Submergible/Floating tanks controlled by Arduino.

Hello Community, I was introduced to Arduino by a friend, that works with electronics. I would like to let you know that my formation is in Marine Biology and I am not familiar with programs language. I have some knowledge in computer, but most of my computer problems I solved them by googling and try to understand how others had solve similar problems.

I was introduce to Arduino because I want to automatized a system that I build, but at the moment it requires a lot of valves and hoses. My friend told me that I can reduce a lot of work if I manage to automatize it, or at least bring the control to the computer. By the search that I have done in google and in this forum I think it will be possible to build the automatize version.

I will describe the system and how it works.

  • Mainly is a set of tanks that goes up and down in the sea water. They are at bottom of the sea and when I need it I bring them up to the surface, when I finish the work, I send them back to the sea bottom.
  • Each tank (HDPE pipe) has three hoses that are linked to the surface to a control valve panel. All the valves (gate and ball valves) are at surface. Two hoses are linked to the water system and the third hose is linked to the air system.
  • When I want to bring the tanks up, I connect all the hoses to my valve panel in my boat. The water valves system are connected to the water pump, the air valve system are connected to the air compressor. By sending air through the air hose the water inside the tank is pushed away and get out through the water hoses at surface. Slowly each tank start to come to surface.
  • When I want to send the tanks to the sea bottom, I reverse the system. Send water through the water hoses and the air inside the tank get out by the air hoses at the surface. All the system works with pressure up to 8 bar. The tanks are located at 15 meters deep.

Why do I want to automatized. - There are too many valves to control the movement of all tanks simultaneous. Ideally I would like to have all the tanks arising at surface at same time and be able to stop the ascending of the tanks a one determined depth. But if I manage to reduce the number of valves and hoses at surface have the same control, I will be satisfied :) I think it could be possible to have one air and one water hose arising at the surface, and down at the tank have the splits. And having the electrovalves controlling the water/air that get in or out of each tank

What I have been searching: - Sensor depth - to allow the control of the depth of each tank or to let me know at what depth are the different tanks. - Electrovalves - to control the open and close of the valves by electrical signal in the tank, instance of gate and ball valve at surface;

What I found - I found in the web that exist a depth sensor (http://www.practicalarduino.com/projects/water-tank-depth-sensor) - I found in the web electrovalves controlling water irrigation systems, being controlled by Arduino (http://www.youtube.com/watch?v=lsM2dBF2Lwk) - I found in the web air pressure control devices controlled by arduino (http://www.zachrattner.com/Cannon.php)

Help - Need help to understand how can manage to build a prototype in a small scale with a arduino device and the right sensors. I do not have any gear at the moment, but I want to build this small scale prototype before buy the full scale devices. This small scale prototype will be tested in a pool. I will work with aquarium air/water pumps. Just need to understand how to control the up and down movement through arduino. How to make the pumps to stop when the tank is at surface and when is at the bottom. And how to start the ascending or descending.

Hope some one can help me and guideline me through the different set ups that I will require, if it is possible to build it!

Thank you Gonçalo Murta

You probably only need one hose going to the top of the tank and a drain hole in the bottom of the tank, a three way (supply-off-vent) lever pneumatic valve on top of the water, and possibly a large servo to operate the valve lever.

Thank you for the tip. I will look for fittings to connect the tank to the hose and the valve control at the surface.

The "open" bottom concept (whether large or relatively small holes) is the same as generally used in submarine design. The only problem is, if the tank turns upside down then injected air (to raise the tank) will simply bleed out the upturned open base. You might be better to keep the open bottom concept but fit a bladder (balloon) into the base of the tank such that expanding the bladder to raise the tank displaces water through the open bottom but, in the event of capsize, the air supply still acts against the bladder and does not leak out the base. jack