I am a great fan of your Sailboat works too, especially sailing around SailDrone and your intro to Sailboat on SITL video, and sailing in strong winds. Have watched them all!
The balanced una rig works very well. The balanced nature of the rig means it is fast to repond and doesn’t use much power, so you can use a sail arm servo rather than a winch. It is also very simple to rig. I want to try it on a real life version of the Ardupilot SITL Gazebo catamaran model, mentioned above, where basically the same rig is used. Only downside is that it really needs a lathe, milling machine etc, to make the torsion bar, but that is not a problem if you have access to a makerspace near you. I have access to a fantastic set of tools at my local makerspace Swindon Makerspace as well as amazing tech support from them.
The P3022 encoder is a great solution and would definitely recommend it for a keelboat, but I opted to try and make something that is rated to IP68 , since I am working on a Catamaran which once it flips stays upside down, so I have to pay more attention to waterproofing everything.
Thanks for the help, skyscraper, Tim, and Pete.
I managed to get the AS5600 working with its analog output. I’m using the common white AS5600 boards you see all over Amazon. Analog out only works if you remove the R4 resistor. Also, the specs don’t say it but these boards seem to work well at 5V. I’m running mine at 3.3V tho, as my FC analog rssi input is 3.3V. Using a simple RC filter with non-shielded wires and don’t seem to have any impedance matching issues yet. Will see how it goes
Tested out the new AS5600 wind vane at the lake today with @playertr and it seemed to works great!
Made some modifications to my boat including a super long bulb keel and larger rudder. Now sailing at 45 degrees off the wind seems like no problem. And its decently fast!
With pretty much all default parameters it seems to do a pretty good job running waypoint missions. Although its tough to say, because I have no experience with what a well tuned ArduPilot sailboat looks like. Moving forward, I have a few questions:
In the documentation I read “The servo min (SERVOx_MIN ) and max (SERVOx_MAX ) end points should be set such that the main wing is held in a maximum lift angle of attack on both tacks.” Is there a good way to find these values? I would assume it’s just manually sailing around and figuring out what elevator angle results in the highest speed? Would too much elevator angle result in the wing sail stalling?
Also, in high winds my boat has trouble carrying speed through a tack and sometimes starts to go backwards. Is there a feature that makes it do a 270 degree downwind turn (jibe?) instead of turning into the wind?
The key thing here is that lower elevator always means less lift so the heal controller does not get into positive feedback where reducing the elevator un-stalls the wing and actually heals over the more. If your after performance then yeah some manual testing would show how far you could push it before stall.
This is not currently supported, although we do have a open PR (which I need to review) for some tacking improvements. I see you have a motor setup, this should kick on automatically and help get it going again if it does get stuck in a tack.
@rctestflight The Sailboat “Get out of irons” PR is here. It is currently only designed to work for a traditional sail. Getting it to work for a wing sail shouldn’t be too difficult. Instead of sheeting out, maybe it should set the trim tab to max one way or another to get maximum drag and also use the wing to turn the boat.
