Obstacle Avoidance Control for the REMUS Autonomous Underwater Vehicle
Obstacle Avoidance Control for the REMUS Autonomous Underwater Vehicle

Author: Christopher D. Chuhran

Publisher:

Published: 2003-09

Total Pages: 63

ISBN-13: 9781423547617

DOWNLOAD EBOOK

As the Navy continues its development of unmanned underwater vehicles, the need for total autonomous missions grows. Autonomous Underwater Vehicles (AUV) allow for advances in mine warfare, harbor reconnaissance, undersea warfare and more. Information can be collected from AUVs and downloaded into a ship or battle group's network. As AUVs are developed it is clear forward-look sonar will be required to be able to detect obstacles in front of its search path. Common obstacles in the littoral environment include reefs and seawalls which an AUV will need to rise above to pass. This thesis examines the behavior and control system required for an AUV to maneuver over an obstacle in the vertical plane. Hydrodynamic modeling of a REMUS vehicle enables a series of equations of motion to be developed to be used in conjunction with a sliding mode controller to control the elevation of the AUV. A two-dimensional, 24 deg. vertical scan forward look sonar with a range of 100 m is modeled for obstacle detection. Sonar mappings from geographic range-bearing coordinates are developed for use in MATLAB simulations. The sonar 'image' of the vertical obstacle allows for an increasing altitude command that forces the AUV to pass safely over the obstacles at a reasonable rate of ascent and pitch angle. Once the AUV has passed over the obstacle, the vehicle returns to its regular search altitude. This controller is simulated over different types of obstacles.

Biomimetic Improvement of the Maneuvering Qualities of Unmanned Underwater Vehicles
Biomimetic Improvement of the Maneuvering Qualities of Unmanned Underwater Vehicles

Author: Yuri Trakht

Publisher:

Published: 2019

Total Pages: 73

ISBN-13:

DOWNLOAD EBOOK

In recent years, biomimetics has been used as a source of inspiration to improve the performance of engineered systems in several disciplines. In this thesis, we emulate the function of the retractable dorsal fins in tunas to improve the maneuvering performance of a typical autonomous underwater vehicle, the REMUS 100 AUV. We are introducing dorsal-like fins on the AUV that can be erected to alter its maneuvering hydrodynamic coefficients, and hence affect the transient and steady-state turning response. In order to study systematically the effect of adding dorsal fins, we built a six degrees of freedom simulation model of the REMUS AUV. The model included body and rudder lift forces and moments, added mass forces and moments, gyroscopic and centrifugal forces, drag forces and moments, and body forces and moments such as buoyancy and gravity terms. To target the horizontal plane maneuvering characteristics, we reduced the model to a 3 DOF simulation, allowing the dorsal fin to vary in area, location along the length of the AUV, as well as having a turning angle with respect to the REMUS x-axis. We find that the addition of the fin can improve the performance, as measured by the radius of turning and rate of turning, moderately only when placed ahead of the center of gravity. However, when the dorsal fin is also allowed to rotate in the opposite direction that the rudder, substantial improvement in maneuvering performance is noted, increasing the turning rate up to 25%.

Autonomous Underwater Vehicles
Autonomous Underwater Vehicles

Author: Nuno Cruz

Publisher: BoD – Books on Demand

Published: 2011-10-21

Total Pages: 274

ISBN-13: 9533074329

DOWNLOAD EBOOK

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

Guidance and Control of Underwater Vehicles 2003 (GCUV 2003)
Guidance and Control of Underwater Vehicles 2003 (GCUV 2003)

Author: G. N. Roberts

Publisher: Elsevier Science & Technology

Published: 2003

Total Pages: 260

ISBN-13:

DOWNLOAD EBOOK

This volume contains forty papers from the 1st IFAC Workshop on Guidance and Control of Underwater Vehicles. The aim of the Workshop was to bring together academic practitioners and industrialists involved in this important and expanding area of interest in order to exchange experiences on recent advances in this field. Topics covered by the papers in this proceeding include UUV Control Applications, System Identification, UUV Architectures, Navigation, Modelling, Fault Detection and Reconfiguration. Contributors from Italy, Ireland, Japan, Portugal, Spain, Turkey, USA and the United Kingdom were represented at the workshop.The Workshop was voted a resounding success by all delegates and in the light of this vote of confidence the Technical Committee on Marine Systems is planning to run this event again in 2005, with the slightly amended title of Navigation, Guidance and Control of Underwater Vehicles

Reactive Obstacle Avoidance for the REMUS Autonomous Underwater Vehicle Utilizing a Forward Looking Sonar
Reactive Obstacle Avoidance for the REMUS Autonomous Underwater Vehicle Utilizing a Forward Looking Sonar

Author:

Publisher:

Published: 2006

Total Pages: 79

ISBN-13:

DOWNLOAD EBOOK

One day fully autonomous AUV's will no longer require human interactions to complete its missions. To make this a reality, the AUV must be able to safely navigate in unfamiliar environments with unknown obstacles. This thesis builds on previous work conducted at NPS's Center for AUV Research to improve the autonomy of the REMUS class of AUVs with an implemented FLS. The first part of this thesis deals with accurate path following with the use of look-ahead pitch calculations. With the use of a SIMULINK model, constraints surrounding obstacle avoidance path planning are then explored, focusing on optimal sensor orientation issues. Two path planning methods are developed to address the issues of a limited sonar field of view and uncertainties brought on by an occlusion area. The first approach utilizes a pop-up maneuver to increase the field of view and minimize the occlusion area, while the second approach creates a path with the addition of a spline. Comparing the two methods, it was concluded that spline addition planner provided a robust optimal obstacle avoidance path and along with the look-ahead pitch controller completes the design of a back-seat driver to improve REMUS s survivability in an unknown environment. REMUS, AUV, UUV, Autonomous Underwater Vehicle, Reactive Obstacle Avoidance, Forward Looking Sonar, Vertical Plane, Pitch Controller, Spline, Gaussian, Occlusion, Optimal Sensor Orientation.

Experiments with the REMUS AUV
Experiments with the REMUS AUV

Author: Matthew D. Phaneuf

Publisher:

Published: 2004-06-01

Total Pages: 77

ISBN-13: 9781423517474

DOWNLOAD EBOOK

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.

Obstacle Avoidance Control for the REMUS Autonomous Underwater Vehicle
Obstacle Avoidance Control for the REMUS Autonomous Underwater Vehicle

Author: Lynn Fodrea

Publisher:

Published: 2002

Total Pages: 63

ISBN-13:

DOWNLOAD EBOOK

Future Naval operations necessitate the incorporation of autonomous underwater vehicles into a collaborative network. In future complex missions, a forward look capability will be required to map and avoid obstacles such as sunken ships. This thesis examines obstacle avoidance behaviors using a forward-looking sonar for the autonomous underwater vehicle REMUS. Hydrodynamic coefficients are used to develop steering equations that model REMUS through a track of specified points similar to a real-world mission track. Control of REMUS is accomplished using line of sight and state feedback controllers. A two-dimensional forward-looking sonar model with a 1200 horizontal scan and a 110 meter radial range is modeled for obstacle detection. Sonar mappings from geographic range-bearing coordinates are developed for implementation in MATLAE simulations. The product of bearing and range weighting functions form the gain factor for a dynamic obstacle avoidance behavior. The overall vehicle heading error incorporates this obstacle avoidance term to develop a path around detected objects. REMUS is a highly responsive vehicle in the model and is capable of avoiding multiple objects in proximity along its track path.