October 2004

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Inside this Issue


Welcome to our 2nd Edition, Lee Lynd
"Hooked on Earth Systems," Christopher Yang, Former Link Fellowship Recipient
"From the Chair of the Board," David M. Gouldin
Donor Listing
News Updates

Energy (2004-2006)
Simulation and Training (2004-2005)
Ocean Engineering (2004-2005)
James Kinsey

Department of Mechanical Engineering. The Johns Hopkins University
Louis L. Whitcomb, Dept of Mech. Eng.
Contact: jkinsey@jhu.edu
Title: Improved Navigation Techniques for Deep Oceanographic Submersibles

We are presently unable to navigate deep oceanographic submersibles with the precision necessary to fully exploit the quantitative data from high-resolution oceanographic sensors such as bathymetric sonars, cameras, and gravimeters. This limits the accuracy, resolution, and repeatability of the quantitative scientific data obtained with these vehicles. My research with the Link Foundation focuses on developing techniques to improve the navigation precision of deep oceanographic submersibles. Of particular interest is the utilization of novel sensors such as Doppler sonars and inertial measurement units, and the implementation of techniques that utilize our knowledge of the vehicle’s non-linear dynamics. My methodology is to (i) develop mathematically concise state estimation algorithms; (ii) validate these algorithms in actual oceanographic deployments; and (iii) make these tools available for use by the oceanographic research community.

I received a Bachelor’s degree in mechanical engineering from the State University of New York at Stony Brook and a Master’s degree in mechanical engineering from the Johns Hopkins University, where I am currently pursing my PhD in mechanical engineering. Prior to graduate school, I worked as an automation engineer at the Center for Thermal Spray Research and as a design engineer in industry. In graduate school I’ve participated in the development and sea trials of a navigation program currently used on over half a dozen oceanographic submersibles and overseen the development of a facility for hydrodynamics research.

Stephen Licht

Department of Ocean Engineering, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution

Investigation of the Maneuvering and Hovering Capabilities of a Flapping Foil Propelled Autonomous Underwater Vehicle

The oceanographic community uses unmanned underwater vehicles, both remotely operated and autonomous, to reduce the cost and the risk of basic ocean research. In particular, autonomous robots are now being use as platforms for extended operations that would be prohibitively expensive with manned or piloted vehicles.

Existing AUVs are optimized primarily for high cruising efficiency, leaving them uncontrollable at low speeds and unable to rapidly generate or respond to maneuvering forces. They are unsuited for use in confined spaces and in unsteady flow and, as a result, fundamentally interesting volumes of the ocean remain inaccessible to this cutting-edge, cost-effective technology.

The goal of my research is to investigate the maneuvering and hovering capabilities of an AUV using a specific biomimetic propulsor known as a flapping foil. If successful, this new vehicle may bring us a step closer to closing the gap the between the current state of the art in underwater vehicles and the extraordinary capabilities of the oceans current inhabitants.

Jonathan Pompa

Applied Ocean Science, Scripps Institution of Oceanography
Robert Pinkel
Contact: jpompa@ucsd.edu
Title: Wire Walker Drifting Profiler

Profiles of oceanographic data are important because processes in the ocean occur in a vertically stratified environment. Oceanographic instruments, therefore, must either span vertical distance or be moved through a vertical range, taking samples along the way. Sometimes economics allow multiple instruments to be hung on a single wire to make an array, but this introduces a question of calibration error. A fast and reliable profiling system allows better resolution in depth, simplifies calibration, and saves instrument costs.

I am currently developing a wave-powered, vertically profiling oceanographic instrument platform. This system, called a WireWalker, uses the motion of the surface waves to provide mechanical power to move the instruments through the upper ocean and electrical power for data collection and communications. This system will bring the cost of upper ocean profiling down significantly by eliminating the need for complex profiling hardware and shipboard deployments. Some potential uses include near-shore nutrient and biological monitoring and open ocean mixed layer observations.

At the completion of this project, I will have a system that will provide very low cost and simple profiling ability to scientists. This will be major change from the profiling systems now available and will facilitate experiments that have never before been operationally feasible. Several researchers around the country are already using WireWalkers with success during evaluation trials.