Winter QA Testing
Generally it's not a great idea to do AMOS testing in the winter-time. The local rivers and lakes are frozen, so an hour's drive is required to find the nearest available liquid water in the Bay of Fundy. And careful planning is required to ensure that tides, wind, waves, and the cold are all manageable.
Two recent AMOS robot sales however required that the testing be done, so the van was loaded up in early January for a test down to McLaren Beach, just outside of St. John.
Both AMOS robots were equipped with underwater camera modules. Unfortunately, these proved to be problematic for the air temperatures of -7 deg C and water temperatures of 5 deg C. The plastic tubing, normally quite flexible at room temperature, became as stiff as steel in the cold. In shallow water, this meant that AMOS would get stuck (if it was moving slowly) or might snap off the top connector of the tubing if it struck the bottom at a high speed. So I packed everything up and headed back to make a couple of plugs for the camera holes; the underwater testing component would have to happen indoors. Fortunately the final destinations for these robots are considerably warmer than Canada in the wintertime, so freezing camera tubing won't be an issue.
A return trip was then made to the Irving Nature Park a few days later, as McLaren Beach was inaccessible due to a recent snowstorm. The waves were stronger here, as it was less sheltered, but the first AMOS went through its sampling course flawlessly. The second one had trouble even starting however. It started up fine prior to leaving, and started up fine inside the van, but within a few minutes of having it outside on the beach (again about -7 deg C) it abruptly lost power and the LED light on the power switch went out. My guess at this point was that the switch was faulty and didn't perform well in the cold, so after driving back I replaced it.
A third trip was then made a few days later to Lorneville, as there was a strong wind out of the south that day, and the selected spot offered a bit of shelter from the strong open-water waves. Once again however, the AMOS robot lost power in the cold, usually shortly after the propeller was driven at high speed. This time I thought to carefully check the solar charge controller, and realized that its short-circuit protection circuit was engaging. This was a newer version of a controller which I've been using for the last 3 years; previous versions allowed you to disable the short-circuit protection feature, but this version did not. So back to Fredericton, to replace the solar charge controller with an older model.
On the fourth trip back (to McLaren Beach), the 2nd AMOS robot also worked flawlessly:
So now both units have been shipped out and are due to arrive early this week. I'm looking forward to seeing how they will be used over the next few months. Hopefully around the middle of this year I will be able to provide an update blog with some details!
In support of these systems, the support page has been updated, and a number of YouTube instructional videos for assembly and testing have been created. These are a bit rough at present, but they should be effective I think.