A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis; and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses; and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and each control unit comprises: a belt coupled to the support assembly and a drive unit coupled to the first belt, to cause the rotation of the first support assembly with respect to said transmission device.

A vibration attenuation system as shown and described.

In one aspect, the present disclosure provides a system for reducing vibrations or stresses in a rotor blade system. The system may include at least three rotor blades configured to be rotated about a main rotor axis, where each of the three rotor blades may be adjusted by at least one electrically-adjustable control rod of a plurality of control rods. The plurality of control rods may include a first number of control rods forming a first group, and the plurality of control rods may include a second number of control rods forming a second group. A first circuit for may activate or deactivate the first group of control rods, and a second circuit may activate or deactivate the second group of control rods.

A rotary blade aircraft includes an airframe, a rotor shaft driven about a rotor axis, and a plurality of rotor blades driven by the rotor shaft about the rotor axis. The rotary blade aircraft includes a swashplate assembly coupled to the plurality of rotor blades. The swashplate assembly is operable to move the plurality of rotor blades about a respective longitudinal axis. The rotary blade aircraft includes a hydraulic control servo coupled between the airframe and the swashplate assembly. The hydraulic control servo is operable to move the swashplate assembly relative to the rotor axis. The rotary blade aircraft includes a harmonic control actuator coupled between the airframe and the swashplate assembly. The harmonic control actuator is operable independently relative to the hydraulic control servo to move the swashplate assembly relative to the rotor axis to reduce vibration at selected frequencies in the airframe.

Systems and method for active vibration control on an aircraft. An active vibration control system (AVCS) is configured for an aircraft having an aircraft structure and a gun. The AVCS includes at least one control sensor on the aircraft, at least one force generator on the aircraft, and at least one controller in electronic communication with the sensor and the force generator. The controller is configured for determining, using the at least one control sensor, force generating commands for controlling vibrations acting on the aircraft structure, sending the force generating commands to the at least one force generator, causing the at least one force generator to produce a vibration canceling force, determining that the gun is firing, and in response to determining that the gun is firing, determining different force generating commands and sending the different force generating commands to the at least one force generator.

Systems and methods relate to a vertical takeoff and landing (VTOL) platform that can include a stator and a rotor magnetically levitated by the stator. The rotor and stator can be annular, such that the rotor rotates about a rotational axis. The stator can include magnets that provide guidance, levitation, and drive forces to drive the rotor, as well as to control operation of rotor blades of the rotor that can be independently rotated to specific pitch angles to control at least one of lift, pitch, roll, or yaw of the VTOL platform. Various controllers can be used to enable independent and redundant control of components of the VTOL platform.

Systems and methods relate to a vertical takeoff and landing (VTOL) platform that can include a stator and a rotor magnetically levitated by the stator. The rotor and stator can be annular, such that the rotor rotates about a rotational axis. The stator can include magnets that provide guidance, levitation, and drive forces to drive the rotor, as well as to control operation of rotor blades of the rotor that can be independently rotated to specific pitch angles to control at least one of lift, pitch, roll, or yaw of the VTOL platform. Various controllers can be used to enable independent and redundant control of components of the VTOL platform.

A rotor for a hover-capable aircraft is described that comprises: a hub rotating about an axis and, in turn, comprising a plurality of blades, a mast connectable to a power unit of the aircraft and operatively connected to the hub to drive the hub in rotation about said axis, and an attenuating device to attenuate the transmission of vibrations from the mast to the aircraft parallel to said; the attenuating device, in turn, comprising a casing, a first mass free to oscillate parallel to said axis with respect to the casing and elastically connected to the casing, a second mass free to oscillate parallel to said axis, connection means adapted to make the first and second masses integrally movable along said axis when the angular speed of the mast assumes a first value, and actuator means activatable to decouple the first and second masses when the angular speed of the mast assumes a second value, different from the first value.

A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis, and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses, and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and comprises a set of drive gear teeth integral with the first support assembly, a cogwheel with a set of control gear teeth meshing with the drive gear teeth, and an actuator to cause the rotation of the cogwheel about a second axis and of the first mass about said first axis.

An aircraft is provide including an airframe, an extending tail, and a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly. A translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe. At least one flight control computer configured to independently control the upper rotor assembly and the lower rotor assembly through a fly-by-wire control system. A plurality of sensors to detect sensor data of at least one environmental condition and at least one aircraft state data, wherein the sensors provide the sensor data to the flight control computer.