Patent Description:
Currently, an artificial intelligence has become a hot spot, as a part of the artificial intelligence, a speech recognition technology is also becoming more and more familiar to people. Under a market driving of a plurality of intelligent equipments including a smart audio and a smart TV, the speech recognition technology has become a synonymous of intelligence. Although the speech recognition technology in a field of the artificial intelligence has achieved a great progress in recent years, there are still a plurality of problems, especially when it is practically applied to a plurality of smart devices, there are still a plurality of specific usage problems. For example, when a smart TV is making a speech recognition, if a volume of the smart TV is turned up to a certain volume value, a speech recognition rate of the smart TV will be very low, and even turning the volume of the smart TV down again, during a long period of time, the speech recognition rate will still be pretty low. A main reason, from an analysis, is that, a signal captured by a microphone at a high volume has appeared a clipping distortion, which causes an echo cancellation algorithm to require a reconvergence, while a convergence process takes a certain time, and an echo cancellation effect is very poor during the convergence process, bringing a very bad experience to user.

Therefore, the current technology needs to be improved and developed.

<CIT>, <CIT> and <NPL>, are relevant background arts in this field.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description.

According to a plurality of defects described above in the current technology, the present invention is providing a method for solving an echo cancellation failure caused by the clipping distortion, in order to solve a plurality of defects and deficiencies in the prior art, by presetting a maximum amplitude value for a signal intensity that a microphone is allowed to receive, when a signal intensity received by the microphone is greater than or equal to the amplitude value, a volume of the television is turned down to ensure that the signal intensity received by the microphone is less than the amplitude value, so that the echo cancellation is performed without the clipping distortion of the signal, avoiding the echo cancellation failure caused by a multiple convergence of a self-adapting filter due to the clipping distortion of the microphone signal.

In order to achieve the above mentioned goals, the technical solution of the present invention to solve the technical problems is depicted in the independent claims <NUM>,<NUM>,<NUM>. Preferred embodiments are depicted in the dependent claims.

Comparing to a case in the current technology that, when the volume of the smart television is larger than a certain value, the signal that the microphone receives will make a clipping distortion, that further makes the self-adapting filter converge multiple times, and affects the echo cancellations, the present invention presets a maximum amplitude value for a signal intensity that a microphone is allowed to receive, and adjusts the volume of the smart television, by real time monitoring the signal intensity that the microphone receives, to ensure the echo cancellation is achieved in a case that the signal the microphone receives is not larger than the maximum amplitude value, without any clipping distortions, thus it has avoided causing a problem that the self-adapting filter converges multiple times, making the coefficient of a self--adapting filter function W(n) unstable, and affecting the echo cancellation.

Any embodiment in the description that does not fall within the scope of the claims shall be regarded as an example for understanding the present invention.

In order to make the purpose, technical solution and the advantages of the present invention clearer and more explicit, further detailed descriptions of the present invention are stated here, referencing to the attached drawings and some preferred embodiments of the present invention. It should be understood that the detailed embodiments of the invention described here are used to explain the present invention only, instead of limiting the present invention.

At present, both machine learning and artificial intelligence are hotspots in a field of technology, and a speech recognition technology, as a part of the artificial intelligence, is becoming more and more familiar. Especially driven by a plurality of smart devices including a smart stereo and a smart television, the speech recognition technology has become a synonymous of intelligence. Although the speech recognition technology has made great progresses in recent years, there are still some problems. In the smart television, it has found that when a sound played by the television is adjusted to a certain volume value, a speech recognition rate will be very low, and even if the volume is adjusted low again, in a long period of time, the speech recognition rate is still low. After an analysis, a main reason is found that a clipping distortion has occurred in the signal received by the microphone at a large volume, which causes an echo cancellation algorithm requiring a re-convergence, and a convergence process takes a certain amount of time, while an effect of the echo cancellation during this period of time is very poor.

A core content of the echo cancellation is a self-adapting filter, which is an algorithm or a device that adopts a certain algorithm and automatically adjusts a plurality of filter coefficients to achieve an optimal filtering characteristic, based on an estimation of a plurality of statistical characteristics of both input and output signals. The self-adapting filter can be in a continuous domain or a discrete domain. A discrete domain self-adapting filter consists of a set of mechanisms including a tap delay line, a variable weighting coefficient, and an automatically adjusting coefficient. <FIG> illustrates a signal flow chart of a self-adapting filter in a discrete domain applied to simulating an unknown discrete system in the present invention, the self-adapting filter updates and adjusts the variable weighting coefficient for each sample of an input signal sequence X(n) according to a specific algorithm, making a mean squared error minimum of an output signal sequence Y(n) compared to a desired signal sequence d(n), that is, the output signal sequence Y(n) approximates the desired signal sequence d(n), and an echo path function to be solved is a process of a self-adapting filter function W(n) converging. The input signal sequence X(n) applied is an echo reference signal, and the desired signal sequence d(n) is an echo signal received by the microphone, and the W(n) after the self-adapting filter converges is the echo path function. After converging, when an actual echo occurs, the echo reference signal is passed through the function W(n), and a very accurate echo signal will be got. Subtracting the echo signal from a mixed signal E(n) directly, and obtaining an actual voice signal W(n) that needs to be sent, an echo cancellation task will be achieved.

Shown as <FIG>, a processing flow for the echo cancellation in the prior art is: after an echo cancellation algorithm starts, a self-adapting filter converges quickly, and after converged, the coefficient of the self-adapting filter function W(n) will tend to stable. As long as the echo path is unchanged or the microphone signal does not have a clipping distortion, the coefficient of the self-adapting filter function W(n) will remain stable. However, when a sound played by the television becomes larger, which causes the signal received by the microphone to have a clipping distortion, a self-adapting filtering needs to be reconverged, by adjusting the coefficient of the filter function W(n), a plurality of filtering requirements in a new state is adapted. While it takes a relatively long time to finish re-converging in such a state. Therefore, when a re-convergence occurs, even if a user turns down the volume of the television again, to make the signal received by the microphone not being clipped, in a short time, the echo cancellation function still cannot be restored to a normal working state.

According to a plurality of defects in the prior art, the present invention provides a method for solving an echo cancellation failure caused by the clipping distortion, a flow chart for a preferred embodiment of a method for solving the echo cancellation failure in the present invention is shown as <FIG>, the preferred embodiment of the method in the present invention comprises a plurality of steps following:.

When the microphone signal has a clipping distortion, the self-adapting filter function requires a re-convergence, by adjusting the coefficient of the self-adapting filter function W(n), a filtering requirement in a new state is adapted, and in the new state, the re-convergence will require a relatively long time to finish, so as to keep the coefficient of the self-adapting filter function W(n) stable.

Step S200, presetting a maximum amplitude value for a microphone signal, and detecting if the microphone signal is lower than the maximum amplitude value;
Specifically, in the present embodiment, if the signal received by the microphone is too large, it is generally caused by an excessive sound played by the television itself. So presetting a maximum amplitude value for the microphone signal, before detecting and deciding an intensity of the sound played by the television, and making the signal that the microphone receives lower than the maximum amplitude value. By detecting the intensity of the sound played by the television, and combining with the intensity of the sound played by the television, the present step presets a maximum amplitude value for a signal intensity that the microphone is allowed to receive, so as to make the signal that the microphone receives smaller than the maximum amplitude value.

Step S300, when the microphone signal is larger than or equal to the maximum amplitude value, turning down a volume of the television, and making the microphone signal smaller than the maximum amplitude value;
Specifically, when the microphone signal is larger than or equal to the maximum amplitude value, a user is reminded to turn the volume lower, and making the signal that the microphone received smaller than the amplitude value, so as to make sure the echo cancellation is processed in a case of the signal having no distortions, and avoid a multiple convergence caused by the signal distortion.

Step S400, performing an echo cancellation to the microphone signal by adopting the filter function in the stable state before.

Specifically, in the present embodiment, when the microphone signal is smaller than the maximum amplitude value, and the signal has no distortions, the filter function in a stable state is still adopted for an echo cancellation, and the self-adapting filter needs no re-convergence. As long as the volume is lowered, the echo cancellation function recovers ASAP, without any disable period for the echo cancellation function.

In order to better explain a preferred embodiment for the method in the present invention, and to better understand a plurality of specific implementation steps of the preferred embodiment for the method in the present invention, a specific flow chart of a preferred embodiment for the method in the present invention is provided herein. Shown as <FIG>, a specific flow chart for a preferred embodiment is illustrated. First, starting an echo cancellation algorithm for the echo cancellation, and a self-adapting filter performing a convergence, while a plurality of coefficients of a filter function is stable, then the microphone signal is decided to have a clipping distortion or not, if there is no clipping distortion appearing, then the coefficients of the self-adapting filter function W(n) keep stable, while a clipping distortion appears, the user adjusts the volume of the television manually or automatically by starting a system, and deciding if the microphone signal has the clipping distortion or not, after adjusting the volume, if the clipping distortion still appears, then the volume is adjusted continuously, if there is no more clipping distortion appears, then keeping the coefficients of the self-adapting filter function W(n) stable. By effectively monitoring the intensity of the signal received by the microphone and controlling the volume of the television, the signal recorded by the microphone does not have any clipping distortions, the coefficient of the self-adapting filter function W(n) is kept in a stable state, and the echo cancellation function is normal and effective.

The present invention further provides a system for solving the echo cancellation failure, applied to solving a problem that the echo cancellation function is disabled in a certain period, caused by the clipping distortion of the microphone signal. <FIG> illustrates a schematic diagram for a preferred embodiment of a system for solving the echo cancellation failure in the present invention, Shown as <FIG>, the system comprises: an echo cancelation module <NUM>, a microphone signal control module <NUM> and a volume control module <NUM>.

The echo cancelation module <NUM> is applied to starting the echo cancellation algorithm for the echo cancellation, converging the self-adapting filter, so as to make the coefficients of the filter function stable;
Specifically, in the present embodiment, a specific function of the echo cancelation module achieving an echo cancelation task is as following: a core content of the echo cancelation is the self-adapting filter, a working principle of the self-adapting filter may refer to the working process of the self-adapting filter described above, and no more descriptions will be made here.

After starting the echo cancellation algorithm, the self-adapting filter makes a fast convergence, after the convergence is done, the coefficients of the self-adapting filter function W(n) tend to be stable, when the echo path is unchanged or the microphone signal does not appear a clipping distortion, the coefficients of the self-adapting filter function W(n) will keep remaining stable; when the voice of the television played increases, and makes the signal that the microphone received have a clipping distortion, the self-adapting filter will require a reconvergence, by adjusting the coefficients of the filter function W(n), to adapt a filtering requirement under a new status, while the re-convergence in the new status requires a relatively long time to finish, to make the coefficients of the self-adapting filter function W(n) remain stable.

The microphone signal control module <NUM> is applied to detecting the signal intensity of the microphone, and deciding if the signal intensity that the microphone receives is larger than the maximum amplitude value preset.

Specifically, in the present embodiment, the microphone signal control module <NUM> is applied to detecting the signal intensity of the microphone, and deciding if the signal intensity that the microphone receives is larger than the maximum amplitude value preset, the intensity of the signal that the microphone received is closely related to a size of the sound played by the television itself. Thus presetting a maximum amplitude value for the intensity of the signal that the microphone is allowed to receive, and when the microphone signal is larger than or equal to the maximum amplitude value, the volume of the television is lowered, to ensure the echo cancelation is processed without the signal distortion, so as to avoid a problem of the multiple convergence caused by the clipping distortion of the microphone signal, which affects the echo cancelation.

The volume control module <NUM> is applied to controlling the volume of the television, making the signal that the microphone receives smaller than the maximum amplitude value.

Specifically, in the present embodiment, the volume control module <NUM> is applied to controlling the volume of the television, making the signal that the microphone receives smaller than the maximum amplitude value, when the microphone signal control module <NUM> detects that the microphone signal is larger than or equal to the maximum amplitude value of the microphone signal preset, the volume control module <NUM> is noticed, and the volume control module <NUM> controls lower the volume of the television, makes the signal that the microphone received not exceed the maximum amplitude value, and ensures the echo cancelation module <NUM> is making the echo cancelation without any signal distortions.

The intensity of the signal that the microphone receives is closely related to the size of the voice that the television itself plays, when the signal that the microphone receives is larger than or equal to the maximum amplitude value preset, the volume of the television is required to be lower, while lowering the volume of the television comprises noticing the user to lower the volume of the television to a suitable volume value.

When the microphone signal control module <NUM> detects the signal that the microphone receives is larger than the maximum amplitude value preset, the volume control module <NUM> lowers the volume of the television, and makes the signal that the microphone receives smaller than the maximum amplitude value, which is achieved by the echo cancelation module <NUM> making the echo cancelation by adopting the filter function in the stable state. Other working principle may refer to the preferred embodiments of the method described above, and no more descriptions will be stated herein.

The present invention further provides a storage medium, the storage medium is a computer readable storage medium, the storage medium has a program for solving the echo cancellation failure stored, when the program for solving the echo cancellation failure is executed by a processor, the steps of the above method for solving the echo cancellation failure is achieved.

Claim 1:
A method for solving an echo cancellation failure, applied to solving a problem of a television with an echo cancellation function failure caused by a clipping distortion of a microphone signal, wherein the method for solving the echo cancellation failure comprises a plurality of following steps:
A. starting an echo cancellation algorithm, and a self-adapting filter performing a convergence, to make a plurality of coefficients of a filter function to be stable (S100);
D. performing an echo cancellation to a microphone signal by adopting the filter function in a stable state (S100),
characterized in that the method further comprises:
B. presetting a maximum amplitude value for the microphone signal, and detecting if the microphone signal is lower than the maximum amplitude value (S200);
C. turning down a volume of the television, and making the microphone signal smaller than the maximum amplitude value, when the microphone signal is larger than or equal to the maximum amplitude value (S300);
wherein in the step C, when the microphone signal is larger than or equal to the maximum amplitude value, turning down the volume, making the signal that the microphone receives smaller than the maximum amplitude value, and ensuring that the echo cancellation is performing without any signal distortions, so as to avoid a multiple convergence,
wherein lowering the volume of the television is achieved by noticing a user to lower the volume of the television to a suitable volume value.