automatic pitch controler

nukepower

Hi,
Ive been building RC submarines now for about 2 years.· I enjoy this hobby because of the amount of fabrication required due to lack of commercial parts.· But there are some things that i cannont make.· One would be a switching system for energizing and denergizing solenoids for my ballast tank system. Another is an automatic pitch controller, which is useful to keep the sub from porpusing uncontrollably.· I want to make a pitch controller that will control a servo to maintain level "flight".·· Would this be possible using a stamp and what would be the minimum level stamp to get.· Keep in mind I have not used a stamp before.· Any direction is useful even if the road is long to get to my goal.

Kevin

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http://spitcool.com/thesubpen/SUBCOMDEEPSOUTH.htm

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Post Edited (nukepower) : 10/12/2007 11:57:53 AM GMT

Larry

controlling a servo to achieve level fight is pretty easy with almost any Stamp. It would involve using an accelerometer like this one:
www.parallax.com/detail.asp?product_id=28017
At submarine speeds, I think it would be safe to assume all the accelerations would be due to gravity, so it would be essentially an electronic level.


If by level, you mean maintaining the same depth, it would be a somewhat different issue. You'd need a pressure sensor. Honeywell make some that are reasonable in price. I suspect other forum members have one to recommend, but here's a place to start:
www.ssec.honeywell.com/pressure/


you may also have to get an ADC to actually read the output:
www.parallax.com/detail.asp?product_id=28129

will steer you in the right direction.


Hope that helps

Larry

Sorry, I focussed so much on the level part I ignored the switching solenoids part.

a circuit for that can be as simple as a TIP 120 transistor and a resistor. the TIP 120 has an internal clamping diode.

But to really give you advice on that, we'd need to know the current draw of the solenoid.

this should get you started:
www.me.umn.edu/courses/me2011/robot/robotfaq.html

In the schematic shown, the solenoid goes where the Motor is shown.

Post Edited (Larry) : 10/12/2007 12:57:01 AM GMT

nukepower

Larry

I am bassically trying to achive an automatic leveler.· An automatic depth controller is a later goal.· I just want the circuit to re level the boat after a change in depth( up or down) therefore arresting the up or down movement after it has been inputed.

Correct me if im wron but you are saying a basic stamp 1 can handle the acceleromete/compas and a servo output?

Kevin



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Like Submarines?

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Larry

a Stamp1 would read the result, but it would be a 5 times coarser reading. The memsic 2125 is read with the PULSIN command which is read to 10µsec on a Stamp 1, and 2 µsec on a stamp2.

On a Stamp2, the numbers range from 1775 to 3125, or 1350 steps per 180º.

On a Stamp1 there would be 270 steps for 180º.


In either case, I'm sure there would be some noise which might require several readings to sort out.


You can read more here:

http://www.parallax.com/dl/docs/prod/compshop/SICMemsicTut.pdf

Kevin Wood

You might be interested in looking at this page:

www.parallax.com/html_pages/resources/custapps/main.asp

You'll find some very cool projects built with Basic Stamps, including some underwater vehicles.

Phil Pilgrim (PhiPi)

nukepower,

When I read the title of your post, "automatic itch controller", I was thinking, "Stamp-mediated electro-desensitization for hives?"

-Phil

OzStamp

Same here .. I thought what the ... have we got now... an itch controller ...
Hayfever season here... the old Vaseline up the nose time...somehow related...


anyway Nukepower..
Sounds like an interesting project...
How do you communicate with the Sub via RF ?

Ron

nukepower

yes umm oppss looks like i missed a letter in there. I fixed it no more confusion but maybe an automatic itcher would be nice. It would certainly give my wife a break [noparse]:)[/noparse]

OZStamp
My little project keeps my brain busy at night thinking of the new possibilities in my hobby using stamps. There is another member of my club that has used them in his sub to designate targets and automaticly track them via a fiber optic camer scope. He has also used to pressure sensors forward and aft to controll a motor to transfer water ballast to control depth and trim. But he makes robots for the cinemas and is way beyond me.

To control my subs I use a Polk Tracker 3 8ch hobby radio on a 75mhz frequency. It uses futaba style connectors to the reviever. I am also using standard 10 dollar futaba servos.

Im starting to think I could utilize the stamp to controll much more then just my pitch. It sounds like i could integrate alot of my submarine functions into a stamp therefore minimizing the amount of electronics in my boat.
If I am correct (please correct me if im wrong) I could route the inputs from the various channels of my rx into pins on the stamp and assign them as input in the program then once i flip a switch on my transmitter of a move a joystick the various inputs could tell my out puts to latch solenoids for ballasting or automaticly control pitch or even shift on running lights all through one stamp and a series of transistors and optoisolators to cut down on noise.
How many functions can a stamp handle at once. I would like to be able to do at least three at this momment. It sounds like i would need to go with atleast a stamp 2 to handle what i owuld like.
Kevin

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Like Submarines?

http://spitcool.com/thesubpen/SUBCOMDEEPSOUTH.htm

Post Edited (nukepower) : 10/12/2007 12:21:41 PM GMT