A method for cancelling vibration includes receiving, from a first accelerometer, a first accelerometer measurement; receiving, from a second accelerometer, a second accelerometer measurement; determining a counter torque value based on the first accelerometer measurement and the second accelerometer measurement; and selectively controlling a lift mechanism according to the counter torque value using a motor, the motor being in mechanical communication with the lift mechanism and the lift mechanism being configured to allow a platform to travel in one of a first direction and a second direction.

A vibration suppression unit for an aircraft comprising a mass having a center of mass, a first rotor, a second rotor, a first coupling between the first rotor and the mass, a second coupling between the second rotor and the mass, the first and second couplings having first and second coupling centers offset perpendicularly from a central axis of rotation by different radial distances and offset in axially from the center of mass with respect to the central axis by different axial distances, the first and second coupling centers having a selectively variable displacement angle defined by the angle between lines extending between the central axis of rotation and the first coupling center and the second coupling center, respectively, wherein the first rotor and the second rotor are controllable to produce a vibration control force vector having a controllable magnitude and frequency about the central axis.

The present damper device includes a large hysteresis mechanism, generating a large hysteresis torque, and a hysteresis inhibiting mechanism. In a positive-side torsional region, when relative rotation is performed until reaching a maximum torsion angle from a neutral position, the hysteresis inhibiting mechanism deactivates the large hysteresis mechanism until the relative rotation reaches a first torsion angle from the neutral position, but activates the large hysteresis mechanism until the relative rotation reaches the maximum torsion angle from the first torsion angle; and when the relative rotation is performed until reaching the neutral position from the maximum torsion angle, the hysteresis inhibiting mechanism deactivates the large hysteresis mechanism until the relative rotation reaches a second torsion angle less than the first torsion angle from the maximum torsion angle, but activates the large hysteresis mechanism until the relative rotation reaches the neutral position from the second torsion angle.

A method for cancelling vibration includes receiving, from a first accelerometer, a first accelerometer measurement; receiving, from a second accelerometer, a second accelerometer measurement; determining a counter torque value based on the first accelerometer measurement and the second accelerometer measurement; and selectively controlling a lift mechanism according to the counter torque value using a motor, the motor being in mechanical communication with the lift mechanism and the lift mechanism being configured to allow a platform to travel in one of a first direction and a second direction.

A method for cancelling vibration includes receiving, from a first accelerometer, a first accelerometer measurement; receiving, from a second accelerometer, a second accelerometer measurement; determining a counter torque value based on the first accelerometer measurement and the second accelerometer measurement; and selectively controlling a lift mechanism according to the counter torque value using a motor, the motor being in mechanical communication with the lift mechanism and the lift mechanism being configured to allow a platform to travel in one of a first direction and a second direction.

Circular force generator devices (100), systems, and methods for damping vibrations which include two complementary rotor assemblies (110, 120) that are rotatable together about a common shaft (102) but that have an adjustable rotational position (P1, P2) with respect to one another such that a significant reduction in rotor inertia and bearing drag relative to conventional CFG configurations is provided. The present architecture creates virtually zero rotating moment.

Circular force generator devices (100), systems, and methods for damping vibrations which include two complementary rotor assemblies (110, 120) that are rotatable together about a common shaft (102) but that have an adjustable rotational position (P1, P2) with respect to one another such that a significant reduction in rotor inertia and bearing drag relative to conventional CFG configurations is provided. The present architecture creates virtually zero rotating moment.

A torsional vibration damper includes a planetary rotary unit and an elastic body that couples two rotary elements of three rotary elements so that the two rotary elements can rotate relatively to each other. The torsional vibration damper includes a shaft supporting member by which a rotation center axis of at least any one rotary element of the two rotary elements and a rotation center axis of the rotary element other than the planetary rotary unit and the two rotary elements are held on the same axis. The shaft supporting member has a holding section that is disposed in a position between fellow planetary rotary elements and not making contact with the planetary rotary elements and that fits with and thereby suppresses movement of the rotary element other than the planetary rotary unit and the two rotary elements in the axial direction.

A torsional vibration damper includes a planetary rotary unit and an elastic body that couples two rotary elements of three rotary elements so that the two rotary elements can rotate relatively to each other. The torsional vibration damper includes a shaft supporting member by which a rotation center axis of at least any one rotary element of the two rotary elements and a rotation center axis of the rotary element other than the planetary rotary unit and the two rotary elements are held on the same axis. The shaft supporting member has a holding section that is disposed in a position between fellow planetary rotary elements and not making contact with the planetary rotary elements and that fits with and thereby suppresses movement of the rotary element other than the planetary rotary unit and the two rotary elements in the axial direction.

The disclosure is directed at a method and apparatus for controlling unwanted vibrations in a mechanical system. The apparatus includes a set of different eccentric and/or concentric masses mounted to the mechanical system for generating forces to counteract the sensed unwanted vibrations. The apparatus further includes a set of motors that control movement of the set of masses.