From: Bellingham, James
Sent: Tuesday, February 11, 2003 17:10
To: Sibenac, Mark
Subject: RE: [dockers] Kick-Off Meeting Notes

Hi Mark,

Nice meeting.  Off to a good start.

My comment: "We need to assess the cost of losing a vehicle. That may drive the maximum cost per AUV."

Was actually: "We need to set a target for percentage success at docking."

This would indeed influence vehicle cost, because it would set a loss rate.  It also begs the question of MTTF for the AUV as a whole (i.e. one can lose a vehicle for other reasons than docking).

So, lets say our mission time is T and our MTTF for the AUV is tf.  Then probability of loosing a vehicle in time t goes as  f(t) = (1/tf) exp(-t/tf).  The probability of loosing a vehicle in N missions of time T is:

Integral(f(t), (t, 0, NT))

If the probability of a failed docking event is fd, then the equivalent computation of the probability of loosing the vehicle in N missions is:

1 - (1-fd)^N

Presumably one would design to have these two reliabilities about the same....  I think the math is right, but it has been a little while since I did these sorts of calculations.

-Jim   

________________________________________________
James G. Bellingham, Ph.D.
Director of Engineering 
Monterey Bay Aquarium Research Institute
7700 Sandholdt Road, Moss Landing, CA 95039-9644
Phone 831-775-1731     FAX: 831-775-1646     http://www.mbari.org/


> -----Original Message-----
> From: Sibenac, Mark [mailto:sib@mbari.org]
> Sent: Tuesday, February 11, 2003 4:14 PM
> To: AUV Docking Discussion List
> Cc: Ryan, John
> Subject: [dockers] Kick-Off Meeting Notes
> 
> 
> AUV Docking Meeting Notes from 11 February 2003
> 
> People Present: Mark Sibenac, Ed Mellenger, Tarun Podder, Rob 
> McEwen, Farley Shane, Andy Hamilton, Hans Thomas, Bill 
> Kirkwood, Keith Raybould, Jim Bellingham, Rich Henthorn, John 
> Ryan, Mike Parker
> 
> The powerpoint presentation can be found at 
> \\Polarbear\docking\Meetings\AUV-Docking-Kick-Off-2003-02-11.p
> pt  These meeting notes and all future ones can be found in 
> this directory \\Polarbear\docking\Meetings
> 
> Here are some comments made during the meeting:
> 
> Keith-	There is no longer a subsurface float on the 
> MOOS Mooring.
> Bill-	The concepts of operation should play a key role in 
> determining the functional requirements.
> Sib-	Bill put together a nice set of Concepts of Operation. 
> The link is here 
> \\Polarbear\docking\Docking_Documents\MOOSDocking.ConOps.revE.doc 
> Jim-	Don't involve the AUVUC until June during the 
> functional requirements review.
> Jim-	An external web page is important so outside institutes 
> and collaborators can see what we are doing.
> Bill-	When we set up the web page, dedicate a webmaster to 
> maintain it.
> Sib-	I want to store all project documents on the polarbear 
> file server, and not create an internal web page. The Samba 
> share is \\Polarbear\docking\
> Bill-	The dock should accommodate other AUVs besides ours; 
> i.e. REMUS, ABE, and ABE II should be able to dock.
> Sib-	The requirement so far reads "Shall be capable of 
> capturing and releasing non-hovering, survey class AUV(s)." 
> That means there is no requirement for a hover capability on 
> the AUV. It does not limit the dock to only MBARI vehicles.
> Tarun-	Eurodocker is being commercialized by an 
> Italian company.
> Ed-	If there is a concept of shuttling power between a 
> mooring/cabled dock and a RIN/BIN, make the power requirement 
> to go both ways on the dock.
> Ed-	The OASIS moorings are swapped once a year. The MOOS 
> mooring is designed for a 3 year life span at sea, with once 
> a year servicing visits to clean barnacles and biofouling.
> Jim-	We need to assess the cost of losing a vehicle. That 
> may drive the maximum cost per AUV.
> Keith-	Will there be regularly scheduled meetings? 
> Sib's reply was that the general meetings will take place 
> every 2-3 weeks until June when the project really ramps up. 
> Then the meetings will occur weekly.
> 
> 
> ----------------------------------------------------------------
> 
> Original announcement:
> AUV Docking Kick-Off Meeting
> 11 February 2003
> Surface Commons
> 10:00 - 11:00
> 
> Formal Invitations to: John Ryan, Keith Raybould, Mark 
> Chaffey, Jim Bellingham, Bill Kirkwood, Hans Thomas, Tarun 
> Podder, Farley Shane, Andy Hamilton, Rob McEwen, Rich 
> Henthorn, and Ed Mellenger
> 
> Informal Invitations to: the rest of the MBARI community
> 
> The purpose of the meeting is to kick-off MBARI project# 
> 900393, AUV Docking, which is a sub-system of the MOOS 
> project. At the meeting, I will be presenting a list of 
> people involved with the project, some concepts of operation, 
> a rough schedule of milestones, budget information, and the 
> work breakdown structure for this year.
> 
> 
>