Quadrotor configuration I think is the most common configuration for drones. Why has it not been made into a full-size production aircraft? I think that it could be better than helicopters as it does not need a tail.
In: Engineering
Quadrotors don’t scale up well because of how they are controlled.
A traditional helicopter has the blades spinning at a more or less constant speed. Control comes from altering the pitch of the blades, either one at a time at a certain part of the rotor disc for pitch and bank (cyclic) or all at once to increase and decrease overall lift (collective).
A quadrotor, on the other hand, uses blades with a fixed pitch. It is controlled by varying the speeds of the blades. This means that the speed of control inputs is limited by how rapidly the speed of the blades can be changed.
With small plastic blades a few inches long, the torque required to rapidly increase or decrease the speed at which the blades are spinning is manageable.
On a quadrotor the size of a large helicopter, on the other hand, this would require massive amounts of torque applied very rapidly. You’d need to use heavy, hugely overbuilt electric motors, stronger, thicker blades, and a power system that can buffer that kind of sudden shift in power delivery. All of this would add a good deal of weight, and simply wouldn’t be practical.
Latest Answers