Automatic Propeller Pitch Governing Algorithm (APPGA)

You can now both control your propeller pitch manually and automatically in flight!

Description

A simple proof of concept that an automatic algorithm can be developed to control the propeller blade pitch automatically using funky trees to extract the most amount of thrust from any power level/RPM. With this discovery, reverse thrust with a propeller engine is now possible as you can now freely switch between manual and automatic blade pitch control in flight.

How

In short, this is possible by taking the derivative/slope of thrust generated with respect to the blade pitch very rapidly, and then keeping that value at or near 0 with a PID controller. If the thrust is plotted against blade pitch on a chart, it forms a parabolic curve, where the top of the curve is the most thrust generated and the position of the most optimum blade pitch angle. At that point, the derivative/slope of the curve is 0, thus forming the basis of the algorithm.

In reality, the value should be kept slightly above 0 (in this build it is kept at 0.35) so that the engine stays within the permissible RPM and does not overspeed easily. The value is the second term of the PID controller, so feel free to play around and modify it to suit your own engine.

I highly encourage you to modify, tinker, and learn from this build to implement it in your engine!

If you have any questions, drop it in the comments below or find me on discord @kuatta4