RE: [PSUBS-MAILIST] Joysticks

["Atul Patel" <apatel@elt-inc.com>]

I'm all for KISS and I'm trying my best to do that and meet my
objectives.  Maybe there is a way to do what I need using hydraulics...
any recommended reading or guidelines? 

I'm planning on having a pc in the sub for seafloor graphing and so I
have it available for use for other activities.  

The primary reason for going fly-by-wire is that I'm exploring different
flight profiles and controls.  For example, when traveling to and from
target location I'd like to use the controls in normal flight mode.
Once on target, I'd like to be able to change to "hover" mode for
observation purposes.  I'd also like to build in corectional capabilites
into the flight system to account for current.

Through the use of the pc, I can log my control commands and log actual
flight performance(command,reaction,time,power draw,etc) for analysis
later.  

I'd also like to be able to control and monitor as many of the onboard
systems as possible through the use of as few controls and feedback
interfaces as possible.  

Having a fly-by-wire provides some interesting benefits as well as
risks.  The FCS can disregard "unsafe" commands for example, pitching
down while near operating depth limit.  This system would also give me a
foundation for adding  other control systems to the sub such as a
grappler arm or two.

I know this sounds like a lot of work and expensive, but what can I say,
I'm passionate about learning and solving problems and I come from a
software background :)

Thanks for all the comments.  Question. Has anyone else in the group
built a fly-by-wire system?

(By the way, I'm still planning on having manual controls for everything
-- I'm not about to trust Windows with my life :) )

-----Original Message-----
From: Dan H. [mailto:machine@epix.net]
Sent: Thursday, November 22, 2001 5:53 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Joysticks


Didn't this joystick topic get started with trying to control hydraulics
with a joystick?
If your trying to control two functions, each in two directions, with a
typical joystick, why even get involved with a pc of any kind?  Sure you
can probably waterproof the electronics, but do you even need
electronics?
Remember K I S S!  Keep It Simple Stupid!!!!  Especially in a PSUB.  The
more complicated it is, the more there is to turn a fun thing into a
disaster. Why not just use straight hydraulics?

Dan H.

Bjorn Johnsson wrote:

> Here is a watertight and flexible keyboard
> http://www.ece.utexas.edu/~sooter/blake.html
>
> --- Lew Clayman <lew_clayman@yahoo.com> wrote:
> > --- Paul B <paul_victor@hotmail.com> wrote:
> > > I'm afraid a watertight laptop would cost too much, if it is
> > possible at
> > > all. You have over 80 keys on the keyboard to make watertight.
> > And then you
> > > have your com ports, lpt port, usb, pc card adapter and so on..
> > >
> > > And it's hard to make a waterproof case for it, because if
> > there's not
> > > enough air to cool it down, it may overheat, lock up and there
> > goes your sub
> > > control..
> >
> > It's certainly possible, if perhaps fiduciarily challenging...
> > there are
> > mil-spec computers and machines made for nasty industrial
> > locations.
> > Waterproofing the keyboard is pretty easy, you use a continous
> > plastic
> > membrane: the action on the keys is pretty poor, but it works, as
> > do the
> > even-lousier pressure-membrane keyboards, cheap variants on which
> > are used on
> > kiddie toys (may you never be so afflicted).  Waterproofing the
> > ports is no
> > harder than waterproofing anything else that opens, you have a
> > fitted cover
> > with a rubber seal.  I'm not sure how they handle heat dissipation,
> > but I'm
> > guessing conduction, not convection.  Can't be that hard.
> >
> > Another "solution" is to use old, cheap, used machines.  They might
> > fail, but
> > who cares?  This of course only works if you have a manual control
> > system that
> > doesn't need the computer, or in some other use where the computer
> > is
> > inessential.
> >
> > > If I had to make the whole thing safe from electric shock, I
> > would take a
> > > laptop with external battery and make something like a watertight
> > emergency
> > > power off switch on the external battery itself. Maybe some sort
> > of
> > > automatic relay, activated by water?
> >
> > This should work, too.
> >
> > -L
> >
> > =====
> > "It's never happened in the World Series competition, and it still
> > hasn't."
> >              - Yogi Berra
> > =====
> >
> > __________________________________________________
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