Showing papers on "Intervention AUV published in 1995"

Autonomous Underwater Vehicle Navigation

Abstract: The development of autonomous underwater vehicles (AUVs) has finally reached the point that their use on commercial projects is now being seriously considered. Much of the research and development efforts to date have been funded primarily by military organizations to meet defense objectives. In this paper the authors examine the navigation problems and their potential solutions that will permit the reliable use of AUVs on commercial survey and inspection operations. These techniques include the global positioning system, inertial navigation systems, Doppler speed logs, bathymetry- aided navigation, acoustic measurements from chase ships, acoustic measurements from transponders (bread- crumb technique), and multiple cooperative AUVs. The current level of development for each of the approaches will be discussed and its future potential assessed. Finally, the authors’ development efforts and current level of implementation relating to the XP-21 AUV will be presented.

Mission Programming: Application to Underwater Robots

Abstract: In this paper, mission programming issues for autonomous vehicles with a gateway to teleoperation for online user intervention in dynamic environments are addressed. We define the various requirements of a generic and yet efficient mission programming method. The proposed solution can be integrated into various existing control architectures. To focus the presentation, special emphasis is place on the programming of a complex and generic mission executed by the Vortex underwater vehicle. Experimental results illustrate the “Find Target and Operate with Obstacle Avoidance” mission.

Pipeline inspection using an autonomous underwater vehicle

Abstract: Pipeline inspection can be carried out by means of small Autonomous Underwater Vehicles (AUVs), operating either with a control link to a surface vessel, or totally independently. The AUV offers an attractive alternative to conventional inspection methods where Remotely Operated Vehicles (ROVs) or paravanes are used. A flatfish type AUV ``MARTIN`` (Marine Tool for Inspection) has been developed for this purpose. The paper describes the proposed types of inspection jobs to be carried out by ``MARTIN``. The design and construction of the vessel, its hydrodynamic properties, its propulsion and control systems are discussed. The pipeline tracking and survey systems, as well as the launch and recovery systems are described.

Sensing the Position of a Remotely Operated Underwater Vehicle

Abstract: The importance of remotely operated underwater vehicles for construction, inspection, and maintenance of off-shore structures has been continuously increasing in the recent years. Especially oil prospecting in water depths inaccessible for human divers (>300m) needs unmanned vehicles. For a great variety of tasks a robust positioning control of the vehicle is required. This control is complicated not only due to nonlinearities involved in the system including the umbilical and parameter uncertainties [1,7] but also because of the lack of precise position information. The positioning problem can be split into two domains: the region far from the structure, where the navigation from the basis ship to the structure takes place and the region close to the structure, where the position of the vehicle relative to the structure must be kept for a task to be performed.

'theseus': a multipurpose canadian auv

Abstract: The article describes the development of an under-ice-capable autonomous underwater vehicle (AUV) for 3,000 foot, 250 nautical mile missions. The AUV is 35 feet in length and 50 inches in diameter. With a typical mission payload installed, it displaces just over 19,500 pounds, making it one of the largest AUVs in existence. The vehicle can be launched under a variety of conditions and is capable of being lowered through shore-fast ice into relatively shallow water. Since it will be able to operate in waters that may be completely ice covered, sources of input to the navigation system must be derived from sources either internal to the vehicle, available in the water column, or relative to the seafloor. At intervals during a mission, it is possible to augment this information with data delivered to the vehicle via an acoustic link from a waystation on the ice surface. For most of its mission, however, the AUV will navigate by dead-reckoning, using onboard, inertial navigation unit supported by velocity information from the doppler sonar.

Autonomous underwater vehicles for survey operations: theory and practice

Abstract: This paper provides an overview of some of the missions and vehicle control functionality being considered for the rapidly developing technology of autonomous underwater vehicles. Spawned from the availability of small embedded processors and the increasing capabilities of underwater communications, these small untethered vehicles are expected to play a role as a force multiplier in expanding our ability to survey ocean areas. Missions expected to become viable in the near future include environmental monitoring, underwater inspection, geological survey as well as the current focus on military missions in mine countermeasures. This paper gives an outline of the functionality required of such vehicles and their relation to intelligent control technology, some implementation details, and the future needs for research that continue to drive our field toward a practical reality.

The researching and designing of the recovering system for autonomous underwater vehicles

Abstract: This paper introduces the recovering system developed by us for the 1000-meter and 6000-meter untethered autonomous underwater vehicles(AUVs)which are two of the projects in the State High-tech863 Program. This recovering system can recover the underwater robots in a 4 grade sea condition withoutthe help of specific surface supporting vessels.Two different recovering schemes and recovering units arerepresented according to surface supporting vessel, sea status,AUV and other conditions.Results of sea tri-als show that this recovering system is effective and reliable.