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Re: [PSUBS-MAILIST] Minn Kota - Thrust
On Sat, 11 Mar 2000 19:47:57 PST, "Paul Suds" <paul_suds@hotmail.com>
wrote:
> Jon, I really like your AUV design. You have a real talent for graphic
> design.
Thanks... I suck as an artist, but I can lay stuff out in 3-space like
there's no tomorrow :-)
> I would however, rethink your speed sensor. I designed air flow
> sensing in the past for air samplers. Hall Effect sensors such as Alegro"s
> are easy to use and design stuff with, and they are good from a purely
> digital perspective. Unfortunately, if this unit was operating in areas of
> variable current, your location mapping would be in error.
Yeah, I know. The speed sensor is one input into the state of the system,
and it will have some error percentage included with it. The AUV will also
(eventually) have input from other techiques, like the ones you mentioned,
and other methods such as periodically surfacing to take GPS readings.
Dead reckoning is a technique that can have large errors from any number of
inputs, and that has to be factored into the overall control software. Of
course, using several methods, including the GPS, allows the system to
figure out (more or less) exactly what the error is, and it will hopefully
be able to figure out from that what portion of the error is due to current
in the particular area that it is operating in, and thus can factor that
into future dead-reckoning calculations.
This particular AUV I am designing (and am about to start building) is
purely a research platform, to test sensors and control software and
hardware. It will most likely only be run in swimming pools and lakes,
although of course how far it goes (like ocean testing) depends a great
deal on how well it ends up working...
> If you have
> already broached the sonar and ultrasonics detection for depth and collision
> avoidance, you may want to also incorporate this knowledge of yours into
> determining speed as well.
Yeah, when I get sonar working and in the design, that will be another
variable added to the whole speed equation.
> Again, I love your designs and concepts. Keep up the good work.
Thanks, I've worked pretty hard on the design, and hopefully I'll be far
enought along with the construction by the end of the summer to start
wet-testing it by then.
Later,
Jon
--------------------------------------------------------------
Jon Hylands Jon@huv.com http://www.huv.com/jon
Project: Micro Seeker (Micro Autonomous Underwater Vehicle)
http://www.huv.com