Abstract: An actively controlled mount system to control vibration which permits static forces from a machine while decoupling the transmission of dynamic vibrational forces. The mount system provides a reduction of force losses from a first generating area to a second force applying area to actively control vibrations of a vibrating element. These force losses are minimized due to minimization of the mass and velocity of fluid pumped by pumping the fluid through short large cross-sectional area passageways. The device provides for channeling of the forces to the vibrating element in a uniaxial direction and constrains the application of forces in non-working directions.

Abstract: A method and system for altering the frequency or harmonic spectra of a disturbance characterized by an output generator (26) and a response generator (24) that cooperate to produce shaped control signals in response to first input signals (23).

Abstract: A method and apparatus is described for actively canceling a primary noise source to produce a desired noise level at at least one location. The apparatus comprises a signal processor which drives at least one actuator, at least one error sensor and a primary noise reference signal. The error sensors are positioned proximate to each of the locations. The output of the error sensors and the primary noise reference signal are sent to the signal processor. The relationship between the driving output of the processor and the output of the error sensors is modeled by a block of filter coefficients. Based upon the model and the primary noise reference signal, the processor drives the actuator to generate a canceling noise at the location. The processor calculates differences between the desired noise level and the output of the sensors. A variable convergence factor and a gradient block are derived from the residual noise and are used to adapt the filter coefficients.

Abstract: Active system for both attenuating mechanical vibration and the noise occasioned by the operation of vibratory feeder bowls in manufacturing having accelerometer (20) adjacent feeder bowl (21) and an inertial actuator (57) and a controller (59) to control both disturbances.

Abstract: A wireless remote active noise canceling headset including residual microphones (35, 34) mounted on the headset (30) with speakers (32, 33) located adjacent to the residual microphones and an algorithm driven synchronous controller to operate said headset.

Abstract: A multiple-input, multiple-output adaptive control system which utilizes perturbations to the frequency components of the outputs to determine the desired changes to said coefficients. The control system is particularly suited to the active control of noise and vibration.

Abstract: An actively controlled mount system to control vibration which permits static forces from a machine while decoupling transmission of dynamic vibration forces. The mount system includes opposed force chamber (156, 160) with pistons which control movement of an engine connected bushing (3) to allow compensatory force generated by the opposed chambers to transfer thereto to attenuate vibration from the engine.

Abstract: An apparatus and method of actively cancelling undesirable acoustic noise generated by a patient diagnosing apparatus during a diagnosis operation which includes a remotely located active noise cancellation unit. The undesirable acoustic noise is transferred via hollow tubes from the patient diagnosing apparatus to the remote location to be detected thereat. A control unit thereafter generates cancellation waves based upon the detected undesirable acoustic noise. The cancellation waves are transferred to the patient area via additional hollow tubes to cancel the undesirable acoustic noise. The use of hollow tubes of non-magnetic, non-metallic material ensures that the undesirable acoustic noise and the cancellation waves do not interfere with the diagnosis of operation.

Abstract: An active high transmission loss panel for quieting either one or two way sound radiation which incorporates a number of cells (11) which contain sensors and actuators (12) adapted to be controlled independently or interactively so as to attenuate noise attempting to pass through said panel.

Abstract: An active force cancellation system adapted to contain vibrations in flexible structures which utilizes co-located vibration sensors and counter-vibration devices to offset linear disturbances without setting off sub-structure vibrations.

Abstract: An in wire active cancelling system cancels undesirable repetitive signal components from a primary electronics signal controlling desired intelligent signal components and undesirable repetitive signal components. The primary electronic signal is fed as an input to an electronic mixer. A second input to the electronic mixer is a repetitive cancelling signal which is applied by the mixer to cancel the undesirable repetitive signal component from the primary signal without interfering with passage of the primary signal intelligent signal components. The repetitive cancellation signal is developed from a residual signal developed by the mixer and a timing signal obtained from a timing signal generator.

Abstract: A digital virtual earth active cancellation system which receives a phenomena input signal representing residual phenomena to be cancelled and has an adaptive filter which generates a cancellation signal. A system impulse response is convolved with the cancellation signal and is subtracted from the input signal to produce an estimate of noise. This substantially eliminates the problems associated with destructive feedback due to phase shifts. The residual signal is used to control an adaptive filter that receives the estimated noise as an input. The adaptive filter produces the cancellation signal by filtering the estimated noise with filter weights that are adapted using the residual signal and the estimated noise convolved with the system impulse response.

Abstract: A detector used in apparatus for measuring variations in the composition of a liquid includes a cell utilizing the Christiansen effect on light transmitted by the liquid flowing through the cell filled with particulate matter. The liquid and the particulate matter have indices of refraction that are substantially equal to one another at a specific wavelength. Variations of the transmitted light can determine changes of the refractive index of the liquid.Differences in the intensity of light transmitted through a sample cell and a reference device can be determined.

Abstract: A confined system of sound transmission from a frequency attenuation compensated source through plastic pneumatic tubes in series with liquid tubes of considerable length, transmitting audio to and through pneumatic headphones to the ear canals of the user. It is an audio system suitable for use in Nuclear Magnetic Resonance scanning environments and for use in CAT scan environments. The system includes a stereo program source playing into a stereo frequency compensation amplifier driving right and left loudspeaker pneumatic drivers feeding audio to and through long liquid tubes in series with pneumatic tubes extended to left and right earphones of plastic headphones worn by a patient in a scan room environment.