View Full Version : Autopilot research
06-16-2016, 10:54 AM
Way way back in early aughts, as a pure research project, I built an RC servo wing-leveler for my RV-3. It used a small trim tab. The solid state gyros then where very primitive with poor accuracy. It had a bad habit of drifting quickly and ultimately, it was a failure.
Wow have things changed. You can buy a $10 12-dof controller for multi-copters which should clearly keep an aircraft perfectly level. Each axis has separately configurable feedback coefficients which can be set for the mass / roll inertia of a full-scale.
Has anyone experimented with using RC Quad Copter controllers as auto pilot?
06-16-2016, 11:30 AM
This has been on my mind for quite a while. It would work fine in my opinion, like the eco. I actually took my homebuilt quad flying in the back of my -4 with it connected to my nexus thru Bluetooth, to experiment, to see if the horizon would keep level. Seemed to work pretty well. My experiment ended there, with plans to at the very least, have a cheap artificial horizon.
06-16-2016, 11:51 AM
I made a post to my blog on what I had in mind. If you find it interesting, let me know.
08-10-2017, 12:16 AM
So I've been busy on other projects, like repairing an RV-6 and purposely let my electronics projects drop off.
Since I made this, I've had boards made to support this.
It's quite basic, and I haven't tried flight yet. I recall when I set this aside, I had it mostly working on the bench, but it need further refinement and flight testing/debugging.
The core of it is up to 8 channels of analog input with handy through holes for pull-up/down resistors to match the most resistance sensor (OilT, OilP,CHT,EGT,OAT,MP...). For more complicated sensors that require special component, I have two I2C inputs. There are lots of really cheap I2C modules for pressure, inertia/gyros and magnetic compass. Basically you can build your own air/engine data collector.
Let me know what you think. I have a few extra boards I'd send to anyone who's serious.
Here's the GitHub repo on the very basic LCD display version of this.
08-10-2017, 06:37 AM
It's quite tempting to request a board, but I can't claim to be serious at the moment. Once the Twinstar restoration is complete, and the RV-7 flies, you may hear from me again.
Thanks for the links, and if you decide to dive back into the project, please keep us updated.