West south west of passage island

August 10 2014
Exploring the edge of a small undersea mountain. Read background

August 10 2014

Tags: 
air
land
sea
urban
backyard

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Debriefing Stage

Testing individual Batteries: voltage 3.3v (each) (measured 2 days after dive)
On Screen at end of recording: 9.1V (it was between 7.1 and 9.2V near the end, depending on if motor use)

The tether was broken in 2 places. But the break occurred in the middle of the twisted mess, so the rov was held fast. Phew!

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I am happy with how the ROV performed. I was concerned that I would have issues with the salt water, since that seemed to trigger my previous rov issues. It is awesome to be past those issues and on to dealing with newer challenges.

Improvements for next time:

Deal with the small leak on the one battery tube.

Laser cut an improved e-chassis that allows the camera to move. Then I can use the (amazing) depth hold function to hover over the bottom and tilt the camera as needed.

Floats for tether nearest the rov at least

Adjust the PS3 controller settings to have a larger dead zone. Some of the murk was caused by the controller being nudged ever so slightly forward, and my failure to notice it. Booo!

Add standard OpenROV leds. I will keep the beams as well. They worked better than was apparent to me during the dive. The sun was very bright and my sunshade was fail. This meant I only saw the brightest spot on the screen. In later viewing I noticed that the foreground was actually well lit also, however, once the camera can tilt, I could have issues seeing things off plane. It would be preferable if I could have them controlled separately for easier comparison. I need to look into that.

Better sunshade. The sun is like, super bright. One time, it was foggy and kinda gloomy, then the fog lifted and the sun lit up, like, everything in sight, all at the same time! And crazy bright too! I was squinting. It sounds unbelievable I know. You will just have to take my word for it.

Toughen up! Or buy drugs. Or pay a wizard to magic me up.

Please leave comments if you have any suggestions to make future trips better.

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This is a story from a fellow member of VHS (Vancouver hacker space) who used to fly ROVs and get paid for it.

"A story about umbilical and prop. These guys are flying back to the surface, and the skipper decide to re-position the mother ship. Boom, video goes out, telemetry goes out, everything flat-lines, umbilical goes limp at the deck crane. Everybody goes white, they know they have lost the sub, it got cut off by the propeller. Tense silence, as the managers compute the loss vs insurance vs future rates in their heads, then one call the crew to complete the reel in 'cause might as well see how much umbilical we have left.... The crane re starts and .... Start getting loaded. Eventually, the ROV appear on the surface, along with both ends of the umbilical, messily knotted together by the same prop action that sliced them apart in the first place. Sometimes, you can't lose.

You got yourself a nice hobby, Darcy!

By the way, notwithstanding the heaving*, you should record voice comments along during the dive, or even after, pointing out stuff and intents, etc...

SDY

  • nothing to be ashamed of, yours truly get seasick walking on morning dew..."

Written by Steven young

Here is the 'Bouncy Castle'.

The wood console did not stay like that for the whole trip out. The water was quite rough, and I must admit to a fair bit of cursing (at) English Bay. I called it a brother trucker. I know, harsh.

The bench the console is attached to came off on one side, so I put the whole thing on the floor of the boat and kept my foot on it. Turns out that is an effective way of keeping it in place!

It is bigger than it needs to be for an ROV adventure, though it is still suited to depth testing due to the larger spool.

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So the burning question: was it worth it?

Dramamine next time?

I haven't been sea sick before. It just came out of nowhere. I am in no way opposed to taking drugs that stop me from puking. :)
Did you see the prawn? I was looking at the screen and from the bottom left corner he just sort of strolls out and I was like "Creature!" pointing at it on the screen to no one in particular.

Mission Underway

Seems the coral had an accomplice.

There was a little bit of water in one battery tube, but no where else. I brought a milk jug of water for just such an occasion which I poured into the battery tube when I arrived at shore.

Looks like the tether (including the traitorous zap strap whose job was to keep this from happening. You had one job man!) wrapped so tight it broke. I am just happy it wrapped so tight that it didn't let go when I reeled it in. :)

2 reasons immediately come to mind (in addition to old zaapy, who will be dealt with) as causes:

1 - No blade duct (housing, cowling, tube...?) I keep forgetting to order that tubing.

2 - I let out too much tether, and worse, I didn't reel in the excess when I saw it on the screen. I blame that sick guy who marred the side of my boat.

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This is the last frame of the video. I was trying to turn and then everything died.

I started to reel in the rov, then paused while the sea sick guy chummed the waters a bit more, then back to reeling in the rov.

I was concerned that all the wriggling around, trying to move, broke the seal and flooded the rov. Or that it was eaten by a shark/giant prawn.

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The realities of ocean exploration!

ya! and I was barely in the ocean! I mean he was...

Darcy, your videos are the best! You should use screencastify so we can get more Darcy commentary! http://crwd.mp/1pGLZ6Z

I just now checked the settings and clicked the box to include webcam video. For next time. ;)

Some deep sea coral. :)

It did not want me to turn any further to starboard.

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Here is the video of the expedition. I added links, in the details and comments sections, to points in the video of note.

Some portions of the video should be skipped completely, others might have points of interest I have missed. I will try to steer you clear of the bad parts. I would just edit them out, but I already went through the video marking points of note and I don't want to do that again. :P

The ROV doesn't move very much. It seemed to be caught on something, then at 36:45 I saw what might be the cause.

So cool! You should use screencastify so we can get some Darcy commentary: http://crwd.mp/1vyKBZE

Cool. Are you using a touchscreen device to control the ROV? If not, on the alter builds you can disable the touchscreen controls.

The ROV seemed a little heavy. But it hung at 103M a long time!

I am curious if it would have been easier to control with the depth hold enabled. Especially since it can take care of running the thrusters as needed to keep you off of the bottom which would help with turning up the silt.

I used screencastify to record. But I foolishly failed to test it out ahead of time and had to figure it out in the rocky boat. And like I mentioned before, some guy kept getting sick...

From 39:53 to 42:21 I used depth hold. :) It worked awesomely!

I was just testing it out really, but it is during that part of the video that you can tell that the creatures swimming around are Prawns. :) They hang out a bit. Its not super clear, but clear enough to tell.

Turning off the touch screen controls is another thing I meant to do, but didn't try it ahead of time, and didn't remember. The screen controls have good response time now. :) But they don't all work on my Surface 2 pro.

I think the rov was pretty close to neutral. Once it was off the bottom, it some times ascended (with motors off) though it also sometimes descended. I was expecting there to be an up draft(?) current, because of the sea-mount, and I think there was some evidence of that in the footage from when I was going slow. That would suggest you are right, that it was heavy, probably from the tether and slight loss of buoyancy in one battery tube. The IMU is great. It took me a while to notice, but the artificial horizon shows what a slope the rov was on. Nice!

I think the depth hold will be very useful once I get my camera servo un-stuck. I made an error somewhere when I modded the e-chassis so as to have thicker endcaps. So the camera arm is jammed against the e-tube and can't move. It is functioning (I am using a servo with metal gears that is less prone to stripping) but I have to re-cut the e-chassis with proper proportions.

Preparation Stage

I dropped my anchor on top of the mini seamount and let out all of my 100+ m line.

I'm not certain where it caught, but it grabbed on nicely. I was very happy, because:

A - it was my first use of an anchor, and a fairly small target.
B - someone started to feel sea sick right after letting the line out. I'm not saying it was me, but no one else was there...

The first pin represents where the boat was after dropping anchor and settling in. The second pin is where I estimate the rov landed. I lined it up with the line the current was pulling me at the time of deployment. It changed angle a bit by the time I pulled anchor.

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Zoom of the general area

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Expedition Background

Choosing the right area to explore can be challenging. I wanted to explore a deep area of my local seabed, but getting within range is usually difficult.

The first option is to limit your expedition slack tide on a windless day, but that requires a fairly open schedule.

I instead looked for a steep drop from a point I could anchor.

I looked at the charts and found a few miniature seamounts 20 - 30 meters below the surface and one that was within 100 meters of deep water.

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Cool Charts! What brand is this?

Navionics.

It works really well. Available for iPad/iPhone and android.

I use it as my speedometer too. :)