Buoyancy Control of ROV's


Thread Starter

Paul Gill

Does anyone have any simple methods of controling buoyancy of model ROV's. Possibly using syringes and solenoid valves.

there are a couple of ways of controlling submersible weight:

1/ charged-air bladders / lift bags: only really useful at low depth and at incremental forces

2/ permanent weight loss/gain (dumping air or lead/sand/equivalent)

3/ constant-volume, air-filled, pressure-resistant ballast tanks

A good way to do both repeatably is to use a fixed-bolume, depth-rated instrumentation canister and a HP, low-V seawater pump.

The can is filled to 1 atm, and contains an internal level switch to give feedback about spare buoyancy.

I've worked with these systems on manned and autnonmous vehicles at ISE and oceaneering, and they are not difficult to put together as long
as you consider the human factors and safety wrt. charging the can at depth. A variation of this system has a dump valve at the bottom of the can that dumps teh water when the Pout < Pin and Pin < 2Atm(eg).

The only feedback to the ROV system are the can water level (this can be done with a resistance system - ie analog signal or with opto systems) and the pump activator: add/remove/stop.

Let me know if you need more details. As I am sure you know, the buyancy/volume you will get out of one of these depends greatly on depth.

Alternately, if you would like a black-box offer to build you one to spec, feel free to contact me offline. I've worked on buyancy systems for manned and unmanned, tethered and free-swimming vehicles including SRS, Trailblazer, Dolphin AUV, Theseus AUV, and misc. defense projects.


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