Hi all, I deployed our BlueROV2 after a round of recent maintenance and hardware checks and ran into a few critical issues during and after the dive. Hoping to get some insight on a few things.
Last week I replaced a finnicky BEC which was causing intermittent power failure to the Raspberry Pi.
Things went pretty smoothly for about an hour at 100-115’ in saltwater. I was having issues with power to the thrusters at depth, so I figured that the ROV might be fighting the scope of the cable in the surge of the water column (approximately 150-180’ cable off the boat). I pulled it up to change the battery and observed no water in either housing.
I added an extension tether and a new battery and went down to approximately 115’ depth, and I noticed issues with the thrusters being far less responsive. I noticed that we were slower to descend and ascend, and after bringing it up the surface, my thrusters were much slower in the x and y axis (despite gain being all the way up). Despite the battery reading approximately 15V, we changed out the battery again and encountered more of the same with sluggish thrusters, and we got our first alert in QGroundcontrol about EKF Lane 3. At the same time we noticed some fogging in the camera dome in the upper housing.
I opened it up and observed no sitting water anywhere in the upper housing, and both our moisture sensors were dry. When I opened it up, I noticed that the BEC (and Raspberry Pi) were off. I reseated the positive and negative terminals of the BEC and got power back to both, but then I started encountering video issues.
I’m not sure what was causing the video issues. I reseated all the USB connections, and I would have video up and until I put the housing on again and then I would lose the video feed. Eventually, I put the housing on and when the ROV was sitting on the deck of our vessel, I could watch the video feed go in and out. I considered that the extension tether may be the culprit. I removed the extension tether which seemed to improve (but not solve) video issues, resulting in a live ffed approximately 90% of the time. I redeployed it and observed the thrusters being much faster and more responsive except for ascending in the z-axis.
After an approximately 2 minute dive I brought it to surface and observed an alarm sound inside the housing and another EKF lane 3 warning. I opened the housing again and observed no visible water intrusion, but the middle of the three internal side-mounted LED modules showed a flashing red light with the ones on the top and bottom showing a constant green. I’m assuming this is a leak or humidity sensor but I’m not 100% sure. When I opened up the housing again, I also lost all connection to the topside computer.
Altogether, I’m not sure whether this is indicative of power issues, water intrusion, wire strain, or a combination of all three. I’d greatly appreciate some help, thanks!
- Erik