Showing papers on "Intervention AUV published in 1997"

Control architectures for autonomous underwater vehicles

Abstract: Autonomous underwater vehicles (AUVs) share common control problems with other air, land, and water unmanned vehicles. In addition to requiring high-dimensional and computationally intensive sensory data for real-time mission execution, power and communication limitations in an underwater environment make it more difficult to develop a control architecture for an AUV. In this article, the four types of control architectures being used for AUVs (hierarchical, heterarchical, subsumption, and hybrid architecture) are reviewed. A summary of 25 existing AUVs and a review of 11 AUV control architecture systems present a flavor of the state of the art in AUV technology. A new sensor-based embedded AUV control system architecture is also described and its implementation is discussed.

A docking system for REMUS, an autonomous underwater vehicle

Abstract: The future of autonomous underwater vehicles (AUVs) lies in making them affordable and easy to use. Ease of use must encompass not just the man-machine interface to the vehicle, but also address the requirements for vehicle launch and recovery. As long as ships and crews must be mobilized for each AUV mission, their utility will be limited. Development of a docking capability will allow these vehicles to remain on station as part of an autonomous ocean sampling network. This paper describes the docking system developed for REMUS (Remote Environmental Monitoring UnitS), a low cost AUV designed by the Oceanographic Systems Laboratory at the Woods Hole Oceanographic Institution. The paper discusses the solutions developed for enabling the vehicle to acoustically find and then home on the docking system; mechanically latching the vehicle to the dock; electro-mechanical techniques for power and data transfer from the docking system to the vehicle; remote data download from the vehicle and mission upload to the vehicle; and in situ battery recharge without opening the vehicle housing. Results from successful tests of the system are discussed.

MARIUS: an autonomous underwater vehicle for coastal oceanography

Abstract: An autonomous underwater vehicle (AW), named MARIUS, has been developed under the MAST Programme of the Commission of the European Communities. The primary envisioned missions of the prototype AW are environmental surveying and oceanographic data acquisition in coastal waters. The authors describe the design and implementation of the AW systems for vehicle and mission control, and report the results of the sea trials conducted with the vehicle in Sines, Portugal.

Station keeping of an ROV using vision technology

Abstract: This paper will present the results of a demonstration of two degree-of-freedom automatic station keeping of a remotely operated vehicle (ROV) in an ocean environment using vision feedback. This work was done as a collaborative effort in vehicle control between the Aerospace Robotics Laboratory (ARL) and the Monterey Bay Aquarium Institute (MBARI). The results show how the transfer of technology from a testbed autonomous underwater vehicle (AUV) to an ocean-going ROV can be applied to the creation of pilot aids that reduce ROV pilot workload during certain tasks.

Autonomous underwater vehicle maps seafloor

Abstract: Autonomous underwater vehicles (AUVs)—which operate without a tether or human supervision—represent an emerging technology that can be used to solve many scientific problems in the deep ocean, the last unexplored frontier on Earth. AUVs are well suited to “lawn-mower” style geophysical surveys for mapping bathymetry, magnetic field, or water column properties. They are fast and efficient synoptic mappers and are inexpensive to operate. Manned submersibles and remotely operated vehicles (ROVs) allow intensive study of an area, but can remain at a site for only a few hours, days, or weeks. AUVs can remain in an area gathering data in between submersible and ROV visits to provide information on temporal variations and can respond rapidly to events such as volcanic eruptions when large oceanographic vessels and equipment cannot be mobilized quickly.

A simulation environment for the coordinated operation of multiple autonomous underwater vehicles

Abstract: A simulation environment of the coordinated operation of multiple Autonomous Underwater Vehicles (AUVs) is presented. The primary application of this simulation environment is the specification and analysis of an innovative approach to coastal oceanography based on the Generalized Vehicle [GV] concept. A Generalized Vehicle is a group of vehicles whose spatial and logic organization is coordinated in such a way that the group behaves as a single entity. The simulation environment was developed in Shift, a new specification language for describing dynamic networks of hybrid automata. These constitute the most adequate modeling formalism for this problem domain. The expressive power of Shift provides a compact notation for modeling spatial and logical relationships in a dynamic environment and for modeling and analyzing control strategies governing object interactions.

Development of autonomous underwater vehicle 'AQUA EXPLORER 2' for inspection of underwater cables

Abstract: A new autonomous underwater vehicle (AUV) named AQUA EXPLORER 2 (AE-2) has been developed. AE-2 can trace buried underwater cables and can measure their burial depth at a low operating cost. It can be controlled through a low-bit-rate acoustic link, and can send a video signal through another high-bit-rate acoustic link. Compared with its prototype AQUA EXPLORER 1000 (AE-1000), performance has been considerably improved due to an overall revamping of the mechanical and electrical design. The continuous operating period is now six times longer for a total of 24 hours at a velocity of one knot, while its dry weight has been reduced by half to 260 kilograms. The first long pool test and the first sea trial were successfully carried out.

Autosub-1. Implicatons of using distributed system architectures in AUV development

Abstract: Autonomous underwater vehicles (AUV) normally consist of a large number of subsystems such as navigation, mission control, propulsion, communications and data logging which need to be linked together to form a complete working system. The traditional approach has been to use point to point connections between these subsystems, or to use one large central computer which would take the data from all the vehicle sensors and send control signals out to all the actuators. Both of these approaches would entail the use of a large complex wiring looms. These are both difficult to modify and upgrade when additional sensors or subsystems need to be added and suffer from the increased likelihood of connector failure. This paper describes an alternative networked distributed architecture approach that has been used on the Autosub-1 AUV.

Human/robot interface and mission management in MAUVE, a multi-purpose autonomous underwater vehicle

Abstract: The overall objective of the MAUVE project is to develop and test a mobile and autonomous instrumented underwater vehicle, dedicated to multipurpose survey. One of the main points of this project is the implementation of the navigation and mission management systems. This paper describes the principal results achieved so far in the design of human/autonomous underwater vehicle interactions in the specification phase of the robot mission.

From autonomous underwater vehicles (AUVs) to supervised underwater vehicles (SUVs)

Abstract: The past fifteen years have seen the development of a new family of unmanned underwater vehicles without umbilical. Initially, those vehicles were operated in the direct vicinity of the mother-ship. With the increase in range and reliability, users are now willing to operate without support vessels. This creates new challenges as traditional equipment cannot cope with the constraints attached to these new missions. After describing the new requirements in terms of underwater navigation and communication, the authors explain how LEGS (low Earth orbital satellites) and wideband underwater acoustics transmissions can offer new perspectives to accurately locate the vehicles and control them from an Earth based remote station, giving them the supervision capability. During the 1995-96 period, a complete prototype was developed including 4 surface relay GIB (GPS Intelligent Buoys), a local radio network, a remote control station and the vehicle electronics. Results from sea trials performed in 1996-97, in water depth varying from 10 to 300 meters, are presented and discussed. The perspectives and future developments are also described.

Remote monitoring and control of autonomous underwater vehicles

Abstract: Oceanographic data gathering techniques are moving away from simple sensors completely under the control of the user, towards smart systems such as autonomous underwater vehicles (AUVs) that are capable of operating without user intervention. However, artiicial intelligence cannot yet match human intelligence, and the ability to remotely monitor and control these otherwise autonomous systems throughout the data collection process is highly desirable. Communications links to these underwater systems via acoustic modems and the Internet are becoming increasingly viable. This thesis investigates the problems arising from combining these developing technologies for oceanographic data-gathering purposes. Towards the goal of remotely monitoring and controlling an AUV during a mission, this thesis explores various methods of vehicle control, mission reconnguration, data transmission , data robustness, interconnectivity with the Internet, and communication with and between multiple AUVs. We have run tests using laboratory simulation and over 25 eld experiments in the Charles River and Buzzard's Bay with MIT Sea Grant's Odyssey II AUV, using a pair of radio modems to simulate the acoustic link. Our primary research accomplishment has been to demonstrate control of the Odyssey II during a Charles River mission from a workstation located on the Internet back at the MIT Sea Grant computer laboratory. Acknowledgments The author would like to thank the following people without whom this thesis would not have been possible. Mom and Dad for supporting my decision to go into engineering, even though they wanted me to go into medicine. Chrys Chryssostomidis for heading and directing the MIT Sea Grant Laboratory where this research took place. James Bellingham, for founding the MIT Sea Grant AUV Lab, and spearheading the development of the Odyssey II class AUV. Seamus Tuohy for his assistance with multicasting protocols on the Internet. Thomas Consi for introducing me to MIT Sea Grant. Bradley Moran for his programming assistance with the software produced in this research. James Bales and Cliiord Goudey for a thorough introduction to the Odyssey II AUV, and assistance with hardware used in this research. Robert Grieve and Joe Ziehler for their invaluable help producing, xing, and operating the equipment used in this research. for their assistance during eld operations and presence as friends. Zengotita for keeping the organization running. And John Leonard for all the reasons outlined above, but most importantly for his guidance and steadfast support throughout the course of my research and writing.