Keeping a sub level

[Michael]

Hi,

Ok I have a r/c submarine and i need some form of electronic sensor to keep
it level. Onboard power is 7.2V.

Anyone any ideas?

Thanks

Michael

 

[Jasen Betts]

On 2005-10-22, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:

Hi,

Ok I have a r/c submarine and i need some form of electronic sensor to keep
it level. Onboard power is 7.2V.

mercury tilt switches are the traditional tool for detecting tilts.

but would it be possible to lower the centre of gravity enough that it
could be self-leveling?

Bye.
Jasen

 

[Michael]

"Jasen Betts" <jasen-b@free.net.nospam.nz> wrote in message
news:sv7r23-dnd.ln1@news.compass.net.nz...

On 2005-10-22, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:
Hi,

Ok I have a r/c submarine and i need some form of electronic sensor to
keep
it level. Onboard power is 7.2V.

mercury tilt switches are the traditional tool for detecting tilts.

but would it be possible to lower the centre of gravity enough that it
could be self-leveling?

Bye.
Jasen

The problem is that you have to alter the angle to dive. So if it was
self-levelling then it would never get under.

Michael

 

[Alexander]

"Michael" <miQchaelQhQims@Qblueyonder.co.uk> schreef in bericht
news:RYH6f.167541$RW.71651@fe2.news.blueyonder.co.uk...

"Jasen Betts" <jasen-b@free.net.nospam.nz> wrote in message
news:sv7r23-dnd.ln1@news.compass.net.nz...
On 2005-10-22, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:
Hi,

Ok I have a r/c submarine and i need some form of electronic sensor to
keep
it level. Onboard power is 7.2V.

mercury tilt switches are the traditional tool for detecting tilts.

but would it be possible to lower the centre of gravity enough that it
could be self-leveling?

Bye.
Jasen

The problem is that you have to alter the angle to dive. So if it was
self-levelling then it would never get under.

Michael

Have you tried gyros???

 

[John Fields]

On Sat, 22 Oct 2005 21:00:25 GMT, "Michael"
<miQchaelQhQims@Qblueyonder.co.uk> wrote:

Hi,

Ok I have a r/c submarine and i need some form of electronic sensor to keep
it level. Onboard power is 7.2V.

Anyone any ideas?

---
What you're looking for is called a 'clinometer'

Google for 'miniature electronic clinometer' and you'll get a lot of
hits.

Digi-Key has some at:

http://www.digikey.com/scripts/DkSearch/dksus.dll?Criteria?Ref=36230&Site=US&Cat=33490035

--
John Fields
Professional Circuit Designer

 

[Jasen Betts]

On 2005-10-23, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:

"Jasen Betts" <jasen-b@free.net.nospam.nz> wrote in message
news:sv7r23-dnd.ln1@news.compass.net.nz...
On 2005-10-22, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:
Hi,

Ok I have a r/c submarine and i need some form of electronic sensor to
keep
it level. Onboard power is 7.2V.

mercury tilt switches are the traditional tool for detecting tilts.

but would it be possible to lower the centre of gravity enough that it
could be self-leveling?

Bye.
Jasen


The problem is that you have to alter the angle to dive.

I thought subs dived by emptying thier float tanks...

So if it was
self-levelling then it would never get under.

that's not a big problem just have fins at the bow or a movable weight
that can point the front up or down.

--

Bye.
Jasen

 

[Michael]

"Jasen Betts" <jasen-b@free.net.nospam.nz> wrote in message
news:3fvt23-ami.ln1@news.compass.net.nz...

On 2005-10-23, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:

"Jasen Betts" <jasen-b@free.net.nospam.nz> wrote in message
news:sv7r23-dnd.ln1@news.compass.net.nz...
On 2005-10-22, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:
Hi,

Ok I have a r/c submarine and i need some form of electronic sensor to
keep
it level. Onboard power is 7.2V.

mercury tilt switches are the traditional tool for detecting tilts.

but would it be possible to lower the centre of gravity enough that it
could be self-leveling?

Bye.
Jasen


The problem is that you have to alter the angle to dive.

I thought subs dived by emptying thier float tanks...

So if it was
self-levelling then it would never get under.

that's not a big problem just have fins at the bow or a movable weight
that can point the front up or down.

--

Bye.
Jasen

In a real sub, you first fill the ballast tanks and that gets them under,
then you use the 'fins' at the front and back to change depth. However some
of ours just use the planes to go under.

Thanks for the answers, however I have one question:
I have a play controller from many years ago now, that when you turn it, it
turned the car, character whatever on screen. There is a little window on
it, and through that window you could see a chip. Couldn't I use a chip like
that?
Michael

 

[John Fields]

On Mon, 24 Oct 2005 16:02:27 +1300, Jasen Betts
<jasen-b@free.net.nospam.nz> wrote:

On 2005-10-23, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:

The problem is that you have to alter the angle to dive.

I thought subs dived by emptying thier float tanks...

So if it was
self-levelling then it would never get under.

that's not a big problem just have fins at the bow or a movable weight
that can point the front up or down.

---
Why don't you just give him what he wants instead of trying to force
him to do it your way?

--
John Fields
Professional Circuit Designer

 

[Jasen Betts]

On 2005-10-24, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:

In a real sub, you first fill the ballast tanks and that gets them under,
then you use the 'fins' at the front and back to change depth. However some
of ours just use the planes to go under.

Thanks for the answers, however I have one question:
I have a play controller from many years ago now, that when you turn it, it
turned the car, character whatever on screen. There is a little window on
it, and through that window you could see a chip. Couldn't I use a chip like
that?
Michael

it really depends on how that controller works...

the earth turns at 15 degrees per hour so if that device
is detecting rotation after half an hour your sub will be
7.5 degrees off level...

If it's detecting gravity (acceleration) it'll give incorrect readings while
the sub is accerleating (speeding up, slowing down, or cornering)

If it's detecting torque it'll probably drift over time...

--

Bye.
Jasen

 

[Jasen Betts]

On 2005-10-24, John Fields <jfields@austininstruments.com> wrote:

On Mon, 24 Oct 2005 16:02:27 +1300, Jasen Betts
jasen-b@free.net.nospam.nz> wrote:

On 2005-10-23, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:

The problem is that you have to alter the angle to dive.

I thought subs dived by emptying thier float tanks...

So if it was
self-levelling then it would never get under.

that's not a big problem just have fins at the bow or a movable weight
that can point the front up or down.

---
Why don't you just give him what he wants instead of trying to force
him to do it your way?

I don't know how. no solution is perfect.

measuring (or comparing) the water pressure (ie depth) at each end of the
sub might be another option...

Bye.
Jasen

 

[John Fields]

On Thu, 27 Oct 2005 22:21:52 +1300, Jasen Betts
<jasen-b@free.net.nospam.nz> wrote:

On 2005-10-24, John Fields <jfields@austininstruments.com> wrote:
On Mon, 24 Oct 2005 16:02:27 +1300, Jasen Betts
jasen-b@free.net.nospam.nz> wrote:

On 2005-10-23, Michael <miQchaelQhQims@Qblueyonder.co.uk> wrote:

The problem is that you have to alter the angle to dive.

I thought subs dived by emptying thier float tanks...

So if it was
self-levelling then it would never get under.

that's not a big problem just have fins at the bow or a movable weight
that can point the front up or down.

---
Why don't you just give him what he wants instead of trying to force
him to do it your way?

I don't know how. no solution is perfect.

---
_Many_ solutions are perfect, and if you don't know how to give him
what he wants, then it stands to reason that the way _you_ want him
to solve his problem probably isn't relevant to him. I don't recall
reading where he said that he wanted advice on building a sub, all
he asked for, initially, was a sensor he could use to level the
boat.

You suggested a mercury switch. Fair enough, but you left out the
part where it would have to be a SPDT type of affair in order to
detect bow-up or bow-down, and your comment about adding weight
seems to indicate that you were thinking about roll instead of
pitch. Am I wrong?
---

measuring (or comparing) the water pressure (ie depth) at each end of the
sub might be another option...

---
I don't think so.

Dynamic pressure variations due to hull geometry while maneuvering
at different velocities will surely swamp out the static
about-a-half-a-PSI-per-foot contribution of the head of water above
the bow and the stern of the boat while it's under way.

--
John Fields
Professional Circuit Designer

 

[quietguy]

I am not really sure what you are after - do you mean level while moving
forward? Or level while stationary? Or level out after a dive/surface?

If you just want to keep level while moving forward then I presume you would use
servo controlled 'fins' (whatever they are called) to set the sub level. Feed
the fins servo with a signal derived from a sensor that detects level - you could
make one easily - say use a circular 'wheel' of material (perspex?) that has been
coated with a paint of variable graded transluctance (eg ranging from almost
black to clear) use a LED one side and a LDR the other - both mounted to the subs
hull - and arange a small weight hanging down from the wheels axle.

What you will get from this arrangement is a resistance that varies according to
the angle of the hull in respect to the earths centre. Use that resistance to
drive a PWM PICAXE and bobs your aunty - a self leveling sub

David

J

 

[Anthony Fremont]

"Michael" <miQchaelQhQims@Qblueyonder.co.uk> wrote in message
news:JLx6f.40655$MF6.34706@fe1.news.blueyonder.co.uk...

Hi,

Ok I have a r/c submarine and i need some form of electronic sensor to
keep
it level. Onboard power is 7.2V.

You can use a "static" accelerometer to measure tilt. www.sparkfun.com
has allot of really neat stuff for reasonable prices. You can get a
two-axis accelerometer pre-mounted for as low as $25. Using one that
has a voltage output, you can use relatively simple circuitry to detect
level.

They also have gyroscopes, magnetometers and electronic compass modules.
For the really obsessed, they have a complete IMU module w/bluetooth.