Propulsion Control Method? What do you do?

[rvanscotter]

There are two theories for ROV control with respect to vertical control. The Elevator vs. the Airplane. Some ROV use vertical thrusters to move up and down while it remains fairly level, the Elevator. While others use an off-center vertical thruster to pitch the ROV up or down and then use the main thrusters to move, the Airplane theory. The Airplane style seem to be less comon, but the "GNOM Baby" seems to do this and thats the size and style I'm eventually going to use. The VideoRay series also seems to fall somewhere in between but I've never used one and haven't found any good video that shows either of the two.

Any thoughts or real world experience would be helpful?

[sthone]

Cant' say I've tried an "airplane style" Rov, but I think it would be a lot harder to pilot then a standard Rov because you wouldn't be able to make precise vertical depth changes without moving forward. Using a manipulator would be damn near impossible I would think.

As for the Baby GNOM =, even though the vertical thruster is off centered it still operates like a standard Rov where it surfaces and dives without moving forward. They must have the balance must just right so it doesn't pitch with the vertical thruster.

You can actually try a Baby GNOM online at http://www.divecommander.com/

-Steve

[rvanscotter]

I know its a wierd approach, I've seen a few videos now where I see ROV's moving about in unusualy ways. The bigger Gnom's have two vertical thrusters in a fore aft arrangment so they could affectively do both. I would agree that the stabil platform is the best way to go for most and that is my intention as well.

[sthone]

There is a weird one being sold on eBay right now made by http://www.deeptrekker.com where it only has two thrusters and it looks like the entire internals (camera and everything) of the Rov rotate to change the balance of the Rov so then it goes in any direction the Camera is pointing. (so basically if flies like an R/c airplane) Pretty weird, but cool concept I think.

Here's so video if it in action


-Steve

[Deep Trekker]

Thank you for your recognition of the Deep Trekker DTG2 system. The pitching system on the DTG2 admittedly took a while to develop, but seems to work very well. It has been well received by our customers. We have just now received the US patent on the concept, while it is still pending internationally. The initial thought was to reduce the number of thrusters which are the bulk of the cost in an ROV (in ours at least), but it seems to have some other advantages too.

From our website:
1) Less thrusters to operate
2) Absence of a vertical thruster allows for greatly increased camera visibility
3) Allows the powerful left and right thrusters to thrust vertically as well as horizontally (and anywhere in between)
4) Positions the tether connection always directly behind the ROV and in line with the thrust

Note on the camera: it is fixed by servo in relation to the internal frame, which is always level to the earth. The camera rotates independently of the exterior shell, however you can electronically lock it in line with the thruster if you wish to maintain a forward view.

Note on the grabber: Our first thought was in line with the above comment; cannot mount a grabber on it since the outer shell is dynamic (rotates). However after some thought here, we decided that this may not be the case. The rotating body actually gives the grabber another degree of freedom. You can now take the claws and point them straight down to pick something out of a hole, or straight up at something such as a boat bottom. We also added the claw continuous rotate, that makes things a little easier to grab. These two features give our grabber a lot more flexibility than a standard open/close fixed mounted claw you will find on the competition.

See it here;
http://www.youtube.com/watch?v=RLd_vuPEgAc

Any other questions let me know!

Thanks,
Jeff Lotz
Designer – DTG2
Deep Trekker Inc.

[bikerbones1968]

Hey Deep Trekker you interested in a Canadian Rep in Nova Scotia? I will gladly demo the hell out of it for you

[Deep Trekker]

Sounds like a plan! Check your PM for details. Anyone else in different regions.....? let me know.

Thanks
Jeff

[KR2_Diving]

I will gladly demo the hell out of it for you

You are a legend!

...Let me know if it works!

[sthone]

Wow I didn't even put two and two together with your name (Deep Trekker) when I activated you.

Note on the camera: it is fixed by servo in relation to the internal frame, which is always level to the earth. The camera rotates independently of the exterior shell, however you can electronically lock it in line with the thruster if you wish to maintain a forward view.

Wow this concept looks and sounds cooler the more I hear about it, if you ever do demonstrations stateside let me know I'd love to see one of these in person.

-Steve

[bikerbones1968]

I have been in contact with Jeff and Sam of Deep Trekker Inc a few times since this last post. I have some paperwork to finish and submit and hopefully will have one of these rigs in hand very soon and will be testing it and demoing it heavily. I will keep you all posted. Looking forward to working with Deep Trekker in the future.

Anthony