ROV - The "Spitoon"

[Sunktwice]

Hi everyone,
I've finally started building my latest ROV - based on a simple PS2 dualshock controller interface running on and Arduino UNO. I'm not great on Coding, so that part is taking a bit longer than i'd hoped - but the internet is an amazing place full of resources, so i've done quite well already and managed to find a base code for the interface. I'm still deciding if i want to keep the controls on both of the sticks (like a tank), or code in a differential joystick control on one side and free up the other stick for the camera pan/tilt.

Ill be using a dragon OSD and an I2C compass module to save time on making an overlay module, or coding something.

The plan is to run Two cameras - one colour, and one B&W, using IR lamps for the darker waters here in the UK.

Basic design will be based on Urethane gas pipe it's got a good sized internal diameter, it has a really thick sidewall so I can mount on a good sized front pressure window, and obviously it's got a massive pressure rating -WAAAAYYYY over what i'll ever need.

Simple thrusters based on the good ol' bilge pump modifications - big fan of this mod - cheap and easy to repair/replace.

I started on an original ROV design last year, by hacking an old RC controller and using the PPM signal from the trainer port - it was OK, but lacked finesse and expandability. Plus the drainpipe design i used was somewhat......cumbersome

So here I am, posting on the forum that inspired my early last year, finally posting about a build i'm hopefully going to be satisfied with!

Heres my "MK1"

[sthone]

It's looking great so far... I'm curious where did you find the dome?

-Steve

[Sunktwice]

Ah, the the dome is part of the CCTV security dome i purchased from that well know auction site. Its not as thick as i was hoping, but for the depth i'm going down to, it's not an issue.

[Sunktwice]

I've been in for an operation before Christmas - now i'm out, i've plenty of time to carry on bashing away at my Arduino code and Ebox control system. I'm a firm believer in hacking and modification, only resorting to "virgin work" where absolutely necessary.

I'm using a PS2 for the main control interface, with an Arduino UNO for the main processor. Buttons galore !!

Camera will still be via AV and a Dragonlabs OSD - rather than an IP camera. This is mainly due to the lack of faith in my own aptitude, and a relatively tight budget.

Illumination will be via IR flood and also a CREE LED lenser.

I'll also be feeding the Dlabs OSD with telemetry data with an I2C tilt compensated compass.

It'll initially have 3x thrusters Port/Stbd and dive/surface. some Coding is complete for the port/Stbd thrusters - each one on the relative analogue stick, and the dive/surface on the SQ/Tri buttons.
I've got some sample code to make the steering differential on one stick - but as the ESCs (Mtroniks viper marine 15) neutral points are not identical the joystick Deadzone is somewhat elliptical.

Drive is via the old favourite - modified Bilge motors on outriggers - im not spending a fortune on brushless motors and ESCs.

Lights are on the "O" button, controlled by a relay (driven by a transistor, to protect the board.
Camera tilt/pan will be driven by the direction buttons.
ALL power will be on board to limit tether weight and interference - 12V sealed batteries x2, a pair of voltage regulators for the electronics and a shielded power supply for the AV.
Tether will be superflex UTP shrouded in Scubadive braiding. and a length of paracord.
Still undecided if i'm going to use the 220mm gas tube I have and put a large perspex dome on the front, and a nice thick pressure cap on the other end or re-engineer and make a basic cube frame design.
The gaspipe idea works as it's an 11mm thick wall, allowing a great surface to bolt/screw into - and unbelievable pressure tolerance. But it'd be expensive to get right.

Cube frame is cheap, but limits me to using a handful of watertight modules and glands etc. Although it's easy to assemble, and allows modular modifications.

Bodged "Testrig" =p
I'm keeping the Electronics as compact as possible using a tiered shield layout - I did think of fitting a set of H-Bridge PCBs but as I already have the ESCs floating about - I though "What the heck".

[Sunktwice]

I just found a seller on good ol' ebay over here that sells Acrylic domes
I've decided that i'll be using the plastic gas Pipe for the Spitoon and to seal the rear of her i'll be using a gas pipe tester plug - I don't have access anymore to a CNC or lathe, so making my normal model sub method of a tech rail and WTC with o-ring end cap for this isn't an option

[Sunktwice]

A few pics - donor parts being taken from other ROV, the MK1. Mocking up the x/y thruster positions and Z axis thruster. ALL power is going to be on board, with a 6v backup power source, and internal watertight bulkheads.

Coding is almost finished, and dome is on order. Happy days.

[Sunktwice]

Quick Video of Camera gimbal and error reporting tests.
I'm using a compound operator to increment the servo steps in pulses of 5. Although it makes for a slightly jumpy movement, it serves as a perfect "sweep and hold". I'll tune it later to make it a bit smoother.

[Sunktwice]

Sketchup. It's like CAD...but not quite =p



but once your "in the zone"...it comes almost intuitivley...

[Sunktwice]

Sketchup is now my new(rather clunky) friend.

I've been primarily designing the layouts the last few days, and have started to upload models to the warehouse. So far there is only a 1:1 scale Bilgepump thruster i've created, but it's there if anyone wants to use it - my user name is "dirtyrhino". I'll upload some other models later on.

I've hit a snag in so much as i'm running out of space due a minor mis-calculation. I MAY have to run shoreside power instead, which makes my tether a lot heavier. I'm hoping I can condense and stack some of the electronic items onto a smaller PBA.

Also may have to drop the machined endplug as my budget is starting to spiral =(

[scubersteve]

Budgets do that...