The Controls Impact on excessive aeroelasticity in the design of passenger drones

When one reviews the design of larger drones, one is tantalized by the heavy structural design of the propeller support struts. It is partially due to the very large power outputs – i.e, thrust, on an extended cantilever arm. This can also provide an excessive twisting stress on the fuselage, particularly in yawing flight. This causes structural design of composite VTOL aircraft to be complexly multilayered layups. Reminds me of the early geodesic approach used on some British aircraft.

How to do these layups can be easily taught with good engineering drawings, and can be heavily automated , but it still needs extensively trained, skillful artisans in design application practices. There are still far too many uncertainties in flying machine design for it to be successfully developed without testing.

The extent of necessary testing is usually seriously underestimated, particularly with respect to new designs. Good thing there are a lot of people out there trying out different one-person flying machines to test their concepts. A lot like the 20’s and 30’s in that respect. Just remember the mortality rate on aircraft designers of light aircraft is around 25%. A lot of them will die trying to extend personal liberty.

But to get to the point, when tuning your PID flight controller algorithms, oversize the torsional structure to minimize the associated deflections when pushing roll, yaw and pitch axes to their limits. If you don’t, your flight controller will be dealing with unsynchronized deflections of the propeller axis. If the PID algorithm design doesn’t know to correct for this, it can make for a really wild, literally uncontrollable ride when you start pushing the limits of thrust output.

Flying one of these things is not going to be like stomping on the gas and running through the gears. Think of them as flying motorcycles with no wings, but a parachute. The good thing is the autopilot isn’t going to let you run out of gas above the ground. (Unless the code for it is open source and you can modify it to make it your own, like not wearing a helmet when you ride a Hog. )