Abstract: A sound synthesis system is provided with a loudspeaker to project sound indicative of synthesized motor sound in response to receiving a synthesized sound (SS) signal, and a processor. The processor is programmed to: estimate motor sound based on a sensor signal indicative of sound present within a passenger compartment; identify a dominant motor harmonic of the motor sound with an amplitude and a frequency; determine an enrichment value of the motor sound; determine if the motor sound is unenriched based on a comparison of the enrichment value to an enrichment threshold value; generate at least one additional motor harmonic with a first frequency that is different than the frequency of the dominant motor harmonic in response to the motor sound being unenriched; and provide the SS signal to the loudspeaker, wherein the SS signal is indicative of the at least one additional motor harmonic.

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 sensor is configured to infer a rotational speed of a tire of a vehicle. A frequency generator is configured to synthesize frequencies of a tire cavity resonance according to the rotational speed of the tire to generate a sense signal. An active noise control filter is configured to generate an antinoise signal from the sense signal. A loudspeaker configured to convert the antinoise signal into antinoise and to radiate the antinoise to a listening position. The antinoise signal is configured so that the antinoise reduces sound of the tire cavity resonance at the listening position.

Abstract: A sound synthesis system is provided with a loudspeaker to project sound indicative of synthesized motor sound in response to receiving a synthesized sound (SS) signal, and a processor. The processor is programmed to: estimate motor sound based on a sensor signal indicative of sound present within a passenger compartment; identify a dominant motor harmonic of the motor sound with an amplitude and a frequency; determine an enrichment value of the motor sound; determine if the motor sound is unenriched based on a comparison of the enrichment value to an enrichment threshold value; generate at least one additional motor harmonic with a first frequency that is different than the frequency of the dominant motor harmonic in response to the motor sound being unenriched; and provide the SS signal to the loudspeaker, wherein the SS signal is indicative of the at least one additional motor harmonic.

Abstract: A vehicle sound synthesis system is provided with a controller and a loudspeaker. The controller is programmed to receive an input indicative of at least one of a gear selection, an engine speed, and a pedal position and to generate an audio signal indicative of synthesized engine noise (SEN). The controller is further programmed to attenuate the audio signal at a first rate in response to at least one of the gear selection, the engine speed, and the pedal position indicating first vehicle conditions. The loudspeaker is adapted to project sound within a passenger compartment of a vehicle in response to receiving the attenuated audio signal.

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 disclosed method includes monitoring an audio signal energy level while having a noise suppressor deactivated to conserve battery power, buffering the audio signal in response to a detected increase in the audio energy level, activating and running a voice activity detector on the audio signal in response to the detected increase in the audio energy level and activating and running a noise estimator in response to voice being detected in the audio signal by the voice activity detector. The method may further include activating and running the noise suppressor only if the noise estimator determines that noise suppression is required. The method activates and runs a noise type classifier to determine the noise type based on information received from the noise estimator and selects a noise suppressor algorithm, from a group of available noise suppressor algorithms, where the selected noise suppressor algorithm is the most power consumption efficient.

Abstract: A vehicle sound synthesis system is provided with a loudspeaker, a microphone and a controller. The loudspeaker is adapted to project sound indicative of synthesized engine noise (SEN) within a cabin of a vehicle in response to receiving an adjusted SEN signal. The microphone is disposed in the cabin and adapted to provide a microphone signal having a SEN component and a noise component. The controller is programmed to receive the microphone signal, adjust a SEN signal based on the microphone signal, and provide the adjusted SEN signal to the loudspeaker.

Abstract: A heat exchanger with a monocoque structure transfers heat between a first fluid and a second fluid. The heat exchanger in has a plurality of tubes through which the first fluid may flow in a direction, each of the plurality of tubes has a first mouth end, an N opposing second mouth end and a waist region between the first mouth end and the second mouth end. The heat exchanger also has one or more interconnected fluid channels through which the second fluid may flow, the one or more fluid channels lay generally in a plane, the plurality of tubes and the one or more fluid channels interleave such that heat may be transferred between the plurality of tubes and the one or more fluid channels, and the direction of flow of the first fluid is generally perpendicular to the plane of the one or more fluid channels.

Abstract: A disclosed method includes monitoring an audio signal energy level while having a plurality of signal processing components deactivated and activating at least one signal processing component in response to a detected change in the audio signal energy level. The method may include activating and running a voice activity detector on the audio signal in response to the detected change where the voice activity detector is the at least one signal processing component. The method may further include activating and running the noise suppressor only if a noise estimator determines that noise suppression is required. The method may activate and runs a noise type classifier to determine the noise type based on information received from the noise estimator and may select a noise suppressor algorithm, from a group of available noise suppressor algorithms, where the selected noise suppressor algorithm is the most power consumption efficient.

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: Engine order cancellation (EOC) systems generate feed forward noise signals based on the engine or other rotating shaft RPM and use those signals and adaptively configured W-filters to reduce the in-cabin SPL by radiating anti-noise through speakers. An EOC system may include a signal analysis controller for detecting non-stationary events, such as speech, based on parameters sampled from a current frame of error signals output from microphones positioned in various locations of a vehicle passenger cabin. Upon detection, the signal analysis controller may mitigate the effects of the non-stationary event to prevent the EOC system from boosting noise or contributing to a speech-like post-echo in the passenger cabin. For example, if speech is detected in a frame, then the adaptation can be frozen for that frame. Alternatively, the signal analysis controller may adaptively subtract voice signals out of the error microphone signal.

Abstract: Engine order cancellation (EOC) systems generate feed forward noise signals based on the engine or other rotating shaft RPM and use those signals and adaptively configured W-filters to reduce the in-cabin SPL by radiating anti-noise through speakers. An EOC system may include a drive mode detector for detecting different vehicle drive modes based on an analysis of signals indicative of current vehicle operating conditions. Upon detection, the EOC system may adaptively adjust various tuning parameters for the EOC algorithm based on the current vehicle drive mode. The EOC system may also selectively target different sets of engine orders for noise cancellation according to the current vehicle drive mode based on which engine orders are dominant during that drive mode.

Abstract: A propagation delay identification system for active noise cancelation for a vehicle audio system may include at least one sensor configured to transmit sensor data indicative of acceleration data, hammer data and microphone data, at least one output sensor configured to transmit an impulse response, and a processor. The processor may be programmed to receive the sensor data and pulse function, identify a propagation path delay between the microphone data and a cross-correlation between the acceleration data and hammer data, and generate a source pulse function. The processor further identify a secondary path delay based on an arrival time of peak energy of a convolution of the impulse response and filtered pulse function, and apply a binary limiter to a reference signal in response to the secondary path delay exceeding the propagation path delay to reduce boosting of an audio signal based on coherent reference and error signals.

Abstract: Engine order cancellation (EOC) systems generate feed forward noise signals based on the engine or other rotating shaft RPM and use those signals and adaptively configured W-filters to reduce the in-cabin SPL by radiating anti-noise through speakers. An EOC system may include a signal analysis controller for detecting non-stationary events, such as speech, based on parameters sampled from a current frame of error signals output from microphones positioned in various locations of a vehicle passenger cabin. Upon detection, the signal analysis controller may mitigate the effects of the non-stationary event to prevent the EOC system from boosting noise or contributing to a speech-like post-echo in the passenger cabin. For example, if speech is detected in a frame, then the adaptation can be frozen for that frame. Alternatively, the signal analysis controller may adaptively subtract voice signals out of the error microphone signal.

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 road noise cancellation (RNC) system may include a signal analysis controller for detecting non-stationary, transient events based on sensor signals having a spectral or temporal character significantly different from steady-state road or cabin noise. Upon detection of such non-stationary events, the RNC system may modify the sensor signals to mask the non-stationary event, thereby preventing the RNC system's adaptive filters from mis-adapting because of transient, non-stationary events. Alternatively, the RNC system may pause or slow or pause adaptation of its controllable filters for the duration of a frame that includes the non-stationary event.

Abstract: A propagation delay identification system for active noise cancelation for a vehicle audio system may include at least one sensor configured to transmit sensor data indicative of acceleration data, hammer data and microphone data, at least one output sensor configured to transmit an impulse response, and a processor. The processor may be programmed to receive the sensor data and pulse function, identify a propagation path delay between the microphone data and a cross-correlation between the acceleration data and hammer data, and generate a source pulse function. The processor further identify a secondary path delay based on an arrival time of peak energy of a convolution of the impulse response and filtered pulse function, and apply a binary limiter to a reference signal in response to the secondary path delay exceeding the propagation path delay to reduce boosting of an audio signal based on coherent reference and error signals.

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.