Directional broadcasting method, device and equipment of sound box and storage medium

Abstract

The invention relates to the technical field of broadcasting, and discloses a directional broadcasting method, device and equipment for a sound box and a storage medium, and the method comprises the steps: receiving a first sound signal through employing a plurality of sound sensors in a preset first time window; calculating a covariance matrix of the sound signal by using a linear constraint minimum variance algorithm, and determining a direction vector of a target direction; determining a target weight vector according to the direction vector of the target direction and the constraint condition thereof; the target weight vector is a beam forming weight vector; solving the target weight vector by adopting a Lagrange multiplier method to obtain a first optimal weight vector; performing weighted summation on the first sound signal by using the first optimal weight vector to generate an output signal; and playing the output signal by using the sound box. By applying the technical scheme of the invention, the signal in the required direction can be effectively enhanced through a reasonable signal processing and control strategy, and interference from other directions can be suppressed at the same time, so that high-quality audio output is realized.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of broadcasting technology, and specifically to a directional broadcasting method, device, equipment and computer-readable storage medium for a speaker. Background Art

[0002] In the current technology implementation of speaker directional broadcasting, traditional speaker designs often lack precise sound wave control mechanisms and have poor directivity, which results in the inability to effectively focus sound in a specific direction during propagation, and the layout of the speakers and the phenomenon of sound wave interference are not fully utilized. This makes the energy in the desired direction account for a low proportion when the sound is dispersed in all directions, and it is difficult for listeners to clearly receive the broadcast content when they deviate from the predetermined receiving area, which greatly affects the accuracy of information dissemination.

[0003] There are various noise sources in the environment. However, the existing technology has limited capabilities in noise reduction and anti-interference, and cannot effectively distinguish the target broadcast sound from these interference signals. When multiple sounds are mixed together, the clarity and intelligibility of the broadcast sound are greatly reduced. Furthermore, it is difficult to accurately control some speakers when setting the coverage range. Either the coverage range is too large, resulting in the dispersion of sound energy and insufficient sound intensity at a long distance; or the coverage range is too small to meet the needs of actual scenarios, resulting in waste of resources and poor broadcasting effects. This is mainly due to the lack of in-depth analysis of the sound propagation model and the lack of effective algorithms for fine-tuning the coverage range during signal processing. Summary of the invention

[0004] In view of the above problems, the embodiments of the present invention provide a directional broadcasting method, apparatus, device and computer-readable storage medium for a speaker, which can effectively enhance the signal in the desired direction through reasonable signal processing and control strategies, while suppressing interference from other directions, thereby achieving high-quality audio output.

[0005] According to one aspect of an embodiment of the present invention, a directional broadcasting method of a speaker is provided, the method comprising: receiving a first sound signal by using a plurality of sound sensors within a preset first time window;

[0006] Using a linear constrained minimum variance algorithm, the covariance matrix of the sound signal is calculated to determine the direction vector of the target direction; according to the direction vector of the target direction and its constraint conditions, a target weight vector is determined; the target weight vector is a beamforming weight vector;

[0007] The target weight vector is solved by using the Lagrange multiplier method to obtain the first optimal weight vector;

[0008] Performing weighted summation on the first sound signal using the first optimal weight vector to generate an output signal;

[0009] The output signal is played by a speaker.

[0010] Specifically, the present invention realizes speaker directional broadcasting through a linear constrained minimum variance algorithm, and through reasonable signal processing and control strategies, can effectively enhance the signal in the desired direction while suppressing interference from other directions, thereby achieving high-quality audio output.

[0011] In an optional manner, a target signal is determined according to the first sound signal and the direction vector of the target direction;

[0012] According to the target signal and the output signal, using a least mean square LMS algorithm of an adaptive filter, adjusting the target weight vector to obtain a second optimal weight vector;

[0013] Using the second optimal weight vector to perform weighted summation on the second sound signal to generate a second output signal; the second sound signal is received by a plurality of sound sensors within a preset second time window;

[0014] The second output signal is played by a speaker.

[0015] Specifically, the present invention uses the LMS algorithm to adjust the weights and adjusts the weight vectors through a feedback mechanism (error signal) to adaptively enhance the target signal in a dynamic environment. This process allows the system to automatically optimize its performance under different signal conditions, thereby achieving efficient directional broadcasting.

[0016] In an optional manner, a linear constrained minimum variance algorithm is used to calculate the covariance matrix of the first sound signal, determine the direction vector of the target direction, and determine the target weight vector according to the direction vector of the target direction and its constraint conditions, including:

[0017] The expression of the covariance matrix of the first sound signal is:

[0018] R = E[x(n)x H (n)];

[0019] Wherein, R is the covariance matrix of the first sound signal, E represents the expected value, x H (n) is the conjugate transpose of x(n);

[0020] x(n) is the signal vector of the first sound signal, and its expression is:

[0021]

[0022] x N(n) is the first sound signal received by the Nth sound sensor, N=1, 2, ..., M; M is the number of sound sensors;

[0023] The expression for calculating the direction vector of the target direction is:

[0024]

[0025] Among them, α is the direction vector of the target direction, j is an imaginary unit, and j satisfies 2 = -1, d is the array spacing, λ is the signal wavelength;

[0026] The constraint condition of the direction vector of the target direction is expressed as:

[0027] α H ω=1;

[0028] Where ω is the target weight vector.

[0029] In an optional manner, the target weight vector is solved by using the Lagrange multiplier method to obtain the first optimal weight vector, including:

[0030] Derivative the Lagrangian function, and substitute the derived Lagrangian function into the constraint condition of the direction vector of the target direction to obtain a first optimal weight vector;

[0031] Among them, the expression of Lagrangian function is:

[0032] L(ω,λ)=ω H Rω-λ(α H ω-1);

[0033] The expression of the first optimal weight vector is:

[0034]

[0035] In an optional manner, the Lagrangian function is derived, and the derived Lagrangian function is substituted into the constraint condition of the direction vector of the target direction to obtain a first optimal weight vector, which is specifically:

[0036] The partial derivatives of the Lagrangian function with respect to ω and λ are calculated respectively, and the partial derivatives are set to zero to obtain the target equation;

[0037] Among them, the expression of the partial derivative of the Lagrangian function with respect to ω is:

[0038]

[0039] The expression of the partial derivative of the Lagrangian function with respect to λ is:

[0040]

[0041] The expression of the objective equation is:

[0042]

[0043] Substituting the target equation into the constraint condition of the direction vector of the target direction, a first optimal weight vector is obtained.

[0044] In an optional manner, according to the target signal and the output signal, using a least mean square LMS algorithm of an adaptive filter, adjusting the target weight vector to obtain a second optimal weight vector, further comprising:

[0045] Subtracting the target signal from the output signal to obtain an error signal;

[0046] Iteratively update the target weight vector according to a preset step size factor until the termination condition is met to obtain a second optimal weight vector;

[0047] ω(n+1)=ω(n)+μe(n)x'(n);

[0048] Wherein, ω(n) is the target weight vector, ω(n+1) is the updated target weight vector, μ is the step factor, e(n) is the error signal, and x'(n) is the signal vector of the second sound signal;

[0049] The expression of the signal vector of the second sound signal is:

[0050] x'(n)=[x1'(n), x2'(n),...,x M '(n)];

[0051] Among them, x' N (n) is the second sound signal received by the Nth sound sensor, N=1, 2, ..., M; M is the number of sound sensors;

[0052] The termination condition is: reaching the number of iterations, the error signal is lower than the error threshold, or the mean square value of the error signal is lower than a preset mean square value threshold.

[0053] According to another aspect of an embodiment of the present invention, there is provided a directional broadcasting device for a speaker, comprising: a receiving module, a weight calculation module, a signal calculation module and an output module;

[0054] A receiving module, used to receive a first sound signal using a plurality of sound sensors within a preset first time window;

[0055] A weight calculation module is used to calculate the covariance matrix of the sound signal using a linear constrained minimum variance algorithm to determine a direction vector of a target direction; determine a target weight vector according to the direction vector of the target direction and its constraints; the target weight vector is a beamforming weight vector; and solve the target weight vector using a Lagrange multiplier method to obtain a first optimal weight vector;

[0056] a signal calculation module, configured to perform weighted summation on the first sound signal using the first optimal weight vector to generate an output signal;

[0057] The output module is used to play the output signal using a speaker.

[0058] In an optional manner, the device further includes: a weight updating module;

[0059] A weight updating module, configured to determine a target signal according to the first sound signal and a direction vector of the target direction;

[0060] According to the target signal and the output signal, using a least mean square LMS algorithm of an adaptive filter, adjusting the target weight vector to obtain a second optimal weight vector;

[0061] Using the second optimal weight vector to perform weighted summation on the second sound signal to generate a second output signal; the second sound signal is received by a plurality of sound sensors within a preset second time window;

[0062] The second output signal is played by a speaker.

[0063] According to another aspect of an embodiment of the present invention, a directional broadcasting device for a speaker is provided, comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; the memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute the operation of the directional broadcasting method for the speaker as described in any one of the above items.

[0064] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is provided, wherein the storage medium stores at least one executable instruction, wherein the executable instruction enables the directional broadcasting device / apparatus of the speaker to perform the operation of the directional broadcasting method of the speaker as described in any one of the above.

[0065] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings:

[0067] Figure 1 A schematic flow chart of an embodiment of a directional broadcasting method of a speaker provided by the present invention is shown;

[0068] Figure 2 A structural schematic diagram of an embodiment of a directional broadcasting device of a speaker provided by the present invention is shown;

[0069] Figure 3 A structural schematic diagram of an embodiment of a directional broadcasting device of a speaker provided by the present invention is shown. DETAILED DESCRIPTION

[0070] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0071] Embodiment 1, Figure 1 The flowchart of an embodiment of the directional broadcasting method of the speaker provided by the present invention is shown. The method is executed by a target device, and the target device is a directional broadcasting device of the speaker. Figure 1 As shown, the method comprises the following steps:

[0072] Step 110: Receive a first sound signal using a plurality of sound sensors within a preset first time window.

[0073] Specifically, before receiving the first sound signal, the method further includes: the target device confirms the number of linear arrays, such as the number of microphones or speakers (M), determines the signal source position and the interference source position, and confirms the target gain direction and constraints. The target device initializes the weight vector ω, which can be set to 0 or a random value. The target device sets the sampling frequency and time window, such as the time window length for signal processing.

[0074] Specifically, the plurality of sound sensors form a linear array, and the plurality of sound sensors have a uniform spacing, which should generally be less than or equal to half of the shortest wavelength of the processed signal to ensure that the array can effectively distinguish signals from different directions. The sound sensor is used to receive signals from the environment, including the target sound source and background noise; the location of the sound source can be inferred by using the time difference between the signal reaching each sensor; the direction of the sound source can be identified based on the signal strength and phase received by the sensor; the sensor array can be used to distinguish the target sound source from the interference sound source, and the beamforming algorithm is used to adjust the weight based on the feedback from the sensor to maximize the target signal and suppress the interference signal.

[0075] The sound sensor is usually installed at a height of 1.5 to 2 meters to capture the voice of children and avoid interference from ground reflections. It should be placed directly in front of the main activity area and away from large obstacles to reduce reflection and diffraction of sound waves. It should not be placed near noise sources to reduce interference from background noise. Several sound sensors should be placed in front of or around the speakers to receive the sound from the speakers as well as echoes and interfering noise in the environment.

[0076] Step 120: Calculate the covariance matrix of the sound signal using a linear constrained minimum variance algorithm to determine the direction vector of the target direction; determine the target weight vector based on the direction vector of the target direction and its constraints; the target weight vector is a beamforming weight vector; and solve the target weight vector using a Lagrange multiplier method to obtain a first optimal weight vector.

[0077] In some embodiments of the present invention, a linear constrained minimum variance algorithm is used to calculate the covariance matrix of the first sound signal, determine the direction vector of the target direction, and determine the target weight vector according to the direction vector of the target direction and its constraint conditions, including:

[0078] The expression of the covariance matrix of the first sound signal is:

[0079] R = E[x(n)x H (n)];

[0080] Wherein, R is the covariance matrix of the first sound signal, E represents the expected value, x H (n) is the conjugate transpose of x(n);

[0081] x(n) is the signal vector of the first sound signal, and its expression is:

[0082]

[0083] x N(n) is the first sound signal received by the Nth sound sensor, N=1, 2, ..., M; M is the number of sound sensors;

[0084] The expression for calculating the direction vector of the target direction is:

[0085]

[0086] Among them, α is the direction vector of the target direction, j is an imaginary unit, and j satisfies 2 = -1, d is the array spacing, λ is the signal wavelength;

[0087] The constraint condition of the direction vector of the target direction is expressed as:

[0088] α H ω=1;

[0089] Among them, ω is the target weight vector.

[0090] In some embodiments of the present invention, the target weight vector is solved by using the Lagrange multiplier method to obtain the first optimal weight vector, including:

[0091] Derivative the Lagrangian function, and substitute the derived Lagrangian function into the constraint condition of the direction vector of the target direction to obtain a first optimal weight vector;

[0092] Among them, the expression of the Lagrangian function is:

[0093] L(ω,λ)=ω H Rω-λ(α H ω-1);

[0094] The expression of the first optimal weight vector is:

[0095]

[0096] In some embodiments of the present invention, the Lagrangian function is derived, and the derived Lagrangian function is substituted into the constraint condition of the direction vector of the target direction to obtain a first optimal weight vector, which is specifically:

[0097] The partial derivatives of the Lagrangian function with respect to ω and λ are calculated respectively, and the partial derivatives are set to zero to obtain the target equation;

[0098] Among them, the expression of the partial derivative of the Lagrangian function with respect to ω is:

[0099]

[0100] The expression of the partial derivative of the Lagrangian function with respect to λ is:

[0101]

[0102] The expression of the objective equation is:

[0103]

[0104] Substituting the target equation into the constraint condition of the direction vector of the target direction, a first optimal weight vector is obtained.

[0105] Specifically, the target device achieves optimal beamforming by minimizing power, and the optimal weight vector is found using the Lagrange multiplier method, which is:

[0106] Setting the partial derivative of the Lagrangian function with respect to ω to zero gives:

[0107] 2Rω-λα=0

[0108] We can get:

[0109]

[0110] Then we get the expression about ω:

[0111]

[0112] Setting the partial derivative of the Lagrangian function with respect to λ to zero gives:

[0113] α H ω-1=0

[0114] Substituting the expression for ω into the constraints, we obtain:

[0115]

[0116] Therefore, we can obtain the expression for λ:

[0117]

[0118] Substituting the expression for λ into the expression for ω, we get:

[0119]

[0120] Finally, the first optimal weight vector is obtained:

[0121]

[0122] Step 130: Perform weighted summation on the first sound signal using the first optimal weight vector to generate an output signal.

[0123] Use the obtained weight vector to perform weighted summation on the input signal to generate the output signal: y(n) = ωH x(n).

[0124] Step 140: Use a speaker to play the output signal.

[0125] In some embodiments of the present invention, a target signal is determined based on the first sound signal and the direction vector of the target direction;

[0126] According to the target signal and the output signal, using a least mean square LMS algorithm of an adaptive filter, adjusting the target weight vector to obtain a second optimal weight vector;

[0127] Using the second optimal weight vector to perform weighted summation on the second sound signal to generate a second output signal; the second sound signal is received by a plurality of sound sensors within a preset second time window;

[0128] The second output signal is played by a speaker.

[0129] Specifically, the present invention dynamically adjusts the weight vector as needed, and can update the covariance matrix and weight each time a new signal arrives. It can be implemented by a recursive algorithm, for example, using an adaptive filter, such as the least mean square LMS algorithm to adjust the weight vector to adapt to changes in the environment. The present invention evaluates the quality of the output signal, checks the enhancement effect in the target direction and the suppression effect in other directions. If the effect is not ideal, the calculation method or constraint conditions of the weight can be adjusted to achieve optimal performance.

[0130] In some embodiments of the present invention, according to the target signal and the output signal, using a least mean square LMS algorithm of an adaptive filter to adjust the target weight vector to obtain a second optimal weight vector, further comprising:

[0131] Subtracting the target signal from the output signal to obtain an error signal;

[0132] Iteratively update the target weight vector according to a preset step size factor until the termination condition is met to obtain a second optimal weight vector;

[0133] ω(n+1)=ω(n)+μe(n)x'(n);

[0134] Wherein, ω(n) is the target weight vector, ω(n+1) is the updated target weight vector, μ is the step factor, e(n) is the error signal, and x'(n) is the signal vector of the second sound signal;

[0135] The expression of the signal vector of the second sound signal is:

[0136] x'(n)=[x1'(n), x2'(n),...,xM '(n)];

[0137] Among them, x' N (n) is the second sound signal received by the Nth sound sensor, N=1, 2, ..., M; M is the number of sound sensors;

[0138] The termination condition is: reaching the number of iterations, the error signal is lower than the error threshold, or the mean square value of the error signal is lower than a preset mean square value threshold.

[0139] The present invention realizes speaker directional broadcasting through a linear constrained minimum variance algorithm, and through reasonable signal processing and control strategies, can effectively enhance the signal in the desired direction while suppressing interference from other directions, thereby achieving high-quality audio output.

[0140] The present invention uses the LMS algorithm to adjust the weights and adjusts the weight vectors through a feedback mechanism (error signal) to adaptively enhance the target signal in a dynamic environment. This process allows the system to automatically optimize its performance under different signal conditions, thereby achieving efficient directional broadcasting.

[0141] Figure 2 FIG. 1 is a schematic structural diagram of an embodiment of a directional broadcasting device for a speaker provided by the present invention; Figure 2 As shown, the device 200 includes: a receiving module 210, a weight calculation module 220, a signal calculation module 230 and an output module 240.

[0142] The receiving module 210 is used to receive a first sound signal using a plurality of sound sensors within a preset first time window;

[0143] The weight calculation module 220 is used to calculate the covariance matrix of the sound signal using a linear constrained minimum variance algorithm to determine the direction vector of the target direction; determine the target weight vector according to the direction vector of the target direction and its constraints; the target weight vector is a beamforming weight vector; and solve the target weight vector using a Lagrange multiplier method to obtain a first optimal weight vector;

[0144] A signal calculation module 230, configured to perform weighted summation on the first sound signal using the first optimal weight vector to generate an output signal;

[0145] The output module 240 is used to play the output signal using a speaker.

[0146] In an optional manner, the device 200 further includes: a weight updating module;

[0147] A weight updating module, configured to determine a target signal according to the first sound signal and a direction vector of the target direction;

[0148] According to the target signal and the output signal, using a least mean square LMS algorithm of an adaptive filter, adjusting the target weight vector to obtain a second optimal weight vector;

[0149] Using the second optimal weight vector to perform weighted summation on the second sound signal to generate a second output signal; the second sound signal is received by a plurality of sound sensors within a preset second time window;

[0150] The second output signal is played by a speaker.

[0151] In an optional manner, in the weight calculation module 220, a linear constrained minimum variance algorithm is used to calculate the covariance matrix of the first sound signal, determine the direction vector of the target direction, and determine the target weight vector according to the direction vector of the target direction and its constraint conditions, including:

[0152] The covariance matrix of the first sound signal is expressed as:

[0153] R = E[x(n)x H (n)];

[0154] Wherein, R is the covariance matrix of the first sound signal, E represents the expected value, x H (n) is the conjugate transpose of x(n);

[0155] x(n) is the signal vector of the first sound signal, and its expression is:

[0156]

[0157] x N (n) is the first sound signal received by the Nth sound sensor, N=1, 2, ..., M; M is the number of sound sensors;

[0158] The expression for calculating the direction vector of the target direction is:

[0159]

[0160] Among them, α is the direction vector of the target direction, j is an imaginary unit, and j satisfies 2 = -1, d is the array spacing, λ is the signal wavelength;

[0161] The constraint condition of the direction vector of the target direction is expressed as:

[0162] α H ω=1;

[0163] Where ω is the target weight vector.

[0164] The Lagrange multiplier method is used to solve the target weight vector and obtain the first optimal weight vector, including:

[0165] Derivative the Lagrangian function, and substitute the derived Lagrangian function into the constraint condition of the direction vector of the target direction to obtain a first optimal weight vector;

[0166] Among them, the expression of Lagrangian function is:

[0167] L(ω,λ)=ω H Rω-λ(α H ω-1);

[0168] The expression of the first optimal weight vector is:

[0169]

[0170] The Lagrangian function is derived, and the derived Lagrangian function is substituted into the constraint condition of the direction vector of the target direction to obtain the first optimal weight vector, which is specifically:

[0171] The partial derivatives of the Lagrangian function with respect to ω and λ are calculated respectively, and the partial derivatives are set to zero to obtain the target equation;

[0172] Among them, the expression of the partial derivative of the Lagrangian function with respect to ω is:

[0173]

[0174] The expression of the partial derivative of the Lagrangian function with respect to λ is:

[0175]

[0176] The expression of the objective equation is:

[0177]

[0178] Substituting the target equation into the constraint condition of the direction vector of the target direction, a first optimal weight vector is obtained.

[0179] In an optional manner, the weight updating module uses a least mean square LMS algorithm of an adaptive filter to adjust the target weight vector according to the target signal and the output signal to obtain a second optimal weight vector, and further includes:

[0180] Subtracting the target signal from the output signal to obtain an error signal;

[0181] Iteratively update the target weight vector according to a preset step size factor until the termination condition is met to obtain a second optimal weight vector;

[0182] ω(n+1)=ω(n)+μe(n)x'(n);

[0183] Wherein, ω(n) is the target weight vector, ω(n+1) is the updated target weight vector, μ is the step factor, e(n) is the error signal, and x'(n) is the signal vector of the second sound signal;

[0184] The expression of the signal vector of the second sound signal is:

[0185] x'(n)=[x1'(n), x2'(n),...,x M '(n)];

[0186] Among them, x' N (n) is the second sound signal received by the Nth sound sensor, N=1, 2, ..., M; M is the number of sound sensors;

[0187] The termination condition is: reaching the number of iterations, the error signal is lower than the error threshold, or the mean square value of the error signal is lower than a preset mean square value threshold.

[0188] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0189] Figure 3 A schematic structural diagram of an embodiment of a directional broadcasting device for a speaker provided by the present invention is shown. The specific embodiment of the present invention does not limit the specific implementation of the directional broadcasting device for a speaker.

[0190] like Figure 3 As shown, the directional broadcasting device of the speaker may include: a processor (processor) 302 , a communication interface (Communications Interface) 304 , a memory (memory) 306 , and a communication bus 308 .

[0191] The processor 302, the communication interface 304, and the memory 306 communicate with each other via the communication bus 308. The communication interface 304 is used to communicate with other devices such as a client or other server network elements. The processor 302 is used to execute the program 310, which can specifically execute the relevant steps in the above-mentioned embodiment of the directional broadcast method for the speaker.

[0192] Specifically, the program 310 may include program code including computer executable instructions.

[0193] The processor 302 may be a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiment of the present invention. The one or more processors included in the directional broadcasting device of the speaker may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0194] The memory 306 is used to store the program 310. The memory 306 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0195] The algorithms or displays provided herein are not inherently related to any particular computer, virtual system or other device. In addition, the embodiments of the present invention are not directed to any particular programming language.

[0196] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0197] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive.

[0198] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A directional broadcasting method of a speaker, characterized in that: The method comprises: In a preset first time window, a first sound signal is received by using a plurality of sound sensors; Using a linear constrained minimum variance algorithm, the covariance matrix of the sound signal is calculated to determine the direction vector of the target direction; according to the direction vector of the target direction and its constraint conditions, a target weight vector is determined; the target weight vector is a beamforming weight vector; The target weight vector is solved by using the Lagrange multiplier method to obtain the first optimal weight vector; Performing weighted summation on the first sound signal using the first optimal weight vector to generate an output signal; The output signal is played by a speaker.

2. The directional broadcasting method of a speaker according to claim 1, characterized in that: Also includes: determining a target signal according to the first sound signal and the direction vector of the target direction; According to the target signal and the output signal, using a least mean square LMS algorithm of an adaptive filter, adjusting the target weight vector to obtain a second optimal weight vector; Using the second optimal weight vector to perform weighted summation on the second sound signal to generate a second output signal; the second sound signal is received by a plurality of sound sensors within a preset second time window; The second output signal is played by a speaker.

3. The directional broadcasting method of a speaker according to claim 1, characterized in that: Using a linear constrained minimum variance algorithm, calculating the covariance matrix of the first sound signal, determining a direction vector of a target direction, and determining a target weight vector according to the direction vector of the target direction and its constraint conditions, including: The expression of the covariance matrix of the first sound signal is: R=E[x(n)x H (n)]; Wherein, R is the covariance matrix of the first sound signal, E represents the expected value, x H (n) is the conjugate transpose of x(n); x(n) is the signal vector of the first sound signal, and its expression is: x N (n) is the first sound signal received by the Nth sound sensor, N=1, 2, ..., M; M is the number of sound sensors; The expression for calculating the direction vector of the target direction is: Among them, α is the direction vector of the target direction, j is an imaginary unit, and j satisfies 2 = -1, d is the array spacing, λ is the signal wavelength; θ is the angle of the target direction; is the direction vector of the Nth sound sensor, N = 1, 2, ..., M; where M represents the number of sound sensors; The constraint condition of the direction vector of the target direction is expressed as: a H ω=1; Among them, ω is the target weight vector.

4. The directional broadcasting method of a speaker according to claim 3, characterized in that: The Lagrange multiplier method is used to solve the target weight vector and obtain the first optimal weight vector, including: Deriving the Lagrangian function, substituting the derived Lagrangian function into the constraint condition of the direction vector of the target direction, and obtaining a first optimal weight vector; Among them, the expression of the Lagrangian function is: L(ω,λ)=ω H Rω-λ(a H ω-1); The expression of the first optimal weight vector is:

5. The directional broadcasting method of a speaker according to claim 4, characterized in that: The Lagrangian function is derived, and the derived Lagrangian function is substituted into the constraint condition of the direction vector of the target direction to obtain the first optimal weight vector, which is specifically: The partial derivatives of the Lagrangian function with respect to ω and λ are calculated respectively, and the partial derivatives are set to zero to obtain the target equation; Among them, the expression of the partial derivative of the Lagrangian function with respect to ω is: The expression of the partial derivative of the Lagrangian function with respect to λ is: The expression of the objective equation is: Substituting the target equation into the constraint condition of the direction vector of the target direction, a first optimal weight vector is obtained.

6. The directional broadcasting method of a speaker according to claim 2, characterized in that: According to the target signal and the output signal, using the least mean square LMS algorithm of the adaptive filter, adjusting the target weight vector to obtain a second optimal weight vector, further comprising: Subtracting the target signal from the output signal to obtain an error signal; Iteratively update the target weight vector according to a preset step size factor until the termination condition is met to obtain a second optimal weight vector; ω(n+1)=ω(n)+μe(n)x'(n); Wherein, ω(n) is the target weight vector, ω(n+1) is the updated target weight vector, μ is the step factor, e(n) is the error signal, and x'(n) is the signal vector of the second sound signal; The expression of the signal vector of the second sound signal is: x'(n)=[x1'(n),x2'(n),...,x M '(n)], Among them, x' N (n) is the second sound signal received by the Nth sound sensor, N=1, 2, ..., M; M is the number of sound sensors; The termination condition is: reaching the number of iterations, the error signal is lower than the error threshold, or the mean square value of the error signal is lower than a preset mean square value threshold.

7. A directional broadcasting device for a speaker, characterized in that: The device comprises: a receiving module, a weight calculation module, a signal calculation module and an output module; A receiving module, used to receive a first sound signal using a plurality of sound sensors within a preset first time window; A weight calculation module is used to calculate the covariance matrix of the sound signal using a linear constrained minimum variance algorithm to determine a direction vector of a target direction; determine a target weight vector according to the direction vector of the target direction and its constraints; the target weight vector is a beamforming weight vector; and solve the target weight vector using a Lagrange multiplier method to obtain a first optimal weight vector; a signal calculation module, configured to perform weighted summation on the first sound signal using the first optimal weight vector to generate an output signal; The output module is used to play the output signal using a speaker.

8. The directional broadcasting device of the speaker according to claim 7, characterized in that: Also includes: Weight update module; A weight updating module, configured to determine a target signal according to the first sound signal and a direction vector of the target direction; According to the target signal and the output signal, using a least mean square LMS algorithm of an adaptive filter, adjusting the target weight vector to obtain a second optimal weight vector; Using the second optimal weight vector to perform weighted summation on the second sound signal to generate a second output signal; the second sound signal is received by a plurality of sound sensors within a preset second time window; The second output signal is played by a speaker.

9. A directional broadcasting device for a speaker, characterized in that: include: A processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute the operation of the directional broadcasting method of the speaker as described in any one of claims 1-6.

10. A computer-readable storage medium, characterized in that: The storage medium stores at least one executable instruction, and when the executable instruction is executed on the directional broadcasting device / apparatus of the speaker, the directional broadcasting device / apparatus of the speaker executes the operation of the directional broadcasting method of the speaker as described in any one of claims 1-6.

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