AUVAC

SUB-ICE EXPLORATION OF AN ANTARCTIC LAKE: RESULTS FROM THE ENDURANCE PROJECT

Abstract

The ENDURANCE autonomous underwater vehicle was developed and deployed to explore and map a unique environment: the waters of Lake Bonney in Taylor Valley, one of the McMurdo Dry Valleys of Antarctica. This permanently ice-covered lake presented several unique challenges and opportunities for exploration and mapping with an AUV. ENDURANCE was successfully deployed in the west lobe of Lake Bonney in the 2008-2009 and 2009-2010 austral summer seasons, completing the rst full synoptic 3-D chemical prole and high-resolution 3-D geometric mapping of such a body of water. ENDURANCE successfully traversed the entire 1 km x 2 km lobe of the lake, including successful automated spooling of a science payload and automated docking into a deployment/recovery melt hole 0.25 m larger in diameter than the vehicle.

Feature Based Navigation for a Platform Inspection AUV

Under the Offshore Platform Inspection System (OPIS) program, an LM AUV, the MARLIN(TM), is being outfitted with a mission package which includes a 3D imaging sonar and processors in order to inspect and build 3D models of subsea structures, and to detect large scale damage to these structures relative to a reference model. A key component of this model building and change detection functionality is a process by which sonar data is aligned to the reference model and the vehicle/sensor pose is recovered. An interesting by-product of this is the use of this recovered pose for feature based navigation. This paper presents a method to fuse the estimated pose from an inertial navigation system with the pose recovered from the alignment of sonar data with a reference model, and the use of this fused estimate in vehicle guidance, 3D model building and change detection, and to improve inertial navigation performance. While the technology is developed for an underwater platform inspection system, the methods have broader applicability. Results are presented to demonstrate the performance of the feature-based navigation system.

From High Technology to Solutions: The Experience of iXSea

In any business school in the world, you will learn that there are just two ways to develop and lead a company: a manager must choose between being “techno-driven” or “market-driven”. However, all previous success stories demonstrate that the reality is far removed from this highly theoretical vision: in most cases, successful development results from an overlap between an idea and a need. This means that in practice the main issue for a manager is to invent new concepts while getting a feel for market orientation and trying to reach the best decision as to ‘when and how’ the company can bridge the two.

In 2000, IXSea focused on a single goal: ensuring that it was capable of providing the right technical solutions ocean exploration would be looking for throughout the coming century.

Why this choice?

There can be no doubt that one of the challenges of the 21st century will be to become the masters of the largest part of our planet – its oceans – and it is also obvious that at present we have no idea of the means we will employ to accomplish that. However, what is absolutely certain is that all those involved in this challenge, scientists, oil and gas industries, naval forces, etc… have their eyes on the same goals: deeper, faster and easier!

For example, in just five years iXSea brought fiber optic gyro technology to unmanned underwater vehicles, designed USBL plug-and-play systems, democratized Synthetic Aperture Sonar and invented real-time magnetic imaging. We saw here a need for interdependence between wide-ranging R&D in optoelectronics, acoustics, signal processing and NMR, of which we had complete mastery in our research labs, and easy-to-use solutions for the most demanding applications.

The main purpose of the present paper is to look again at some of our technologies, and see how they could solve some of the most challenging underwater problems of the early 2000s, and also to describe the solutions on which iXSea is working in order to meet the latest challenges in positioning and imagery.

Key Words: Fiber Optic Gyro

Abstract 

The HUGIN II untethered underwater vehicle (UUV) provides detailed seabed survey services to the offshore industry on a commercial basis. This paper discusses the resulting depth accuracy of the digital terrain model (DTM) that can
be achieved with an UUV using standard commercially available multibeam echosounders, navigation sensors, pressure transmitters, CTD sensors, sound velocity sensors and international standards for computation of salinity and density.
The results are also applicable for remotely operated vehicles (ROV) and towed fish.