Today we ran into several issues with the thrusters.
Over the last few days, Lilly and I swapped the thruster Arduino from a Nano Every to a Nano with the hope that it would fix the disconnect issues we’ve been having. We also swapped the bottom mono camera for a new one. We had to take out a few wetlink penetrators to do this.
Our plan was to test the barrel roll and coin flip. We first put the robot in the water without turning it on and manually barrel rolled it to check for any leaks. We did not observe any water inside the capsule.
We then started testing the barrel roll task. Immediately, we noticed that the thrusters weren’t behaving correctly. The bottom back left thruster wasn’t spinning at all, and the other thrusters were spinning at unintended speeds and directions. We reuploaded to the thruster Arduino a few times, power cycled the blue switch several times, and even power cycled the robot a couple times. We did get all the other thrusters to start behaving correctly, but the bottom back left thruster still wouldn’t turn on.
We then took the robot out of the water and took the capsule off. We didn’t observe any water inside. We didn’t see anything obviously wrong from an electrical standpoint. We kept trying to power cycle and reupload. After many repeated attempts, miraculously, the bottom back left thruster did turn on and stayed on for the rest of the test.
We put the robot back in the water and resumed our barrel roll testing. The robot could initiate, but not complete a barrel roll, as the thrusters seemed to not be supplying enough thrust. motion.launch also reported that the moment the thrusters activated, voltage would briefly drop to below 13V – something we have never observed before.
At 7:45, the pool closed due to lightning in the area. After coming back to the Foundry, we took the capsule off and observed a small amount of water at the bottom.
I did some thruster testing on land. At the beginning of my on-land testing, all thrusters could spin when spun at our usual testing speed of 0.05. I then tried to spin just one thruster very fast (none of the others were told to spin). I found that when commanded to spin at a speed of 0.95 or greater, the thruster would not spin. Instead, randomly, some other thrusters would spin at a lower speed, and after a few seconds, the entire robot would power cycle (red and blue). If more than one thruster was commanded to spin very fast, the robot would power cycle immediately. Near the end of my testing, the bottom back left thruster stopped spinning again.
There is a serious issue with thruster power.