A helicopter includes a propulsion system, gimbal assembly, and a controller. The propulsion system includes a first and second rotor assembly, wherein the first rotor assembly comprises a first motor coupled to a first rotor, the first rotor comprising a plurality of first fixed-pitch blades and the second rotor assembly comprises a second motor coupled to a second rotor, the second rotor comprising a plurality of second fixed-pitch blades. The second rotor is coaxial to the first rotor and is configured to be counter-rotating to the first rotor. The controller is communicably coupled to the gimbal assembly and is configured to provide instructions to at least one of the first or second gimbal motors in order to orient the plurality of first and second fixed-pitch blades into a position that permits wind to rotate the first and second fixed-pitch blades and thereby charge the power source.

A collapsible flying device is provided having a housing including first and second housing sections forming an enclosure, and a motorized assembly that includes a drive motor and a drive shaft driven by the drive motor. The drive shaft matingly receives the first housing section and is coupled to the second housing section, wherein operation of the drive motor drives the drive shaft to move the first housing section from a closed position adjacent the second housing section to an open position spaced from the second housing section. A rotor hub is rotatingly driven by the drive motor. At least two rotor blades are coupled thereto and positioned within the enclosure in a collapsed position when the first housing section is in the closed position, and extend beyond the enclosure in an expanded position when the first housing section is in the open position.

Aerial vehicles may be equipped with propellers having pivotable blades that are configured to rotate when the propellers are not rotating under power. A pivotable blade may rotate about an axis of a propeller with respect to a hub until the pivotable blade is coaligned with a fixed blade. When the propeller is rotating a lifting force from the blade may cause the blade to rotate to a deployed position that is not coaligned with the fixed blade.

A rotary wing drone according to one embodiment of the present invention comprises: a flight control unit for controlling the flight of the rotary wing drone; a main body including a first motor and a second motor; an upper shaft vertically inserted into the main body and rotating in a first direction around a first axis by means of the force of the first motor; a plurality of upper rotor blades connected to the upper shaft such that the plurality of upper rotor blades rotate in the first direction around the first axis at a fixed pitch angle; a lower shaft vertically inserted into the main body and rotating in a second direction opposite to the first direction around the first axis by means of the force of the second motor; a plurality of lower rotor blades and a swash plate connected to the lower shaft so as to rotate in the second direction around the first axis and having a variable pitch angle; a slope regulator for regulating the slope of the swash plate; a link part for connecting the swash plate to the plurality of lower rotor blades; and a pitch control unit positioned at the lower ends of the plurality of lower rotor blades.

This disclosure describes aerial vehicles and systems for altering the noise generated by the rotation of a propeller during flight of the aerial vehicle. In some implementations, propellers of the aerial vehicle are paired in a coaxially aligned configuration in which the pair of propellers both rotate in the same direction, are rotationally phase aligned, and separated a defined distance so that the noise from high pressure pulse of the induced flow from the lower propeller is at least partially canceled out by the noise of the high pressure pulse of the induced flow from the upper propeller.

An Unmanned Aerial Vehicle (UAV) has a first blade assembly configured to rotate in a first direction about an axis of rotation and a second blade assembly configured to rotate in a second direction opposite the first direction about the axis of rotation, wherein the second blade assembly can be selectively cocked relative to the axis of rotation.

A vertical take-off and landing aircraft includes a primary rotor unit having a rotor axis, an upper rotor system, and a lower rotor system. The upper rotor system includes an upper swashplate configured to translate along the rotor axis and not configured to tilt relative to the rotor axis and a pair of top blades configured to rotate about the rotor axis. Translation of the upper swashplate causes a pitch of each of the top blades to change equally. The lower rotor system includes a lower swashplate configured to translate along the rotor axis and not configured to tilt relative to the rotor axis and a pair of bottom blades configured to rotate about the rotor axis. Translation of the lower swashplate causes a pitch of each of the bottom blades to change equally. The aircraft further includes a plurality of secondary rotors each having fixed-pitch rotor blades.

A vertical take-off and landing aircraft includes a primary rotor unit having a rotor axis, an upper rotor system, and a lower rotor system. The upper rotor system includes an upper swashplate configured to translate along the rotor axis and not configured to tilt relative to the rotor axis and a pair of top blades configured to rotate about the rotor axis. Translation of the upper swashplate causes a pitch of each of the top blades to change equally. The lower rotor system includes a lower swashplate configured to translate along the rotor axis and not configured to tilt relative to the rotor axis and a pair of bottom blades configured to rotate about the rotor axis. Translation of the lower swashplate causes a pitch of each of the bottom blades to change equally. The aircraft further includes a plurality of secondary rotors each having fixed-pitch rotor blades.

A hover-capable flying machine such as a drone includes a robotic arm extending from the body, and an instrumentality for balancing the machine in response to disturbances such as those caused by picking up and dropping of the payload by the extended robotic arm. In embodiments, the end of the arm is equipped with a balancing rotor assembly that may provide lift sufficient to counteract the weight of the payload and/or of the arm. In embodiments, the machine's power pack is shifted in response to the disturbances. The power pack may be moved, for example, on a rail within and/or extending beyond the machine in a direction generally opposite to the extended arm. The power pack may also be built into a bandolier-like device that can be rolled-in and rolled out, thus changing the center of gravity of the machine.

Sounds are generated by an aerial vehicle during operation. For example, the motors and propellers of an aerial vehicle generate sounds during operation. Systems, methods, and apparatus may actively adjust the position and/or configuration of one or more propeller blades of a propulsion mechanism to generate different sounds and/or lifting forces from the propulsion mechanism.