Autonomous vehicles make a regular appearance around here, as does [Daniel Riley] aka [rctestflight]. His fascination with building long-endurance autonomous vehicles continues, and this time he built an autonomous air boat.
This craft incorporates a lot of the lessons learnt from his autonomous boat that used a plastic food container. One of the biggest issues was the submerged propellers kept getting tangled in weeds. This led [Daniel] to move his props above water, sacrificing some efficiency for reliability, and turning it into an air boat. The boat itself is catamaran design with separate 3D printed hulls connected by carbon fibre tubes. As with the tupperware boat, autonomous control is done by the open source Ardupilot software.
During testing [Daniel] had another run in with his old arch-nemesis, seaweed. It turns out the sharp vertical bow is a nice edge for weeds to hook on to, create drag, and screw up the craft’s control. [Daniel]’s workaround involved moving the big batteries to the rear, causing the bows lift almost completely out of the water.
With a long endurance in mind right from the start of the project, [Daniel] put it to the test with a 13 km mission on Lake Washington very early one morning. For most of the mission the boat was completely on its own, with [Daniel] stopping at various points along the lake shore to check on its progress. Everything went smoothly until 10 km into the mission when the telemetry showed it slowing down and angling off course, after which is started going in circles. Lucky for Daniel he was offered a kayak by a lakeside resident, and he managed to recover the half sunken vessel. He suspects the cause of the failure was a slowly leaking hull. [Daniel] is already working on the next version, and were looking forward to seeing what he comes up with. Check out the video after the break.
[Daniel]’s other projects include a multiple solar powered planes, a RC flying stick and 3D printed lifting body aircraft.
Flex Seal to the rescue!
Great Project! Prety rugged hull. next time however have a look at spray expanding foam. 3D print it, make something that is the same size and the batters and fill it full of expanding foam, pull out the fake batteries and put your good ones in. Reason for the fake batteries is that stuff heats up a little and last thing you want is to expose the batteries to heat while the foam cures.
Glad you were able to recover it.
I was a bit surprised he didn’t have a plan B to rescue the boat in case of trouble. But he got lucky and it turned out okay in the end.
As far as propulsion, I think a jet ski type pump system might work okay with an appropriately designed intake. Perhaps have a large grilled area for the intake such that a big leaf would be unlikely to cover it, as well as to reduce the amount of suction at any one spot.
Next time, boogie board hull. Self floating, mostly above water even with a good payload. Cheap.
I’d like to see him try this too – especially to find out if it suffers from being more easily driven by a cross wind than something with a deeper hull.
Adding a low height keel made from a strip of plastic or wood, with rounded corners front and back, extending from mid hull to stern would solve that.
I’ve been through this some 15 years ago with rc airboats and flat bottom coroplast boats.
Definitely a fun to watch video :)
Cool! But I wonder why he didn’t let the boat send its telemetry to a cloud so he don’t have to worry about a direct connection. It would save a lot of battery, too.
I think if u tried our marine GPS autopilot software instead of the code ur using ur boat would be able to do the waypoint defined course in reverse and or under sail and power. Drop me a note at john.neyland@neyseapilot.com if tour interested in beta testing for us. I have been following your catamaran boat build and testing project for a few months now. Cool stuff. Thx j