Flight Dynamics

From past Penn MEAM Senior Design projects, we inherited an incomplete MATLAB dynamics model, which calculates the forces and moments on an RC model airplane due to the airplane's current state and inputs. Through motor characterization and thrust testing, the model was improved to more accurately reflect the roll moment and thrust of the airplane during flight. Additionally, more accurate geometric and theoretical plane parameters were calculated that are specific to the Super Cub. The result is a completed dynamics model of the Super Cub that is used in conjunction with the Simulink model to test the control scheme without the need for extraneous test flights.

The same flight dynamics can be used to estimate the safe takeoff weight for our plane. By calculating the excess power of the plane for a given speed of the propeller, maximum takeoff weight can be calculated, as shown on the right. Since our propeller typically operates around 5000 rpm in flight, the maximum takeoff weight is estimated to be 0.931 kg. The Super Cub weighs 0.770 kg with all of the electronics; thus, it is possible to safely carry up to 0.161 kg of payload. All test drops were conducted with a 0.100 kg mass attached to a parachute.