A second generation survey AUV

Mueller

J. Am. Soc. Mass Spectrom.

2008

Two mass spectrometers (MS) are tested for the measurement of volatile substances, such as hydrocarbons and metabolic gases, in natural waters. KOALA is a backpackable MS operated from above the water surface, in which samples are pumped through a flow cell using a syringe. NEREUS is an underwater instrument hosted by an autonomous underwater vehicle (AUV) that is linked to a communications network to provide chemical data in real time. The mass analyzers of the two MS are nearly identical cycloids, and both use flat-plate membrane inlets. Testing took place in an eutrophic, thermally stratified lake exhibiting steep chemical gradients and significant levels of methane. KOALA provided rapid multispecies analysis of dissolved gases, with a detection limit for methane of 0.1 ppm (readily extendable to 0.01 ppm) and savings of time of at least a factor of 10 compared to that of conventional analysis. The AUV-mounted NEREUS additionally provided rapid spatial coverage and the capability of performing chemical surveys autonomously. Tests demonstrated the need for temperature control of a membrane inlet when steep thermal gradients are present in a water body, as well as the benefits of co-locating all sensors on the AUV to avoid interference from chemically different waters entering and draining from the free-flooding outer hull. The ability to measure dissolved volatiles provided by MS offers potential for complementarity with ionic sensors in the study of natural waters, such as in the case of the carbonate system. (J Am Soc Mass

Section: Autonomous Underwater Vehicle (Auv)mentioning

confidence: 99%

Field testing of lake water chemistry with a portable and an AUV-based mass spectrometer

Mueller

J. Am. Soc. Mass Spectrom.

2008

“…a hole in the ice. Bellingham et al (1994) reports an example of this application, where the vehicle typically returned to within 30 cm of the homing transponder. Note that both LBL and USBL navigation systems only provide a relative navigation reference.…”

Section: Navigation 331 Acoustic Navigationmentioning

confidence: 99%

Using Autonomous Underwater Vehicles as Sensor Platforms for Ice-Monitoring

Norgren¹,

Skjetne

2014

MIC

Due to the receding sea-ice extent in the Arctic, and the potentially large undiscovered petroleum resources present north of the Arctic circle, offshore activities in ice-infested waters are increasing. Due to the presence of drifting sea-ice and icebergs, ice management (IM) becomes an important part of the offshore operation, and an important part of an IM system is the ability to reliably monitor the ice conditions. An autonomous underwater vehicle (AUV) has a unique capability of high underwater spatial and temporal coverage, making it suitable for monitoring applications. Since the first Arctic AUV deployment in 1972, AUV technology has matured and has been used in complex under-ice operations. This paper motivates the use of AUVs as an ice-monitoring sensor platform. It discusses relevant sensor capabilities and challenges related to communication and navigation. This paper also presents experiences from a field campaign that took place in Ny-Ålesund at Svalbard in January 2014, where a REMUS 100 AUV was used for sea-floor mapping and collection of oceanographic parameters. Based on this, we discuss the experiences related to using AUVs for ice-monitoring. We conclude that AUVs are highly applicable for ice-monitoring, but further research is needed.

The International Journal of Robotics Research

“…Optical guidance systems, which give precise resolution at very short distances, have been used for the AUV's close-range homing and docking abilities [Cowen et al, 1997, Park et al, 2007, Bellingham et al, 1994. Alternatively, long baseline and ultra-short baseline acoustic beacons have also been used for docking [Singh et al, 1997].…”

Section: Related Workmentioning

confidence: 99%

Experiments with Cooperative Control of Underwater Robots

Dunbabin

Corke

Vasilescu

et al. 2009

In this paper we describe cooperative control algorithms for robots and sensor nodes in an underwater environment. Cooperative navigation is defined as the ability of a coupled system of autonomous robots to pool their resources to achieve long-distance navigation and a larger controllability space. Other types of useful cooperation in underwater environments include: exchange of information such as data download and retasking; cooperative localization and tracking; and physical connection (docking) for tasks such as deployment of underwater sensor networks, collection of nodes, and rescue of damaged robots. We present experimental results obtained with an underwater system that consists of two very different robots and a number of sensor network modules. We present the hardware and software architecture of this underwater system. We then describe various interactions between the robots and sensor nodes and between the two robots, including cooperative navigation. Finally, we describe our experiments with this underwater system and present data.