Tesla improves automotive hands-free telecommunication by patenting the adaptive noise cancelling system. This invention will improve the quality of use of the function and give owners the comfort of making calls while driving.
Traditional hands-free protocol telephony systems (HFP) are required for phone conversations while driving in many countries around the world. As a result, automakers may provide a speakerphone system to allow a hands-free phone conversation, where the speech may be recorded using microphones. However, microphones can pick up high levels of vehicle noise, making human communication difficult. Reducing road noise at highway speeds is a major concern, as noise suppression signal processing techniques also distort speech. Thus, there is a need for a system that can subtract road noise from the speech signal of an HFP telephone system microphone without distorting speech.
With this in mind, Tesla filed for a patent on "Adaptive noise cancelling system for automotive hands-free telecommunication" on July 27, 2021, and published it on February 3, 2022. The disclosed subject matter generally relates to systems and methods for adaptive noise cancelling for automotive hands-free telecommunications.
The company has created an adaptive noise reduction system for vehicles, which includes: a plurality of multi-axis accelerometers mounted to the vehicle; a plurality of microphones located in the cabin of the vehicle; and a telephony noise canceller configured to receive signals from the plurality of multi-axis accelerometers and plurality of microphones, while the plurality of microphones also provide a speech signal of a user of the vehicle to the telephony cancel noiseler, while the telephony noise canceller is configured to remove correlated road noise via linear subtraction.
In another embodiment, Tesla introduces an adaptive noise reduction system that includes: a plurality of multi-axis accelerometers; a plurality of microphones, while the plurality of multi-axis accelerometers and the plurality microphones in combination pick up vibrations on a chassis of a vehicle for canceling background noise, while the plurality of microphones is an array of microphones processed via a beamformer to generate a virtual microphone signal with road noise of the vehicle; and a telephony noise canceller receiving the virtual microphone signal and signals from the plurality of multi-axis accelerometers to remove correlated road noise via linear subtraction. In addition, the company can use a different set of hardware and software to get the maximum suppression of road noise when using hands-free.
A diagram illustrating an adaptive noise cancelling system, according to some embodiments of the present disclosure/Tesla patent
Embodiments of the invention relate to a system which incorporates one or more accelerometers attached to positions on the vehicle. The accelerometers may act as coherent noise references by measuring vibrations occurring on different portions of the vehicle and using those measured vibrations as an input into the noise cancellation system for subtracting road noise from the speech signal. Unlike using cabin noise as an input, it was discovered that using accelerometers or other vehicle-based sensors as input to a noise cancellation system did not result in distorted speech as the output. Some applications of the disclosed technology for cancelling noise may include: 1. Telephony (eg, hands-free phone calls and improved statistics for beamforming and noise suppression), 2. Voice chat and/or videoconferencing, 3. Voice chat during gaming, 4. In-car communication (front seat to rear seat), 5. Karaoke, and 6. Voice commands and/or voice assistant.
Alternative embodiments of the disclosed technology may include adding microphones near tire locations (e,g., suspension knuckle) in addition to accelerometers to increase the frequency range of the noise that is measured, and then cancelled. An additional alternative embodiment may include positioning the accelerometers to locations on the vehicle that are not zoned around the suspension and/or tire systems of the vehicle. For example, the accelerometers may be placed on the undercarriage, body, doors, windows, sills, bumpers, or other areas of a vehicle to measure road noise and provide input into the noise cancellation system. Further, an additional alternative embodiment includes replacing the accelerometers with a set of microphones spread at or near the floor panel of the vehicle.
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