Virginia Tech Intellectual Properties, Inc.

Ford Global Technolgoies, LLC

E.i. Dupont De Nemours and Company

Defense Research Technologies, Inc.

Christopher R Fuller

Kathleen Kondylas

Keng D Hsueh

Francois Charette

Ricardo A Burdisso

Andrew Dayton Phillips

Vy Tran

Pierre E Cambou

Gary Boes

Bill Covitz

Tadeusz M Drzewiecki

Joseph A King, Jr

Mark Allan Lamontia

Natalia V Levit

Russell H Thomas

Jerome Peter Smith

John B Niemczuk

Larry Duane Hollingsworth

Julien Maillard

Garland Lee

David M Mellen

Joseph A King

Vibration or acoustic sound control is achieved using an elastic layer of thermal or insulation material in which a plurality of discrete masses are distributed throughout. The elastic layer may be installed as a pre-formed layer, or be blown into position within a structure where vibration or acoustic sound control is required.

Active/passive distributed absorber for vibration and sound radiation control

A passive distributed vibration absorber that utilizes multiple discrete mass elements and a viscoelastic layer and that effectively attenuates vibration in modally dense structures excited by a broadband input noise excitation. and is tunable to multiple natural frequencies in such modally dense vibrating structures including low frequencies.

Broadband passive distributed tuned vibration and acoustic absorber for modally dense structures

The active/passive absorber for extended vibration and sound radiation control includes principally two layers. The first layer has a low stiffness per unit area which allows motion in the direction perpendicular to its main plane. The second layer is principally a mass layer. These two combined layers have a frequency of resonance close to one of the main structure. The dynamic behavior of the coupled system makes the active/passive absorber a passive absorber; however, the first layer can be electrically actuated to induce motion in the direction perpendicular to its main plane. This addition property induces and/or changes the motion of the mass layer and therefore improves the dynamic properties of the active/passive absorber system. The active/passive absorber can have multiple mass layers and multiple elastic layers stacked one on top of the other. In addition, the mass layers can be continuous or discretized, and have varying thicknesses and shapes for sections and/or segments in the mass layer.

The active/passive absorber for extended vibration and sound radiation control includes principally two layers. The first layer has a low stiffness per unit area which allows motion in the direction perpendicular to its main plane. The second layer is principally a mass layer. These two combined layers have a frequency of resonance close to one of the main structure. The dynamic behavior of the coupled system makes the active/passive absorber a passive absorber; however, the first layer can be electrically actuated to induce motion in the direction perpendicular to its main plane. This addition property induces and/or changes the motion of the mass layer and therefore improves the dynamic properties of the active/passive absorber system. The acive/passive absorber can have multiple mass layers and multiple elastic layers stacked one on top of the other. In addition, the mass layers can be continuous or discretized, and have varying thicknesses and shapes for sections and/or segments in the mass layer.

The active/passive absorber for extended vibration and sound radiation control includes principally two layers. The first layer has a low stiffness per unit area which allows motion in the direction perpendicular to its main plane. The second layer is principally a mass layer. These two combined layers have a frequency of resonance close to one of the main structure. The dynamic behavior of the coupled system makes the active/passive absorber a passive absorbe; however, the first layer can be electrically actuated to induce motion in the direction perpendicular to its main plane. This addition property induces and/or changes the motion of the mass layer and therefore improves the dynamic properties of the active/passive absorber system.

An extracting assembly for extracting a component signal generated by a component source from a composite signal is disclosed wherein a reference sensor generates a reference signal relating to activity of the component source, a composite sensor senses the composite signal, an adaptive filter is operatively connected to the reference sensor and the composite sensor to filter the component signal from the composite signal as a function of the reference signal generated by the reference sensor, and a normalizer operatively connected to the adaptive filter for normalizing the step size of each iteration taken by the adaptive filter to minimize the time to adapt the adaptive filter to transform the reference signal into the component signal.

Method and apparatus for extracting a component signal from a composite signal

The recreation of vibration levels at certain points in a stationary vehicle interior that are representative of realistic road conditions are achieved using road measurements in conjunction with a technique known as 'reciprocal filtering.' The reciprocal filtering technique consists of using an inverse transfer function, or impulse response in the time domain, between an excitation transducer and an accelerometer to calculate the excitation signal needed to recreate the vibrations measured on the road when squeak and rattle are present in a component of the vehicle. A set of excitation signals may be recorded for each component in the vehicle which is suspected of producing squeak and rattle noise. When a complaint is made that a vehicle is producing squeak and rattle, a service technician may reproduce noise by inducing vibrations through a kit having a CD player, an amplifier, a bass shaker and a CD with the set of excitation signals stored on separate tracks thereof. The bass shaker is attached, for example with two side tape, to the component suspected of producing noise, and noise inducing vibrations are played from the CD, through the CD player and amplifier, to the bass shaker. In this way, squeak and rattle may be quickly identified and repaired.

System for diagnosing unexpected noise in a multi-component assembly

Method for determining and reproducing noise inducing vibrations in a

Reduction or cancellation of acoustic noise is achieved by providing an amplified, oppositely phased version of the noise by means of an acousto-fluidic amplifier. The amplified acoustic output noise is delivered through an impedance matching horn in destructively interfering relation with the original noise. Depending on the acoustic noise source and its spatial distribution, the acousto-fluidic amplifier may be a single stage amplifier or multiple stages connected in parallel and/or cascade, with output horns spatially distributed to have the maximum cancellation effect. Sensed noise, prior to fluidic amplification, may be processed in a manner to effect feedback or feedforward control of the amplified acoustic output signals.

Acousto-fluidic driver for active control of turbofan engine noise

Growing community of inventors

Virginia Beach, VA, United States of America

Christopher R Fuller