A vibration control element includes a nanovoided polymer layer having a first damping coefficient and a first resonance frequency in a first state and a second damping coefficient and a second resonance frequency in a second state, where the first damping coefficient is different from the second damping coefficient and the first resonance frequency is different from the second resonance frequency.

An electronic device is provided, including: a vibration plate; a frame structure supporting the vibration plate, the frame structure including an installation portion parallel to and opposite to the vibration plate and a border bent at an edge of the installation portion and extending along both sides of the installation portion. The vibration plate is supported on a side of the installation portion, and a preset gap is provided between the vibration plate and the border. The electronic device further includes a middle frame fixed between the installation portion and the vibration plate. The middle frame is fixedly connected to the vibration plate, an actuator is fixed to the middle frame and drives the middle frame so that the middle frame drives the vibration plate to vibrate and sound. The electronic device further includes a damper sandwiched between the middle frame and the installation portion.

An aircraft seat assembly for supporting a seat occupant, and a method for fabricating an aircraft seat assembly for supporting a seat occupant are provided. In one non-limiting example, the aircraft seat assembly includes a seat structure and a seat cushion that is supported by the seat structure. A vibration mitigating apparatus is operatively coupled to the seat structure to prevent or reduce vibrations from transferring to the seat occupant.

A vibration control device of a plate-like member 11 includes: a plurality of piezoelectric element actuators 14; at least one piezoelectric element sensor 15; and a control circuit 17 that performs feedback control of operation of the piezoelectric element actuators 14 based on an output voltage of the piezoelectric element sensor 15 so as to suppress vibration of the plate-like member 11. A layout of the piezoelectric element sensor 15 and the piezoelectric element actuators 14 is set such that anti-resonance occurs in an output voltage of the piezoelectric element sensor 15 in a range where the vibration frequency of the plate-like member 11 is equal to or less than a predetermined value. Therefore, generation of noise can be prevented at the frequency. As a result, a gain can be increased at a control target frequency. Therefore, vibration can be suppressed, and noise can be reduced.

An aircraft seat assembly for supporting a seat occupant, and a method for fabricating an aircraft seat assembly for supporting a seat occupant are provided. In one non-limiting example, the aircraft seat assembly includes a seat structure and a seat cushion that is supported by the seat structure. A vibration mitigating apparatus is operatively coupled to the seat structure to prevent or reduce vibrations from transferring to the seat occupant.

The disclosure relates to an active vibration absorption system for absorbing the vibrations of a vibrating element. The vibration absorption system comprises a structure-borne sound exciter having a coupling element for coupling to the vibrating element and having an electrical coil for moving the coupling element by means of a coil current. The structure-borne sound exciter is designed to provide a measurement signal correlated with a detected induced voltage. Furthermore, the vibration absorption system comprises a control device, which is designed to identify a target current intensity of the coil current in accordance with the measurement signal and to control an actual current intensity of the coil current to the target current intensity. The target current intensity is designed to adjust the motion of the coupling element in such a way that the vibrations of the element are at least partly absorbed. Moreover, the control device is designed to identify a detection component and a control component from the measurement signal and to identify the target current intensity in accordance with the detection component.

A system for airfoil vibration control is generally provided. The system includes an airfoil including a ferromagnetic material, and a static structure including an electromagnet adjacent to the ferromagnetic material of the airfoil. A method for controlling vibration at an airfoil of a turbo machine is further provided. The method includes placing a ferromagnetic material at the airfoil, placing an electromagnet at a static structure adjacent to the ferromagnetic material at the airfoil, and applying an electromagnetic force to the ferromagnetic material at the airfoil via the electromagnet at the static structure.

A system for proactively adjusting to impact forces has first and second walls spaced apart from one another to define a stationary enclosed cavity therebetween; a movable member inside the enclosed cavity; an actuator; a proximity sensor; computer memory; a processor in data communication with the actuator, the proximity sensor, and the computer memory; programming causing the processor to determine a potential impact location on at least one of the first and second walls using data obtained from the proximity sensor; and programming causing the processor to activate the actuator based on the potential impact location, activation of the actuator causing the movable member to move inside the enclosed cavity prior to receiving the impact forces.

A computer of an active vibration damping device calculates operation command values for an actuator from rotation information of a drive source, and corrects the operation command values in accordance with an internal temperature of the actuator. The computer applies a drive voltage to the actuator using a voltage duty ratio based on the corrected operation command values. The computer also estimates the internal temperature on the basis of an average duty ratio as an average of the voltage duty ratios in a predetermined interval.

In one embodiment, certain aspects of forces at a structural interface applied by one actuator are mitigated by a secondary actuator that applies a secondary force. In some embodiments the secondary actuator applies a static force. In yet another embodiment, an actuator is used to apply a force on a wheel assembly of a vehicle to detect and/or ameliorate the effect of certain tire incongruities.