Showing papers on "iRobot Seaglider published in 2013"

Sound Silencing Problem of Underwater Vehicles

Abstract: This paper describes some common problems associated with negative influence of UUV self noise on detection aspect in water environment. Some tasks of military applications require silent behavior of UUVs: Intelligence, Surveillance, and Reconnaissance (ISR), Rapid Environmental Assessment (REA), Mine Countermeasure (MCM) etc. Moreover, this paper review methods of underwater sound measurement and on the end as a summary presents results of an experiment from the water tank trials where were investigated three UUVs: one ROV and two biomimetic autonomous underwater vehicle.

Low cost underwater gliders for littoral marine research

Abstract: Current off-the-shelf underwater gliders (UGs) are large, heavy, expensive, and difficult to modify, both in hardware and software, which limits their use for multivehicle coordination experiments and deployment in high risk environments. To address these challenges, the Nonlinear and Autonomous Systems Laboratory (NAS Lab) at Michigan Tech has designed two types of UGs for concept development, testing, and problem solving, and additionally, for scaffolding advanced interest and education in engineering. The first, a Glider for Underwater Presentation and Promoting Interest in Engineering (GUPPIE), nationally targets high school students and undergraduates to provide these students a UG platform for hands-on experience in concept development, testing, and problem solving. The second platform is a Glider for Autonomous Littoral Underwater Research (GALUR). At 10% of the cost of current models, the GALUR was designed to serve as a low cost multivehicle control testbed for disparate research groups who need to test and validate control algorithms. Still a highly-maneuverable UG, the GALUR allows researchers to address underwater communication issues by implementing control strategies for individual and multiple vehicle underwater data collection and mapping. Through the process of developing and testing these two UGs, the research team is ultimately working toward their long term goal of developing a fleet of low cost highly maneuverable underwater gliders. This paper details the challenges and milestones of the development process, and outlines the future research trajectory and goals.

Hydrographic observations of oxygen and related physical variables in the North Sea and western Ross Sea polynya : investigations using seagliders, historical observations and numerical modelling

Abstract: Shelf seas are one of the most ecologically and economically important ecosystems of the planet. Dissolved oxygen in particular is of critical importance to maintaining a healthy and stable biological community. This work investigates the physical, chemical and biological drivers of summer oxygen variability in the North Sea (Europe) and Ross Sea polynya (Antarctica). In particular, this work also focuses on the use of new autonomous underwater vehicles, Seagliders, for oceanographic observations of fine scale (a few metres) to basin-wide features (hundreds of kilometres). Two hydrographic surveys in 2010 and 2011 and an analysis of historical data dating back to 1902 revealed low dissolved oxygen in the bottom mixed layer of the central North Sea.We deployed a Seaglider in a region of known low oxygen during August 2011 to investigate the processes regulating supply and consumption of dissolved oxygen below the pycnocline. Historical data highlighted an increase in seasonal oxygen depletion and a warming over the past 20 years. Regions showing sub-saturation oxygen concentrations were identified in the central and northern North Sea post-1990 where previously no depletion was identified. Low dissolved oxygen was apparent in regions characterised by low advection, high stratification, elevated organic matter production from the spring bloom and a deep chlorophyll maximum. The constant consumption of oxygen for the remineralisation of the matter exported below the thermocline exceeded the supply from horizontal advection or vertical diffusion. The Seaglider identified cross-pycnocline mixing features responsible for reoxygenation of the bottom mixed layer not currently resolved by models of the North Sea. Using the data, we were also able to constrain the relative importance of different sources of organic matter leading to oxygen consumption. iii From November 2010 to February 2011, two Seagliders were deployed in the Ross polynya to observe the initiation and evolution of the spring bloom. Seagliders were a novel and effective tool to bypass the sampling difficulties caused by the presence of ice and the remoteness of the region, in particular they were able to obtain data in the polynya before access was possible by oceanographic vessels. Seagliders were able to survey the region at a fraction of the cost and inconvenience of traditional ship surveys and moorings. We present observations of a large phytoplankton bloom in the Ross Sea polynya, export of organic matter and related fluctuations in dissolved oxygen concentrations. The bloom was found to be widespread and unrelated to the presence of Ross Bank. Increased fluorescence was identified through the use of satellite ocean colour data and is likely related to the intrusion of modified circumpolar deep water. In parallel, changes in dissolved oxygen concentration are quantified and highlight the importance of a deep chlorophyll maximum as a driver of primary production in the Ross Sea polynya. Both the variability of the biological features and the inherent difficulties in observing these features using other means are highlighted by the analysis of Seaglider data. The Seaglider proved to be an excellent tool for monitoring shelf sea processes despite challenges to Seaglider deployments posed by the ice presence, high tidal velocities, shallow bathymetry and lack of accurate means of calibration. Data collected show great potential for improving biogeochemical models by providing means to obtain novel oceanographic observations along and across a range of scales.

Development of an Autonomous Underwater Vehicle ISiMI6000 for Deep-sea Observation

Abstract: Gyeong-Mok Lee, Jin-Yeong Park, Banghyun Kim, Hyuk Baek, Sungwoo Park, Hyungwon Shim, Go Choi, Bo-Ram Kim, Han-Goo Kang, Bong-Huan Jun, Pan-Mook Lee*, Phil-Yeob Lee and Hun-Sang Jeong Korea Institute of Ocean Science & Technology, KIOST 1312-32 Yuseong-daero, Yuseong-gu, Daejeon, Republic of Korea 2 R&D Center, Hanwha Corporation 52-1 Woisam-dong, Yuseong-gu, Daejeon, Republic of Korea [E-mail: pmlee@kiost.ac , powerman2@hanwha.co.kr\]

Underwater Glider: Its Applicability in the East/Japan Sea

Abstract: : The underwater glider is an autonomous vehicle that can glide through the ocean interior byusing a pair of wings attached to its body and can move up and down through the water column bychanging its buoyancy. As of now, there are three widely-used gliders, namely, the Spray that was co-developed by Scripps Oceanographic Institution and Woods Hole Oceanographic Institution, the Slocumproduced by the Webb Research Cooperation, and the Seaglider that was produced by the University ofWashington. In this paper, I will introduce these three gliders and discuss the principles and proceduresrelated to glider operation as well as the application and extendability of modern physical and bio-geochemical sensors to gliders. My experiences in developing a glider for measuring ocean turbulence andtesting it 7 times during 12 days are shared in this paper. On the basis of my experiences and knowledge,different kinds of aspects that should be considered for successful glider operation are discussed. Inaddition, a suggestion is made as to what would be the ideal way to operate underwater gliders in the East/Japan Sea. At the end, the current status of active glider operation teams is presented and the efforts toproceed toward future gliders are briefly introduced. Key words :underwater glider, Argo float, bio-geochemical sensor

Diver-based Control of a Tethered Unmanned Underwater Vehicle

Abstract: Human-robot communication with an underwater vehicle is a complex problem. Standard wireless communication protocols are unavailable, and the lack of direct supervision from surface-based operators reduces situational awareness and operational efficiencies. Here we describe recent research results with tethered operation of autonomous vehicles at depth by diving operators. We review different operational designs and describe a novel system based on exploiting advances in lightweight computational platforms (tablet devices) as the basis of the operator control console. Recent field experiments are also described.

The Improvements and Trends of the Unmanned Underwater Vehicles

Abstract: This paper Introduced the latest achievements of the unmanned underwater techniques, and illuminated the most classical UUVs in the world. Then the trends of the unmanned underwater techniques are analyzed, and the value of UUV in terms of the military applications is forecasted.

Deployment apparatus for a small unmanned underwater vehicle

Abstract: A swiveling arm (21) fastens on the side of a platform and swivels out over the edge of the platform. A suspension device (22) for an unmanned small submarine vessel (17) is held on the swiveling arm, which links on one side to the suspension device and on the other side to a fastening device (25) so as to swivel. The fastening device is designed to be supported on one side on a bulge (11) on the edge of a rubber/inflatable dinghy (10) and designed on the other side for fastening on a rubber/inflatable dinghy's boarded floor-insert.