Thursday, October 20, 2022

Zippy Mini-AMOS

 Shortly after fixing the software issues for control of the upside-down servo motor on Mini-AMOS, an improved mechanical attachment was created for the servo, and the boat was brought back to Kelly's Creek for a new test. Only about an hour was available for the test, but the boat was able to travel down the river past a small island about 2 km away and back in less than an hour. The top speed was probably ~ 7 km/h, but with stops at checkpoints and pauses to periodically check the boat's heading, the average speed worked out to ~ 4 km/h. Probably some room for trade-offs there, i.e. sacrificing some positional accuracy for speed. Here's a short video of Mini-AMOS as it sped back past the island:


Various software improvements have also been made for both Mini-AMOS and the regular surfboard AMOS. The water propeller on Mini-AMOS can now also be driven backwards, which gives it some extra maneuverability when being manually driven with either the PC or mobile app. Some bugs / stability issues were fixed in the AMOS robot and PC software, and all of the software has been brought into Jira (an online issue & project tracking software: https://www.atlassian.com/software/jira) and bitbucket (https://bitbucket.org/) for easier issue tracking and organization of all of the various AMOS software pieces. 

Next up will be an interesting citizen science sort of test of AMOS right here in our backyard. Every year about this time, we empty most of the water in the pool before it freezes. Since we use a salt-water chlorinator for the pool, the water being drained is a bit salty, and I have often wondered what kind of an environmental impact there might be on the small stream / pond in our backyard, about 80 m slightly downhill from the pool. The demo surfboard AMOS will be placed in the stream / pond with an anchor and a conductivity / temperature sensor, and allowed to float there for a day or two before the pool is drained, and then while the pool is drained (probably about another day). If a significant amount of salt reaches the stream / pond, the conductivity sensor should register a change. AMOS will be configured to be in sleep mode most of the time to conserve power, as there isn't much sunlight in that part of the backyard, especially at this time of year, but it will wake up to take readings every hour.