Download or read book Integrating Acoustic Communications with Underwater Autonomy written by Connor L Webb and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the properties of the underwater environment, the most reliable form of long-distance communication utilized by autonomous underwater vehicles is acoustic communications. This thesis explores the integration of acoustic communications with the autonomy software of an autonomous underwater vehicle. The integration of these two subjects transforms the autonomous underwater vehicle into a mobile platform in an underwater acoustic communications network. A software defined acoustic modem was installed as a payload to an autonomous underwater vehicle, which runs MOOS-IvP as the autonomy software. A group of MOOS applications was created to integrate the acoustic modem with the user computer. First, the Unetstack API, used on the modem as an interface, was used to inform the modem of its location based upon sensor information obtained from the vehicle main computer. Second, additional applications were created to send and receive acoustic commands to control the movement of the vehicle, such as aborting the current mission or switching between different mission tracks. Similarly, the Unetstack API was used send and receive commands that controlled the signal power level of an acoustic transmission remotely. Finally, the first steps were made in acoustic networking by creating a MOOS application that forwards information between different vehicles. The applications were used in multiple field experiments at Lake Tuscaloosa. One experiment involved two autonomous underwater vehicles to form a three-node underwater acoustic network.
Download or read book Advances in Integrating Autonomy with Acoustic Communications for Intelligent Networks of Marine Robots written by Toby Edwin Schneider and published by . This book was released on 2013 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous marine vehicles are increasingly used in clusters for an array of oceanographic tasks. The effectiveness of this collaboration is often limited by communications: throughput, latency, and ease of reconfiguration. This thesis argues that improved communication on intelligent marine robotic agents can be gained from acting on knowledge gained by improved awareness of the physical acoustic link and higher network layers by the AUV's decision making software. This thesis presents a modular acoustic networking framework, realized through a C++ library called goby-acomms, to provide collaborating underwater vehicles with an efficient short-range single-hop network. goby-acomms is comprised of four components that provide: 1) losslessly compressed encoding of short messages; 2) a set of message queues that dynamically prioritize messages based both on overall importance and time sensitivity; 3) Time Division Multiple Access (TDMA) Medium Access Control (MAC) with automatic discovery; and 4) an abstract acoustic modem driver. Building on this networking framework, two approaches that use the vehicle's "intelligence" to improve communications are presented. The first is a "non-disruptive" approach which is a novel technique for using state observers in conjunction with an entropy source encoder to enable highly compressed telemetry of autonomous underwater vehicle (AUV) position vectors. This system was analyzed on experimental data and implemented on a fielded vehicle. Using an adaptive probability distribution in combination with either of two state observer models, greater than 90% compression, relative to a 32-bit integer baseline, was achieved. The second approach is "disruptive," as it changes the vehicle's course to effect an improvement in the communications channel. A hybrid data- and model-based autonomous environmental adaptation framework is presented which allows autonomous underwater vehicles (AUVs) with acoustic sensors to follow a path which optimizes their ability to maintain connectivity with an acoustic contact for optimal sensing or communication.
Download or read book The ICoN Integrated Communication and Navigation Protocol for Underwater Acoustic Networks written by Rupesh R. Kanthan and published by . This book was released on 2005 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The deployment of autonomous underwater devices has increased dramatically in the last several years, presenting a strong and growing need for a network protocol to mediate acoustic communications between devices. This network protocol must also provide an infrastructure for acoustic navigation, while ensuring that provisions for communication and navigation do not interfere with each other. To approach this difficult problem, we begin with a discussion of the limitations of traditional networking protocols when subjected to the complexities introduced by the underwater acoustic environment. We then present ICoN, a proposed network protocol, designed to integrate acoustic communication and navigation and optimized to operate in the low-bandwidth, high-loss underwater environment. A working description of ICoN and a discussion of its features are followed by analysis of the protocol through simulation, indicating its potential for improved performance over traditional networking protocols. The simulation results are reinforced through real-world experimental validation of ICoN, which, though limited, appears to confirm the effectiveness of the new protocol. We conclude with possible future extensions to ICoN, discussing various methods that might increase its potency in dealing with more demanding underwater acoustic applications.
Download or read book OFDM for Underwater Acoustic Communications written by Sheng Zhou and published by John Wiley & Sons. This book was released on 2014-03-21 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: A blend of introductory material and advanced signal processing and communication techniques, of critical importance to underwater system and network development This book, which is the first to describe the processing techniques central to underwater OFDM, is arranged into four distinct sections: First, it describes the characteristics of underwater acoustic channels, and stresses the difference from wireless radio channels. Then it goes over the basics of OFDM and channel coding. The second part starts with an overview of the OFDM receiver, and develops various modules for the receiver design in systems with single or multiple transmitters. This is the main body of the book. Extensive experimental data sets are used to verify the receiver performance. In the third part, the authors discuss applications of the OFDM receiver in i) deep water channels, which may contain very long separated multipath clusters, ii) interference-rich environments, where an unintentional interference such as Sonar will be present, and iii) a network with multiple users where both non-cooperative and cooperative underwater communications are developed. Lastly, it describes the development of a positioning system with OFDM waveforms, and the progress on the OFDM modem development. Closely related industries include the development and manufacturing of autonomous underwater vehicles (AUVs) and scientific sensory equipment. AUVs and sensors in the future could integrate modems, based on the OFDM technology described in this book. Contents includes: Underwater acoustic channel characteristics/OFDM basics/Peak-to-average-ratio control/Detection and Doppler estimation (Doppler scale and CFO)/Channel estimation and noise estimation/A block-by-block progressive receiver and performance results/Extensions to multi-input multi-output OFDM/Receiver designs for multiple users/Cooperative underwater OFDM (Physical layer network coding and dynamic coded cooperation)/Localization with OFDM waveforms/Modem developments A valuable resource for Graduate and postgraduate students on electrical engineering or physics courses; electrical engineers, underwater acousticians, communications engineers
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 High Data Rate Acoustic Communications for an Autonomous Underwater Vehicle written by Jeremy Peter Breen and published by . This book was released on 2008 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Communication Networks for Distributed Autonomous Underwater Platforms written by Milica Stojanovic and published by . This book was released on 2010 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ultimate goal of this project is to design and develop an experimental platform for testing and evaluation of mobile underwater acoustic networking. This report represents a cumulative summary of research and engineering efforts pursued from the beginning of the project up to this date. The project has focused on three topics: 1. Design and performance analysis of communication protocols for mobile acoustic networks; 2. Development of the software-defined reconfigurable acoustic modem, and 3. Design and development of a small autonomous underwater vehicle (the micro AUV). Below, we comment on the work accomplished in each of these areas.
Download or read book Underwater Acoustic Digital Signal Processing and Communication Systems written by Robert Istepanian and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underwater acoustic digital signal processing and communications is an area of applied research that has witnessed major advances over the past decade. Rapid developments in this area were made possible by the use of powerful digital signal processors (DSPs) whose speed, computational power and portability allowed efficient implementation of complex signal processing algorithms and experimental demonstration of their performance in a variety of underwater environments. The early results served as a motivation for the development of new and improved signal processing methods for underwater applications, which today range from classical of autonomous underwater vehicles and sonar signal processing, to remote control underwater wireless communications. This book presents the diverse areas of underwater acoustic signal processing and communication systems through a collection of contributions from prominent researchers in these areas. Their results, both new and those published over the past few years, have been assembled to provide what we hope is a comprehensive overview of the recent developments in the field. The book is intended for a general audience of researchers, engineers and students working in the areas of underwater acoustic signal processing. It requires the reader to have a basic understanding of the digital signal processing concepts. Each topic is treated from a theoretical perspective, followed by practical implementation details. We hope that the book can serve both as a study text and an academic reference.
Download or read book Underwater Communications written by Marco Lanzagorta and published by Morgan & Claypool Publishers. This book was released on 2013 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underwater vehicles and underwater moorings are increasing in tactical importance. As such, it is critical to have a robust and secure communication system connecting underwater vehicles on a long seaborne mission and a ground station. As a matter of fact, the deployment of efficient communication links with underwater vehicles is one of the greatest technological challenges presently confronted by the world's naval forces. To circumvent most of the limitations involved in the use of RF or acoustic channels for perfectly secure communications with underwater vehicles, it is worth considering the feasibility of an optical channel to facilitate a two-way satellite communication link secured via perfectly secure ciphers enabled by a quantum key distribution protocol. This book offers a concise review of underwater communications systems. Our approach is pedagogical, making a strong emphasis on the physics behind the attenuating properties of the oceanic environment and the propagation of electromagnetic signals in the ELF, VLF, and optical bands. We assume the reader is familiar with the basic principles of classical electrodynamics and optics. The system design, components, and noise analysis of an underwater optical communications device are discussed in detail. Furthermore, we offer simulations of the performance of the communication system for different types of ocean waters. Our final conclusion is that it appears to be feasible to design and build underwater communications using optical classical and quantum channels secured with quantum key distribution protocols.
Download or read book Digital Underwater Acoustic Communications written by Lufen Xu and published by Academic Press. This book was released on 2016-09-16 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital Underwater Acoustic Communications focuses on describing the differences between underwater acoustic communication channels and radio channels, discusses loss of transmitted sound in underwater acoustic channels, describes digital underwater acoustic communication signal processing, and provides a comprehensive reference to digital underwater acoustic communication equipment. This book is designed to serve as a reference for postgraduate students and practicing engineers involved in the design and analysis of underwater acoustic communications systems as well as for engineers involved in underwater acoustic engineering. - Introduces the basics of underwater acoustics, along with the advanced functionalities needed to achieve reliable communications in underwater environment - Identifies challenges in underwater acoustic channels relative to radio channels, underwater acoustic propagation, and solutions - Shows how multi-path structures can be thought of as time diversity signals - Presents a new, robust signal processing system, and an advanced FH-SS system for multimedia underwater acoustic communications with moderate communication ranges (above 20km) and rates (above 600bps) - Describes the APNFM system for underwater acoustic communication equipment (including both civil and military applications), to be employed in active sonar to improve its performance
Download or read book Mobile Ad Hoc Networking written by Stefano Basagni and published by John Wiley & Sons. This book was released on 2013-02-07 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An excellent book for those who are interested in learning the current status of research and development . . . [and] who want to get a comprehensive overview of the current state-of-the-art." —E-Streams This book provides up-to-date information on research and development in the rapidly growing area of networks based on the multihop ad hoc networking paradigm. It reviews all classes of networks that have successfully adopted this paradigm, pointing out how they penetrated the mass market and sparked breakthrough research. Covering both physical issues and applications, Mobile Ad Hoc Networking: Cutting Edge Directions offers useful tools for professionals and researchers in diverse areas wishing to learn about the latest trends in sensor, actuator, and robot networking, mesh networks, delay tolerant and opportunistic networking, and vehicular networks. Chapter coverage includes: Multihop ad hoc networking Enabling technologies and standards for mobile multihop wireless networking Resource optimization in multiradio multichannel wireless mesh networks QoS in mesh networks Routing and data dissemination in opportunistic networks Task farming in crowd computing Mobility models, topology, and simulations in VANET MAC protocols for VANET Wireless sensor networks with energy harvesting nodes Robot-assisted wireless sensor networks: recent applications and future challenges Advances in underwater acoustic networking Security in wireless ad hoc networks Mobile Ad Hoc Networking will appeal to researchers, developers, and students interested in computer science, electrical engineering, and telecommunications.
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 Underwater Acoustic Sensor Networks written by Yang Xiao and published by CRC Press. This book was released on 2010-05-19 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed review of underwater channel characteristics, Underwater Acoustic Sensor Networks investigates the fundamental aspects of underwater communication. Prominent researchers from around the world consider contemporary challenges in the development of underwater acoustic sensor networks (UW-ASNs) and introduce a cross-layer approach for effec
Download or read book Autonomous Vehicles in Support of Naval Operations written by National Research Council and published by National Academies Press. This book was released on 2005-08-05 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous vehicles (AVs) have been used in military operations for more than 60 years, with torpedoes, cruise missiles, satellites, and target drones being early examples.1 They have also been widely used in the civilian sector-for example, in the disposal of explosives, for work and measurement in radioactive environments, by various offshore industries for both creating and maintaining undersea facilities, for atmospheric and undersea research, and by industry in automated and robotic manufacturing. Recent military experiences with AVs have consistently demonstrated their value in a wide range of missions, and anticipated developments of AVs hold promise for increasingly significant roles in future naval operations. Advances in AV capabilities are enabled (and limited) by progress in the technologies of computing and robotics, navigation, communications and networking, power sources and propulsion, and materials. Autonomous Vehicles in Support of Naval Operations is a forward-looking discussion of the naval operational environment and vision for the Navy and Marine Corps and of naval mission needs and potential applications and limitations of AVs. This report considers the potential of AVs for naval operations, operational needs and technology issues, and opportunities for improved operations.
Download or read book Inter glider Underwater Communication and Coordination for Ocean Monitoring and Coastal Tactical Surveillance written by Baozhi Chen and published by . This book was released on 2012 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to achieve efficient and cost-effective sensing of the vast under-sampled 3D aquatic volume, intelligent adaptive sampling strategies involving teams of Autonomous Underwater Vehicles (AUVs) endowed with underwater wireless communication capabilities become essential. These autonomous vehicles should coordinate and steer through the region of interest, and cooperatively sense and transmit multimedia data to onshore stations for real-time data processing and analysis. Because of the propagation limitations of Radio Frequency (RF) and optical waves, the typical wireless physical-layer communication technology in underwater networks, for distances above a hundred of meters, relies on acoustic waves. Due to the stringent constraints of the underwater acoustic channels, as of today existing works on underwater acoustic communications are mostly focused on enabling delay-tolerant low-bandwidth applications tailored for measuring only scalar physical phenomena. Hence, it is necessary to design solutions for reliable, high data-rate multimedia underwater acoustic communications and to seamlessly integrate the control and communication of AUVs. In this dissertation, I propose solutions to improve the performance of inter-vehicle acoustic communication and coordination among AUVs. In particular, these solutions are based on underwater gliders and can be extended to other classes of AUVs following predictable trajectories. Due to the inaccessibility of Global Positioning System (GPS) signal underwater, location estimates of a node may be inaccurate. Inaccuracies in models for deriving position estimates, self-localization errors, and drifting due to ocean currents, however, cause uncertainty when estimating an AUV's position. In this dissertation, I first propose a statistical model to estimate an AUV's position and its associated position uncertainty. Then, the position uncertainty under the influence of ocean currents is further predicted using the Unscented Kalman Filter. Based on this model, in order to optimize the inter-vehicle communications, I propose a delay-tolerant networking solution exploiting the predictability of AUV trajectories and the directional radiation pattern of transducers, a reliable geocasting solution for AUVs with high position uncertainty, and an under-ice localization solution that can minimize localization uncertainty and communication overhead. Based on these underwater communication techniques, I also propose efficient team-formation and -steering algorithms for underwater gliders in order to take measurements in space and time from the under-sampled vast ocean. Team formation and steering algorithms relying on underwater acoustic communications are proposed to enable glider swarming that is robust against ocean currents and acoustic channel impairments. These algorithms use real underwater acoustic modems and are combined with realistic underwater communication models. Additionally, novel bio-inspired underwater acoustic communication techniques are also proposed to improve the coordination performance. I also designed and implemented an underwater network emulator using WHOI Micro-Modems, and the performance of the proposed solutions is evaluated using this emulator as well as software simulations. Communication protocols were also implemented on acoustic modems and tested in ocean experiments.
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.
