This is incredibly impressive. I'd love to hear more about what relevant skills & knowledge you started with, and how you worked out what you'd need to know to complete the project.
How much customisation did you need to make to Ardupilot? Is your drone's control unique, or somehow standardised?
Thanks! I'm using the standard Ardupilot control systems for hover, transition and cruise flight. On the firmware side, it's just some parameters and tuning that is customized.
What I started with - Had built one VTOL before from foamboard, not 3D printed. - Familiar with Ardupilot from that project and assembling a multicopter and COTS VTOL. - So I had a little experience building a structurally sound airframe for VTOL loads, but 3D printing was a wrinkle. - How I worked it out is a hard question. But it was being focused with design, flight testing and troubleshooting. LLMs, Youtube, forums, etc for help when needed. - Building in public helped paradoxically. It actually saves me time to build in public because of the motivation boost that helps me move faster and to share progress sooner. Even though there's a higher lift to document and share.
Ardupilot is very, very mature software. A lot of the drone video coming out of Ukraine, the HUD overlay is likely from Ardupilot. If you can think of it, Arduipilot supports it. Airplanes, helicopter, VTOL, speedboat, even sailboats.
As someone who works with ArduPilot professionally, I have very mixed feelings about it. It’s mature, definitely. It supports all kinds of vehicles, like you say. It’s beautifully modular and supports a crapload of flight control and sensor hardware. And there are definitely pieces of it that are aggravating and exceptionally janky.
The HUD overlay you’re referring to is technically Mission Planner (GCS software), not ArduPilot (flight control software). Mission Planner and ArduPilot both talk Mavlink, and they’re both developed by the same community. MP is flexible. You can set it up to do almost anything you’d ever want. It’s also terrible and exceptionally janky… but extremely powerful. And they’re both free.
I think the problem with both of them is that they’re good enough that there isn’t likely to be a huge critical mass developing a better alternative. On the GCS side there is also QGroundControl and APM Planner 2 (which was a fork or reimplementation of Mission Planner). Both of them have their own upsides and downsides, but neither one of them is as mature or as powerful/flexible as Mission Planner. PX4 on the flight controller side is popular commercially because it’s BSD-licensed instead of GPL, but the net result is that it has nowhere near as many features as ArduPilot because companies build proprietary features and don’t push them back upstream.
This stuff is definitely in the worse-is-better domain. ArduPilot is free, ArduPilot is amazing and ArduPilot sucks. :)
Anyway, off to bed. I’m in a long test campaign right now and we’ve got to be up at 0430 to fly the ArduPilot-based aircraft again before the weather goes sideways.
It doesn't look like it required any AP customization, AP will do VTOL out of the box.
Yes, one of the challenges though is airframe structural integrity when building it yourself. Need to have good enough understanding of multicopter and fixed wing plane design