Sunday, September 14, 2014

It's totally the hardware...unless it's not

Just a brief update today.  After our latest test flight, we had some positive signs, and some negative ones.  On the positive side, we've built a watertight craft with a bunch of lights, lasers, and cameras that all work now, so that's awesome!  But on the negative side, we've had yet more trouble with the motors, and with some bumps underwater causing the craft to die.  Like Danny mentioned in the last post, we're going to get our hot glue on to combat the issue of bumps knocking us out.  We're also going to be replacing these guys:

The ESC's we are using

We have noticed that on both dry runs and test flights, our motors are not responding correctly 100% of the time.  At times, the ESC's have lost their programming, and other times even with correct programming they act all crazy.  This team has put a lot of time and effort into this project, and the last thing any of us want is an ROV that only kind of works right and gets lost in a cave because the motors betray us.  So we're going to replace the ESC's and see how the motors act.  If they're still acting crazy, we need to look at the software, and we'll just have some spare ESC's out of it.

Another thing the team is doing is putting together a flight path for our first real world test flight (aka not in a swimming pool) that will be taking place at Spring Lake in San Marcos.  We're going to put our navigation and charting skills to the test in an environment where we can still see the ROV pretty clearly, since once we hit the caves, the difficulty will ramp up considerably.

Overall, while disappointing that we're still not quite there yet, it's also good that we're working our way through all of these mission-ending kinks now while we're diving in swimming pools, rather than 40 meters deep in a lightless cave. 
As always thanks for reading and don't forget to check us out on OpenExplorer where we'll be documenting our dives out in the world, and you can actually donate to the project there as well if you feel so inclined.  Cheers!

Sunday, September 7, 2014

Troubled so hard

We enthusiastically went for our third test dive, after having put away the ROV in 100% working order. Or so we thought. Our expedition was fraught with troubles.

outside underwater ROV view

One of our issues was the vertical propeller, which came unstuck from the motor bell and tried to escape out the finger guard.

vertical propeller escape attempt

Lag was also a huge issue. The ping times and responsiveness of the ROV vary wildly while in use, making it hard to predict and control. Speaking of control, I brought along a joystick which I think added much more confusion than it was worth. I do hope to set up a custom mapping for my many button joystick but that is going to be sidelined in favor of getting a reliable experience.

The ROV died at the bottom of the pool, ending the day.

dead, but with full batteries

This day ending loss of contact has happened to us once before, so we were already looking at the tether on the topside for failure points. The last time that this happened, it was the cat5 cable going into the beaglebone that shook loose. We fixed that with a piece of tape but wondered if maybe it came loose again. This time it was something on the tenda homeplug adapter, sandwiched between the beaglebone and the cape. A simple re-seat fixed the issue, but for how long?

Richard (and team) perplexed by the many issues

I'm thinking about hot-gluing the tenda homeplug adapter and cat5 connectors (at least) to keep them from bumping loose and killing the ROV.