Beam forming method and system in end-fire direction, storage medium and electronic equipment

Abstract

The invention discloses a beam forming method and system in an end-fire direction, a storage medium and electronic equipment, and the method comprises the steps: constructing an end-fire array, and obtaining an actual beam pattern; constructing a target beam of which the expected direction is the end-fire direction; enabling the actual beam pattern to approach a target beam to obtain a beam equation, and solving the beam equation through minimum norm constraint to obtain a weight vector of an end-fire array; the invention provides a beam forming scheme in an end-fire direction, which not only can realize the formation of a high-gain beam in the end-fire direction, but also can effectively improve the white noise gain of the system and remarkably reduce the beam pattern error of the system in a low-frequency band.

Description

Technical Field

[0001] The present invention relates to the technical field of beamforming, and particularly to a beamforming method, system, storage medium and electronic device in the end-fire direction. Background Art

[0002] In the field of speech signal processing, microphone array technology is widely used in application scenarios such as speech enhancement, sound source localization, and speech recognition.

[0003] A microphone line array can form a high-gain beam in the end-fire direction. However, when a traditional line array composed of omnidirectional microphones performs beamforming in the end-fire direction, there is a problem of insufficient gain of low-frequency white noise. This problem easily causes the white noise in the circuit to be amplified, thus affecting the overall performance of the system.

[0004] Therefore, researching and proposing a solution that can achieve high-gain beamforming in the end-fire direction and simultaneously improve the white noise gain of the system has important practical significance and application value. Summary of the Invention

[0005] The purpose of the present invention is to provide a beamforming solution in the end-fire direction, which can not only achieve the formation of a high-gain beam in the end-fire direction, but also effectively improve the white noise gain of the system and significantly reduce the beam pattern error of the system in the low-frequency band. Through this solution, the robustness of the system is enhanced, and at the same time, the beam pattern generated by the array can more accurately approximate the target beam, thereby improving the overall performance.

[0006] To achieve the above object, on the one hand, the present invention proposes a beamforming method in the end-fire direction, including:

[0007] S1, constructing an end-fire array to obtain an actual beam pattern, where the end-fire array is formed by combining at least one omnidirectional microphone and at least one bidirectional microphone, and the at least one omnidirectional microphone forms a first end-fire array, the at least one bidirectional microphone forms a second end-fire array, and the actual beam pattern is the sum of the first actual beam pattern of the first end-fire array and the second actual beam pattern of the second end-fire array;

[0008] S2, constructing a target beam with the desired direction being the end-fire direction, where the target beam is an Nth-order difference beam;

[0009] S3, approximating the actual beam pattern to the target beam to obtain a beam equation, and solving the beam equation through minimum norm constraint to obtain the weight vector of the end-fire array.

[0010] In a preferred embodiment, the sound pickup direction of the microphones of the end-fire array is the same as the axial direction, and / or, the actual beam pattern is expressed as:

[0011]

[0012] Among them, B(w, k, θ) represents the actual beam pattern, w represents the weight vector, (·) H represents the conjugate transpose, d(θ) represents the steering vector of the array, where represents the first actual beam pattern, represents the second actual beam pattern, L O is the number of omnidirectional microphones, w l (k) is the weight coefficient of the l-th omnidirectional microphone unit, (·) * is the conjugate symbol, k is the wave number, θ represents the incident direction of sound, i represents the imaginary unit, x l is the position coordinate of the l-th omnidirectional microphone unit, L D is the number of bidirectional microphones, is the weight coefficient of the m-th bidirectional microphone unit, is the position coordinate of the m-th bidirectional microphone unit.

[0013] In a preferred embodiment, the S1 includes:

[0014] S11, respectively perform Jacobi series expansion on the first actual beam pattern and the second actual beam pattern of the actual beam pattern;

[0015] S12, determine the order N of the designed desired difference beam, and respectively truncate the first actual beam pattern and the second actual beam pattern after Jacobi series expansion to the N-th order and the N - 1-th order;

[0016] S13, add the truncated second actual beam pattern after transformation using Euler's formula to the first actual beam pattern truncated to the N-th order to obtain the truncated actual beam pattern.

[0017] In a preferred embodiment, the truncated actual beam pattern is expressed as:

[0018]

[0019] Among them, β n (·) = (i) n J n (·), the function J n (·) refers to the Bessel function of the first kind of order n,

[0020] In a preferred embodiment, S2 includes: representing the target beam in the form of an exponential function of an Nth-order difference beam pattern.

[0021] In a preferred embodiment, in S2, the target beam is represented as:

[0022]

[0023] where α N,n represents the coefficient of the target beam;

[0024] and / or, if N in the formula is an even number, the exponential function form of the target beam is represented as:

[0025]

[0026] where

[0027] if N in the formula is an odd number, the exponential function form of the target beam is represented as:

[0028]

[0029] where N' = (N + 1) / 2,

[0030]

[0031] In a preferred embodiment, S3 includes: transforming the beam equation into a matrix form, solving the matrix through minimum norm constraint, and obtaining the weight vector of the end-fire array; and / or, in S3, the matrix form of the beam equation is represented as:

[0032] Φw = γ;

[0033] where

[0034] the minimum norm solution of the matrix is:

[0035] w = Φ H (ΦΦ H ) -1 γ.

[0036] On the other hand, the present invention proposes an end-fire direction beamforming system, including:

[0037] A beam pattern construction module is used to construct an end-fire array and obtain an actual beam pattern. The end-fire array is formed by combining at least one omnidirectional microphone and at least one bidirectional microphone. The at least one omnidirectional microphone constitutes a first end-fire array, and the at least one bidirectional microphone constitutes a second end-fire array. The actual beam pattern is the sum of the first actual beam pattern of the first end-fire array and the second actual beam pattern of the second end-fire array.

[0038] A target beam construction module is used to construct a target beam with an expected direction being the end-fire direction. The target beam is an Nth-order difference beam.

[0039] A weight vector solving module is used to approximate the actual beam pattern to the target beam to obtain a beam equation, and solve the beam equation through minimum norm constraint to obtain the weight vector of the end-fire array.

[0040] On the other hand, the present invention proposes a readable storage medium in which a computer program is stored. When the computer program is run, it executes the steps in the above-mentioned beamforming method in the end-fire direction.

[0041] On yet another hand, the present invention proposes an electronic device. The electronic device includes a memory and a processor. A computer program is stored in the memory. When the computer program is run by the processor, it executes the steps in the above-mentioned beamforming method in the end-fire direction.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] By designing the structure of the end-fire array and combining corresponding algorithms, specifically by constructing a beam equation from the actual beam pattern and the target beam with an expected direction being the end-fire direction, and solving the beam equation through minimum norm constraint to obtain the corresponding weight vector, the present invention provides an innovative beamforming scheme in the end-fire direction. It can not only achieve the formation of a high-gain beam in the end-fire direction, but also effectively improve the white noise gain of the system and significantly reduce the beam pattern error of the system in the low-frequency band. Through this scheme, the robustness of the system is enhanced, and at the same time, the beam pattern generated by the array can more accurately approximate the target beam, thereby improving the overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic structural diagram of an end-fire array in a specific embodiment of the present invention;

[0045] Figure 2 It is a schematic flowchart of the beamforming method in the end-fire direction of the present invention;

[0046] Figures 3a to 3dSimulation comparison diagrams of the actual beam pattern and the target beam of the present invention at different frequencies respectively;

[0047] Figure 4 Broadband beam pattern of the end-fire direction beamformer designed by the present invention;

[0048] Figure 5a Schematic diagram of the DF performance comparison between the end-fire direction beamformer designed by the present invention and the existing traditional microphone array, both of which are omnidirectional microphones in the end-fire direction beamformer;

[0049] Figure 5b Schematic diagram of the WNG performance comparison between the end-fire direction beamformer designed by the present invention and the existing traditional microphone array, both of which are omnidirectional microphones in the end-fire direction beamformer;

[0050] Figure 6 Schematic diagram of the error comparison between the end-fire direction beamformer designed by the present invention and the existing traditional microphone array, both of which are omnidirectional microphones in the end-fire direction beamformer. Detailed implementation manners

[0051] The following will describe the detailed implementation manners of the present invention in detail, but it should be understood that the protection scope of the present invention is not limited by the detailed implementation manners.

[0052] Unless otherwise clearly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "having" etc. will be understood to include the stated elements or components, without excluding other elements or other components.

[0053] As Figure 2 shown, a beamforming method in the end-fire direction disclosed by the present invention mainly includes the following steps:

[0054] S1. Construct an end-fire array to obtain an actual beam pattern. The end-fire array is formed by combining at least one omnidirectional microphone and at least one bidirectional microphone. The at least one omnidirectional microphone constitutes a first end-fire array, and the at least one bidirectional microphone constitutes a second end-fire array. The actual beam pattern is the sum of the first actual beam pattern of the first end-fire array and the second actual beam pattern of the second end-fire array.

[0055] Specifically, different from existing microphone arrays formed entirely by omnidirectional microphones or entirely by directional microphones, the end-fire array of the present invention is formed by combining at least one omnidirectional microphone and at least one bidirectional microphone and arranging them coaxially (such as in a straight line), and the omnidirectional microphones and bidirectional microphones are distributed at intervals, that is, one omnidirectional microphone is arranged at an interval of one bidirectional microphone. Of course, it is not necessarily limited to being distributed at intervals, that is, the distribution of omnidirectional microphones and bidirectional microphones in the end-fire array is not restricted. During implementation, the omnidirectional microphones and bidirectional microphones of the end-fire array are preferably arranged at uniform intervals, that is, the intervals between the microphones are equal. Of course, the intervals can also be unequal, and the present invention does not limit this. The end-fire array formed by combining bidirectional microphones and omnidirectional microphones according to the present invention can improve the white noise gain of the array and reduce the influence of the inconsistency between microphones and the microphone position error on the system. In addition, the sound pickup directions of all the microphones of the end-fire array of the present invention are the same as the axial direction, that is, the orientations of the sound pickup surfaces of the microphones are all axial. For example, the sound pickup direction of the microphones in the present invention is the end-fire direction (0° or 180°). Moreover, all the omnidirectional microphones in the end-fire array form the first end-fire array, and all the bidirectional microphones form the second end-fire array.

[0056] In a specific embodiment, the end-fire array is formed by combining 7 microphone units arranged in a straight line. Among them, there are 4 omnidirectional microphone units and 3 bidirectional microphone units. That is to say, 4 omnidirectional microphone units form the first end-fire array, and 3 bidirectional microphone units form the second end-fire array. The distance between adjacent two microphone units is 0.005 m, and the array distribution is as Figure 1 shown.

[0057] After constructing the end-fire array, the actual beam pattern of the end-fire array can be obtained. The actual beam pattern of the present invention is the sum of the first actual beam pattern of the first end-fire array and the second actual beam pattern of the second end-fire array. It can be specifically expressed by the following formula:

[0058]

[0059] where B(w,k,θ) represents the actual beam pattern, w represents the weight vector, (·) H represents the conjugate transpose, d(θ) represents the steering vector of the array, where, represents the first actual beam pattern, represents the second actual beam pattern; L O is the number of omnidirectional microphones, w l (k) is the weight coefficient of the l-th omnidirectional microphone unit, (·) * is the conjugate symbol, k is the wave number, θ represents the incident direction of the sound, i represents the imaginary unit, x lis the position coordinate of the l-th omnidirectional microphone unit, L D is the number of bidirectional microphones, is the weight coefficient of the m-th bidirectional microphone unit, is the position coordinate of the m-th bidirectional microphone unit.

[0060] The process of obtaining the above actual beam pattern specifically includes the following steps:

[0061] S11, perform Jacobi series expansion on the first actual beam pattern and the second actual beam pattern of the above actual beam pattern respectively.

[0062] Specifically, use the Jacobi series expansion formula (i.e., Jacobi-Anger formula): to expand the first actual beam pattern and the second actual beam pattern. Among them, β n (·) = (i) n J n (·), the function J n (·) refers to the Bessel function of the first kind of order n. Specifically, substitute formula 1.2 into the above formula 1.1 to obtain:

[0063]

[0064] Let: That is, B I is the first actual beam pattern after Jacobi series expansion, and B II is the second actual beam pattern after Jacobi series expansion.

[0065] S12, determine the order N of the designed desired difference beam, and perform N-order and N-1-order truncations on the first actual beam pattern and the second actual beam pattern after Jacobi series expansion respectively.

[0066] Specifically, perform N-order truncation on the above formula B I , and perform N-1-order truncation on the formula B II , then the following are obtained respectively:

[0067]

[0068] S13, add the truncated second actual beam pattern after transformation using Euler's formula to the first actual beam pattern after N-order truncation to obtain the truncated actual beam pattern.

[0069] Specifically, using Euler's formula, the above formula B II can be expressed as after transformation:

[0070]

[0071] Among them,

[0072] In this way, substituting Formula 1.7 and Formula 1.5 into Formula 1.3, the truncated actual beam pattern can be expressed as:

[0073]

[0074] S2. Construct a target beam with the desired direction being the end-fire direction, and the target beam is an Nth-order difference beam.

[0075] Specifically, the designed target beam with the desired direction being the end-fire direction is an Nth-order difference beam pattern, which is specifically expressed by the following formula:

[0076]

[0077] If N in the formula is an even number, the above target beam can be transformed into the exponential function form of the Nth-order difference beam pattern, specifically as follows:

[0078]

[0079] In the formula,

[0080] When N is an odd number, the target beam of Formula (1.9) can be transformed into the exponential function form of the Nth-order difference beam pattern, specifically as follows:

[0081]

[0082] Among them,

[0083]

[0084] S3. Use the above actual beam pattern to approximate the above target beam to obtain a beam equation, and solve the beam equation through minimum norm constraint to obtain the weight vector of the end-fire array.

[0085] Specifically, using the above Formula 1.8 to approximate Formula 1.10, we get:

[0086]

[0087] Writing the above Formula 1.11 in the form of a vector-vector product is:

[0088] β n w O +ζ n w D =γn , n = -N, -N + 1, ..., N - 1, N. (Equation 1.12);

[0089] Wherein,

[0090]

[0091] According to symmetry, Equation 1.12 is written in matrix form (i.e., the matrix form of the obtained beam equation) as:

[0092] Φw = γ (Equation 1.13)

[0093] Wherein,

[0094] Φ = [Β Z],

[0095] Β = [β 0 … β N H ,

[0096] Z = [ζ 0 … ζ N H ,

[0097] γ = [γ 0 … γ N T ,;

[0098] If the number of all microphone units of the end-fire array is greater than the order plus 1, i.e., (L M + L D ) > (N + 1), then the above Equation 1.13 is solved by minimum norm constraint, and the minimum norm solution of this equation is:

[0099] w = Φ H (ΦΦ H ) -1 γ (Equation 1.14), that is, the weight vector w of the end-fire array is obtained.

[0100] Next, a specific embodiment is combined to illustrate the effect achieved by the method proposed by the present invention, and a simulation comparison is made with the traditional beamforming method for realizing the end-fire direction using the same type of microphone.

[0101] As Figure 1 shown, in this embodiment, the number of microphones used in the end-fire array is 7, among which, there are 4 omnidirectional microphone units and 3 bidirectional microphone units, and the array spacing is 0.005 m. As Figures 3a to 3d ​​​As shown, they are respectively the simulation comparison diagrams of the beam of this case and the target beam at different frequencies (500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz respectively). It can be seen from the figures that for the beamforming scheme of the present invention, the actual beam pattern and the target beam completely or substantially completely coincide at different frequencies.

[0102] Figure 4 The broadband beam pattern of the array is shown. It can be observed from the figure that the method proposed by the present invention can form a stable beam pattern in the frequency range of 100 Hz to 4 kHz, and this pattern does not change with the change of frequency. This characteristic enables the method to stably pick up acoustic signals in the target area in the end-fire direction.

[0103] In addition, the indexes for evaluating the performance of a beamformer usually include white noise gain (WNG), beam pattern, and directivity factor (DF). Among them, WNG shows the ability of the beamformer to suppress spatially uncorrelated noise, and it is also the most convenient method to evaluate the sensitivity of the beamformer to some of its defects (such as sensor noise, position error, etc.). It is specifically expressed as: The beam pattern shows the direction sensitivity of the beamformer to the plane wave incident on the array at the incident angle θ. The directivity factor (DF) is defined as the ratio between the array output response power in the required steering direction and the average power in the direction from 0° to 360°. It is specifically expressed as:

[0104] As Figure 5a and Figure 5b shown, they are respectively the schematic diagrams of the comparison of the directivity factor (DF) and white noise gain (WNG) performance between the end-fire beamformer designed by the present invention and the traditional omnidirectional microphone array in the broadband frequency range of 100 Hz to 4 kHz. From Figure 5a it can be observed that although in the entire evaluation frequency band, the performance of the present method and the traditional method in terms of DF is basically equivalent, from Figure 5b it can be observed that the present method shows higher WNG values in the entire frequency band range. This result indicates that compared with the traditional array, the method proposed by the present invention has better anti-noise performance and system robustness.

[0105] Figure 6 The comparison results of the beamforming error (Error) between the end-fire beamformer designed by the present invention and the traditional array using omnidirectional microphones are shown. It can be clearly seen from the figure that in the low-frequency band below 500 Hz, the present method shows significantly lower beam pattern error. This comparison result fully indicates that compared with the traditional method, the method proposed by the present invention has better beam approximation performance in the low-frequency band and can more accurately achieve the desired beam pattern.

[0106] The error is specifically expressed as:

[0107] The advantages of the present invention are as follows. By designing the structure of the end-fire array and combining corresponding algorithms, specifically, a beam equation is constructed by using the actual beam pattern and the target beam whose desired direction is the end-fire direction, and the beam equation is solved by minimum norm constraint to obtain the corresponding weight vector, thereby providing an innovative beamforming scheme for the end-fire direction. It can not only achieve the formation of a high-gain beam in the end-fire direction, but also effectively improve the white noise gain of the system and significantly reduce the beam pattern error of the system in the low-frequency band. Through this scheme, the robustness of the system is enhanced, and at the same time, the beam pattern generated by the array can more accurately approximate the target beam, thereby improving the overall performance.

[0108] Corresponding to the above beamforming method, the present invention also discloses a beamforming system for the end-fire direction, specifically including:

[0109] A beam pattern construction module, configured to construct an end-fire array to obtain an actual beam pattern. The end-fire array is formed by combining at least one omnidirectional microphone and at least one bidirectional microphone. The omnidirectional microphones and the bidirectional microphones are distributed at intervals, and the at least one omnidirectional microphone constitutes a first end-fire array, and the at least one bidirectional microphone constitutes a second end-fire array. The actual beam pattern is the sum of the first actual beam pattern of the first end-fire array and the second actual beam pattern of the second end-fire array;

[0110] A target beam construction module, configured to construct a target beam whose desired direction is the end-fire direction. The target beam is an Nth-order difference beam;

[0111] A weight vector solving module, configured to approximate the actual beam pattern to the target beam to obtain a beam equation, and solve the beam equation by minimum norm constraint to obtain the weight vector of the end-fire array.

[0112] Wherein, the working principles of these three modules can be respectively referred to the descriptions in the above steps S1 to S3, and will not be elaborated here.

[0113] On the other hand, the present invention also provides a readable storage medium, on which a computer program is stored, and when the program is run, it implements the steps in the beamforming method for the end-fire direction provided in the above embodiment.

[0114] On another aspect, the present invention also provides an electronic device, including a memory and a processor. A computer program is stored in the memory, and when the computer program is run by the processor, it executes the steps in the beamforming method for the end-fire direction.

[0115] The logic and / or steps represented in the flowchart or otherwise described herein can, for example, be considered as a definitional sequence of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

[0116] More specific examples (non-exhaustive list) of the readable storage medium include the following: an electrical connection part (electronic device) having one or more wirings, a portable computer disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the readable storage medium can even be paper or other suitable medium on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpretation, or otherwise processing as appropriate, and then storing it in a computer memory.

[0117] It should be understood that the various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one of the following techniques known in the art or a combination thereof can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having suitable combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0118] The foregoing description of the specific exemplary embodiments of the present invention is for purposes of illustration and exemplification. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many changes and variations are possible in light of the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the invention and its practical applications, so that those skilled in the art can implement and utilize the various different exemplary embodiments of the invention, as well as various different selections and changes. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A beamforming method in an end-fire direction, characterized in that: The method comprises: S1, constructing an end-fire array to obtain an actual beam pattern, wherein the end-fire array is formed by combining at least one omni-directional microphone and at least one bi-directional microphone, and the at least one omni-directional microphone constitutes a first end-fire array, and the at least one bi-directional microphone constitutes a second end-fire array, and the actual beam pattern is the sum of a first actual beam pattern of the first end-fire array and a second actual beam pattern of the second end-fire array; S2, constructing a target beam whose desired direction is an end-fire direction, wherein the target beam is an N-order differential beam; S3, using the actual beam pattern to approximate the target beam to obtain a beam equation, solving the beam equation through a minimum norm constraint to obtain a weight vector of the end-fire array.

2. The end-fire beamforming method according to claim 1, characterized in that: The pickup direction of the microphone of the end-fire array is the same as the axial direction, and / or the actual beam pattern is expressed as: Where B(w,k,θ) represents the actual beam pattern, w represents the weight vector, (·) H represents the conjugate transpose, d(θ) represents the steering vector of the array, where represents the first actual beam pattern, represents the second actual beam pattern, L O is the number of omnidirectional microphones, w l (k) is the weight coefficient of the lth omnidirectional microphone unit, (·) * is the conjugate symbol, k is the wave number, θ represents the incident direction of the sound, i represents the imaginary unit, and x l is the position coordinate of the lth omnidirectional microphone unit, L D is the number of bidirectional microphones, For the The weight coefficient of the two-directional microphone unit, For the The position coordinates of the two-directional microphone units.

3. The end-fire beamforming method according to claim 2, characterized in that: The S1 includes: S11, performing Jacobian series expansion on a first actual beam pattern and a second actual beam pattern of the actual beam pattern respectively; S12, determining the order N of the designed desired differential beam, and performing N-order and N-1-order truncations on the first actual beam pattern and the second actual beam pattern after the Jacobian series expansion, respectively; S13, transforming the truncated second actual beam pattern using the Euler formula and adding the transformed second actual beam pattern to the first actual beam pattern after N-order truncation to obtain the truncated actual beam pattern.

4. The end-fire beamforming method according to claim 3, characterized in that: The actual beam pattern after truncation is expressed as: in, Function J n (·) refers to the Bessel function of the first kind of order n, 5. The end-fire beamforming method according to claim 1, characterized in that: The S2 includes: expressing the target beam as an exponential function form of an N-order differential beam pattern.

6. The end-fire beamforming method according to claim 5, characterized in that: In S2, the target beam is expressed as: Among them, α N,n represents the coefficient of the target beam; And / or, if N is an even number, the exponential function form of the target beam is expressed as: in, If N is an odd number, the exponential function form of the target beam is expressed as: in, 7. The end-fire beamforming method according to claim 6, characterized in that: The S3 includes: transforming the beam equation into a matrix form, solving the matrix through a minimum norm constraint, and obtaining a weight vector of the end-fire array; and / or, in the S3, the matrix form of the beam equation is expressed as: Φw=γ; in, The minimum norm solution of the matrix is: w=Φ H (F) H ) -1 c.

8. A beamforming system in an end-fire direction, characterized in that: The system comprises: a beam pattern construction module, configured to construct an end-fire array to obtain an actual beam pattern, wherein the end-fire array is formed by combining at least one omni-directional microphone and at least one bi-directional microphone, wherein the at least one omni-directional microphone constitutes a first end-fire array, and the at least one bi-directional microphone constitutes a second end-fire array, and the actual beam pattern is a sum of a first actual beam pattern of the first end-fire array and a second actual beam pattern of the second end-fire array; A target beam construction module, used to construct a target beam whose desired direction is an end-fire direction, wherein the target beam is an N-order differential beam; The weight vector solving module is used to approximate the target beam with the actual beam pattern to obtain a beam equation, solve the beam equation through a minimum norm constraint, and obtain a weight vector of the end-fire array.

9. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed, the steps of the end-fire beamforming method according to any one of claims 1 to 7 are executed.

10. An electronic device, characterized in that: The electronic device comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the steps of the end-fire direction beamforming method according to any one of claims 1 to 7 are executed.

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