Download or read book Real Time Modeling of Cross Body Flow for Torpedo Tube Recovery of the Phoenix Autonomous Underwater Vehicle AUV written by Kevin Michael Bryne and published by . This book was released on 1998-03-01 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: A virtual world provides an exceptional resource for the testing and development of an Autonomous Underwater Vehicle (AUV). The difficulties associated with the underwater environment are numerous and complex. In order to properly verify vehicle results in the laboratory such a world must accurately model the physics associated with the vehicle, its submerged hydrodynamics characteristics, and interactions with the environment. Environmental effects such as wave motion, currents, and flow forces created by bodies moving through the water can cause unpredicted performance variations and failures in the ocean environment. The current Phoenix AUV virtual world includes steady state ocean currents, but does not take into account the environmental effects of waves and flow forces induced by adjacent vehicles (such as a moving submarine docking target). This work provides a thorough real time simulation of these complex factors using physically based models. The problem is broken down into wave motion effects, submarine induced flow fields, and virtual sensors to improve AUV motion control. Simulated testing is performed across a range of easy to worst case scenarios in order to justify assumptions. Extensive testing using virtual sensors is used to develop adequate control algorithms in the presence of turbulent cross body flow. The result of this research is an enhanced virtual world which more accurately depicts the ocean environment, along with the models and control algorithms required to design and operate an AUV during submarine launch and recovery. A platform independent approach to virtual environment simulation is presented through the use of the Virtual Reality Modeling Language (VRML) and Java. Finally, simulation test results provide strong evidence that AUV control with actual cross body flow sensors can enable stable navigation, first through a turbulent flow field and then for subsequent docking with

Download or read book Precision Control and Maneuvering of the Phoenix Autonomous Underwater Vehicle for Entering a Recovery Tube written by Duane T. Davis and published by . This book was released on 1996-09-01 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of range limitations imposed by speed and power supplies, covert launch and recovery of Autonomous Underwater Vehicles (AUVs) near the operating area will be required for their use in many military applications. This thesis documents the implementation of precision control and planning facilities on the Phoenix AUV that will be required to support recovery in a small tube and provides a preliminary study of issues involved with AUV recovery by submarines. Implementation involves the development of low-level behaviors for sonar and vehicle control, mid-level tactics for recovery planning, and a mission planning system for translating high-level goals into an executable mission. Sonar behaviors consist of modes for locating and tracking objects, while vehicle control behaviors provide the ability to drive to and maintain a position relative to a tracked object. Finally, a mission-planning system allowing graphical specification of mission objectives and recovery parameters is implemented. Results of underwater virtual world and in-water testing show that precise AUV control based on sonar data and its use by higher-level tactics to plan and control recovery. Additionally, the mission-planning expert system has been shown to reduce mission planning time by approximately two thirds and results in missions with fewer logical and programming errors than manually generated missions.

Download or read book Phoenix Autonomous Underwater Vehicle Recovery Software Reference written by Duane Davis and published by . This book was released on 1996-09-01 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of range limitations imposed by speed and power supplies convert launch and recovery of Autonomous Underwater Vehicles (AUVs) near the operating area will be required for their use in many military applications. This report contains source code implemented on the Phoenix AUV in support of recovery in a small stationary tube. Implementation involves the development of low-level behaviors for sonar and vehicle control, mil-level tactics for recovery planning, and a mission-planning system for translating high-level goals into an executable mission. Sonar behaviors consist of modes for locating and tracking objects, while vehicle control behaviors include the ability to drive to and maintain a position relative to a tracked object. Finally, a mission-planning system allowing graphical specification of mission objectives and recovery parameters is implemented.

Download or read book Merging Virtual and Real Execution Level Control Software for the Phoenix Autonomous Underwater Vehicle written by Michael L. Burns and published by . This book was released on 1996-09-01 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Naval Postgraduate School (NPS) is developing an AUV, Phoenix. The Phoenix has the capability of precise navigation, however too much time is needed to validate a new section of code. NPS is also developing a virtual AUV, which has the capability of being networked, having flexible missions, and having a quick feedback of results when validating new portions of code. The virtual AUV has a drawback of never being tested for real world precision. This thesis discusses the steps taken to combine these two sets of control code to obtain the maximum functionality that will drive either the virtual or actual AUV and produce a faster feedback response to newly developed code. As a result of this effort, the newly developed control code has successfully driven both the actual and virtual AUVs and provides a means for readily validating new code. Also this new control code has given the AUV research group the ability to perform distributed software development, test all AUV hardware from either the onboard or offboard computers, conduct flexible missions, and test missions in the virtual world prior to conducting them with the AUV.

Download or read book Cross Body Thruster Control and Modeling of a Body of Revolution Autonomous Underwater Vehicle written by Sean Michael Doherty and published by . This book was released on 2011 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cross body thrusters permit a body of revolution Autonomous Underwater Vehicle to retain the energy efficiency of forward travel while increasing the ability to maneuver in confined areas such as harbors and piers. This maneuverability also permits more deliberate underwater surveys using a fixed, mounted forward and downward looking sonar. This work develops the necessary hydrodynamic coefficients, using methods applied to earlier vehicles, to develop a valid computer simulation model. Additionally, this work develops a polynomial regression translating thruster input in RPM to an applied force output, which is incorporated into the vehicle model. This model is then employed to examine the response and control, specifically at low speed, of a body-of-revolution Autonomous Underwater Vehicle equipped with off-axis cross-body thrusters. These results are then utilized to develop a series of PID controllers for use onboard the REMUS Autonomous Underwater Vehicle.

Download or read book 6 DOF Nonlinear AUV Simulation Toolbox written by and published by . This book was released on 1997 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the organization of 6 DOF nonlinear autonomous underwater vehicle (AUV) simulation toolbox, which is currently under development for the Ocean Explorer (OEX) series AUVS developed at Florida Atlantic University. This software development is part of 5-year ONR MURI effort of which its goal is to develop innovative tools and methodologies for the control of complex nonlinear dynamic systems. The purpose of this software simulation is to supply a flexible 3D-simulation platform for motion visualization, in-lab debugging and testing of mission-specific strategies as well as those related to C3 purposes. This software is currently jointly developed by the Ocean Engineering Department at Florida Atlantic University and Naval Postgraduate School for the FAU OEX and NPS Phoenix AUVs.

Download or read book NPS AUV Integrated Simulator written by Donald P Brutzman and published by . This book was released on 1992 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development and testing of Autonomous Underwater Vehicle (AUV) hardware and software is greatly complicated by vehicle inaccessibility during operation. Integrated simulation remotely links vehicle components and support equipment with graphics simulation workstations, allowing complete real-time, pre-mission, pseudo-mission and post-mission visualization and analysis in the lab environment. Integrated simulator testing of software and hardware is a broad and versatile method that supports rapid and robust diagnosis and correction of system faults. This method is demonstrated using the Naval Postgraduate School (NPS) AUV. High-resolution three-dimensional graphics workstations can provide real-time representations of vehicle dynamics, control system behavior, mission execution, sensor processing and object classification. Integrated simulation is also useful for development of the variety of sophisticated artificial intelligence applications needed by an AUV. Examples include sonar classification using an expert system and path planning using a circle world model. The flexibility and versatility provided by this approach enables visualization and analysis of all aspects of AUV development. Integrated simulator networking is recommended as a fundamental requirement for AUV research and deployment. Autonomous underwater vehicles, Graphics, Simulation, Path planning, Sonar classification, Expert systems, Real-Time operating systems.

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 Real Time Implementation of an Adaptive Depth Controller for a Submersible written by James M. Williams and published by . This book was released on 1989 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Autonomous Underwater Vehicle (AUV) is an unmanned submersible vehicle capable of performing a variety of missions. The AUV, which is the subject of this research, is a small prototype vehicle equipped with various control surfaces as well as telemetry devices which provide pertinent measurements of the vehicle states. This research is directed toward the development and implementation of a digital-control program which provides robust depth control of the vehicle. An adaptive parameter estimation routine is used to develop the model of the relationship between the actuator commands and vehicle response. State feedback is then provided using a variable-structure approach. The control algorithm has been implemented through a Turbo Pascal digital-control program executed on a PC/AT computer. Results of the parameter estimation routine and controller implementation are discussed. Keywords: Theses; Analog simulation; Experimental data. (kr).

Download or read book Autonomous Underwater Vehicle AUV Path Planning and Adaptive On board Routing for Adaptive Rapid Environmental Assessment written by Ding Wang (Ph. D.) and published by . This book was released on 2007 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) As a special case, a thermocline- oriented AUV yoyo control and control parameter optimization methods for AREA are also developed. Finally, some AUV control algorithms for capturing fronts are developed. A frame-work for real-time TL forecasts is developed. This is the first time that TL forecasts have been linked with ocean forecasts in real-time. All of the above ideas and methods developed were tested in two experiments, FAF05 in the northern Tyrrhenian Sea in 2005 and MB06 in Monterey Bay, CA in 2006. The latter MB06 sea exercise was a major field experiment sponsored by the Office of Naval Research and the thesis compiles significant findings from this effort.

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 Analytical Modeling and Simulation of an AUV with Five Control Surfaces written by John Tomasi (Mechanical engineer) and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research describes the dynamic modeling and numerical simulation of an autonomous underwater vehicle (AUV) with five hydrodynamic control surfaces, necessary for the development of an autopilot algorithm, based solely upon analytical methodologies. The purpose of this research was to demonstrate the ability to develop a low. order approximation of the dynamics and control characteristics of an underwater vehicle that is complete enough to validate a specific design before physical construction begins; therefore, allowing for a more cost effective virtual design, test, and evaluation process. The AUV model developed in this study takes into consideration inertia, hydrostatic forces, hydrodynamic forces, propulsion forces, control fin forces, added mass, and damping. The model assumes that the vehicle is sufficiently far enough away from the ocean bottom and surface so that their effects can be ignored. The necessary stability and control derivatives were determined through the use of engineering formulae. The mathematical model represents a general, nonlinear, six degrees of freedom model, and it is similar to those used to carry out atmospheric flight simulations. The non-linear model was linearized about the design (equilibrium) condition to obtain a linear state-space vehicle model.

Download or read book Computational Hydrodynamics and Control Modeling for Autonomous Underwater Vehicles written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The long term objective of the program is to develop predictive technologies to support virtual design and evaluation of underwater vehicles systems. CFD technologies will be used to protect hydrodynamic models for AUVs and those models will be coupled with control system design and modeling tools to allow vehicle conceptual design to be evaluated within the context of a realistic mission. The objectives of this effort were to compare the forces and moments acting on a maneuvering AUV predicted by computational fluid dynamics (CFD) code with similar data collected aboard an operational AUV. In particular, the multi-block Navier-Stokes flow solver UNCLE (Unsteady Computational of Field Equations) was used in this effort.

Download or read book A Hybrid Control Architecture for an Autonomous Underwater Vehicle AUV written by Georgios A. Demetriou and published by . This book was released on 1998 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Leveled Flight Control of an Unmanned Underwater Vehicle Operating in a Wave Induced Environment written by Joshua J. Potesta and published by . This book was released on 2014 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous Underwater Vehicle (AUV) depth control methods typically use a pressure sensor to measure the depth, which results in the AUV following the trajectory of the surface waves. Through simulations, a controller is designed for the Ocean Explorer AUV with the objective of the AUV holding a constant depth below the still water line while operating in waves. This objective is accomplished by modeling sensors and using filtering techniques to provide the AUV with the depth below the still water line. A wave prediction model is simulated to provide the controller with knowledge of the wave disturbance before it is encountered. The controller allows for depth keeping below the still water line with a standard deviation of 0.04 and 0.65 meters for wave amplitudes of 0.1-0.25 and 0.5-2 meters respectively and wave frequencies of 0.35-1.0 rad/sec, and the wave prediction improves the depth control on the order of 0.03 meters.

Download or read book PATH FOLLOWING AUTONOMOUS UNDERWATER VEHICLE AUV WITH COLLISION AVOIDANCE written by CHEOK KEL VIN (TP015556) and published by . This book was released on 2013 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling and Simulation of the Autonomous Underwater Vehicle Autolycus written by Sia Chuan Tang and published by . This book was released on 1999 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: