Introducing the "OughtToPilot
It seems the parallel processing ability of the prop makes it a top candidate for autopilot brains. This project was entered in the Parallax Design Contest and won second place!! The designer opted for a fuzzy-logic algorithm over a kalman filter for the IMU.
The OughtToPilot employs a non-linear fuzzy-logic algorithm to blend two different types of inertial sensors (accelerometers and gyros) in a computationally efficient manner. This model free blending and estimation method was chosen over Kalman filtering to reduce the design-side system modeling effort and the real-time computational burden. All computations are conducted upon integer based pseudo float numbers with most values corresponding to a fractional number with three digits after the decimal point, multiplied by a thousand.
The source code and material list is available from the link above.