Hello!
Quadrs got a brilliant feachure - they takes RPM signals from motors and filter only thise frequensies. So, really bad quadr become fly awesome!
Why dont apply this idea to helis? We got motor RPM, we can count main and tail blades RPM and we can get a very fast and precise filter.
RPM filtering
Our sensor signal processing is working in the very similar way, except it is even more advanced. Helicopters have various noise signals as there are many gears and bearings and mechanics is much more complicated.
Spirit System developer