Let there be Autopilot!

Back in 2002-3 I experimented with a roll-axis autopilot that used a single axis solid state gyro on my RV-3.  Ultimately the project failed for several reasons.  But mostly the technology was not ready for my level of knowledge.  It is no-longer that way.  You easily access 10-dof Quad Copter controller boards which can be reconfigured for the larger mass and inertia of full-scale.

Roll/Pitch - Heavy-duty sealed waterproof metal gear digital R/C Servo.  Connected to an aileron/elevator trim tab.

Integration is where it gets messy.   So you have an Android Car PC, which has USB output.  You can directly connect the Quad Controller to the Android PC.  Normally this would be done to run the setup of the quad controller.  But it could be permanently connected and there should be a way to command the quad board between normal flight and autopilot mode from the USB via this configuration mode.  Normally this would happen via an Auxiliary transmitter channel.  Furthermore, there should be means to steer the autopilot for navigation on that same usb connection.  There are three AP modes; off, steer and hold.

Steer - Generally keep the vehicle flying upright, but use the various channel inputs to direct the vehicle

Hold - Ignore the inputs and keep the last Altitude and Heading.

I can see both of these modes being utilized by the high level Autopilot function in the EFIS.

The roll axis can be directly controlled by the quad controller.  When AP-mode is disengaged it will act as roll-trim getting input from the Arduino PC via USB connection.

The pitch axis will require a controller that can translate the servo output PWM signal to stepper motor.  I'd build a small board to do that.  Probably us a Arduino Mini or an ATTiny88.


At the end of the day.. What I want the pilot to have is completely naturally intuitive integrated autopilot.  So ahead of time, you plan your flight on a third party Android app.  We'll upload the plan to our app.

When you take off at 1000 AGL, an AP-FP button pops in the corner.  You press it,  it uses your airspeed to drive climb rate (constant airspeed) and steers you on flight plan.  Let's say you're not ready to go on flight plan heading yet.  You fight the roll to wings level.  A button pops... AP-HH.  Press it, your on heading hold... still climbing.  You fight the servo and push the nose over... button pops AP-AH, altitude hold.

So now you're flying along.  And there's Class-C airspace at your altitude.  Pop-up... AP Airspace [Through] [Over] [Under] [Left] [Right] (This would be icons as depicted below, not words).

AP: Airspace
       ^
    < 0 >
       v

Flying along.. ADS-B finds a traffic conflict

AP: Traffic
       ^
    <   [>]     [recomended]
       v

Keep flying and you get to the vertical intercept.  Where you need to descend.  Pop up, AP-DES.