Adaptive noise-canceling system for hands-free communication in automobiles

Abstract

This invention provides an adaptive noise-canceling system that removes road noise from the microphone's audio signal during hands-free calls inside a vehicle without distorting the audio. [Solution] The telephony voice processing system 400 includes a plurality of accelerometers 420, a plurality of microphones 430, and a telephony noise canceller (TNC) 300. The plurality of accelerometers 420 measure vibrations occurring in different parts of the vehicle and use these measured vibrations as input to the telephony noise canceller (TNC) 300, thereby functioning as a coherent noise reference for removing road noise from the voice signal. The plurality of microphones 430 are located inside the vehicle cabin and provide the user's voice signal to the telephony noise canceller (TNC) 300. The telephony noise canceller (TNC) 300 removes correlated road noise by linear subtraction.

Description

Technical Field

[0001] The disclosed subject matter generally relates to an adaptive noise cancellation system and method for hands-free communication in an automobile.

Background Art

[0002] Conventional hands-free protocol (HFP) telephony systems are required in many jurisdictions around the world for making calls in a vehicle while driving an automobile vehicle. Some automobile vehicles can provide a speakerphone system that allows for hands-free calling during a call, in which case the voice can be recorded using a microphone. However, the microphone may pick up a high level of vehicle noise. When suppressing road noise at highway speeds, signal processing methods for suppressing the noise also distort the voice, which is a major problem. Therefore, there is a need for a system that can remove road noise from the voice signal of the microphone in an HFP telephony system without distorting the voice.

Summary of the Invention

Means for Solving the Problems

[0003] For the purpose of summarization, certain aspects, advantages, and novel features are described herein. It should be understood that not all of such advantages are realized in accordance with any one particular embodiment. Thus, the disclosed subject matter may be embodied or implemented in a manner that realizes or optimizes one advantage or group of advantages without necessarily realizing all of the advantages that may be taught or suggested herein.

[0004] Details of one or more variations of the subject matter described herein are given in the accompanying drawings and the following description. Other features and advantages of the subject matter described herein will become apparent from the description and drawings, as well as the claims. However, the disclosed subject matter is not limited to any particular embodiment disclosed.

[0005] One embodiment relates to an adaptive noise-canceling system for a vehicle. This embodiment may include a plurality of multi-axis accelerometers mounted on the vehicle, a plurality of microphones located in the vehicle's cabin, and a telephony noise canceller configured to receive signals from the plurality of multi-axis accelerometers and the plurality of microphones, wherein the plurality of microphones further provide the telephony noise canceller with the voice signals of the vehicle's users, and the telephony noise canceller is configured to remove correlated road noise by linear subtraction.

[0006] Another embodiment relates to an adaptive noise-canceling system comprising: a plurality of multi-axis accelerometers; a plurality of microphones, the plurality of multi-axis accelerometers and the plurality of microphones jointly pick up vibrations on the vehicle chassis to cancel out background noise, and the plurality of microphones are processed by a beamformer to generate a virtual microphone signal having the road noise of the vehicle; and a telephony noise canceller that receives the virtual microphone signal and signals from the plurality of multi-axis accelerometers and removes the correlated road noise by linear subtraction.

[0007] Another embodiment relates to a method for removing noise inside a vehicle. This method includes reading accelerometer data from a plurality of multi-axis accelerometers mounted on the vehicle, acquiring audio data from a plurality of microphones placed inside the vehicle's cabin, and inputting the accelerometer data and audio data into a telephony noise canceller and removing correlated road noise by linear subtraction. [Brief explanation of the drawing]

[0008] The accompanying drawings incorporated herein and constituting part of this specification illustrate specific aspects of the subject matter disclosed herein and, together with the description, help to illustrate some of the principles relating to the embodiments disclosed below.

[0009] [Figure 1] This figure shows an adaptive noise-canceling system according to several embodiments of the present disclosure.

[0010] [Figure 2Aa] This figure shows a configuration illustrating an exemplary placement position @0022 of a microphone according to some embodiments of the present disclosure. [Figure 2Ab] This figure shows a configuration illustrating exemplary placement of a microphone according to some embodiments of the present disclosure.

[0011] [Figure 2Ba] This figure further illustrates a configuration showing exemplary arrangement of accelerometers in a vehicle according to some embodiments of the present disclosure. [Figure 2Bb] This figure further illustrates a configuration showing exemplary arrangement of accelerometers in a vehicle according to some embodiments of the present disclosure. [Figure 2Bc] This figure further illustrates a configuration showing exemplary arrangement of accelerometers in a vehicle according to some embodiments of the present disclosure. [Figure 2Bd]FIG. showing an exemplary arrangement of an accelerometer in a vehicle and further showing a configuration for displaying the @0027 position.

[0012] [Figure 3] FIG. showing an @0028 adaptive noise cancellation process for hands - free communication in an automobile according to some embodiments of the present disclosure.

[0013] [Figure 4A] FIG. showing the usage of accelerometer input for @0029 adaptive noise cancellation in a telephony voice processing system according to some embodiments of the present disclosure.

[0014] [Figure 4B] FIG. showing an @0030 embodiment of the components of an adaptive noise cancellation system shown in FIG. 4A.

[0015] [Figure 5A] FIG. showing @0031 sample data of load noise when an adaptive noise cancellation system is not provided.

[0016] [Figure 5B] FIG. showing @0032 sample data of load noise when the adaptive noise cancellation system of the present application is properly arranged.

[0017] [Figure 6] FIG. showing @0033 sample data of accelerometer arrangement in an embodiment of an adaptive noise cancellation system.

[0018] [Figure 7A] FIG. showing a @0034 comparison of spectra between the case where an adaptive noise cancellation system is provided and the case where it is not provided.

[0019] [Figure 7B] A line graph showing the amount of removal by an adaptive noise cancellation system that may result from the example of FIG. 7A.

[0020] These drawings need not be to scale, either absolutely or relatively, and are intended to be exemplary. The relative arrangements of features and elements may be changed to clearly illustrate. In fact, the same or similar reference numbers indicate the same, or similar, or equivalent structures, features, aspects, or elements according to one or more embodiments.

Embodiments for Carrying Out the Invention

[0021] To provide a sufficient description of various embodiments, a number of specific details are set forth below. Certain embodiments may be practiced without these specific details or with some variations in detail. In some cases, certain features are not described in as much detail so as not to obscure other aspects. The level of detail associated with each element or feature should not be construed as diminishing the novelty or importance of one feature over the novelty or importance of other features. Overview

[0022] Hands-free protocol (HFP) telephony systems are required in many jurisdictions around the world for making calls while driving. Automobile vehicles can provide a speakerphone system that enables hands-free calls during a phone call. Voice can be input into the hands-free system using a microphone placed inside the vehicle cabin. However, the microphone may pick up a high level of vehicle noise. The main sources of noise specifically arise from wind and roads when the vehicle is traveling at high speed. When suppressing road noise at highway speeds, signal processing methods for suppressing noise also tend to distort the voice, which is a major problem.

[0023] Embodiments of the present invention relate to a system equipped with one or more accelerometers mounted in a position on a vehicle. The accelerometers can function as a coherent noise reference by measuring vibrations occurring in different parts of the vehicle and using these measured vibrations as input to a noise-canceling system for removing road noise from an audio signal. Unlike using cabin noise as input, it has been found that using accelerometers or other vehicle-based sensors as input to a noise-canceling system does not result in distorted audio as output. Some applications of the disclosed noise-canceling techniques include: 1. Telephony (e.g., hands-free calling and improved statistics for beamforming and noise suppression), 2. Voice chat and / or video conferencing, 3. Voice chat during gaming, 4. In-vehicle communication (from front to rear seats), 5. Karaoke, and 6. Voice commands and / or voice assistants.

[0024] Alternative embodiments of the disclosed technique may include adding microphones near the tire location (e.g., suspension knuckles) in addition to accelerometers to extend the frequency range of noise that is measured and then removed. Further alternative embodiments may include placing accelerometers at undivided locations on the vehicle around the vehicle's suspension and / or tire system. For example, accelerometers may be placed on the vehicle's chassis, body, doors, windows, sills, bumpers, or other parts to measure road noise, which is then fed into a noise-canceling system. Further alternative embodiments may also include replacing the accelerometers with a set of microphones distributed on or near the vehicle's floor panel. Exemplary System

[0025] Figures 1 to 2B of this disclosure illustrate embodiments of an adaptive noise-canceling system 100 for hands-free communication in an automobile. Figure 1 shows the adaptive noise-canceling system 100. The adaptive noise-canceling system is configured to pick up vibrations on the chassis 110 of a vehicle 105 via a combination of an accelerometer and a microphone that outputs audio rate accelerometer data 120. The accelerometer is positioned on the vehicle chassis at a location that has high coherence to structurally propagated noise, where noise can also be detected at the location of the telephony microphone.

[0026] As shown in Figure 1, microphone data 130 is transmitted and received from microphones 132 and 134 located on the left and right sides of the driver's headrest inside the vehicle, and / or in their vicinity. An additional microphone 136 is located on and / or in the driver's sun visor.

[0027] In some embodiments, additional microphones may also be located on the left and right sides of the headrests of any of the passenger seats in the vehicle, and / or in their vicinity, or on the passenger sun visors of the vehicle, and / or in their vicinity. In some embodiments, microphone data (e.g., voice data) passing through the entire adaptive noise-canceling system corresponds to three channels (e.g., one channel per microphone, including a visor microphone, a left headrest microphone, and a right headrest microphone). Furthermore, accelerometer data 120 may be transmitted from multi-axis accelerometers located on and / or in the vehicle's suspension knuckles 122 and 124 and / or suspension joints. In some embodiments, accelerometer data 120 passing through the entire adaptive noise-canceling system corresponds to twelve channels (e.g., four 3-axis accelerometers, each located on and / or in the vicinity of the four suspension knuckles of each wheel of the vehicle, with one axis corresponding to one channel). The system may further include a speaker 142 that removes road noise based on audio rate accelerometer data via an accelerometer and a microphone and outputs it. In some embodiments, the speaker output of the adaptive noise-canceling system (e.g., audio output data) corresponds to two channels (e.g., a left channel and a right channel).

[0028] In certain embodiments, accelerometer data 120 is manipulated by an active noise control (ANC) controller 150 that utilizes filter weights (W) 160 derived by an algorithm that models a transfer function (P) 170 between vibrations on the vehicle chassis and sound pressure at the microphone placement location. Using the filter weights W, a road noise signal (d) can be predicted to be compared against an acoustic and electrical path (C) 165. This results in an error signal (e), which is fed back to the ANC controller 150.

[0029] Figures 2Aa and 2Ab show, for example, configurations 200 of the placement of microphones inside a vehicle. In Figure 2Aa, microphone 132 is located to the left of the driver's headrest 210, and microphone 134 is located to the right of the driver's headrest. In Figure 2Ab, microphone 136 is located at the end of the driver's sun visor 220. Figures 2Ba to 2Bd further illustrate a configuration 250 in which accelerometers can be positioned at various locations within the vehicle. In Figure 2Ba, a multi-axis accelerometer 260 is positioned on the vehicle's suspension. In Figure 2Bb, a multi-axis accelerometer 270 is positioned on the first suspension knuckle. In Figure 2Bc, a multi-axis accelerometer 280 is positioned on another suspension link within the vehicle. In Figure 2Bd, a multi-axis accelerometer 290 is positioned on the vehicle's suspension link. Thus, four accelerometers are used, with one accelerometer positioned on each suspension knuckle, resulting in a total of four multi-axis accelerometers positioned on the four suspension knuckles of the vehicle. In certain embodiments, a three-axis accelerometer is used, but other accelerometers may be used in other embodiments. Flowchart of an exemplary system

[0030] Figures 3 and 4 of this disclosure show block diagrams of adaptive noise-canceling systems for hands-free communication in automobiles, according to several embodiments.

[0031] Figure 3 is a block diagram showing components 300 of a telephony noise canceller (TNC), which may be part of an adaptive noise cancelling system 100 for hands-free communication in a vehicle. In this system, an adaptive algorithm such as a least mean squares filter (LMS) derives filter weights (W_telephony) 360 that model the transfer function (P) 370 between vibrations on the chassis of the vehicle (x) 120 and sound pressure at the microphone placement position (y). Using W, a road noise signal (d) is predicted and, based on the voice output by the user 310, this signal is removed from the microphone signal 330. The resulting error signal (e テレフォニー )365 is supplied to a telephony controller 350, which can adjust the filter weights (W_telephony)360.Adaptation can be performed in the time domain using a Normalized Leaky LMS to promote and accelerate convergence, or in the frequency domain using an adaptive frequency domain filter such as a multi-delay filter.

[0032] In some embodiments, other adaptive algorithms can be used to estimate the transfer function. In some embodiments, a recursive least squares filter (RLS) or a Kalman filter may be further used. In some embodiments, the disclosed techniques can be performed simultaneously, or the techniques can be incorporated into or used with an active noise canceling system such as the one shown in Figure 1.

[0033] Figure 4A is a flowchart illustrating the integration of adaptive telephony noise cancellation into a telephony voice processing system 400 in several embodiments. An audio sample rate accelerometer 420 (e.g., the accelerometer detailed in the exemplary system) is connected to the audio system with the same sample clock as the telephony microphone (e.g., the microphone detailed in the exemplary system). In some embodiments, such connection may be achieved using an audio rate accelerometer connected to the same automotive audio bus (A2B) as the digital microphone.

[0034] The microphone array 430 (for example, the microphones detailed in the exemplary system) can be processed by the beamformer (BF) 410 to generate a virtual microphone signal with road noise.

[0035] Beamforming may be used with a single microphone. When a microphone array 430 or multiple microphones are used, a linear signal for performing adaptive noise cancellation can be derived using one of several established microphone beamforming methods. If the beamformer 410 is nonlinear or adaptive, it may be advantageous to apply adaptive noise cancellation to the individual microphone signals before beamforming. Depending on the array design, one of the well-established microphone beamforming methods may be used, namely broadside beamforming, differential beamforming, linearly constrained minimum variance (LCMV), minimum variance distortionless response (MVDR), general sidelobe canceller (GSC), or parametric multichannel Wiener filter (PMWF), or any of their derivatives. The beamformer 410 may be placed before the adaptive noise-canceling block to reduce the number of channels that need to be processed, provided that it is linear and time-invariant.

[0036] Next, the telephony noise canceller (TNC) 300 removes correlated load noise by linear subtraction using virtual microphone signals from the beamformer 410 and accelerometer 420. The signal is then processed by the adaptive echo canceller 440. Residual noise and echoes are estimated and then removed by the noise suppressor and / or residual echo suppressor 450. The processed voice signal is then equalized, range-limited, and then transmitted to a connected telephone via the Bluetooth® interface 460 using the hands-free profile defined by the Bluetooth® standard. In certain embodiments, a different interface may be used, which may include different profiles.

[0037] The noise suppressor 450 may optionally include input from the accelerometer 420. In addition to using the accelerometer 420 to remove noise from the telephony microphone using adaptive filters, or alternatively, information from the accelerometer can be used to improve the performance of the noise suppression (NS) block 450.

[0038] Noise suppressors are a common component in hands-free telephony processing systems and typically function in the spectral domain by estimating the noise spectrum and removing it from the microphone signal. Noise reduction can be achieved by several well-known methods found in the literature, namely spectral subtraction (1994, Martin) or a variation of the Wiener filtering method (1984, Ephraim and Malah). While single-channel NS are well-known for suppressing statistically steady noise, they struggle to suppress transient noise such as the bang of a door closing or road impact noise. Using a noise accelerometer, the noise spectrum attributable to road noise can be more accurately estimated, thereby improving the performance of the noise suppressor.

[0039] This can be done in several ways, including the following: 1) Similar to how post-filtering methods (Cohen, 2004) are applied to beamformers, the noise estimation output of an adaptive filter can be used as a load noise reference in a noise suppressor. This can suppress both steady-state and transient load noise. 2) Estimate the transfer function between the accelerometer and microphone using spectral methods such as MATLAB's tfestimate, and use this estimate to generate a road noise estimate. This can also suppress both steady-state and transient road noise. 3) For example, it is possible to perform various heuristic problem-solving methods in the spectral domain by reusing power spectral density estimators for speech and noise to detect transients of road noise (1994, Martin), and then using the spectra of these transients to modify the speech probability (reducing the speech probability in the noise band and characterizing them as noise to be removed). Then, the speech probability can be used in the usual way to generate a noise estimate that includes transients (2002, Cohen). Similarly, a speech activity detector can be used as a simplified form of the speech probability.

[0040] Figure 4B shows one embodiment of the noise suppressor 450 of the adaptive noise cancellation system 400 shown in Figure 4A. Following one of the above techniques, data from the accelerometer 420 is received by the filter bank 470. After filtering is performed in the filter bank 470, the results are transmitted for transient detection 475. These results are then provided to the noise estimator 480, which also receives input from the microphone 430. After the noise is estimated, the results are provided to the noise suppressor 485, which also receives input from the microphone 430. After noise suppression is performed, the output of the noise suppressor 485 is transmitted to the inverse filter bank 490 for final processing. Exemplary system data

[0041] Figures 5A to 7 of this disclosure illustrate exemplary system data of adaptive noise-canceling systems according to several embodiments, using various charts and graphs.

[0042] Figure 5A is a chart showing sample road noise data that has not been processed by the adaptive noise cancellation system. Figure 5B is a graph showing sample road noise data that has been processed by the adaptive noise cancellation system. As shown in Figure 5A, the amount of road noise is suppressed after processing by this noise cancellation system.

[0043] Figure 6 is a bipartite graph showing sample data for accelerometer placement in an adaptive noise-canceling system. The accelerometer placement may be determined by analyzing the contribution of each accelerometer channel to the microphone signal (shown on the Y-axis of the lower graph), as seen in Figure 6. The optimal transfer function between the accelerometer channel and the microphone channel is estimated in the frequency domain. This transfer function is multiplied by the target accelerometer signal to obtain its contribution. In some embodiments, multi-axis accelerometers are placed on the suspension knuckle and / or on the vehicle body near the suspension joint to obtain the best correlation with noise at the microphone placement location. In some embodiments, multiple accelerometers can be used to detect all structurally propagated noise sources audible at the microphone placement location.

[0044] Figures 7A and 7B are graphs showing sample data of noise suppression using an adaptive noise-canceling system. The graph in Figure 7A shows exemplary noise suppression that can occur between speech segments while driving on a highway at 65 mph. Overall noise is suppressed by up to approximately 13 dB in the 200 Hz to 500 Hz speech band. Figure 7B is a plot of noise cancellation in dB over the same frequency range of 200 Hz to 500 Hz. Spectral peaks caused by road noise are suppressed by approximately 6 dB to 12 dB. The 300 Hz speech component is virtually unaffected. Exemplary implementation examples

[0045] Many modifications and changes can be made to the embodiments described above, and it should be understood that elements of these modifications and changes are present in other acceptable embodiments. All such modifications and changes are intended to be included herein within the scope of this disclosure. The above description details specific embodiments. However, it will be understood that, no matter how detailed the above description may be, the system and method can be practiced in many ways. Also, as stated above, the use of specific terms when describing particular features or aspects of the system and method should not be interpreted as suggesting that such terms are redefined herein to be limited to including any particular characteristics in the features or aspects of the system and method to which they relate.

[0046] The systems, methods, and apparatus described herein each have several embodiments, but no single embodiment alone embodies the desired attributes. Some non-limiting features are briefly described here without limiting the scope of this disclosure. The following paragraphs describe various exemplary implementations of the apparatus, systems, and methods described herein. A system consisting of one or more computers may be configured to perform a specific operation or action by installing software, firmware, hardware, or a combination thereof on the system during operation, causing the system to perform an operation. One or more computer programs may be configured to perform a specific operation or action by containing instructions that, when executed by a data processing device, cause the device to perform an operation.

[0047] Embodiment 1: An adaptive noise-canceling system comprising multiple multi-axis accelerometers and multiple microphones, wherein the system picks up vibrations on the vehicle chassis by using a combination of multiple multi-axis accelerometers and multiple microphones.

[0048] Embodiment 2: The adaptive noise-canceling system according to Embodiment 1, wherein the first microphone among the multiple microphones is located on the right side of the headrest inside the vehicle.

[0049] Embodiment 3: The adaptive noise-canceling system according to Embodiment 1, wherein the second microphone among the multiple microphones is located on the left side of the headrest inside the vehicle.

[0050] Embodiment 4: The adaptive noise-canceling system according to Embodiment 1, wherein the third microphone among the multiple microphones is positioned on the sun visor inside the vehicle.

[0051] Embodiment 5: The adaptive noise cancellation system according to Embodiment 1, wherein multiple multi-axis accelerometers output accelerometer data corresponding to 12 channels.

[0052] Embodiment 6: The adaptive noise-canceling system according to Embodiment 1, wherein at least one of the multiple accelerometers is located in the suspension knuckle of the vehicle.

[0053] Embodiment 7: The adaptive noise-canceling system according to Embodiment 1, wherein at least one of the multiple accelerometers is located on the suspension joint of the vehicle.

[0054] Embodiment 8: The adaptive noise cancellation system according to Embodiment 1, wherein multiple accelerometers output accelerometer data in three channels.

[0055] Embodiment 9: The adaptive noise-canceling system according to Embodiment 1, further comprising a speaker system.

[0056] Embodiment 10: The adaptive noise-canceling system according to Embodiment 9, wherein the speaker system outputs audio data corresponding to two channels.

[0057] Embodiment 11: The adaptive noise cancellation system according to Embodiment 1, using an adaptive algorithm.

[0058] Embodiment 12: The adaptive noise-canceling system according to Embodiment 11, wherein the adaptive algorithm derives one or more filter weights that model the transfer function between vibrations on the vehicle chassis and sound pressure at the placement locations of multiple microphones.

[0059] Embodiment 13: The adaptive noise cancellation system according to Embodiment 11, wherein the adaptive algorithm is a least mean squares filter.

[0060] Embodiment 14: The adaptive noise cancellation system according to Embodiment 11, wherein the adaptive algorithm is a recursive least squares filter.

[0061] Embodiment 15: The adaptive noise cancellation system according to Embodiment 11, wherein the adaptive algorithm is a Kalman filter.

[0062] Embodiment 16: The adaptive noise cancellation system according to Embodiment 1, wherein multiple multi-axis accelerometers use the same sample clock as multiple microphones.

[0063] Embodiment 17: The adaptive noise-canceling system according to Embodiment 1, wherein multiple multi-axis accelerometers use the same automotive audio bus (A2B) as multiple microphones.

[0064] Embodiment 18: The adaptive noise-canceling system according to Embodiment 1, wherein the plurality of microphones constitute a microphone array.

[0065] Embodiment 19: The adaptive noise-canceling system according to Embodiment 18, wherein a microphone array is processed by a beamformer to generate a virtual microphone signal having vehicle road noise.

[0066] Embodiment 20: The adaptive noise cancellation system according to Embodiment 19, wherein a virtual microphone signal is used by a telephony noise canceller and multiple multi-axis accelerometers to remove correlated road noise by linear subtraction.

[0067] Embodiment 21: The adaptive noise cancellation system according to Embodiment 1, wherein multiple microphones are processed by a beamformer to generate a virtual microphone signal having vehicle road noise.

[0068] Embodiment 22: The adaptive noise cancellation system according to Embodiment 19, wherein a virtual microphone signal and multiple multi-axis accelerometers are processed by a telephony noise canceller and correlated road noise is removed by linear subtraction.

[0069] Embodiment 23: The adaptive noise cancelling system according to Embodiment 1, further comprising a telephony noise canceller that receives signals from a plurality of multi-axis accelerometers, wherein a plurality of microphones provide the telephony noise canceller with the voice signals of a vehicle user in order to remove correlated road noise by linear subtraction.

[0070] Embodiment 24: The adaptive noise canceling system according to Embodiment 23, further comprising an adaptive echo canceller configured to receive the output of a telephony noise canceller and remove echoes from the received signal.

[0071] Embodiment 25: The adaptive noise canceling system according to Embodiment 24, further comprising a noise suppressor configured to receive the output of an adaptive echo canceller and to estimate the noise spectrum of the received signal to suppress road noise.

[0072] Embodiment 26: The adaptive noise-canceling system according to Embodiment 25, further comprising a hands-free profile interface configured to receive the output of a noise suppressor, equalize and limit the range of the received signal, and transmit the resulting signal to a connected telephone.

[0073] Embodiment 27: The adaptive noise-canceling system according to Embodiment 26, wherein the hands-free profile interface is a hands-free profile Bluetooth® interface.

[0074] Embodiment 28: The adaptive noise-canceling system according to Embodiment 23, further comprising a hands-free profile interface configured to receive the output of a telephony noise canceller, equalize and range-limit the received signal, and transmit the resulting signal to a connected telephone.

[0075] Embodiment 29: The adaptive noise-canceling system according to Embodiment 28, wherein the hands-free profile interface is a hands-free profile Bluetooth® interface.

[0076] As previously stated, the implementations of the embodiments described above may include hardware, methods or processes, and / or computer software on a computer-accessible medium. Further implementation considerations

[0077] Where a feature or element is referred to as "on" another feature or element in this specification, it may be directly on the other feature or element, or there may be additional intervening features and / or elements. Conversely, where a feature or element is referred to as "directly on" another feature or element, there may be no intervening features or elements. Similarly, where a feature or element is referred to as "connected," "attached," or "coupled" to another feature or element, it will be understood that it may be directly connected to, directly attached to, or directly coupled to the other feature or element, or there may be intervening features or elements. Conversely, where a feature or element is referred to as "directly connected," "directly attached," or "directly coupled" to another feature or element, there may be no intervening features or elements.

[0078] While described or illustrated in relation to one embodiment, features and elements described or illustrated in this manner may also apply to other embodiments. It will also be understood by those skilled in the art that references to structures or features positioned "adjacent" to another feature may have portions that overlap with or lie beneath the adjacent feature.

[0079] The terms used herein are for the sole purpose of describing specific embodiments and implementations and are not intended to limit the invention. For example, as used herein, the singular forms “a,” “an,” and “the” may also be intended to include the plural form unless otherwise explicitly indicated in the context. The terms “comprise” and / or “comprising,” as used herein, indicate the presence of the described features, steps, actions, processes, functions, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, actions, processes, functions, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any combination of one or more of the related enumerated items and may be abbreviated as “ / .”

[0080] In the above description and claims, phrases such as “at least one of” or “one or more of” may appear, followed by a conjunctive list of elements or features. The term “and / or” may also appear in lists of two or more elements or features. Unless implicitly or explicitly contradicted by the context in which they are used, such phrases are intended to mean any of the enumerated elements or features individually, or any of the enumerated elements or features in combination with any of the other enumerated elements or features. For example, the phrases “at least one of A and B,” “one or more of A and B,” and “A and / or B” are intended to mean “A alone, B alone, or A and B together,” respectively. The same interpretation is intended for lists containing three or more items. For example, the phrases “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, and / or C” are intended to mean “A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together,” respectively. The use of the term “based on” in the foregoing and in the claims is intended to mean “based at least in part on,” so as to allow for features or elements that are not enumerated.

[0081] Terms indicating spatial relative relationships, such as “forward,” “rearward,” “under,” “below,” “lower,” “over,” and “upper,” may be used herein to facilitate descriptions of the relationship between one element or feature and one or more other elements or features, as shown in the figures. It will be understood that terms indicating spatial relative relationships are intended to encompass various orientations of the device in use or operation, in addition to the orientations shown in the figures. For example, if the device in the figure is inverted, an element described as being “under” or “beneath” another element or feature will, due to the inversion, be facing “over” the other element or feature. Therefore, the term “under” may encompass both upward and downward directions, depending on the reference point or reference direction. The device may be oriented in other directions (rotated 90 degrees or in other angular directions), and the spatial relative relationship descriptors used herein will be interpreted accordingly. Similarly, terms such as “upwardly,” “downwardly,” “vertically,” and “horizontally” may be used herein for descriptive purposes only, unless otherwise specified.

[0082] The terms “first” and “second” may be used herein to describe various features / elements (including steps or processes), but these features / elements should not be limited by these terms to indicate the order of the features / elements or whether one is primary or more important than the other, unless otherwise indicated in the context. These terms may also be used to distinguish one feature / element from another. Thus, a first feature / element described may be called a second feature / element, and similarly, a second feature / element described below may be called a first feature / element without departing from the disclosure provided herein.

[0083] Where used herein and in the claims, including where used in embodiments, unless otherwise expressly specified, all numbers may be interpreted as beginning with the words “about” or “approximately,” even if the term does not appear expressly. The words “about” or “approximately” may be used when describing size and / or location to indicate that the described value and / or location is within a reasonably expected range of value and / or location. For example, a number may have values ​​such as ±0.1% of the described value (or range of value), ±1% of the described value (or range of value), ±2% of the described value (or range of value), ±5% of the described value (or range of value), ±10% of the described value (or range of value). Any number shown herein should also be understood to include its value approximately unless otherwise indicated in the context.

[0084] For example, if the value "10" is disclosed, then "about 10" is also disclosed. Any numerical range enumerated herein is intended to include all subranges contained therein. As will be well understood by those skilled in the art, if a value is disclosed, then "less than or equal to," "greater than or equal to the value," and effective ranges between values ​​are also disclosed. For example, if the value "X" is disclosed, then "less than or equal to X" and "greater than or equal to X" (for example, if X is a number) are also disclosed. It will also be understood that throughout this application, data is provided in several different formats, and this data may represent a range of endpoints or start points, and any combination of data points. For example, if a specific data point "10" and a specific data point "15" can be disclosed, it is understood that this can be considered to disclose not only the range between 10 and 15, but also the range greater than 10 and greater than 15, greater than or equal to 10 and greater than or equal to 15, less than or equal to 10 and less than or equal to 15, and also equal to 10 and equal to 15. It is similarly understood that each unit between two specific units can also be disclosed. For example, if 10 and 15 can be disclosed, then 11, 12, 13, and 14 can also be disclosed.

[0085] While various exemplary embodiments are disclosed, any of several modifications may be made to these embodiments without departing from the disclosure herein. For example, the order in which the various method steps described are performed may be changed or rearranged in different or alternative embodiments, and one or more method steps may be omitted in other embodiments. Any or desirable features of the various apparatus and system embodiments may be included in some embodiments and not in others. Therefore, the above description is provided primarily for illustrative purposes and should not be construed as limiting the scope of the claims and specific embodiments or any particular details or features disclosed.

[0086] The embodiments and examples included herein, not as limitations but as illustrations, illustrate specific embodiments that can put the disclosed subject matter into practice. As stated above, other embodiments may be utilized and derived from these embodiments so as to allow for structural and logical substitutions and modifications without departing from the scope of this disclosure. Such embodiments of the disclosed subject matter, if two or more are actually disclosed, may be referred to herein individually or collectively by the term “invention” merely for convenience and without the intention of spontaneously limiting the scope of this application to any single invention or inventive concept. Thus, while specific embodiments are illustrated and described herein, any configuration calculated to achieve the intended, practical, or disclosed purpose, whether expressly stated or implied, may be used in place of the specific embodiments shown. This disclosure is intended to cover all possible adaptations or variations of various embodiments. Combinations of the embodiments described above, and other embodiments not specifically described herein, will become apparent to those skilled in the art upon consideration of the above description.

[0087] The subject matter disclosed is shown herein with reference to one or more features or embodiments. Those skilled in the art will recognize and understand that, despite the detailed nature of the exemplary embodiments shown herein, modifications and alterations can be made to such embodiments without limiting or departing from the generally intended scope. These and various other applications and combinations of the embodiments shown herein fall within the scope of the disclosed subject matter, as defined by the disclosed elements and features and their equivalents.

Claims

1. Multiple multi-axis accelerometers mounted on the vehicle, Multiple microphones are placed inside the cabin of the aforementioned vehicle, An adaptive noise-canceling system for a vehicle, comprising: a telephony noise canceller configured to receive signals from a plurality of multi-axis accelerometers and a plurality of microphones, wherein the plurality of microphones further provide the telephony noise canceller with voice signals of the vehicle's users, and the telephony noise canceller is configured to remove correlated road noise by linear subtraction.

2. The adaptive noise-canceling system according to claim 1, further comprising a hands-free profile interface configured to receive the output of the telephony noise canceller, equalize and range-limit the received signal, and transmit the resulting signal to a connected telephone.

3. The adaptive noise-canceling system according to claim 2, wherein the hands-free profile interface is a hands-free profile Bluetooth® interface.

4. The adaptive noise-canceling system according to claim 1, wherein the first microphone among the plurality of microphones is located on the right side of the headrest inside the vehicle.

5. The adaptive noise-canceling system according to claim 1, wherein the second microphone among the plurality of microphones is located on the left side of the headrest inside the vehicle.

6. The adaptive noise-canceling system according to claim 1, wherein the third microphone among the plurality of microphones is positioned on the sun visor inside the vehicle.

7. The adaptive noise cancellation system according to claim 1, wherein the plurality of multi-axis accelerometers output accelerometer data corresponding to 12 channels.

8. The adaptive noise-canceling system according to claim 1, wherein at least one of the plurality of accelerometers is located in the suspension knuckle of the vehicle.

9. The adaptive noise-canceling system according to claim 1, wherein at least one of the plurality of accelerometers is located on the suspension joint of the vehicle.

10. The adaptive noise-canceling system according to claim 1, wherein each of the plurality of accelerometers outputs accelerometer data in three channels.

11. The adaptive noise-canceling system according to claim 1, further comprising a speaker system.

12. The adaptive noise-canceling system according to claim 11, wherein the speaker system outputs audio data corresponding to two channels.

13. The adaptive noise-canceling system according to claim 1, which uses an adaptive algorithm.

14. The adaptive noise-canceling system according to claim 13, wherein the adaptive algorithm derives one or more filter weights that model a transfer function between vibrations on the vehicle chassis and sound pressure at the placement locations of the plurality of microphones.

15. The adaptive noise canceling system according to claim 13, wherein the adaptive algorithm is a least mean squares filter.

16. The adaptive noise canceling system according to claim 13, wherein the adaptive algorithm is a recursive least squares filter.

17. The adaptive noise canceling system according to claim 13, wherein the adaptive algorithm is a Kalman filter.

18. The adaptive noise-canceling system according to claim 1, wherein the plurality of multi-axis accelerometers use the same sample clock as the plurality of microphones.

19. The adaptive noise-canceling system according to claim 1, wherein the plurality of multi-axis accelerometers use the same automotive audio bus (A2B) as the audio bus used by the plurality of microphones.

20. The adaptive noise-canceling system according to claim 1, wherein the plurality of microphones are a microphone array.

21. The adaptive noise-canceling system according to claim 18, wherein the microphone array is processed by a beamformer to generate a virtual microphone signal having the road noise of the vehicle.

22. The adaptive noise-canceling system according to claim 19, wherein the virtual microphone signal is used by the telephony noise canceller and the plurality of multi-axis accelerometers to remove correlated road noise by linear subtraction.

23. The adaptive noise cancelling system according to claim 1, further comprising an adaptive echo canceller configured to receive the output of the telephony noise canceller and remove echoes from the received signal.

24. The adaptive noise canceling system according to claim 23, further comprising a noise suppressor configured to suppress road noise by estimating the noise spectrum of the received signal.

25. The adaptive noise-canceling system according to claim 24, further comprising a hands-free profile interface configured to receive the output of the noise suppressor, equalize and limit the range of the received signal, and transmit the resulting signal to a connected telephone.

26. The adaptive noise-canceling system according to claim 25, wherein the hands-free profile interface is a hands-free profile Bluetooth® interface.

27. Multiple multi-axis accelerometers, Multiple microphones, The aforementioned multiple multi-axis accelerometers and multiple microphones work together to pick up vibrations on the vehicle chassis in order to cancel out background noise. The plurality of microphones is a microphone array that generates a virtual microphone signal having the road noise of the vehicle when processed by a beamformer, and An adaptive noise-canceling system comprising: a telephony noise canceller that receives the virtual microphone signal and the signals from the plurality of multi-axis accelerometers and removes correlated road noise by linear subtraction.

28. The adaptive noise-canceling system according to claim 27, further comprising a hands-free profile interface configured to receive the output of the telephony noise canceller and to equalize and limit the range of the received signal.

29. The adaptive noise-canceling system according to claim 28, wherein the hands-free profile interface is a hands-free profile Bluetooth® interface.

30. Reading accelerometer data from multiple multi-axis accelerometers mounted on the vehicle, The acquisition of audio data from multiple microphones placed inside the cabin of the aforementioned vehicle, A method for removing noise inside a vehicle, comprising inputting the accelerometer data and audio data into a telephony noise canceller and removing correlated road noise by linear subtraction.

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