Yes, those were the days where we were having to recalibrate the compass every startup for some reason, but that issue disappeared when we re-used it recently on the GBR (putting the battery power wires below the batteries as suggested may have fixed that) but I still had the offset behaviour, so I don’t think it was the cause.
Nope, on the last day the weather was essentially dead calm. There might have been some slight tidal currents but nothing that would have challenged it to this point.
I can try cruise speed but run similar missions with another blueboat at the same speed with no issue.
The other two oddities could be driving the issue somewhat, I’ll reset them and hopefully that solves it!
I’ve reverted the compass orientation to default. I did the same with the vertical acceleration parameter, but then the Blueboat was ‘lazy’ in returning to the line and wasn’t correcting enough. I’ve adjusted it to 0.01 instead and that seems to have fixed the problem.
A bit of wave and current out there, I expect what misalignment is left is due to that. I might tinker with the acceleration value some more and the survey speed and see if it changes, but we want to survey as fast as feasible!
Just ran another mission (where the issue was first apparent), this time including using a different Navigator board (in case there was a faulty compass), after having re-calibrated the compass at base camp, and we’re still having the issue (see attached image). One thing I’m noticing is it looks like the Blueboat thinks it’s crabbing: even when going completely straight the compass seems to think it’s pointing slightly to the left. This also happens in Acro mode when going ‘straight’ (with no steering input) it will veer to the right slowly.
Any idea what could be causing this? All compass readings were green, though it does still throw pre-arm issues that seem to disappear. Note this is a separate Navigator board!
Hi @Vincent
Very strange!
Do you have a valid magnetic declination value set? This varies depending on your location, and can be set by your geo-ip on the compass calibration page in BlueOS under vehicle setup…
While on that page, it’s a good idea to check that the arrows representing each compass’s measured heading and the resulting blue EKF look right- if one is very different from the others it could be disabled. This honestly looks to me like a poor calibration or issue with magnetic declination only…
If it’s not a declination problem then it could be the current through the battery and power wires (which you could confirm as an issue by holding the boat still while throttling and seeing if the compass rotates). ArduPilot does support configuring compensation for electromagnetic interference, although this is somewhat rarely used, so the documentation is limited.
Beyond that, consider that heading in the presence of current and/or wind may not match the vehicle’s course (so moving straight at an angle to where the vehicle is actually facing could be correct from both sensors), and it’s also possible that one of your motors is working less effectively than the other (e.g. due to some debris that’s stuck in it, or a damaged propeller).
It’s worth noting that the navigation position controller is pretty good at mixing between line following and corner handling, as long as it’s properly tuned (which works best with reasonable sensor values). This thread is a relevant skim/read…
You may wish to consider only using the two end-points for each track, rather than an extended turn of 4 waypoints, so the navigation controller can focus on making the turn quickly. If you want to get into the details there’s a technical talk on how the controller works, but in short if you’re really pushing performance then extra waypoints can slow things down because of how the controller plans manoeuvres between them.
Thanks both, lots of good suggestions. I’ll make some tests when I get back on the mainland and see what I can do. Certainly seems this has been throwing lots of compass issues for some reason. Will definitely take on the turning end point suggestion!
Sorry to report I’ve had a frustrating arvo! The Blueboat started giving a lot of random errors (“could not connect to host”) and the ping sounder stopped being detected, despite being connected. I thought I’d reset settings to try and fix this and now I can’t seem to either pick up the ping sounder or be able to upload Blueboat parameters in the setup wizard (despite being connected to the internet).
A little lost where to go from here! Though I was able to figure out how to disable the one bad compass that seemed off from the others in BlueOS.
Also as a side (and very frustratingly) resetting settings deletes all logs. Luckily I had just downloaded the latest mission, but this isn’t a logical result when ‘resetting settings’ and could have led to a lot of swearing on my part!
Hi @Vincent -
Sorry for the issue. Where did you see the error message - could not connect to host? You may have been looking at a BlueOS page that didn’t have an active connection to the vehicle, and so threw nuisance errors…
I’ve enquired internally, resetting settings doesn’t seem like it should delete your logs! Are you sure you have an active connection to BlueOS - is the heart icon beating in the upper right?
If you’re trying to check that your BlueBoat autopilot parameters match the default, you can do so via the Vehicle Setup page, with the system connected to a WiFi network with internet.
Does the Ping show up under Ping Sonar devices? How is it connected to your system?
Thanks for raising this - we’ve confirmed there’s a bug in the deletion logic for handling where those files are stored. We’ve got a fix in the works now, and added an explanatory confirmation dialog (for the intended behaviour), which should be available in the next BlueOS release
As always so pleasing to see you are on top of things! Luckily no drama this time but could have been bad if we didn’t back up religiously.
@tony-white I have no idea how to replicate it. I’ve rebooted the boat a few times and it seems to come and go, it may have something to do with the order of powering the blueboat vs having the PC on the network. It’s back to working now, I’ll have to do some tests back on the mainland and see if it persists. I hope disabling the compass solves the tracking issue.
Are the compasses on the Navigator board or the Pi? I would have thought switching Navigator boards would have solved that issue.
Sorry to dig this up but finally doing some TLC on the blueboat! One of the thrusters is rusted solid but not bad for a few hundred km of travel!
I just realised during the antenna mast extension install that the GPS board is separate to the rest of the Navigator, hence why swapping Navigator boards didn’t solve my issue.
Since I clearly have a bad compass that I’ve had to disable, would it be possible to get a replacement GPS unit? I’ve looking on the website but it’s not sold as a spare.
This boat is going out for more surveys in WA in the next month and a bit so it would be great to get this issue sorted!
Hi @Vincent -
You probably can obtain a replacement, but the forum is not the right venue for the enquiry. Reach out to the support team via the help center with your original order #!
but not bad for a few hundred km of travel!