Abstract: 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.

Abstract: In at least one embodiment, an active noise cancellation (ANC) system is provided. The ANC system includes at least one loudspeaker, at least one microphone, and a reference generator. The at least one loudspeaker projects anti-noise sound within a cabin of a vehicle based at least on an estimated reference signal and an anti-noise signal. The at least one microphone to provide a first error signal indicative of noise and the anti-noise sound within the cabin. The at least one filter controller programmed to receive the first error signal and the estimated reference signal; and to control at least one adaptive filter to generate the anti-noise signal based at least on the first error signal and the estimated reference signal. The reference generator is programmed to generate the estimated reference signal based at least on one of vehicle speed, temperature of a tire of the vehicle, or tire pressure.

Abstract: Embodiments are disclosed for enhancing engine sound. An example method for a vehicle comprises acquiring a signal including harmonic content generated by an engine of the vehicle, upmixing the signal into a plurality of channels for a given number of engine orders, adjusting an order filter for each engine order of the given number of engine orders based on operating conditions of the engine, filtering each channel of the plurality of channels with the corresponding order filter, mixing the filtered channels into a mono output, and outputting the mono output to at least one speaker in the vehicle. The mono output is delayed based on a position of the at least one speaker such that an occupant of the vehicle perceives the mono output as originating from the engine.

Abstract: Embodiments are disclosed for enhancing engine sound. An example method for a vehicle comprises acquiring a signal including harmonic content generated by an engine of the vehicle, upmixing the signal into a plurality of channels for a given number of engine orders, adjusting an order filter for each engine order of the given number of engine orders based on operating conditions of the engine, filtering each channel of the plurality of channels with the corresponding order filter, mixing the filtered channels into a mono output, and outputting the mono output to at least one speaker in the vehicle. The mono output is delayed based on a position of the at least one speaker such that an occupant of the vehicle perceives the mono output as originating from the engine.

Abstract: A active noise cancellation (ANC) system may include an adaptive filter divergence detector for detecting divergence of the one or more controllable filters as they adapt, based on various temporal or frequency domain amplitude characteristics. Upon detection of a controllable filter divergence, the ANC system may be deactivated, or certain speakers may be muted. Alternatively, the ANC system may modify the diverged controllable filters to restore proper operation of the noise cancelling system. This may include adjusting a leakage value of an adaptive filter controller.

Abstract: Embodiments are disclosed for enhancing engine sound. An example method for a vehicle comprises acquiring a signal including harmonic content generated by an engine of the vehicle, upmixing the signal into a plurality of channels for a given number of engine orders, adjusting an order filter for each engine order of the given number of engine orders based on operating conditions of the engine, filtering each channel of the plurality of channels with the corresponding order filter, mixing the filtered channels into a mono output, and outputting the mono output to at least one speaker in the vehicle. The mono output is delayed based on a position of the at least one speaker such that an occupant of the vehicle perceives the mono output as originating from the engine.

Abstract: A system for evaluating a noise management module of a vehicle includes a controller programmed to filter speaker signals from the noise management module using an auralization model to produce auralized sound signals that create a spatial effect to simulate sound in the vehicle at a predetermined position within the vehicle that is different than the positions corresponding to microphones used by the noise management module.

Abstract: An active noise cancellation (ANC) system may include an adaptive filter divergence detector for detecting divergence of the one or more controllable filters as they adapt, based on dynamically adapted thresholds. Upon detection of a controllable filter divergence, the ANC system may be deactivated, or certain speakers may be muted. Alternatively, the ANC system may modify the diverged controllable filters to restore proper operation of the noise cancelling system.

Abstract: 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.

Abstract: Embodiments are disclosed for enhancing engine sound. An example method for a vehicle comprises acquiring a signal including harmonic content generated by an engine of the vehicle, upmixing the signal into a plurality of channels for a given number of engine orders, adjusting an order filter for each engine order of the given number of engine orders based on operating conditions of the engine, filtering each channel of the plurality of channels with the corresponding order filter, mixing the filtered channels into a mono output, and outputting the mono output to at least one speaker in the vehicle. The mono output is delayed based on a position of the at least one speaker such that an occupant of the vehicle perceives the mono output as originating from the engine.

Abstract: A active noise cancellation (ANC) system may include an adaptive filter divergence detector for detecting divergence of the one or more controllable filters as they adapt, based on various temporal or frequency domain amplitude characteristics. Upon detection of a controllable filter divergence, the ANC system may be deactivated, or certain speakers may be muted. Alternatively, the ANC system may modify the diverged controllable filters to restore proper operation of the noise cancelling system. This may include adjusting a leakage value of an adaptive filter controller.

Abstract: A active noise cancellation (ANC) system may include an adaptive filter divergence detector for detecting divergence of the one or more controllable filters as they adapt, based on various temporal or frequency domain amplitude characteristics. Upon detection of a controllable filter divergence, the ANC system may be deactivated, or certain speakers may be muted. Alternatively, the ANC system may modify the diverged controllable filters to restore proper operation of the noise cancelling system. This may include adjusting a leakage value of an adaptive filter controller.

Abstract: A active noise cancellation (ANC) system may include an adaptive filter divergence detector for detecting divergence of the one or more controllable filters as they adapt, based on various temporal or frequency domain amplitude characteristics. Upon detection of a controllable filter divergence, the ANC system may be deactivated, or certain speakers may be muted. Alternatively, the ANC system may modify the diverged controllable filters to restore proper operation of the noise cancelling system. This may include adjusting a leakage value of an adaptive filter controller.

Abstract: An active noise cancellation (ANC) system may include an adaptive filter divergence detector for detecting divergence of the one or more controllable filters as they adapt, based on dynamically adapted thresholds. Upon detection of a controllable filter divergence, the ANC system may be deactivated, or certain speakers may be muted. Alternatively, the ANC system may modify the diverged controllable filters to restore proper operation of the noise cancelling system.

Abstract: A system for evaluating a noise management module of a vehicle includes a controller programmed to filter speaker signals from the noise management module using an auralization model to produce auralized sound signals that create a spatial effect to simulate sound in the vehicle at a predetermined position within the vehicle that is different than the positions corresponding to microphones used by the noise management module.

Abstract: The present disclosure relates to systems and methods for active sound management for vehicles. In one embodiment, a process for active sound management for a vehicle includes determining vehicle operation state and powertrain operation for the vehicle, and detecting sound generated by the powertrain operation of the vehicle. A synthesized sound may be determined for output based on selection of at least one frequency of the sound generated by the powertrain to drive a frequency of a sine-wave generator, synthesizing an output wave file with pitch shifting of frequency based on powertrain operation, and blending sine-wave generator output with the synthesized wave file to cancel unwanted powertrain noise and generate desired sounds for vehicles. Output of the synthesized sound may be controlled to provide simultaneous cancellation and synthesis in at least one same frequency range.

Abstract: An active noise cancellation (ANC) system may include an adaptive filter divergence detector for detecting divergence of the one or more controllable filters as they adapt, based on dynamically adapted thresholds. Upon detection of a controllable filter divergence, the ANC system may be deactivated, or certain speakers may be muted. Alternatively, the ANC system may modify the diverged controllable filters to restore proper operation of the noise cancelling system.

Abstract: The present disclosure relates to systems and methods for active sound management for vehicles. In one embodiment, a process for active sound management for a vehicle includes determining vehicle operation state and powertrain operation for the vehicle, and detecting sound generated by the powertrain operation of the vehicle. A synthesized sound may be determined for output based on selection of at least one frequency of the sound generated by the powertrain to drive a frequency of a sine-wave generator, synthesizing an output wave file with pitch shifting of frequency based on powertrain operation, and blending sine-wave generator output with the synthesized wave file to cancel unwanted powertrain noise and generate desired sounds for vehicles. Output of the synthesized sound may be controlled to provide simultaneous cancellation and synthesis in at least one same frequency range.

Abstract: A method for operating an internal combustion engine. The method includes: providing a functional relationship between time rate of change in engine speed, and compression ratio switching engine speed limit; determining time rate of change in engine speed; determining from the determined rate of change of engine speed and the function whether the engine speed exceeds the compression ratio switching engine speed; and commanding the engine to operate at a relatively low compression ratio if the determined time of change in engine speed exceeds the compression ratio switching engine speed limit and commanding the engine to operate at a relatively high compression ratio if the determined time of change in engine speed is less than the compression ratio switching engine speed limit.

Abstract: A method and system for operating an internal combustion engine. The internal combustion engine is operable in a plurality of compression ratio operating modes. The method includes determining a relationship between a base engine threshold load where the high compression and low compression provide substantially the same engine fuel consumption and engine speed. The determined nominal relationship is modified by a factor, such factor being a function of a condition under which such engine is operating, to obtain a modified relationship. The modified relationship is a function of engine speed and the condition has an effect on knock generation in such engine. The modified relationship and engine speed are used in selecting one of the plurality of compression ratio operating modes for the engine.