An input signal representative of an undesired acoustic noise in a region is captured by one or more first sensors and processed to generate a cancellation signal. An output signal is generated based on the cancelation signal to cause one or more acoustic transducers to cancel, at least in part, the undesired acoustic noise in the region. A feedback signal representative of residual acoustic noise in the region is captured by one or more second sensors. A characteristic of each of the feedback signal, the cancellation signal, and a combination of the cancellation signal and the feedback signal is determined. One or more thresholds are compared to a ratio of (i) the characteristic of the combination of the cancellation signal and the feedback signal and (ii) a combination of the characteristic of the feedback signal and the characteristic of the cancellation signal to determine a convergence state.

An embodiment method for active and selective preventive cross-force and noise control in a first vehicle includes determining current driving parameters of a second vehicle that will foreseeably drive by the first vehicle, wherein a prognostic time-dependent path of the second vehicle is estimated based on the current driving parameters of the second vehicle, determining cross-force or noise characteristics caused by the second vehicle, calculating a time window for a drive-by of the second vehicle based on the current driving parameters, determining compensating measures to be taken by the first vehicle to reduce cross-forces or noise expected during the drive-by of the second vehicle based on the determined cross-force or noise characteristics, and executing the determined compensating measures by the first vehicle in the estimated time window.

A noise cancelling system for a vehicle includes a microphone, at least one first sensor configured to collect first data related to an element that generates a noise sound, at least one second sensor configured to collect second data related to an element that changes a secondary path of the noise sound, a controller configured to select a secondary path model corresponding to the second data from among a plurality of pre-stored secondary path models, input the first data to a secondary path filter corresponding to the selected secondary path model, and generate an anti-noise signal based on output data of the secondary path filter and error data received from the microphone, and a speaker configured to output an anti-noise sound based on the anti-noise signal.

An active noise reduction device includes a first adaptive filter, a first filter coefficient updater, and a controller that determines, based on a first parameter of the first adaptive filter, whether first noise control based on a first cancelling sound is in a stable state or an unstable state. The controller transitions the first filter coefficient updater to a restriction state in which an effect of reducing first noise is smaller than in a normal state when it is determined that the first noise control is in the unstable state while the first filter coefficient updater is updating a coefficient of the first adaptive filter in the normal state, and transitions the first filter coefficient updater back to the normal state when it is determined that the first noise control is in the stable state while the first filter coefficient updater is in the restriction state.

In at least one embodiment, a system for providing a frequency dependent dynamic leakage for noise cancellation is provided. The system includes a noise cancellation controller and a current limiter. The noise cancellation controller is programmed to perform noise cancellation in a vehicle based on a limited input signal. The current limiter is programmed to receive a reference signal from one of an accelerometer or a loudspeaker and to convert the reference signal from a time domain and into a frequency domain to limit the reference signal. The current limiter is further programmed to generate the limited input signal in response to limiting the reference signal.

An assembly actively controls the rolling noise for a motor vehicle. The assembly includes a path control device that includes another sensor fastened on the steering knuckle, such as an accelerometer. The path control device is capable of transmitting, to the anti-noise device, measurements obtained by the other sensor. The anti-noise device is capable of generating an anti-noise signal depending on the acceleration measurements obtained and controlling its transmission via the loudspeaker.

An apparatus for predicting an acceleration signal predicts an acceleration signal of an acceleration sensor installed on a vehicle for active noise control (ANC) and includes: a prediction module configured to train a predefined prediction algorithm to predict an acceleration signal after N samples compared to a point in time at which an acceleration signal is acquired by the acceleration sensor (N is a natural number), and to apply a reference acceleration signal acquired at a reference point in time to the completely trained prediction algorithm to generate a predicted acceleration signal after the N samples compared to the reference point in time; and an ANC module configured to perform ANC on the basis of the predicted acceleration signal generated by the prediction module.

An apparatus for improving the sound of a vehicle according to one embodiment of the present invention, may comprise: a window open/closed detection sensor for detecting the open/closed state of a window of the vehicle; a car door open/closed detection sensor for detecting the open/closed state of a car door of the vehicle; a speed sensor for measuring the speed of the vehicle; a microphone; a memory; and a processor for adjusting a coefficient of an adaptive filter used for an engine order cancellation (EOC) function, on the basis of the opened degree of the window and the speed, when the car door is closed, the window is open, and the magnitude of noise inputted to the microphone is less than or equal to a threshold magnitude.

An active noise reduction device includes: a reference signal input terminal that receives a reference signal outputted by a reference signal source and having a correlation with noise in a space in an automobile, the reference signal source being attached to the automobile; a test signal source that outputs a test signal to a loudspeaker attached to the automobile, the loudspeaker being used to output a canceling sound for reducing the noise; and an anomaly determiner that determines whether the reference signal source has an anomaly, based on the reference signal inputted from the reference signal source to the reference signal input terminal when the test signal is outputted to the loudspeaker.

An active noise reduction device includes: a reference signal input terminal that receives a reference signal from a reference signal source attached to an automobile; a simulated vibration transfer characteristics filter unit that generates a second signal by correcting, using simulated vibration transfer characteristics, a first signal for outputting, from a loudspeaker attached to the automobile, a sound different from a canceling sound, the simulated vibration transfer characteristics simulating vibration transfer characteristics from the loudspeaker to the reference signal source; a first subtracter that outputs a corrected reference signal obtained by subtracting the second signal generated, from the reference signal received by the reference signal input terminal; and an adaptive filter unit that applies an adaptive filter to the corrected reference signal outputted from the first subtracter to generate a canceling signal to be used to output the canceling sound.