An abnormality warning system provides an abnormality warning for multiple motor systems that drive a motor used correspondingly to each of multiple rotors included in an electric aircraft. The abnormality warning system includes an abnormality determination unit and a warning level setting unit. The abnormality determination unit determines an abnormal one of the motor systems. The warning level setting unit sets a warning level to warn abnormality, based on at least position information of the rotor in the electric aircraft or the usage of the rotor corresponding to a motor system determined to be abnormal by the abnormality determination unit.

A vibration attenuator for a rotor of an aircraft has a first ring with an eccentric weight, a coaxial second ring with an eccentric weight, and a central ring coaxial with the first and second rings and located therebetween. A first post extends from the first ring toward the central ring and is received in a first arcuate groove formed on the central ring, whereas a second post extends from the second ring toward the central ring and is received in a second groove formed on the central ring. A motor is configured for driving the central ring in rotation about the axis relative to the motor. The grooves are equal in length, and a center of the first groove is located on an opposite side from a center of the second groove. Rotation of the central ring by the motor causes rotation of the first and second rings.

One embodiment includes a structural panel for an aerospace vehicle, including a single sheet of material, the material having a first raised pattern on a first side, and a second raised pattern on a reverse side, wherein a repeating portion of the first raised pattern is substantially identical in size and shape to a repeating portion of the second raised pattern, and is rotated at an angle θ to the first raised pattern.

One embodiment includes a structural panel for an aerospace vehicle, including a single sheet of material, the material having a first raised pattern on a first side, and a second raised pattern on a reverse side, wherein a repeating portion of the first raised pattern is substantially identical in size and shape to a repeating portion of the second raised pattern, and is rotated at an angle θ to the first raised pattern.

A vibration attenuator for a rotor of an aircraft has a housing adapted for rotation with the rotor about an axis. A first ring is rotatably carried within the housing on a first bearing, a first weight being coupled to the first ring for rotation therewith relative to the housing about the axis. A second ring is rotatably carried by the first ring on a second bearing, a second weight being coupled to the second ring for rotation therewith relative to the housing and to the first ring. A first motor is configured for rotating the first ring relative to the housing, and a second motor is configured for rotating the second ring relative to the housing and to the first ring. The first and second motors are operated to rotate the weights within the housing and position the weights relative to each other for attenuating vibrations.

A load balancing system for a system of rotating elements such as a helicopter rotor or an airplane propeller. The load balancing system includes two or more balancing tubes rotationally attached to blades or props on the system of rotating elements. The balancing tubes are slightly curved and enclose a hollow space containing a quantity of weighted fluid such as mercury. During operation of the system of rotating elements, the weighted fluid disperses throughout the hollow space in the balancing tubes so as to counter any imbalance in the system of rotating elements. Centrifugal forces will cause different dispersal of the weighted fluid throughout the hollow space depending on the overall pulling or pushing forces resulting from any imbalance.

A system and method for protecting a rotorcraft from entering a vortex ring state, the method including monitoring a vertical speed of a rotorcraft, comparing the vertical speed to a vertical speed safety threshold, and performing vortex ring state (VRS) avoidance in response to the vertical speed exceeding the vertical speed safety threshold. The performing the VRS avoidance includes determining a power margin available from one or more engines of the rotorcraft, limiting the vertical speed of the rotorcraft in response to the power margin exceeding a threshold, and increasing a forward airspeed of the rotorcraft in response to the power margin not exceeding the threshold.

A vibration suppression unit for an aircraft comprising a vibration control frame adapted to be mounted to the aircraft and to rotate about a central axis, a first motor configured to rotate the vibration control frame about the central axis, a second motor configured to rotate a first and second center of mass about a first and second axis or rotation, a third motor configured to adjust a variable distance between the first and second centers of mass and the first and second axis of rotation, respectively, and a controller for receiving input signals and outputting command signals to the first, second and third motors.

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.

An unmanned aerial vehicle comprising at least one rotor motor. The rotor motor is powered by a micro hybrid generation system. The micro hybrid generator system comprises a rechargeable battery configured to provide power to the at least one rotor motor, a small engine configured to generate mechanical power, a generator motor coupled to the small engine and configured to generate AC power using the mechanical power generated by the small engine, a bridge rectifier configured to convert the AC power generated by the generator motor to DC power and provide the DC power to either or both the rechargeable battery and the at least one rotor motor, and an electronic control unit configured to control a throttle of the small engine based, at least in part, on a power demand of at least one load, the at least one load including the at least one rotor motor.