Dear al,
Any one an idea how to make smooth survey corners in Qgroundcontrol? Is there a function to smooth the 90deg?
A semi circle from the end of the line to the start of the next line is perfect, now is has an U-shape.
Also with our current U-shape line planning, when the next line is on the right of the Blueboat, the drone is turning over left to the new line. Why is that?
And is there an option to slowly ramp up the speed op the Blueboat?
Hi @Willem,
You may get more complete answers in the more general ArduPilot forums, because the main developers of the ArduRover firmware are more commonly there.
From this thread it seems there is at least such an option for aerial vehicles, but I can’t seem to find the options they mention in the rover parameters, so it may not be available for boats at the moment.
There is at least a WP_RADIUS parameter, which allows turning towards the next waypoint before reaching the exact location of the previous one, which could potentially be combined with disabling pivot turns to get at least more rounded corners, but I’m not sure there’s a convenient method available for boats to get properly round or U-shaped turns at this stage.
In what circumstances? There are waypoint parameters controlling both speed and acceleration, which could potentially cover your use-case, but it’s hard to say without more information.
Hi Willem
I am not sure how easy this is to implement on Blueboat (I have never seen one in the wild). But I have done more than my fair share of side scanning and believe the principles are basically the same. I use a excel spreadsheet and utilise UTM and get a CSV route which I convert and upload to the boats Autopilot or Chart plotter
Whenever setting up a survey I always use at least 2 settings scanning
Lane Spacing (sort of self-explanatory)
Run on/in at end/start of transit (I am typically towing a SSS unit so this ensures everything is running straight and in line and is typically say 1.5 times the cable out), given even a fixed SSS on a vessel I would still allow or this at say 0.75 times the range of the SSS so any SSS data during the corner is taken out of the record at the end of the survey I trim this out of the results.
For the semi smooth end of line U turn’s I use 3 points from the Run on waypoint
1st quarter turn this is a point is 22.5 degrees from the Run on waypoint broadly speaking at a distance of Lane Spacing *SIN(RADIANS(22.5)) away
Mid point turn this point is 45 degrees from the Run on waypoint broadly speaking square root (2 x (squared (Lane Spacing/2)) away
3rd quarter turn this point is 67.5 degrees from the Run on waypoint at a distance of SQRT((13/16 x (squared (Lane Spacing))) note the 13/16 is an approximation
If the lanes are really close (ie turning circle of the vessel may be an issue) we use a “lollypop” turn - A trick I was shown several years back which is sort of a “Williamson turn” but looks more like a lollypop
Randy’s blueboat taking corner like champ.
Indeed. He mentions at 2:44 that he’s set that waypoint to use an S-curve corner, so it’s happy to preemptively turn more smoothly with consideration of the waypoint radius.
As I understand it this post is about overshooting the corners rather than cutting between them, but I suppose that could be possible by just extending the survey further than the intended straights and setting a suitable waypoint/turning radius… Perhaps worth a try.
