Showing papers on "iRobot Seaglider published in 2016"

A Compact Autonomous Underwater Vehicle With Cephalopod-Inspired Propulsion

Abstract: In this paper, a bioinspired, compact, cost-effective autonomous underwater vehicle system is presented. Designed to operate in a heterogeneous, multivehicle collaboration hierarchy, the presented vehicle design features 3D printing technology to enable fast fabrication with a complex internal structure. Similar to a previous vehicle prototype, this system generates propulsive forces by expelling unsteady, pulsed jets, inspired by the locomotion of cephalopods and jellyfish. The novel thrusters enable the vehicle to be fully actuated in horizontal plane motions, without sacrificing the low-forward-drag, slender vehicle profile. By successively ingesting water and expelling finite water jets, periodic actuation forces are generated at all possible vehicle velocities, eliminating the need for control surfaces used in many conventional underwater vehicle designs. A semiactive buoyancy control system, inspired by the nautilus, adjusts the vehicle depth by passively allowing water flowing into and actively expelling water out of an internal bladder. A compact embedded system is developed to achieve the control and sensing capabilities necessary for multiagent interactions with the minimum required processing power and at a low energy cost. The new vehicle design also showcases an underwater optical communication system for short-range, high-speed data transmission, supplementing the conventional acoustic communication system. Experimental results show that, with the thruster motors powered at a 60% duty-cycle, the new vehicle is able to achieve a 1/4 zero-radius turn in 3.5 s and one-body-width sway translation in 2.5 s.

Seaglider surveys at Ocean Station Papa: Circulation and water mass properties in a meander of the North Pacific Current

Abstract: A Seaglider autonomous underwater vehicle augmented the Ocean Station Papa (OSP; 50°N, 145°W) surface mooring, measuring spatial structure on scales relevant to the monthly evolution of the moored time series. During each of three missions from June 2008-January 2010, a Seaglider made biweekly 50 km × 50 km surveys in a bowtie-shaped survey track. Horizontal temperature and salinity gradients measured by these surveys were an order of magnitude stronger than climatological values and sometimes of opposite sign. Geostrophically-inferred circulation was corroborated by moored acoustic Doppler current profiler measurements and AVISO satellite altimetry estimates of surface currents, confirming that glider surveys accurately resolved monthly-scale mesoscale spatial structure. In contrast to climatological North Pacific Current circulation, upper ocean flow was modestly northward during the first half of the 18 month survey period, and weakly westward during its latter half, with Rossby number (0.01). This change in circulation coincided with a shift from cool and fresh to warm, saline, oxygen-rich water in the upper-ocean halocline, and an increase in vertical finestructure there and in the lower pycnocline. The anomalous flow and abrupt water mass transition were due to the slow growth of an anticyclonic meander within the North Pacific Current with radius comparable to the scale of the survey pattern, originating to the southeast of OSP. This article is protected by copyright. All rights reserved.

RRS James Cook Cruise 124-125-126 09 Aug-12 Sep 2016. CODEMAP2015: Habitat mapping and ROV vibrocorer trials around Whittard Canyon and Haig Fras

Abstract: The main aim of JC125 was to carry out habitat mapping work in the Whittard Canyon, NE Atlantic, in order to obtain a better insight in the biodiversity patterns, benthic habitat distributions and sediment transport processes of submarine canyons. At the same time, the objective was also to test a number of novel habitat mapping techniques, including sideways multibeam mapping of steep and overhanging cliffs using the Autosub6000 AUV (Autonomous Underwater Vehicle), which was specifically adapted for this task. The four-week expedition was the second cruise of the CODEMAP project (COmplex Deep-sea Ecosystems: Mapping habitat heterogeneity As Proxy for biodiversity), funded by the European Research Council (Grant No 258482). Two short ‘tag-on’ cruises were added to this main expedition: JC124 covered four days of seabed monitoring in the Haig Fras and Canyons Marine Conservation Zones as part of the DEFRA-funded project “Novel AUV and Glider deployments to inform future MPA and MSFD monitoring strategy in UK shelf waters?”. JC126 consisted of three days of ROV vibrocorer trials for the NERC-funded technology grant NERC Grant NE/0176581. Together, the five-week voyage was nick-named ‘CODEMAP2015’. To achieve its goals, CODEMAP2015 made extensive use of deep-water marine robotics: in a first for UK science, the Autosub6000 AUV, the Isis ROV (Remotely Operated Vehicle) and a Seaglider provided by the University of East Anglia were operating in the canyon, simultaneously, deployed from the RRS James Cook. They provided an unprecedented insight in the structure and processes of the submarine canyon. The nested survey design that was adopted throughout the cruise combined canyon-wide shipboard and glider surveys with AUV-based acoustics and ROV-based multibeam and HD video recordings. This enabled the integrated observation of different canyon processes at the scale they occur, ranging from 10s of km to a few mm.

FeelHippo: A low-cost autonomous underwater vehicle for subsea monitoring and inspection

Abstract: The paper describes the development and the main characteristics of a low-cost Unmanned Underwater Vehicles (UUV) built by the Mechatronics and Dynamic Modelling Laboratory (MDM Lab) of the University of Florence. This vehicle is named FeelHippo, and it is an Autonomous Underwater Vehicle (AUV) purposely developed to participate to the 2013 edition of the Student Autonomous Underwater Vehicle Challenge-Europe (SAUC-e, http://sauc-europe.org/) organized by the NATO-STO Centre for Maritime Research and Experimentation (CMRE), La Spezia, Italy. SAUC-e 2013 has been a good test field for the preliminary testing of the AUV capabilities and FeelHippo ranked third in the competition. In the paper some experimental results related to the development of a low-cost vehicle localization system, suitable inside an environment a priori known, are given and discussed.

Autonomous ship hull inspection by omnidirectional path and view

Abstract: We discovered the problems in ship hull inspection operation and build our autonomous underwater vehicle (AUV). The Autonomous Underwater Vehicles will be developed at Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia with the aim of making a research platform in the field of autonomous underwater robotic systems. We studied the omnidirectional movement can go through in every direction. In our autonomous underwater vehicle, we build in omnidirectional application so that during the ship hull inspection the robot can reduce disturbance for viewing. There have three main parts to make it the autonomous underwater vehicle are reliable in real world task which are mechanical, electronic system and software.

Mechanical Design of a Trawl-Resistant Self-Mooring Autonomous Underwater Vehicle

Abstract: The Virginia Tech Trawl-Resistant Self-Mooring Autonomous Underwater Vehicle (TRSMAUV) is designed to reside on the seafloor for extended periods of time. The TRSMAUV shape allows for deployment in areas where trawl fisheries are conducted. TRSMAUV is a two stage vehicle. The ingress vehicle is the delivery device, and it is constructed from two symmetric halves. The top half contains the ingress vehicle propulsion system and control surfaces. The bottom half is the trawl-resistant mooring package. A smaller vehicle, the egress vehicle, is housed within the bottom ingress half and provides the guidance, navigation and control algorithms for the TRSMAUV. This report covers the general design elements of the TRSMAUV, the detail design of several prototypes, the results of the field trials, and the next steps that will be taken to build the final vehicle.

Simultaneous recordings of marine mammal calls by a glider, float, and cabled hydrophone array

Abstract: Recent advances in passive acoustic monitoring (PAM) technologies have led to development of mobile autonomous platforms for recording marine mammals. These instruments may allow greater spatial and temporal sampling than traditional towed or bottom moored systems. However, comparison of recording abilities of these instruments to traditional methods has yet to be performed. We deployed two types of commercially available platforms at the Southern California Offshore Range (SCORE) complex in late December 2015 through early January 2016. The QUEphone, based on the APEX float (Teledyne Webb Research, Falmouth, MA, USA), is a buoyancy driven device capable of descending to 2000 m where it drifts horizontally with the currents. The Seaglider (Kongsberg Underwater Technology, Lynwood, WA, USA) is also buoyancy driven, but dives repeatedly up to 1000 m following a flight path controlled via satellite. We deployed one glider and two floats, each equipped with identical acoustic sensors developed by Oregon State...