Tuesday, December 16, 2014

A Drone with two Rotors and no Swashplate

In order to be able to maintain attitude, a UAV or drone must be able to alter its rotors in some manor to create roll, pitch, yaw (for rotations), or linear motion in any of the three directions. Four rotor devices (quadcopters and tri-quads) do this by alternating the rotation of their props, and then changing each motor speed to attain directional or angular movement. Three rotor devices (tricopters) do this through the use of three props, with the angle of one of them controlled by a servo. Helicopters and other two rotor devices make use of a swash plate on one or both of their rotors.

The guys in the YouTube video above have devised a rotor mechanism that will react to changes in the torque of the motor upon the prop. The technical description is that they phase modulate the motor speed with respect to the other rotor. This, then, induces a change in the pitch of the rotor blades. Check out the video and then go here to check out some of the other devices they're making at UPenn.