Download or read book The Influence of Shallow Water Waves on the REMUS Autonomous Underwater Vehicle written by Daniel E. Sgarioto and published by . This book was released on 2011 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forces and Moments Due to Unsteady Motion of an Underwater Vehicle written by Erik D. Oller and published by . This book was released on 2003 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Tidal Currents on the REMUS Autonomous Underwater Vehicle written by Daniel E. Sgarioto and published by . This book was released on 2009 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Navigation and Target Localization Performance of the AUV Remote Environmental Measuring UnitS written by Christopher John Cassidy and published by . This book was released on 2000 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 9 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 Warship 2017 written by and published by Bloomsbury Publishing. This book was released on 2017-06-15 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warship 2017 is devoted to the design, development and service history of the world's combat ships. Featuring a broad range of articles from a select panel of distinguished international contributors, this latest volume combines original research, new book reviews, warship notes, an image gallery and much more to maintain the impressive standards of scholarship and research from the field of warship history. This 39th edition features the usual range of diverse articles spanning the subject by an international array of expert authors.
Download or read book Verification of a 6 degree of Freedom Simulation Model for the REMUS AUV written by Timothy Jason Prestero and published by . This book was released on 2001 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mproving the performance of modular, low-cost autonomous underwater vehicles (AUVs) in such applications as long-range oceanographic survey, autonomous docking, and shallow-water mine countermeasures requires improving the vehicles' maneuvering precision and battery life. These goals can be achieved through the improvement of the vehicle control system. A vehicle dynamics model based on a combination of theory and empirical data would provide an efficient platform for vehicle control system development, and an alternative to the typical trial-and-error method of vehicle control system field tuning. As there exists no standard procedure for vehicle modeling in industry, the simulation of each vehicle system represents a new challenge. Developed by von Alt and associates at the Woods Hole Oceanographic Institute, the REMUS AUV is a small, low-cost platform serving in a range of oceanographic applications. This thesis describes the development and verification of a six degree of freedom, non-linear simulation model for the REMUS vehicle, the first such model for this platform. In this model, the external forces and moments resulting from hydrostatics, hydrodynamic lift and drag, added mass, and the control inputs of the vehicle propeller and fins are all defined in terms of vehicle coefficients. This thesis describes the derivation of these coefficients in detail. The equations determining the coefficients, as well as those describing the vehicle rigid-body dynamics, are left in non-linear form to better simulate the inherently non-linear behavior of the vehicle. Simulation of the vehicle motion is achieved through numeric integration of the equations of motion. The simulator output is then checked against vehicle dynamics data collected in experiments performed at sea. The simulator is shown to accurately model the motion of the vehicle.
Download or read book Shallow Water Stationkeeping of an Autonomous Underwater Vehicle The Experimental Results of a Disturbance Compensation Controller written by and published by . This book was released on 2005 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The continual development of computer technology has enabled the expansion of intelligent control into the field of underwater robots, where potential uses include oceanographic research, environmental monitoring and military mine countermeasures. With the naval focus shifting to operations in the littorals, and the need to lower cost of operations, tetherless autonomous vehicles are now being proposed for use in very shallow water minefield reconnaissance. These areas are dominated by a highly energetic environment arising from waves and currents. Motion control in such an environment becomes a difficult task and is the subject of this work. The main objective of this paper is to show that intervention tasks performed by intelligent underwater robots are improved by their ability to gather, learn and use information about their working environment. Using a new generalized approach to the modeling of underwater vehicles, which directly includes disturbance effects, a new Disturbance Compensation Controller (DCC) is proposed. The DCC, employing onboard vehicle sensors, allows the robot to learn and estimate the seaway dynamics. This self-derived knowledge is embedded in a non-linear sliding mode control law which allows significantly improved motion stabilization. The performance of the DCC has been experimentally verified in Monterey Harbor using the NPS Phoenix AUV.
Download or read book Dynamics and Control of Autonomous Underwater Vehicles with Internal Actuators written by Bo Li and published by . This book was released on 2016 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation concerns the dynamics and control of an autonomous underwater vehicle (AUV) which uses internal actuators to stabilize its horizontal plane motion. The demand for high-performance AUVs are growing in the eld of ocean engineering due to increasing activities in ocean exploration and research. New generations of AUVs are expected to operate in harsh and complex ocean environments. We propose a hybrid design of an underwater vehicle which uses internal actuators instead of control surfaces to steer. When operating at low speeds or in relatively strong ocean currents, the performances of control surfaces will degrade. Internal actuators work independent of the relative flows, thus improving the maneuvering performance of the vehicle. We develop the mathematical model which describes the motion of an underwater vehicle in ocean currents from first principles. The equations of motion of a body-fluid dynamical system in an ideal fluid are derived using both Newton-Euler and Lagrangian formulations. The viscous effects of a real fluid are considered separately. We use a REMUS 100 AUV as the research model, and conduct CFD simulations to compute the viscous hydrodynamic coefficients with ANSYS Fluent. The simulation results show that the horizontal-plane motion of the vehicle is inherently unstable. The yaw moment exerted by the relative flow is destabilizing. The open-loop stabilities of the horizontal-plane motion of the vehicle in both ideal and real uid are analyzed. In particular, the effects of a roll torque and a moving mass on the horizontal-plane motion are studied. The results illustrate that both the position and number of equilibrium points of the dynamical system are prone to the magnitude of the roll torque and the lateral position of the moving mass. We propose the design of using an internal moving mass to stabilize the horizontal-plane motion of the REMUS 100 AUV. A linear quadratic regulator (LQR) is designed to take advantage of both the linear momentum and lateral position of the internal moving mass to stabilize the heading angle of the vehicle. Alternatively, we introduce a tunnel thruster to the design, and use backstepping and Lyapunov redesign techniques to derive a nonlinear feedback control law to achieve autopilot. The coupling effects between the closed-loop horizontal-plane and vertical-plane motions are also analyzed.
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 Marine Robot Autonomy written by Mae L. Seto and published by Springer Science & Business Media. This book was released on 2012-12-09 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomy for Marine Robots provides a timely and insightful overview of intelligent autonomy in marine robots. A brief history of this emerging field is provided, along with a discussion of the challenges unique to the underwater environment and their impact on the level of intelligent autonomy required. Topics covered at length examine advanced frameworks, path-planning, fault tolerance, machine learning, and cooperation as relevant to marine robots that need intelligent autonomy.
Download or read book Shallow Water Station Keeping of AUVs Using Multi Sensor Fusion for Wave Disturbance Prediction and Compensation written by and published by . This book was released on 2005 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important capability for Autonomous Underwater Vehicles (AUVs) is station keeping. Station keeping is the ability of a vehicle to maintain position and orientation with regard to a reference object. In shallow water this mission most likely will be disrupted by the large wave induced hydrodynamic forces acting on the vehicle. To counter this problem, knowledge of these wave induced disturbances is critical to allow for the design of a control system that will enable the vehicle to accurately navigate and position itself. The ability to develop a so called "predictive" control strategy for underwater vehicles is limited by the methods available to measure and predict the wave induced disturbances. Surface vessels may employ remote sensors such as acoustic probes, lasers or short wavelength radar to determine future disturbances, but this remote sensing is not feasible in a low cost underwater vehicle. AUV control system design is limited to the use of on board sensors for disturbance prediction. In this paper, we present the design of a Sliding Mode Controller (SMC) that employs multisensor data fusion for wave disturbance prediction/estimation. Using data obtained from the vehicle's Doppler, Acoustic Doppler Velocimeter (ADV) and motion package, a dynamic filter is developed that will fuse the information from the various sensors and provide the controller with an estimate of the wave induced disturbance, thus allowing the vehicle to station keep in both heading and position with far greater accuracy.
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 Measures of Effectiveness and Performance for the Remus Autonomous Underwater Vehicle written by Daniel E. Sgarioto and published by . This book was released on 2010 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experiments with the REMUS AUV written by Matthew D. Phaneuf and published by . This book was released on 2004-06-01 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis centers on actual field operations and post-mission analysis of data acguired using a REMUS AUV operated by tbe Naval Postgraduate School center for Autonomous Underwater Vehicle Research. It was one of many platforms tbat were utilized for data collection during AOSN II, (Autonomous Oceanograpbic Sampling Network II), an ONR sponsored exercise for dynamic oceanograpnic data taking and model based analysis using adaptive sampling. Tbe vebicle's ability to collect oceanograpnic data consisting of conductivity, temperature, and salinity during tbis experiment is assessed and problem areas investigated. Of particular interest are the temperature and salinity profiles measured from long transect runs of 18 Km. length into tbe soutbern parts of Monterey Bay. Experimentation witn tne REMUS as a mine detection asset was also performed. Tbe design and development of the mine hunting experiment is discussed as well as its results and tneir analysis. Of particular interest in tbis portion of tne work is tne issue relating to repeatability and precision of contact localization, obtained from vehicle position and sidescan sonar measurements.
Download or read book Exploring the Utility of the REMUS Autonomous Underwater Vehicle for Search classify map Missions written by Daniel E. Sgarioto and published by . This book was released on 2011 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book OCRA II written by Benjamin Francis Polito and published by . This book was released on 1999 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
