Normal Science meeting was usurped by discussion of progress on G3 development.

Doug led meeting with progress to date on design approach.

• Took a Systems Engineering approach, which focuses on the functions we are looking for.

 What do we currently know:

1. Volume of G2 components
2. G3 target and margins (considering a 2' extension to the LRAUV)

Right now, dry housing will hold 20 liters  (current surface can is ~200 liters)

3. G3 system design by function
--this is Doug's "design dependencies" slide
4.  Has 'cost' spreadsheet; helps predict leading costs--currently is Volume.  This model was run on G2 and came up with 171L, close to can's 210L)
5.  First run on G3 concept has run through the predictor.

Concepts developed

1.  Fictional G3;  this is the solidworks model everyone has
2.  Pizza slice idea

Refinement of Functional Requirements

Some things we still need to know:1.  What contextual sensors will be on the AUV?  CTD?  ISUS?

2.  LRAUV needs some 'payload' space in order to fly. (ADCP, compass).  How does that cut into 'our' space?

 Designs we have chosen to bring forward

1.  Linux/Ruby
2.  new CPU (Brent has chosen)
3.  Reuse Dwarf cards bu change CPLD to FPGA
4.  Will use power from vehicle, but they have not provided a power budget.
5.  Mechanical:  Must validate the extension of the AUV  (NOTE: contacted Jim Bellingham who suggested working with their hydrodynamic modeler.  Awaiting contact [3-22])
5. We are going with one pressure housing and a liquid barrier wall between ESP and drive compartment.

Cube/Filter testing

1.  We need a solid baseline to compare filter efficiencies.  Will begin with millipore water.  When we move to particulates, it will require much empirical work to define trade space and decide.

2.  Should also think of fractionation, as scientists will want to analyze many size fractions of filtrate.

re: cube/filter testing -- pure water should should be filtered to a standard spec (e.g. 0.1 or 0.2um) so we can get the most repeatable flow rates/bubble pt measurements as per industry standards for characterizing filters. For seawater samples, we should always include a standard lab bench equivalent (e.g., pressure driven or vacuum manifold) to compare both filtration efficiency and performance of downstream analyses.  With such standard procedures, we will be better placed to evaluate G3 filter/upstream processing with seawater that will vary depending on when/where it's collected. Posted by scholin at Mar 22, 2011 21:27