Reducing audibility of sensor noise floor in a road noise cancellation system
AssigneeHarman International Industries, Incorporated
InventorsKevin J. Bastyr, James May
Life of this patent
Estimating the term…
Abstract
A road noise cancellation (RNC) system may include a controller and attenuator for reducing the audibility of the noise floor caused by the system's vibration sensors. A level of anti-noise at a location in a passenger cabin that may be attributed to the sensor noise floor may be estimated. An actual sound level in the passenger cabin may be measured or estimated, with the sensor noise floor component algorithmically removed. The difference in levels may be compared to a predetermined threshold to determine an amount of attenuation, if any, to be applied to an anti-noise signal to reduce audibility.
Claims20
A method for reducing the audibility of a sensor noise floor in a feed-forward road noise cancellation (RNC) system, the method comprising:
- estimating a sensor noise floor anti-noise (SNFAN) level, the SNFAN level representing an amount of anti-noise at a location in a passenger cabin of a vehicle due to a noise floor of at least one sensor;
- determining an in-cabin sound level in the passenger cabin;
- and
- adjusting an attenuation level of an anti-noise signal to be radiated into the passenger cabin by at least one speaker based on a comparison of the in-cabin sound level to the SNFAN level.
A road noise cancellation (RNC) system for a vehicle comprising:
- at least one sensor configured to generate a noise signal in response to an input, the sensor having a noise floor;
- a controller, including a processor and memory, programmed to:
- estimate a sensor noise floor anti-noise (SNFAN) level, the SNFAN level representing an amount of anti-noise at a location in a passenger cabin of the vehicle due to the noise floor of the at least one sensor;
- determine an in-cabin sound level in the passenger cabin;
- and
- set an attenuation level based on a comparison of the in-cabin sound level to the SNFAN level;
- and
- an attenuator configured receive an anti-noise signal from a controllable filter and generate an attenuated anti-noise signal to be radiated into the passenger cabin as anti-noise by at least one speaker based on the attenuation level.
A computer-program product embodied in a non-transitory computer readable medium that is programmed for road noise cancellation (RNC), the computer-program product comprising instructions for:
- receiving a noise signal from at least one sensor;
- comparing the noise signal to a stored noise floor value indicative of an estimate of a sensor noise floor for the at least one sensor;
- and
- adjusting an attenuation level of an anti-noise signal to be radiated into the passenger cabin by at least one speaker based on the comparison of the noise signal to the stored noise floor value.
Dependencies are inferred from the claim text.