Control filter determination method for sound field partition and sound field partition control method

Abstract

The invention provides a method for determining a control filter for sound field partitioning and a sound field partitioning control method, and relates to the technical field of acoustic signal processing. A sound field constructed by a complex transmission path can be converted into a limited low-order modal coefficient to represent a main propagation mode of the sound field. The low-order modal coefficient adopted in the method is insensitive to environmental disturbance such as noise, temperature and humidity, and has higher stability and robustness. According to the method, each low-order modal coefficient is introduced into the cost function, so that even if a certain error exists in the determination process of the transmission path, the sound field partitioning effect of the control filter cannot be obviously influenced, and the control filter has robustness of resisting mismatch of the transmission path while ensuring the sound field partitioning effect.

Description

Technical Field

[0001] This invention relates to the field of acoustic signal processing technology, and in particular to a method for determining control filters and a method for controlling sound field partitioning. Background Technology

[0002] With the rapid development of multimedia technology, acoustic signal processing and other technologies have been applied to various industries, such as in-vehicle entertainment and home theaters. Among these, sound field zoning technology has received increasing attention from scholars and experts. Sound field zoning technology uses acoustic signal processing and spatial control methods to generate differentiated sound field distributions in different areas. Its core objective is to precisely control the propagation and interference of sound waves, enabling listeners in bright areas to clearly hear the target audio content, while weakening or completely eliminating the audio signal in dark areas, thus forming multiple mutually isolated "acoustic zones." How to achieve better sound field zoning with a superior subjective experience and higher isolation between bright and dark areas is a pressing issue in the field.

[0003] Existing methods for determining control filters for sound field zoning generally follow a unified paradigm of "physical modeling - target setting - constraint optimization - filter solution": First, the transmission path from the loudspeaker to the control points of each region is measured, and a discretized model is established based on this. Second, the application target of sound field zoning is set and a cost function is constructed. Finally, based on the established discretized model and cost function, the control filter coefficients that minimize the cost function are solved by the least squares method.

[0004] Although the control filters obtained by existing methods can achieve a certain zoning effect, they are highly dependent on the accuracy of the transmission path in all dimensions of the measurement. When there is noise during the measurement process, the listener's position shifts, or environmental changes such as temperature and humidity in the actual application cause changes in the transmission path, the zoning effect of the control filter will be significantly degraded. Summary of the Invention

[0005] This invention provides a method for determining control filters and a method for controlling sound field partitioning, in order to overcome the deficiencies existing in related technologies.

[0006] This invention provides a method for determining control filters for sound field zoning, comprising: The transmission paths from different loudspeakers to control points in the bright and dark regions of the target sound field in the spatial domain are determined, and the transmission paths are modeled in the frequency domain to obtain the first transfer matrix of the bright region and the second transfer matrix of the dark region. Spatial Fourier transform decomposition is performed on the first transfer matrix, the second transfer matrix, and the target sound field to obtain each decomposition representation, and the low-order mode coefficients of the first specified order in each decomposition representation are determined. Based on the aforementioned low-order mode coefficients, a cost function is constructed, and the cost function is solved to obtain the control filter coefficients.

[0007] According to the present invention, a method for determining control filters for sound field partitioning is provided, wherein constructing a cost function based on each of the low-order mode coefficients includes: Based on the number of control points in the bright area and the dark area, the low-order modal coefficients are discretized to obtain the low-order modal characteristics of each low-order modal coefficient. The cost function is constructed based on the aforementioned low-order modal features.

[0008] According to the method for determining control filters for sound field partitioning provided by the present invention, the step of constructing the cost function based on each of the low-order modal features includes: Based on the first transfer matrix, the second transfer matrix, and the target sound field, calculate the sound field energy of the dark area and the pressure matching degree between the sound field of the bright area and the target sound field; Based on the low-order modal features, modal constraints are calculated, and the cost function is constructed based on the acoustic field energy of the dark region, the pressure matching degree, and the modal constraints.

[0009] According to the present invention, a method for determining control filters for sound field partitioning includes calculating modal constraints based on the low-order modal characteristics, comprising: Based on the low-order modal features corresponding to the bright area and the low-order modal features corresponding to the target sound field, the feature dimension pressure matching degree between the sound field of the bright area and the target sound field is calculated; Based on the low-order modal features corresponding to the dark region, the characteristic dimension sound field energy of the dark region is calculated, and based on the characteristic dimension pressure matching degree and the characteristic dimension sound field energy of the dark region, the modal constraint is calculated.

[0010] According to the present invention, a method for determining control filters for sound field partitioning includes performing spatial Fourier transform decomposition on the first transfer matrix, the second transfer matrix, and the target sound field to obtain various decomposition representations, including: Using complex exponential functions as the basis functions for spatial Fourier transform, and based on the orthogonality of the basis functions on the circumference, spatial Fourier transform decomposition is performed on the first transfer matrix, the second transfer matrix, and the target sound field to obtain the decomposed representations.

[0011] According to the present invention, a method for determining control filters for sound field zoning includes determining the transmission paths from different loudspeakers to control points in the bright and dark zones of the target sound field within the spatial domain, comprising: Based on the audio acquisition device, the observation signals from each of the speakers to each of the control points are acquired respectively; Based on the observed signals, the transmission path from each loudspeaker to each control point is determined; The control points in the bright area and the control points in the dark area are all distributed on a circle centered on the fixed position of the audio acquisition device.

[0012] The present invention also provides a sound field zoning control method, comprising: Acquire input audio signal; Based on the control filters corresponding to different speakers, the input sound signals are filtered respectively, and the filtered input sound signals are fed back to the corresponding speakers respectively. The control filters corresponding to different loudspeakers are determined based on the control filter determination method for sound field zoning described above.

[0013] The present invention also provides a sound field zoning control system, comprising: a plurality of loudspeakers, a control unit and a configuration unit, wherein the control unit is connected to the configuration unit; The control unit includes multiple control filters, and each speaker is connected to each control filter in a one-to-one correspondence. The configuration unit is used to execute the above-described method for determining control filters for sound field partitioning, determine control filter coefficients, and configure each control filter based on the control filter coefficients.

[0014] According to a sound field zoning control system provided by the present invention, an audio acquisition device is further included, wherein the audio acquisition device is connected to the configuration unit; The audio acquisition device is used to acquire the observation signals from each of the speakers to each of the control points; The configuration unit is specifically used to determine the transmission path from each of the different loudspeakers to each of the control points based on the observed signal; The control points in the bright area and the control points in the dark area are all distributed on a circle centered on the fixed position of the audio acquisition device.

[0015] According to a sound field zoning control system provided by the present invention, the audio acquisition device includes different microphones on an artificial head; The different microphones are located on the same plane and have different acquisition angles.

[0016] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the control filter determination method for sound field zoning as described above, or the sound field zoning control method.

[0017] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the control filter determination method for sound field zoning or the sound field zoning control method as described above.

[0018] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the control filter determination method for sound field zoning or the sound field zoning control method as described above.

[0019] The present invention provides a method for determining a control filter and controlling sound field partitioning. By modeling the transmission path in the frequency domain and further performing spatial Fourier transform decomposition, the sound field constructed by complex transmission paths can be transformed into a finite number of low-order modal coefficients representing the main propagation modes of the sound field. The low-order modal coefficients used in this method are insensitive to environmental disturbances such as noise, temperature, and humidity, exhibiting higher stability and robustness. By introducing each low-order modal coefficient into the cost function, even if there are certain errors in the determination process of the transmission path, it will not significantly affect the sound field partitioning effect of the control filter, enabling the control filter to ensure sound field partitioning while possessing robustness against transmission path mismatch. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating the method for determining control filters for sound field partitioning provided by the present invention.

[0022] Figure 2 This is a schematic flowchart of the sound field zoning control method provided by the present invention.

[0023] Figure 3 This is a schematic diagram of the control filter determination device for sound field zoning provided by the present invention.

[0024] Figure 4 This is a schematic diagram of the sound field zoning control device provided by the present invention.

[0025] Figure 5 This is a schematic diagram of the sound field zoning control system provided by the present invention.

[0026] Figure 6 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0028] Existing sound field zoning methods can achieve good isolation between bright and dark areas and target sound field matching under static and ideal conditions, but they have several obvious problems: First, it is highly sensitive to the measurement accuracy of the transmission path. If there are interference factors such as environmental noise or insufficient measurement equipment accuracy during the measurement stage, the estimation of the transmission path will have amplitude and phase errors. Since the least squares optimization process will strictly fit the measured data, these errors will be directly reflected in the design of the control filter, resulting in more leakage in the dark area and more distortion in the bright area in practical applications. Secondly, in real-world applications, changes in air temperature and humidity can affect the speed of sound and the propagation characteristics of sound waves. The movement of objects indoors and the shift in the listener's position can also alter the reflection path of sound waves. These factors can cause the actual transmission path to deviate from the initial measurement value, resulting in the sound field zoning effect falling far short of expectations.

[0029] Based on this, in order to address the problem of performance degradation caused by transmission path mismatch in existing sound field zoning control methods, this invention provides a method for determining control filters for sound field zoning.

[0030] Figure 1 This is a flowchart illustrating a method for determining control filters for sound field zoning provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the method includes: S11, determine the transmission paths from different loudspeakers to control points in the bright and dark areas of the target sound field in the spatial domain, and perform frequency domain modeling on the transmission paths to obtain the first transfer matrix of the bright area and the second transfer matrix of the dark area; S12, perform spatial domain Fourier transform decomposition on the first transfer matrix, the second transfer matrix and the target sound field respectively to obtain each decomposition representation, and determine the low-order mode coefficients of the first specified order in each decomposition representation; S13. Based on the low-order mode coefficients, construct a cost function and solve the cost function to obtain the control filter coefficients.

[0031] Specifically, the control filter determination method for sound field zoning provided in this embodiment of the invention is executed by a control filter determination device for sound field zoning. This device can be configured within the configuration unit of the sound field zoning control system and is used to configure each control filter in the control unit of the sound field zoning control system. The configuration unit can be a local computer or a cloud computer; the local computer can be a computer, tablet, etc., without specific limitations. The control unit can be a digital signal processor (DSP), a field-programmable gate array (FPGA), or a central processing unit (CPU), etc.

[0032] First, step S11 is executed. Based on the actual application scenario, such as a car cabin or home theater, the spatial positions and ranges corresponding to the bright and dark areas within the target sound field that need to be controlled can be determined. Alternatively, the spatial positions and ranges corresponding to the bright and dark areas can be determined according to user specifications. Here, the target sound field can be represented by an acoustic transfer function.

[0033] Multiple control points can be deployed in both the bright and dark areas. Each control point is a sampling point within its corresponding region. Based on the spatial sampling theorem and the shape of the corresponding region, the control points can be uniformly or adaptively deployed within that region. For example, each control point in both the bright and dark areas can be uniformly deployed on a corresponding circle.

[0034] The number of control points in both the light and dark areas can be the same, and can be set as needed.

[0035] The spatial domain refers to the spatial modal domain. The transmission paths from different loudspeakers to each control point in the bright and dark areas of the target sound field within the spatial domain can be measured using frequency sweep signals.

[0036] Subsequently, Fourier transforms can be performed on each transmission path, and frequency domain modeling can be performed in the form of frequency points to obtain the first transmission matrix in the bright region. The second transfer matrix of the dark area M represents the number of control points in the bright and dark areas, and L represents the number of loudspeakers.

[0037] Here, the first transfer matrix refers to the transfer matrix formed by the acoustic transfer functions of each loudspeaker to each control point in the bright zone, representing the sound field in the bright zone. The second transfer matrix refers to the transfer matrix formed by the acoustic transfer functions of each loudspeaker to each control point in the dark zone, representing the sound field in the dark zone.

[0038] Then, step S12 is executed to perform spatial Fourier transform decomposition on the first transfer matrix, the second transfer matrix, and the target sound field to obtain each decomposition representation. Here, by selecting basis functions that satisfy the orthogonality condition on the circumference, the first transfer matrix, the second transfer matrix, and the target sound field can be expanded in the spatial domain into linear combinations of different basis functions, thereby obtaining the decomposition representations corresponding to the first transfer matrix, the second transfer matrix, and the target sound field.

[0039] Each decomposition representation can include multiple spatial modal terms, and the number of spatial modal terms can be infinite. Each spatial modal term corresponds to a first-order spatial mode, which is obtained by multiplying the basis function of the corresponding order with the modal coefficients.

[0040] Here, the modal coefficients of each order in each decomposition representation can be calculated by the inner product of the object before decomposition and the corresponding basis function. Their physical meaning represents the projection intensity of the object before decomposition on the corresponding spatial mode.

[0041] In the decomposition representation of the first transfer matrix, the modal coefficients of each order can be calculated by the inner product of the first transfer matrix and the basis functions of the corresponding order. Their physical meaning represents the projection intensity of the first transfer matrix on the corresponding spatial mode.

[0042] In the decomposition representation of the second transfer matrix, the modal coefficients of each order can be calculated by the inner product of the second transfer matrix and the basis functions of the corresponding order. Their physical meaning represents the projection intensity of the second transfer matrix on the corresponding spatial mode.

[0043] In the decomposition representation of the target sound field, the modal coefficients of each order can be calculated by the inner product of the target sound field and the basis function of the corresponding order. Their physical meaning represents the projection intensity of the target sound field on the corresponding spatial mode.

[0044] Because the acoustic transfer function has a finite bandwidth in the spatial domain, that is, at a given frequency, the order of the spatial mode will not grow indefinitely. Higher-order spatial modes that exceed the upper limit of the bandwidth carry almost no effective information and their energy is extremely small and can be ignored.

[0045] Based on this, in this embodiment of the invention, only the lower-order spatial modes of the specified order are considered, that is, only the lower-order modal coefficients of the specified order in each decomposition representation are retained, which can accurately characterize the main propagation modes of the sound field constructed by the propagation paths in the bright and dark areas. Here, the specified order can be set as needed, for example, it can be set to order 0, or it can be set to order 2-3.

[0046] The low-order spatial modes of the specified order correspond to the long-wavelength components of sound waves, such as plane wave or low-order spherical wave modes. They are less sensitive to environmental disturbances such as noise, temperature and humidity changes, and measurement errors, and have good stability.

[0047] Finally, step S13 is executed. Modal constraints can be calculated using the low-order modal coefficients. By combining the control filter coefficient variables, a cost function can be constructed. Modal constraints are introduced into the cost function to simultaneously constrain the low-order modal distribution of the bright area, dark area, and target sound field.

[0048] Then, least-squares optimization is performed on the cost function point by point to find the control filter coefficients that minimize the cost function. These control filter coefficients are used to characterize the control filter, and the control filter is obtained by obtaining the control filter coefficients.

[0049] The control filter determination method for sound field zoning provided in this embodiment of the invention first determines the transmission paths from different loudspeakers to control points in the bright and dark regions of the target sound field in the spatial domain, and performs frequency domain modeling on the transmission paths to obtain a first transfer matrix for the bright region and a second transfer matrix for the dark region. Then, it performs spatial domain Fourier transform decomposition on the first transfer matrix, the second transfer matrix, and the target sound field to obtain each decomposition representation, and determines the low-order modal coefficients of the specified order in each decomposition representation. Finally, it constructs a cost function using the low-order modal coefficients and solves the cost function to obtain the control filter coefficients. This method, by modeling the transmission paths in the frequency domain and further performing spatial domain Fourier transform decomposition, can transform the sound field constructed by complex transmission paths into a finite number of low-order modal coefficients representing the main propagation modes of the sound field. The low-order modal coefficients used in this method are insensitive to environmental disturbances such as noise, temperature, and humidity, and have higher stability and robustness. This method introduces low-order mode coefficients into the cost function, so that even if there is some error in the process of determining the transmission path, it will not significantly affect the sound field partitioning effect of the control filter, so that the control filter has robustness against transmission path mismatch while ensuring the sound field partitioning effect.

[0050] Based on the above embodiments, spatial Fourier transform decomposition is performed on the first transfer matrix, the second transfer matrix, and the target sound field to obtain various decomposition representations, including: Using complex exponential functions as the basis functions for spatial Fourier transform, and based on the orthogonality of the basis functions on the circumference, spatial Fourier transform decomposition is performed on the first transfer matrix, the second transfer matrix, and the target sound field to obtain the decomposed representations.

[0051] Specifically, in performing spatial Fourier transform decomposition, a complex exponential function can be selected. As a basis function for the spatial Fourier transform, m represents the order, corresponding to different basis functions. It represents the angle on the circumference, corresponding to the angular distribution of each control point in the bright and dark areas.

[0052] Basis functions satisfy the orthogonality condition on the circumference: ; in, For orders different from m, Let Kronecker function be used.

[0053] Subsequently, taking advantage of the orthogonality of the basis functions on the circumference, spatial Fourier transform decomposition was performed on the first transfer matrix, the second transfer matrix, and the target sound field to obtain the decomposition representations.

[0054] Using basis functions, any function on a circle can be represented. Expanding this into a linear combination of basis functions yields... The expansion formula: ; in, The modal coefficients of the m-th order represent the function's modal coefficients. Energy distribution in this spatial mode.

[0055] The first transfer matrix Second transfer matrix And the target sound field d are substituted into From the expansion formula, we can obtain their respective decomposition representations in the spatial domain.

[0056] In this embodiment of the invention, the complex exponential function is used as the basis function of the spatial domain Fourier transform. Combined with the orthogonality of the basis function on the circle, the process of spatial domain Fourier transform decomposition can be simplified and the decomposition efficiency can be improved.

[0057] Based on the above embodiments, the step of constructing the cost function based on each of the low-order modal coefficients includes: Based on the number of control points in the bright area and the dark area, the low-order modal coefficients are discretized to obtain the low-order modal characteristics of each low-order modal coefficient. The cost function is constructed based on the aforementioned low-order modal features.

[0058] Specifically, since the first and second transfer matrices are measured at a finite number of control points, to reduce the computational load in subsequent solutions and improve the accuracy of sound field zoning control, the low-order modal coefficients can be discretized according to the number of control points in the bright and dark zones, respectively, to obtain the low-order modal characteristics of each low-order modal coefficient. Here, the discrete terms in each low-order modal characteristic correspond one-to-one with each control point.

[0059] Utilizing the orthogonality of basis functions, Multiply both sides of the expansion formula by and in the interval Integrating upwards yields the modal coefficients of the m-th order. Integral form: ; .

[0060] pass As can be seen from the integral expression, the modal coefficients of the m-th order can be obtained by applying the function... The inner product of the basis functions is used to calculate the physical meaning of the function. The projection intensity on this spatial mode.

[0061] If each control point in both the light and dark areas is arranged along a circle, then the angular position of each control point in both the light and dark areas can be expressed as follows: M represents the number of control points in the bright area and also the number of control points in the dark area.

[0062] Based on this, Discretizing the integral expression into a weighted sum of finite control points, we can obtain: Discretized expression: .

[0063] Substitute the first transfer matrix, the second transfer matrix, and the low-order modal coefficients of the target sound field into the following equations: By discretizing the expression, we can obtain the low-order modal features corresponding to the bright area, dark area, and target sound field.

[0064] Subsequently, by utilizing the characteristics of each low-order mode, a cost function is constructed, which greatly reduces the workload of solving the cost function and enables accurate control of the sound field at each control point.

[0065] Based on the above embodiments, constructing the cost function based on each of the low-order modal features includes: Based on the first transfer matrix, the second transfer matrix, and the target sound field, calculate the sound field energy of the dark area and the pressure matching degree between the sound field of the bright area and the target sound field; Based on the low-order modal features, modal constraints are calculated, and the cost function is constructed based on the acoustic field energy of the dark region, the pressure matching degree, and the modal constraints.

[0066] Specifically, in addition to modal constraints, the cost function may also include pressure matching degree and acoustic field energy in the dark region. Both pressure matching degree and acoustic field energy in the dark region contain control filter coefficient variables. The pressure matching degree can be determined by the first transfer matrix, the target acoustic field, and the control filter coefficient variables, while the acoustic field energy in the dark region can be determined by the second transfer matrix and the control filter coefficient variables. The cost function can be expressed as: ; Where J represents the cost function, This represents the first weighting coefficient. Let q represent the first transfer matrix, q represent the control filter coefficient variables, and d represent the target sound field. This represents the sound field energy in the dark area. Indicates the degree of pressure matching. This represents the sound field energy in the dark area. Let L2 norm be denoted as , and Q be the modal constraint.

[0067] Understandably, by minimizing the sound field energy in the dark area, the sound energy contrast is maximized—that is, by maximizing the ratio between the sound power in the bright area and the sound power in the dark area—a higher degree of isolation between the bright and dark areas can be achieved. By minimizing the pressure matching degree, that is, minimizing the difference between the sound field constructed in the bright area and the target sound field, the bright area remains undistorted and has better sound quality.

[0068] In this embodiment of the invention, the cost function can simultaneously constrain sound contrast, sound pressure matching, and low-order modal characteristics, ensuring that the solved control filter achieves good sound field zoning while being robust to transmission path mismatch. This avoids the problem of performance degradation due to environmental and noise changes caused by overfitting in the least squares solution of traditional methods.

[0069] Based on the above embodiments, the calculation of modal constraints based on each of the low-order modal features includes: Based on the low-order modal features corresponding to the bright area and the low-order modal features corresponding to the target sound field, the feature dimension pressure matching degree between the sound field of the bright area and the target sound field is calculated; Based on the low-order modal features corresponding to the dark region, the characteristic dimension sound field energy of the dark region is calculated, and the modal constraint is calculated based on the characteristic dimension pressure matching degree and the characteristic dimension sound field energy of the dark region.

[0070] Specifically, when calculating modal constraints using low-order modal features, we can first use the low-order modal features corresponding to the bright area and the target sound field, combined with the control filter coefficient variables, to calculate the feature dimension pressure matching degree between the sound field in the bright area and the target sound field. Then, using the low-order modal features corresponding to the dark area, combined with the control filter coefficient variables, we can calculate the feature dimension sound field energy in the dark area. Subsequently, by weighted summing the feature dimension pressure matching degree and the feature dimension sound field energy in the dark area, we obtain the modal constraints.

[0071] The feature dimension pressure matching degree and the feature dimension acoustic field energy of the dark area can both be obtained using the L2 norm. For example, the cost function can be expressed as: ; in, and These represent the low-order modal characteristics corresponding to the bright and dark areas, respectively, reflecting the main propagation modes of the sound field in the two regions; This represents the low-order modal characteristics corresponding to the target sound field; This represents the second weighting coefficient. This represents modal constraints.

[0072] In this embodiment of the invention, the pressure matching degree and the sound field energy of the dark area are calculated from the feature dimension, which can realize modal constraints in the feature dimension.

[0073] Based on the above embodiments, determining the transmission path from different loudspeakers to control points in the bright and dark zones of the target sound field within the spatial domain includes: Based on the audio acquisition device, the observation signals from each of the speakers to each of the control points are acquired respectively; Based on the observed signals, the transmission path from each loudspeaker to each control point is determined; The control points in the bright area and the control points in the dark area are all distributed on a circle centered on the fixed position of the audio acquisition device.

[0074] Specifically, when determining the transmission path, audio acquisition equipment can be used to collect observation signals from each speaker to each control point, i.e., the audio acquisition equipment can be deployed in both bright and dark areas. When the audio acquisition equipment is deployed in a bright area, observation signals from each speaker to each control point within that area are collected. In this case, the control points within the bright area are distributed on a circle centered on the fixed position of the audio acquisition equipment. When the audio acquisition equipment is deployed in a dark area, observation signals from each speaker to each control point within that area are collected. In this case, the control points within the dark area are distributed on a circle centered on the fixed position of the audio acquisition equipment.

[0075] Here, the audio acquisition device may include one or more microphones, such as an artificial head, including two microphones on the same plane with different acquisition angles.

[0076] Subsequently, by using the observed signals and deconvolution, the transmission path from each loudspeaker to each control point can be determined.

[0077] In this embodiment of the invention, control points are set up with the fixed positions of the audio acquisition devices in the bright and dark areas as reference points, which can ensure the sound field zoning effect at the reference points.

[0078] like Figure 2 As shown, based on the above embodiments, this embodiment of the invention provides a sound field zoning control method, including: S21, acquire the input audio signal; S22, based on the control filters corresponding to different speakers, the input sound signals are filtered respectively, and the filtered input sound signals are fed back to the corresponding speakers respectively; The control filters corresponding to different loudspeakers are determined based on the control filter determination method for sound field zoning provided in the above embodiments.

[0079] Specifically, the sound field zoning control method provided in this embodiment of the invention is executed by a sound field zoning control device, which can be configured within the control unit of the sound field zoning control system. The control unit includes a control filter connected to each speaker.

[0080] First, step S21 is executed to obtain the input sound signal, which is the sound signal to be played and can be selected and confirmed by the user.

[0081] Then, step S22 is executed, in which the input sound signal is filtered by the control filter corresponding to each speaker, and the filtered input sound signal is fed back to the corresponding speaker to drive each speaker to play the received sound signal.

[0082] In step S22, the control filters corresponding to each loudspeaker can be represented by control filter coefficients, and each control filter coefficient can be determined by the control filter determination method for sound field partitioning provided in the above embodiments.

[0083] The sound field zoning control method provided in this embodiment of the invention employs a control filter that can ensure the sound field zoning effect while possessing robustness against transmission path mismatch.

[0084] like Figure 3 As shown, based on the above embodiments, this embodiment of the invention provides a control filter determination device for sound field zoning, comprising: Modeling module 31 is used to determine the transmission path from different loudspeakers to each control point in the bright and dark areas of the target sound field in the spatial domain, and to perform frequency domain modeling on the transmission path to obtain the first transfer matrix of the bright area and the second transfer matrix of the dark area. The decomposition module 32 is used to perform spatial domain Fourier transform decomposition on the first transfer matrix, the second transfer matrix and the target sound field respectively to obtain each decomposition representation, and to determine the low-order mode coefficients of the first specified order in each decomposition representation. The solver module 33 is used to construct a cost function based on each of the low-order mode coefficients, and solve the cost function to obtain the control filter coefficients.

[0085] Based on the above embodiments, the control filter determination device for sound field zoning provided in this embodiment of the invention, wherein the solving module is specifically used for: Based on the number of control points in the bright area and the dark area, the low-order modal coefficients are discretized to obtain the low-order modal characteristics of each low-order modal coefficient. The cost function is constructed based on the aforementioned low-order modal features.

[0086] Based on the above embodiments, the control filter determination device for sound field zoning provided in this embodiment of the invention, wherein the solving module is specifically used for: Based on the first transfer matrix, the second transfer matrix, and the target sound field, calculate the sound field energy of the dark area and the pressure matching degree between the sound field of the bright area and the target sound field; Based on the low-order modal features, modal constraints are calculated, and the cost function is constructed based on the acoustic field energy of the dark region, the pressure matching degree, and the modal constraints.

[0087] Based on the above embodiments, the control filter determination device for sound field zoning provided in this embodiment of the invention, wherein the solving module is specifically used for: Based on the low-order modal features corresponding to the bright area and the low-order modal features corresponding to the target sound field, the feature dimension pressure matching degree between the sound field of the bright area and the target sound field is calculated; Based on the low-order modal features corresponding to the dark region, the characteristic dimension sound field energy of the dark region is calculated, and based on the characteristic dimension pressure matching degree and the characteristic dimension sound field energy of the dark region, the modal constraint is calculated.

[0088] Based on the above embodiments, the control filter determination device for sound field zoning provided in this embodiment of the invention, wherein the decomposition module is specifically used for: Using complex exponential functions as the basis functions for spatial Fourier transform, and based on the orthogonality of the basis functions on the circumference, spatial Fourier transform decomposition is performed on the first transfer matrix, the second transfer matrix, and the target sound field to obtain the decomposed representations.

[0089] Based on the above embodiments, the control filter determination device for sound field zoning provided in this embodiment of the invention, wherein the modeling module is specifically used for: Based on the audio acquisition device, the observation signals from each of the speakers to each of the control points are acquired respectively; Based on the observed signals, the transmission path from each loudspeaker to each control point is determined; The control points in the bright area and the control points in the dark area are all distributed on a circle centered on the fixed position of the audio acquisition device.

[0090] Specifically, the functions of each module in the control filter determination device for sound field partitioning provided in this embodiment of the invention correspond one-to-one with the operation flow of each step in the above method-like embodiments, and the achieved effects are also the same. For details, please refer to the above embodiments, and this will not be repeated in this embodiment of the invention.

[0091] like Figure 4 As shown, based on the above embodiments, this invention provides a sound field zoning control device. The sound signal acquisition module 41 is used to acquire the input sound signal; The audio signal playback module 42 is used to filter the input audio signal based on the control filter corresponding to different speakers, and to feed back the filtered input audio signal to the corresponding speaker. The control filters corresponding to different loudspeakers are determined based on the control filter determination method for sound field zoning provided in the above embodiments.

[0092] Specifically, the functions of each module in the sound field zoning control device provided in this embodiment of the invention correspond one-to-one with the operation flow of each step in the above method-like embodiments, and the achieved effects are also the same. For details, please refer to the above embodiments, and this will not be repeated in this embodiment of the invention.

[0093] like Figure 5 As shown, based on the above embodiments, this embodiment of the invention provides a sound field zoning control system, including: multiple loudspeakers 51, a control unit 52 and a configuration unit 53, wherein the control unit 52 is connected to the configuration unit 53; The control unit 52 includes multiple control filters 521, and each speaker 51 is connected to each control filter 521 in a one-to-one correspondence; The configuration unit 53 is used to execute the control filter determination method for sound field partitioning provided in the above embodiments, determine the control filter coefficients, and configure each control filter using the control filter coefficients.

[0094] The sound field zoning control system provided in this embodiment of the invention can realize sound field zoning control based on multiple speakers and can be applied to scenarios such as car cabins and home theaters.

[0095] Based on the above embodiments, the sound field zoning control system provided in this embodiment of the invention further includes an audio acquisition device, which is connected to the configuration unit; The audio acquisition device is used to acquire the observation signals from each of the speakers to each of the control points; The configuration unit is specifically used to determine the transmission path from each of the different loudspeakers to each of the control points based on the observed signal; The control points in the bright area and the control points in the dark area are all distributed on a circle centered on the fixed position of the audio acquisition device.

[0096] Based on the above embodiments, the sound field zoning control system provided in this embodiment of the invention includes an audio acquisition device comprising different microphones on an artificial head. The different microphones are located on the same plane and have different acquisition angles.

[0097] Figure 6 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 6As shown, the electronic device may include a processor 810, a communications interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communications interface 820, and the memory 830 communicate with each other via the communication bus 840. The processor 810 can call logical instructions in the memory 830 to execute the control filter determination method or the sound field zoning control method provided in the above embodiments.

[0098] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to related technologies, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0099] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the control filter determination method for sound field zoning or the sound field zoning control method provided in the above embodiments.

[0100] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the control filter determination method or sound field zoning control method for sound field zoning provided in the above embodiments. This computer-readable storage medium can be either a non-transitory computer-readable storage medium or a transient computer-readable storage medium, and is not specifically limited herein.

[0101] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0102] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of software products. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining control filters for sound field zoning, characterized in that, include: The transmission paths from different loudspeakers to control points in the bright and dark regions of the target sound field in the spatial domain are determined, and the transmission paths are modeled in the frequency domain to obtain the first transfer matrix of the bright region and the second transfer matrix of the dark region. Spatial Fourier transform decomposition is performed on the first transfer matrix, the second transfer matrix, and the target sound field to obtain each decomposition representation, and the low-order mode coefficients of the first specified order in each decomposition representation are determined. Based on the aforementioned low-order mode coefficients, a cost function is constructed, and the cost function is solved to obtain the control filter coefficients.

2. The method for determining control filters for sound field zoning according to claim 1, characterized in that, The construction of the cost function based on each of the lower-order modal coefficients includes: Based on the number of control points in the bright area and the dark area, the low-order modal coefficients are discretized to obtain the low-order modal characteristics of each low-order modal coefficient. The cost function is constructed based on the aforementioned low-order modal features.

3. The method for determining control filters for sound field zoning according to claim 2, characterized in that, The construction of the cost function based on each of the low-order modal features includes: Based on the first transfer matrix, the second transfer matrix, and the target sound field, calculate the sound field energy of the dark area and the pressure matching degree between the sound field of the bright area and the target sound field; Based on the low-order modal features, modal constraints are calculated, and the cost function is constructed based on the acoustic field energy of the dark region, the pressure matching degree, and the modal constraints.

4. The method for determining control filters for sound field zoning according to claim 3, characterized in that, The calculation of modal constraints based on each of the aforementioned low-order modal features includes: Based on the low-order modal features corresponding to the bright area and the low-order modal features corresponding to the target sound field, the feature dimension pressure matching degree between the sound field of the bright area and the target sound field is calculated; Based on the low-order modal features corresponding to the dark region, the characteristic dimension sound field energy of the dark region is calculated, and based on the characteristic dimension pressure matching degree and the characteristic dimension sound field energy of the dark region, the modal constraint is calculated.

5. The method for determining control filters for sound field zoning according to any one of claims 1-4, characterized in that, The spatial domain Fourier transform decomposition of the first transfer matrix, the second transfer matrix, and the target sound field yields various decomposition representations, including: Using complex exponential functions as the basis functions for spatial Fourier transform, and based on the orthogonality of the basis functions on the circumference, spatial Fourier transform decomposition is performed on the first transfer matrix, the second transfer matrix, and the target sound field to obtain the decomposed representations.

6. The method for determining control filters for sound field zoning according to any one of claims 1-4, characterized in that, Determining the transmission paths from different loudspeakers to control points in the bright and dark zones of the target sound field within the spatial domain includes: Based on the audio acquisition device, the observation signals from each of the speakers to each of the control points are acquired respectively; Based on the observed signals, the transmission path from each loudspeaker to each control point is determined; The control points in the bright area and the control points in the dark area are all distributed on a circle centered on the fixed position of the audio acquisition device.

7. A method for controlling sound field zoning, characterized in that, include: Acquire input audio signal; Based on the control filters corresponding to different speakers, the input sound signals are filtered respectively, and the filtered input sound signals are fed back to the corresponding speakers respectively. The control filters corresponding to different loudspeakers are determined based on the control filter determination method for sound field zoning as described in any one of claims 1-6.

8. A sound field zoning control system, characterized in that, include: Multiple speakers, a control unit, and a configuration unit, wherein the control unit is connected to the configuration unit; The control unit includes multiple control filters, and each speaker is connected to each control filter in a one-to-one correspondence. The configuration unit is used to perform the control filter determination method for sound field partitioning as described in any one of claims 1-6, determine the control filter coefficients, and configure each of the control filters based on the control filter coefficients.

9. The sound field zoning control system according to claim 8, characterized in that, It also includes an audio acquisition device, which is connected to the configuration unit; The audio acquisition device is used to acquire the observation signals from each of the speakers to each of the control points; The configuration unit is specifically used to determine the transmission path from each of the different loudspeakers to each of the control points based on the observed signal; The control points in the bright area and the control points in the dark area are all distributed on a circle centered on the fixed position of the audio acquisition device.

10. The sound field zoning control system according to claim 9, characterized in that, The audio acquisition device includes different microphones on the artificial head; The different microphones are located on the same plane and have different acquisition angles.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the control filter determination method for sound field zoning as described in any one of claims 1-6, or the sound field zoning control method as described in claim 7.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the control filter determination method for sound field partitioning as described in any one of claims 1-6, or the sound field partitioning control method as described in claim 7.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the control filter determination method for sound field partitioning as described in any one of claims 1-6, or the sound field partitioning control method as described in claim 7.

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