Harman International Industries, Inc.

Harman Becker Automotive Systems Gmbh

Jeffrey Charles Tackett

Ryan J Mihelich

Douglas K Hogue

Sattwik Basu

David Trumpy

Kevin J Bastyr

Tao Feng

James May

Geon-Seok Kim

Todd Edward Tousignant

Shaun Ryan

In at least one embodiment, an active noise cancellation (ANC) system is provided. The system includes at least one audio signal source, at least one loudspeaker, at least one microphone, and at least one controller. The at least one controller is programmed to receive a first error signal and a second error signal and to provide an estimated impulse response based at least on the first error signal and the second error signal. The at least one controller is programmed to select a first pre-stored impulse response from a plurality of pre-stored impulse responses based on the estimated impulse response to filter one or more reference signals at an adaptive filter to generate the anti-noise signal and to select a first plurality of pre-stored tuning parameters from a plurality of pre-stored sets of the tuning parameters based on the first pre-stored impulse response.

System and method for adjusting active noise cancellation tuning parameters

A system and method for estimating secondary path impulse response (IR) for an active noise cancellation (ANC) system to enhance performance of the ANC system in a near-imperceptible manner is provided. An adaptive music interference canceller (AMIC) uses music signals as test signals and ANC error microphones to estimate the secondary path IR between all speakers and microphones. The system validates that the music signals have sufficient audio content to be considered an adequate test signal. Furthermore, the system employs additional signal processing to ensure that a unique IR for all speakers and microphones can be obtained using the audio test signals. New coefficients of the AMIC filter are calculated, in real time, using the music signals and can be copied into the estimated secondary path for the ANC system. A supervisor unit manages enabling and disabling the AMIC as needed for calculating and copying coefficients.

System and method for estimating secondary path impulse response for active noise cancellation

In at least one embodiment, an active noise cancellation (ANC) system is provided. An audio signal source provides an audio signal. At least one loudspeaker projects anti-noise sound within a cabin. At least one microphone provides a first error signal indicative of the noise, the audio signal, and the anti-noise sound and a second error signal indicative of an estimated anti-noise signal. At least one controller is programmed to receive the first error signal and the second error signal and to provide an estimated impulse response based at least on the first error signal and the second error signal. The at least one controller is further programmed to compare the estimated impulse response to one or more pre-stored impulse responses; and to select a first pre-stored impulse response that matches the estimated impulse response to filter one or more reference signals at an adaptive filter to generate the anti-noise signal.

System and method for secondary path switching for active noise cancellation

A system and method for accurately estimating engine noise at a virtual microphone location, such as an occupant's ear position, in an acoustic space in order to enhance performance of an Engine Order Cancellation (EOC) system is provided. A set of weights and transfer functions that are dependent on various vehicle parameters, such as frequency, load, and speed, may be employed to estimate noise at a position where there are no physical microphones present. The accurate estimation of engine noise at virtual location, such as an occupant's ear position, may be achieved using a frequency dependent weighted sum of filtered and unfiltered error signals measured at microphones mounted at various locations inside an acoustic space, such as a vehicle cabin, which may not be located near virtual location.

Virtual location noise signal estimation for engine order cancellation

An audio system includes a diagnostic capability to check for faults to a power source and faults to ground for output audio channels configured to drive loudspeakers. The fault to ground analysis involves analysis of a number of digital samples to determine if a predetermined threshold is exceeded during a predetermined period of time. The analysis may involve both a digital signal processor and a microprocessor performing a zero crossing analysis using the predetermined threshold and the predetermined window of time.

Audio channel fault detection system

An audio power management system manages operation of audio devices in an audio system. The audio power management system includes a parameter computer, a threshold comparator and a limiter. Audio signals generated with the audio system may be provided to the audio power management system. Based on a measured actual parameter of the audio signal, such as a real-time actual voltage and/or a real-time actual current, the parameter computer can derive estimated operational characteristics of audio devices, such as a loudspeaker included in the audio system. The threshold comparator may use the estimated operational characteristics to develop a threshold and manage operation of one of more devices in the audio system by monitoring the measured actual parameter, and selectively directing the limiter to adjust the audio signal, or another device in the audio system to protect or optimize performance.

Audio power management system

Systems and methods for processing encoded digital data for programming a device to be re-programmed in an audio playback system. The system includes an audio media source containing digital data having audio data or encoded data in an audio data format. An audio media reader reads the digital data from the audio media source. A stream detector receives the digital data from the audio media reader and detects whether the received digital data includes encoded data formatted as audio data or audio data. An audio receiver device receives the audio data and processes the audio data for playback. A device to be re-programmed uses the encoded data formatted as audio data.

Software updates via digital audio media

A spectral management system may be used in an audio system to receive and process audio signals having multiple distributed audio channels, such as a right, left, center, right side, left side, right rear and left rear channels. The spectral management system may separate and route a frequency range of audio content included in one or more of the distributed audio channels to other distributed audio channels. The separated and routed frequency range of audio content may be combined with audio content present on the other distributed audio channels to which the separated frequency range of audio content is routed. Separation, routing and combination may include bass audio content routing, mid-bass audio content routing, subwoofer audio content routing and treble audio content routing.

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Allen Park, MI, United States of America

Jeffrey Charles Tackett