AUV with control fins + single propeller, ArduSub or ArduPlane

Build/Make DIY AUVs
1

Hi everyone,

I am in the early planning stage of an AUV project with a single propeller for thrust and control fins (glider-style) configuration instead of the more common multi-thruster vectored setup.

I wanted to ask the community:

  • Has anyone here actually built and flown an AUV with this kind of fin + single-prop layout?

  • If so, which firmware did you end up using ArduSub or ArduPlane (in a submerged/underwater configuration)?

My current thinking on the tradeoffs:

ArduSub is the natural home for underwater vehicles (pressure sensor support, depth hold, underwater-specific modes), but its control allocation is built around thrusters, not aerodynamic/hydrodynamic control surfaces. Getting fin-based control to behave properly seems like it would require some hacking of the motor mixer.

ArduPlane, on the other hand, natively understands control surfaces (elevator, rudder, ailerons) and a single propulsion source, which maps almost 1:1 onto our vehicle mechanically. The downside is everything underwater-specific: depth sensor integration, buoyancy/pitch handling, navigation without GPS, and the fact that “altitude” suddenly means something very different.

Has anyone gone down either path? Especially curious to hear:

  • Which mixer/SERVOx_FUNCTION setup worked for you

  • How you handled depth control on ArduPlane (if that’s the route you took)

Thanks!

Mirko

2

Hi @mirkix -

I’ve been using ArduSub with a towfish being pulled around with a BlueBoat! It “thinks” it is a BROV2 standard frame, but instead of vertical thrusters it has two large fins driven by servos. With the BlueBoat moving, roll stability and depth control “just work” after some adjustment of ATC_RAT_RLL_FLTE
ATC_RAT_RLL_FLTD

autopilot parameters - I had to lower these to prevent jittery, shaky response.

So… in the context of an AUV, ArduSub is a good choice, as long as the vehicle doesn’t come to a stop and lose control authority over the thrusters!

A LUA script could run the vehicle, as it did for this vertical profiling AUV (guide coming very soon!)