Brigham Young University

Caterpillar Inc.

Mag Aerospace Industries, Inc.

Scott D Sommerfeldt

Benjamin Mahonri Faber

Kent L Gee

David C Copley

Scott L Thomson

Razmik B Boodaghians

David A Beach

John Yu

Jonathan Blotter

Garen Bowen Murray

Michael Rose

Curtis Lynn Garner

David Ji Chun Kim

Jonathan Daren Blotter

A system comprises error microphones disposed in a predetermined pattern to capture audio signals including speech and one or more reference sensors to capture a reference noise signal from a noise source. A portion of the reference noise signal is removed from the captured audio signals to generate partially processed audio signals, which are paired to form signal pairs. For each signal pair, a modified cross-correlation vector, with effects of low frequency contents removed, is generated, then converted to a rotated angular domain cross-correlation vector based in part on a physical angle associated with locations of an associated pair of error microphones. The rotated angular domain cross-correlation vectors are summed, and a weighting vector is applied to the sum to identify direction information of a desired audio signal associated with the speech. The directional information is utilized to beamform the partially processed audio signals and output the desired audio signal.

Detection of audio communication signals present in a high noise environment

The embodiments disclosed herein are directed towards vacuum-assisted toilet systems and methods of using the vacuum-assisted toilet systems. An example vacuum-assisted toilet system includes a toilet bowl defining an outlet and a flush valve fluidly coupled to the outlet. The vacuum-assisted toilet system also includes at least one water source fluidly coupled to the toilet bowl. The water source is configured to supply water to the toilet bowl. The vacuum-assisted toilet system also includes at least one water actuator coupled to the water source. The water actuator is configured to control the amount of water that is supplied by the water source to the toilet bowl. The vacuum-assisted toilet system also includes a controller that is configured to at least partially control the operation of one or more components of the vacuum-assisted toilet system, such as at least one of the flush valve or the water actuator.

Vacuum-assisted toilet systems and methods of using the same

Embodiments disclosed herein are directed towards noise reduction pipes, vacuum-assisted toilet systems including the same, and methods of using the same. An example noise reduction pipe includes a first end and a second end that is opposite the first end. The first end is configured to be coupled to an outlet of a toilet bowl and the second end is configured to be coupled to an inlet of a flush valve. The noise reduction pipe defines a fluid flow path that extends between the first end and the second end such that waste may flow from the first end to the second end. The noise reduction pipe also includes one or more bends. Each of the bends exhibits a radius of curvature that is greater than about 5 cm or a length that is greater than about 30 cm.

Noise reduction pipes, vacuum-assisted toilet systems including the same, and methods of using the same

An example vacuum-assisted toilet includes a toilet bowl including an outlet. The outlet of the toilet bowl is fluidly coupled to a first flush valve, for example, using a first pipe. The first flush valve is fluidly coupled to a second flush valve that is positioned downstream from the first flush valve. For example, the first flush valve may be fluidly coupled to the second flush valve using a second pipe. The second flush valve is fluidly coupled to a vacuum source. The vacuum source may include, for example, a holding tank having a vacuum pressure therein, a vacuum pump, or any other suitable vacuum source.

Embodiments of the present disclosure relate generally to systems and methods for reducing sound in vacuum toilets. In one example, multiple rinse injections are used at appropriately timed intervals in order to reduce the vacuum flush sound levels.

Multiple rinse injections to reduce sound in vacuum toilets

A method for measuring performance of a noise cancellation system that is operable to cancel noise is provided. The method includes generating a first model of a target noise. The first model represents the target noise in a form that is received at a location remote from a noise source of the target noise and within a defined environment. The method also includes generating a second model of a cancellation noise. The cancellation noise is configured to at least partially cancel the target noise when combined with the target noise. The second model represents the cancellation noise in a form that is received at the location. The method also includes determining, using the first model and the second model, a cancellation error value indicative of only a portion of the target noise that remains when the target noise and the cancellation noise are combined. The method also includes transmitting the determined cancellation error value to a module operable to monitor a performance level of the noise cancellation system.

Methods and systems for measuring performance of a noise cancellation system

Methods for modeling the secondary path of an ANC system to improve convergence and tracking during noise control operation, and their associated uses are provided. In one aspect, for example, a method for modeling a secondary path for an active noise control system is provided. Such a method may include receiving a reference signal, filtering the reference signal with an initial secondary path model to obtain a filtered reference signal, calculating an autocorrelation matrix from the filtered reference signal, and calculating a plurality of eigenvalues from the autocorrelation matrix. The method may further include calculating a maximum difference between the plurality of eigenvalues and iterating a test model to determine an optimized secondary path model having a plurality of optimized eigenvalues that have a minimized difference that is less than the maximum difference of the plurality of eigenvalues, such that the optimized secondary path model may be utilized in the active noise control system.

Secondary path modeling for active noise control

A method for detecting failure in a noise cancellation system is provided. The noise cancellation system is operable to at least partially cancel an unwanted noise produced by a noise source. The method includes receiving a cancellation noise signal from the noise cancellation system. The cancellation noise signal represents a cancellation noise that, when combined with a target noise, is operable to at least partially cancel the target noise. The method also includes receiving an error signal approximately representing a portion of the target noise that remains after the cancellation noise and the target noise are combined. The method also includes determining whether the signal level changed or remains unchanged for each of the received cancellation noise signal and the error signal. The method also includes assigning a failure state of the noise cancellation system based on the determination and initiating a remedial measure that corresponds with the assigned failure state.

Methods and systems for controlling noise cancellation

A method for controlling a noise cancellation system having an adaptive control portion is provided. The noise cancellation system is operable to generate a cancellation noise configured to at least partially cancel an unwanted noise in a defined environment. The adaptive control portion is operable to adjust the operation of the noise cancellation system based on a level of unwanted noise that remains when the cancellation noise and the unwanted noise are combined. The method includes receiving an error signal representing a portion of a noise not cancelled by a cancellation noise, where the cancellation noise is generated from the noise cancellation system. The method also includes determining whether the level of the error signal exceeds a first threshold value for a first predetermined period of time. The method also includes calculating a crest factor using the error signal. The method also includes determining whether the crest factor exceeds a second threshold value. The method also includes deactivating the adaptive control system and continuing to operate the noise cancellation system if the error value exceeds the first threshold value for the predetermined period of time and the crest factor exceeds the second threshold value.

Methods and systems for determining the effectiveness of active noise cancellation

A system and method of reducing noise in an enclosure is disclosed. The method includes receiving at least one reference signal; receiving pressure signals from no more than two substantially orthogonally placed pairs of acoustic sensors, where one pair of acoustic sensors is in the x-direction and one pair of acoustic sensors is in the y-direction, and where the acoustic sensors are placed in a plane which is substantially parallel and in proximity to an inner surface of the enclosure; using the pressure signals and the reference signal to generate an output signal to minimize energy density at a location of the acoustic sensors; and sending the output signal to an acoustic actuator.

Energy density control system using a two-dimensional energy density sensor

A multi-channel active noise control system and method of reducing tonal noise emanating from a tonal noise source are disclosed. The system may include an adaptive controller, a plurality of loudspeakers driven by the loudspeaker, one or more microphones for generating one or more error signals to feedback to the adaptive controller and optionally a reference signal source to provide the adaptive controller with frequency information associated with the tonal noise source. The system and method of the present invention are applicable to any tonal noise source, including but not limited to axial fans.

Growing community of inventors

Provo, UT, United States of America

Scott D Sommerfeldt