks at how a Service-Oriented Agent Architecture (SOAA) for marine robots is endowed with resilient capabilities in order to build a robust (fault-tolerant) vehicle control approach. Particular attention is paid to cognitive RCAs based on agent technologies and any other smart solution already applied or potentially applicable to UMVs. The book also presents current and future trends of RCAs for UMVs.

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 Advances in Passive Acoustic Detection Localization and Tracking Applied to Unmanned Underwater Vehicles written by Kristen Railey Kita and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detection, classification, localization, and tracking (DCLT) of unmanned underwater vehicles (UUVs) in the presence of shipping traffic is a critical task for passive acoustic harbor security systems. In general, vessels can be tracked by their unique acoustic signature due to machinery vibration and cavitation noise. However, cavitation noise of UUVs is considerably quieter than ships and boats, making detection significantly more challenging. In this thesis, I demonstrated that it is possible to passively track a UUV from its highfrequency motor noise using a stationary array in shallow-water experiments with passing boats. First, causes of high frequency tones were determined through direct measurements of two UUVs at a range of speeds. From this analysis, common and dominant features of noise were established: strong tones at the motor’s pulse-width modulated frequency and its harmonics. From the unique acoustic signature of the motor, I derived a high-precision, remote sensing method for estimating propeller rotation rate. In shallow-water UUV field experiments, I demonstrated that detecting a UUV from motor noise, in comparison to broadband noise from the vehicle, reduces false alarms from 45% to 8.4% for 90% true detections. Beamforming on the motor noise, in comparison to broadband noise, improved the bearing accuracy by a factor of 3.2×. Because the signal is also high-frequency, the Doppler effect on motor noise is observable and I demonstrate that range rate can be measured. Furthermore, measuring motor noise was a superior method to the “detection of envelope modulation on noise” algorithm for estimating the propeller rotation rate. Extrapolating multiple measurements from the motor signature is significant because Bearing-Doppler-RPM measurements outperform traditional bearing-Doppler target motion analysis. In the unscented Kalman filter implementation, the tracking solution accuracy for bearing, bearing rate, range, and range rate improved by a factor 2.2×, 15.8×, 3.1×, and 6.2× respectively. These findings are significant for improving UUV localization and tracking, and for informing the next-generation of quiet UUV propulsion systems.

Download or read book Acoustic Based Tactical Control of Underwater Vehicles written by William J. Marr and published by . This book was released on 2003-06-01 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in command and control of Autonomous Underwater Vehicles (AUVs) using acoustic communications are crucial to future Fleet objectives, particularly in Very Shallow Water Mine Countermeasures (VSW MCM). Understanding of the capability to redirect missions, provide relatively high rate downloads of mission information, and perform cooperative tracking for multi-vehicle systems is cunently limited to some bounding data based on fixed node expenments while the impact of working in the environment presented by a moving vehicle is not understood. The main objectives of this dissertation were to investigate and demonstrate the capabilities of tactical acoustic control of a dynamic, operational underwater vehicle in the Very Shallow Water (VSW) ocean environment. This necessarily required studies on the limitations of Acoustic Control and relatively High Data Rate Transfer when using commercial acoustic modems in underwater vehicles, and an investigation of their acoustic transmission characteristics. Comprehensive empirical evidence through field validation with the ARIES vehicle indicated that reduced ranges were required for successful acoustic communications in a realistic very shallow water environment. Background noise, multipath reflections, and vehicle induced Doppler shifts all limit the communication link. Occasionally, configurations may be found where vehicle body shielding against multipath destructive interference can be used to advantage. A simulation was developed to demonstrate a solution for reducing the range and conducting multi-vehicle behaviors for cooperative tracking and acoustic communications data transfer.

Download or read book Machine Learning in Passive Ocean Acoustics for Localizing and Characterizing Events written by Emma Ozanich and published by . This book was released on 2020 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Passive acoustics, or the recording of pressure signals from uncontrolled sound sources, is a powerful tool for monitoring man-made and natural sounds in the ocean. Passive acoustics can be used to detect changes in physical processes within the environment, study behavior and movement of marine animals, or observe presence and motion of ocean vessels and vehicles. Advances in ocean instrumentation and data storage have improved the availability and quality of ambient noise recordings, but there is an ongoing effort to improve signal processing algorithms for extracting useful information from the ambient noise. This dissertation uses machine learning as a framework to address problems in underwater passive acoustic signal processing. Statistical learning has been used for decades, but machine learning has recently gained popularity due to the exponential growth of data and its ability to capitalize on these data with efficient GPU computation. The chapters within this dissertation cover two types of problems: characterization and classification of ambient noise, and localization of passive acoustic sources. First, ambient noise in the eastern Arctic was studied from April to September 2013 using a vertical hydrophone array as it drifted from near the North Pole to north of Fram Strait. Median power spectral estimates and empirical probability density functions (PDFs) along the array transit show a change in the ambient noise levels corresponding to seismic survey airgun occurrence and received level at low frequencies and transient ice noises at high frequencies. Noise contributors were manually identified and included broadband and tonal ice noises, bowhead whale calling, seismic airgun surveys, and earthquake T phases. The bowhead whale or whales detected were believed to belong to the endangered Spitsbergen population and were recorded when the array was as far north as 86°24'N. Then, ambient noise recorded in a Hawaiian coral reef was analyzed for classification of whale song and fish calls. Using automatically detected acoustic events, two clustering processes were proposed: clustering handpicked acoustic metrics using unsupervised methods, and deep embedded clustering (DEC) to learn latent features and clusters from fixed-length power spectrograms. When compared on simulated signals of fish calls and whale song, the unsupervised clustering methods were confounded by overlap in the handpicked features while DEC identified clusters with fish calls, whale song, and events with simultaneous fish calls and whale song. Both clustering approaches were applied to recordings from directional autonomous seafloor acoustic recorder (DASAR) sensors on a Hawaiian coral reef in February 2020. Next, source localization in ocean acoustics was posed as a machine learning problem in which data-driven methods learned source ranges or direction-of-arrival directly from observed acoustic data. The pressure received by a vertical linear array was preprocessed by constructing a normalized sample covariance matrix (SCM) and used as the input for three machine learning methods: feed-forward neural networks (FNN), support vector machines (SVM) and random forests (RF). The FNN, SVM, RF and conventional matched-field processing were applied to recordings from ships in the Noise09 experiment to demonstrate the potential of machine learning for underwater source localization. The source localization problem was extended by examining the relationship between conventional beamforming and linear supervised learning. Then, a nonlinear deep feedforward neural network (FNN) was developed for direction-of-arrival (DOA) estimation for two-source DOA and for K-source DOA, where K is unknown. With multiple snapshots, K-source FNN achieved resolution and accuracy similar to Multiple Signal Classification (MUSIC) and SBL for an unknown number of sources. The practicality of the deep FNN model was demonstrated on ships in the Swellex96 experimental data.

Download or read book Proceedings of the 10th National Technical Seminar on Underwater System Technology 2018 written by Zainah Md Zain and published by Springer. This book was released on 2019-02-08 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents cutting-edge research papers in the field of Underwater System Technology in Malaysia and Asia in general. The topics covered include intelligent robotics, novel sensor technologies, control algorithms, acoustic signal processing, imaging techniques, biomimetic robots, green energy sources, and underwater communication backbones and protocols. The book showcases some of the latest technologies and applications developed to facilitate local marine exploration and exploitation. It also addresses related topics concerning the Sustainable Development Goals (SDG) outlined by the United Nations.

Download or read book Autonomous Underwater Vehicles Technology and Applications written by Noah Carter and published by . This book was released on 2015-03-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The technology of autonomous underwater vehicles and their various applications are elucidated in a sophisticated and comprehensive way in this book. Autonomous Underwater Vehicles are robotic engines which travel underwater in order to study underwater activities. The successful developments of parallel research and technological studies that were underway; helped to conquer the challenges associated with autonomous operation in tough conditions. The ultimate aim behind all these advancements was to procure accurate data through economical means in lesser time using accurate geo locations. Some new models are already being employed to extract the best out of the present technology by making decisions according to the interpretation of the sensor data. This book is the comprehensive compilation of various aspects of AUV technology and its applications. Vehicle designing, navigation & control techniques and mission preparation & analysis are some of the topics that this book covers. It provides an overview of brighter prospects of vehicle technology and application.

Download or read book Underwater Vehicles written by George M. Roman and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Underwater Vehicles: Design and Applications first explores the application of the adaptive Kalman filter algorithm to the estimation of high speed autonomous underwater vehicle dynamics. The authors investigate the performances of different control schemes, from non-model-based to model-based and adaptive model-based, implemented on a low-inertia underwater vehicle for three-dimensional helical trajectory tracking. Control laws for collision avoidance in three-dimensional environments are introduced, considering scenarios where a vehicle detects arbitrarily shaped and nonconvex obstacles using sensors"--

Download or read book The Operation of Autonomous Underwater Vehicles written by Edward Duncan Brown and published by . This book was released on 2000 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Underwater SLAM for Structured Environments Using an Imaging Sonar written by David Ribas and published by Springer Science & Business Media. This book was released on 2010-07-26 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Robotics is undergoing a major transformation in scope and dimension. From a largely dominant industrial focus, robotics is rapidly expanding into human en- ronments and vigorously engaged in its new challenges. Interacting with, assisting, serving, and exploring with humans, the emerging robots will increasingly touch people and their lives. Beyond its impact on physical robots, the body of knowledge robotics has p- duced is revealing a much wider range of applications reaching across diverse research areas and scienti?c disciplines, such as: biomechanics, haptics, neu- sciences, virtual simulation, animation, surgery, and sensor networks among others. In return, the challenges of the new emerging areas are proving an abundant source of stimulation and insights for the ?eld of robotics. It is indeed at the intersection of disciplines that the most striking advances happen. The SpringerTracts in AdvancedRobotics(STAR) is devoted to bringing to the research community the latest advances in the robotics ?eld on the basis of their signi?cance and quality. Through a wide and timely dissemination of critical - search developments in robotics, our objective with this series is to promote more exchanges and collaborations among the researchers in the community and c- tribute to further advancements in this rapidly growing ?eld.

Download or read book Advanced Sensing Navigation and Autonomy for Unmanned Underwater Vehicles written by Eric Curtis Gallimore and published by . This book was released on 2019 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research results that advance the capabilities of autonomous underwater vehicles (AUVs) to conduct seabed surveys are described. These include the creation of a software framework to enable research and development in sensing and adaptive autonomy, a novel synthetic baseline navigation technique, and a magnetic sensing system that incorporates sense and react behaviors. Field experiments were conducted globally in a wide range of littoral environments to test hypotheses associated with the emerging field of autonomy as applied to underwater systems. To facilitate sensor integration and provide a testbed for autonomous sense and react research, an onboard sensor processing and autonomy system was developed for the REMUS AUV using the Robot Operating System (ROS) that provides high-level control of the vehicle. Multiple vehicles outfitted with this system were used for seabed surveys, sensor evaluation, and engineering tests. This framework enabled the development of novel techniques for undersea navigation and magnetic sensing. A synthetic baseline navigation technique that self-localizes an AUV using intermittent acoustic communications signals received by a single transducer is presented. The methodology is found to offer advantages over traditional acoustic-based navigation, in that it can operate with or without synchronized clocks, does not require acoustic transmissions dedicated to navigation, and can provide faster navigation solution convergence. The method uses the phase measurement at the output of a second-order phase-locked loop (PLL) to create fine-scale pseudo-range estimates in addition to, or in the absence of, a one-way travel time (OWTT) measurement based on the arrival time of the acoustic data packet. These range measurements are incorporated by an adaptive particle filter. This technique allows the vehicle navigation system to take advantage of multiple phase-derived range measurements made over the duration of a communication packet. To enable geophysical and archaeological survey capabilities, a scalar magnetometer system has been developed and integrated into an AUV. Real-time signal processing mitigates platform effects of the vehicle. Development of autonomy for on-board processing and target detection, coupled with reacquisition behaviors, is found to increase the effective survey coverage rate by nearly 300% when searching for magnetic dipole targets. The compact system collects data from a Micro-Fabricated Atomic Magnetometer (MFAM, Geometrics Corporation, San Jose, CA, USA), a total-field atomic magnetometer, and data from the sensor is both streamed to storage and made available to an onboard autonomy engine for real-time sense and react behaviors. Following characterization both in controlled laboratory conditions and at sea to determine its performance limits, methodologies for processing the magnetometer data to correct for interference and error introduced by the AUV platform were developed to improve sensing performance. When conducting seabed surveys, the developed autonomy is found to reliably detect and characterize targets of interest using physics-based algorithms designed to operate in real-time within the computational constraints of the AUV. Over the course of this research, the system was advanced to drive both single- and multiple-vehicle autonomous target reacquisition behaviors. Detailed results from surveys searching for submerged World-War II aircraft wrecks at locations worldwide are presented.

Download or read book Self localization of a Mobile Swarm of Underwater Vehicles Using Ambient Acoustic Noise written by Perry Naughton and published by . This book was released on 2018 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is increasing interest in deploying swarms of underwater vehicles for marine surveys. In such surveys, the cost, endurance, and utility of the vehicle swarm needs to be carefully optimized. One of the main challenges when designing these systems is coming up with an appropriate way to localize each vehicle in relation to the rest of the swarm. Current methods for underwater localization are restrictive in either cost, power consumption, or range. This dissertation considers the self-localization of a deforming swarm of subsurface vehicles using ambient acoustic noise in the ocean. The experiments presented consider a group of independent underwater vehicles that passively record ambient sounds in the ocean with a single hydrophone while they float with subsurface currents. Three different self-localization approaches are considered. The first involves estimating the acoustic impulse response between moving vehicles using cross-correlations of ambient noise, a known first step towards a self-localization estimate. Accurate estimates of the acoustic impulse response are shown between moving vehicle pairs. However, motion between the receivers limits the amount of time averaging that can be done, making the estimation susceptible to anisotropies in the ambient noise field. To overcome these anisotropies, the next approach jointly estimates the vehicle geometry and the directionality of the ambient noise field, without prior knowledge of either estimate. This creates a viable method for estimating the vehicle geometry on short time scales using correlations of low-frequency noise in the ocean. Results are shown for a deployment carried out off of the coast of La Jolla. Last, a self-localization approach using impulsive noise from snapping shrimp is considered. Impulsive sound sources provide high intensity, broadband signals that facilitate accurate arrival time detections by each vehicle. However, the similarity between different signals presents a significant correspondence problem, which must be solved to provide accurate estimates of the changing geometry of the swarm. A geometric solution to this correspondence problem is shown and an estimation procedure is proposed to track the geometry of a swarm as it changes. The self-localization estimates are compared to estimates from an accurate acoustic localization system with good agreement.

Download or read book Quantitative Monitoring of the Underwater Environment written by Benoît Zerr and published by Springer. This book was released on 2016-06-03 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume constitutes the results of the International Conference on Underwater Environment, MOQESM’14, held at “Le Quartz” Conference Center in Brest, France, on October 14-15, 2014, within the framework of the 9th Sea Tech Week, International Marine Science and Technology Event. The objective of MOQESM'14 was to bring together researchers from both academia and industry, interested in marine robotics and hydrography with application to the coastal environment mapping and underwater infrastructures surveys. The common thread of the conference is the combination of technical control, perception, and localization, typically used in robotics, with the methods of mapping and bathymetry. The papers presented in this book focus on two main topics. Firstly, coastal and infrastructure mapping is addressed, focusing not only on hydrographic systems, but also on positioning systems, bathymetry, and remote sensing. The proposed methods rely on acoustic sensors such as side scan sonars, multibeam echo sounders, phase-measuring bathymetric sonars, as well as optical systems such as underwater laser scanners. Accurate underwater positioning is also addressed in the case of the use of a single acoustic beacon, and the latest advances in increasing the vertical precision of Global Navigation Satellite System (GNSS) are also presented. Most of the above mentioned works are closely related to autonomous marine vehicles. Consequently, the second part of the book describes some works concerning the methods associated with such type of vehicles. The selected papers focus on autonomous surface or underwater vehicles, detailing new approaches for localization, modeling, control, mapping, obstacle detection and avoidance, surfacing, and software development. Some of these works imply acoustics sensing as well as image processing. Set membership methods are also used in some papers. The applications of the work presented in this book concern in particular oceanography, monitoring of oil and gas infrastructures, and military field.