Signal processing method, loudspeaker, electronic device, storage medium and program product
By obtaining speaker test data and establishing a nonlinear system model, compensating signals are generated to process excitation signals, the harmonic distortion problem of speakers under large signal excitation is solved, and sound quality improvement and volume satisfaction are achieved, with low cost.
Patent Information
- Application Number
- CN202411372690.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2025-01-03
AI Technical Summary
The signal output by the speaker under large signal excitation contains obvious harmonic components, resulting in a decrease in the clarity of the sound signal and a decrease in the sound quality. The existing methods are difficult to meet the needs of users' high volumes while avoiding harmonic distortion.
By obtaining the test data of the speaker, determining the order of parameters and harmonic components related to its physical structure, establishing a nonlinear system model, generating a compensation signal to preprocess the excitation signal, and eliminating the main harmonic components in the speaker output signal.
It effectively reduces harmonic distortion in the speaker output signal, improves sound quality, and does not limit the volume, meets users' needs for large volume and high sound quality, and adopts digital signal processing technology, which is low cost.
Smart Images
Figure CN119255156A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of digital signal processing, and in particular to a signal processing method, a loudspeaker, an electronic device, a storage medium and a program product. Background Art
[0002] As a device that actually outputs sound signals, the quality of the speaker's broadcasting ability directly affects the final audio quality. Currently, users prefer audio devices with loud volume and high sound quality. Usually, a speaker is driven by an excitation signal to output a sound signal. The excitation signal is usually an electrical signal, such as a current signal or a voltage signal. When the excitation signal is a large signal (such as a signal with a large voltage), the sound signal output by the speaker is also relatively large, that is, the sound is loud.
[0003] However, the signal output by the loudspeaker under the stimulation of a large signal generally contains obvious harmonic components, which may cause serious harmonic distortion, resulting in reduced clarity of the sound signal and deterioration of sound quality, ultimately affecting the user's actual listening experience. Summary of the invention
[0004] In order to solve the problem that the signal output by the loudspeaker under large signal excitation contains obvious harmonic components, which may cause serious harmonic distortion and lead to reduced clarity of the sound signal, the present application provides a signal processing method, a loudspeaker, an electronic device, a storage medium and a program product.
[0005] In a first aspect, the present application provides a signal processing method applied to a speaker, the method comprising: obtaining test data and an original excitation signal of a target speaker; determining a first parameter and a second parameter based on the test data, wherein the first parameter is related to the physical structure of the target speaker, and the second parameter comprises an order corresponding to a first harmonic component in a predicted output signal; determining a first compensation signal based on the first compensation signal and the second parameter; determining a target excitation signal based on the first compensation signal and the original excitation signal; and using the target excitation signal to drive the target speaker to generate a target output signal.
[0006] In a possible implementation of the first aspect, determining the first parameter and the second parameter based on the test data includes: determining the first harmonic component and the second harmonic component in the predicted output signal, and determining the order of the first harmonic component as the second parameter, wherein the signal strength of the first harmonic component is greater than the signal strength of the second harmonic component.
[0007] In a possible implementation of the first aspect, determining the first parameter and the second parameter according to the test data further includes: establishing a nonlinear system model, and determining the first parameter based on the nonlinear system model and the test data.
[0008] In a possible implementation of the first aspect, the nonlinear system model includes a fundamental wave and a first harmonic component, the coefficient of the fundamental wave is a first partial parameter of the first parameter, and the coefficient of the first harmonic component is a second partial parameter of the first parameter.
[0009] In a possible implementation of the first aspect, determining the first parameter based on the nonlinear system model and test data includes: determining an impulse response signal of the nonlinear system model according to the test data; and determining a first part of parameters and a second part of parameters according to the impulse response signal.
[0010] In a possible implementation of the first aspect, determining the first compensation signal according to the first parameter and the second parameter includes: determining a harmonic signal according to the original excitation signal and the second parameter, the order of the harmonic signal being equal to the second parameter; and determining the first compensation signal according to the first parameter and the harmonic signal.
[0011] In a possible implementation of the first aspect, determining a target excitation signal according to the first compensation signal and the original excitation signal includes: inverting the first compensation signal to obtain a second compensation signal; and adding the original excitation signal and the second compensation signal to obtain the target excitation signal.
[0012] In a second aspect, the present application provides a speaker, comprising a preprocessing unit, which is used to determine a first compensation signal based on a first parameter and a second parameter, and to determine a target excitation signal based on the first compensation signal and the original excitation signal, wherein the first parameter is related to the physical structure of the speaker, the second parameter includes an order corresponding to a first harmonic component in a predicted output signal, and the target excitation signal is used to drive the speaker; the speaker is used to generate a target output signal.
[0013] In a possible implementation of the second aspect, the preprocessing unit includes a signal generator and an inverse filter, the signal generator is used to generate a harmonic signal based on the original excitation signal, and the order of the harmonic signal is equal to the second parameter; the coefficient of the inverse filter is related to the first parameter, and the inverse filter is used to determine the first compensation signal based on the harmonic signal.
[0014] In a possible implementation of the second aspect, the preprocessing unit further includes an inverter and an adder, wherein the inverter is used to invert the first compensation signal to determine the second compensation signal; and the adder is used to add the original excitation signal and the second compensation signal to determine the target excitation signal.
[0015] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the processor implements the signal processing method of the first aspect and any possible implementation of the first aspect.
[0016] In a fourth aspect, the present application provides an electronic device, comprising the second aspect and any possible implementation of the second aspect and a speaker and an excitation source; the excitation source is connected to the speaker and is used to output an original excitation signal to the speaker.
[0017] In a fifth aspect, the present application provides a readable storage medium, on which instructions are stored. When the instructions are executed on an electronic device, the electronic device executes the first aspect and any possible signal processing method of the first aspect.
[0018] In a sixth aspect, the present application provides a program product, which includes computer instructions. When executed by an electronic device, the electronic device executes the signal processing method of the first aspect and any possible implementation of the first aspect.
[0019] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:
[0020] The signal processing method provided in the embodiment of the present application is applied to a speaker, comprising: obtaining test data and an original excitation signal of a target speaker; determining a first parameter and a second parameter according to the test data, wherein the first parameter is related to the physical structure of the target speaker, and the second parameter includes the order corresponding to the first harmonic component in the predicted output signal; determining a first compensation signal according to the first parameter and the second parameter; determining a target excitation signal according to the first compensation signal and the original excitation signal; and driving the target speaker with the target excitation signal to generate a target output signal. In this way, the main harmonic components in the output signal of the target speaker can be eliminated, and harmonic distortion can be significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 is a flow chart of a signal processing method provided by an embodiment of the present application;
[0022] Figure 2 is a schematic diagram of a speaker provided in an embodiment of the present application;
[0023] Figure 3 It is a schematic diagram of a preprocessing unit workflow provided in an embodiment of the present application. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following briefly introduces the terms involved in the present application:
[0025] (1) Impulse response
[0026] The zero-state response of a system under the excitation of a unit impulse function is called the "impulse response" of the system. It has a Fourier transform relationship with the transfer function of the system.
[0027] (2) Transfer function
[0028] The transfer function refers to the conversion function between the input signal and the output signal, which plays a key role in the filter design process and the analysis of filter performance and stability.
[0029] (3) Harmonics
[0030] In addition to the fundamental wave, the output signal of a nonlinear device or system usually contains harmonics. The fundamental wave is the lowest frequency component of the signal, while the harmonics are integer multiples of the fundamental frequency. The intensity of each harmonic depends on the signal characteristics and the harmonic order. The harmonic order indicates the multiple relationship between the frequency of the harmonic and the fundamental frequency. The higher the harmonic order, the higher the corresponding frequency. Normally, the fundamental wave (i.e., the original frequency) in the signal has the greatest intensity, and as the order increases, the intensity of the harmonics gradually decreases. This is because in the process of signal transmission and processing, there are factors such as energy loss and noise interference, which cause the energy of high-order harmonics to gradually weaken. However, in some specific cases, such as nonlinear systems or specific signal sources, harmonic enhancement may occur. In this case, the intensity of high-order harmonics may be greater than that of low-order harmonics. But this is not a universal rule and requires specific analysis of specific situations.
[0031] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. The illustrative embodiments of the present application include but are not limited to a signal processing method, a speaker, an electronic device, a storage medium and a program product.
[0032] As mentioned above, a loudspeaker is a commonly used electroacoustic transducer device, including a speaker and a sound box, wherein the speaker may include a driving voice coil and a diaphragm. When the excitation signal drives the speaker, the diaphragm will be displaced, thereby generating an acoustic signal. The acoustic signal generated by the existing loudspeaker under large signal excitation usually has obvious harmonic distortion, the main reason for which is the nonlinearity of important physical parameters (such as stiffness) of the loudspeaker's own device (such as the diaphragm). Since the diaphragm is not completely rigid, but has a certain elasticity, some nonlinear effects will be generated when the diaphragm vibrates, resulting in harmonic components in the output signal of the loudspeaker. Under small signal excitation, the diaphragm displacement of the loudspeaker is relatively small, and its physical parameters are basically constant. At this time, the loudspeaker can be approximated as a linear system, so the harmonic components in the output acoustic signal are small and the distortion is low; however, when the excitation signal increases, the diaphragm displacement of the loudspeaker becomes larger, and its physical parameters will change and cannot be regarded as constants. At this time, the loudspeaker is a nonlinear system, so the harmonic components in the output acoustic signal will become larger, and the harmonic distortion will increase.
[0033] In some embodiments, excessive harmonic signals are avoided by reducing the excitation signal gain or the maximum displacement of the speaker diaphragm. By reducing the maximum displacement of the speaker diaphragm or reducing the excitation signal gain, thereby limiting the diaphragm displacement of the speaker, the physical parameters of the speaker can be kept basically constant, avoiding the generation of excessive harmonic components, thereby reducing harmonic distortion. However, this method also limits the diaphragm displacement of the speaker, that is, limits the volume of the sound signal output by the speaker, sacrificing the speaker's broadcasting ability, and cannot meet the user's high volume requirements.
[0034] In some embodiments, by changing the physical structure of the speaker, adjusting the structure and material of the speaker, etc., the physical parameters of the speaker remain constant under a larger displacement, that is, the linear range of the speaker diaphragm is increased, thereby reducing the generation of harmonic distortion. However, this method requires redesigning and producing the speaker, which is too costly and still cannot avoid the generation of harmonic distortion.
[0035] To solve the above problems, an embodiment of the present application provides a signal processing method. First, the test data of the target speaker is tested and collected to obtain the original excitation signal. Then, a first parameter and a second parameter are determined according to the test data, wherein the first parameter is related to the physical structure of the target speaker, and the second parameter includes the order corresponding to the main harmonic component (i.e., the first harmonic component mentioned in this application) in the predicted output signal of the target speaker. After that, a first compensation signal is determined according to the first parameter and the second parameter, and then a target excitation signal, i.e., a pre-processed excitation signal, is determined according to the first compensation signal and the original excitation signal. Finally, the pre-processed excitation signal is used to drive the target speaker, so that an output signal (i.e., the target output signal mentioned in this application) with the main harmonic components eliminated can be obtained. In this way, by pre-processing the excitation signal and using the pre-processed excitation signal to drive the speaker, the main harmonic components in the speaker output signal can be eliminated, thereby significantly reducing harmonic distortion. The entire process only uses digital signal processing technology, and the implementation cost is low.
[0036] Among them, the first parameter can be determined by methods such as adaptive filters or impulse response measurements. For example, a nonlinear system model can be established, and the impulse response signal of the nonlinear system model can be determined according to the test data, so that the first parameter can be determined. The test data of the target speaker may include an excitation signal (such as a current signal, a voltage signal, etc.) applied to the target speaker and an output signal of the target speaker after the excitation signal is applied, such as a diaphragm displacement signal. By analyzing the test data, the harmonic signal with the largest signal intensity in the diaphragm displacement signal, that is, the main harmonic component, can be found, and the order corresponding to the main harmonic component, that is, the second parameter, can be determined. In addition, the second parameter can be considered to be the order corresponding to the main harmonic component in the predicted output signal.
[0037] It can be understood that the structures of harmonic components in the output signals of the same or the same type of speakers are similar, so the harmonic components in the output signal of the target speaker can be predicted by analyzing the test data of the target speaker.
[0038] It can be understood that due to the nonlinearity of important physical parameters (such as stiffness) of the speaker's own devices (such as the diaphragm), the speaker is similar to a nonlinear system. Therefore, by establishing a nonlinear system model, the process from the excitation signal to the output sound signal of the speaker can be predicted, reflecting the nonlinear distortion (i.e., harmonic distortion) of the speaker.
[0039] Combine the following Figure 1 A signal processing method provided in an embodiment of the present application is introduced. The method can be applied to a loudspeaker or a nonlinear system similar to a loudspeaker. Taking a loudspeaker as an example, Figure 1 is a flow chart of a signal processing method provided by an embodiment of the present application, such as Figure 1 As shown, the method includes:
[0040] S101, obtaining test data and an original excitation signal of a target speaker.
[0041] In some embodiments, test data and an original excitation signal of a target speaker are first acquired. The test data may include an excitation signal (such as a current signal, a voltage signal, etc.) applied to the target speaker and an output signal of the target speaker after the excitation signal is applied. The output signal may include a diaphragm displacement signal or an acoustic signal.
[0042] It can be understood that the excitation signal applied to the target speaker is usually a current or voltage signal. When the target speaker is driven, the diaphragm of the target speaker will vibrate (also called displacement), thereby generating a diaphragm displacement signal. The diaphragm vibration hits the air, causing the target speaker to output an acoustic signal. Since the acoustic signal is generated by the vibration of the diaphragm, the acquisition process of the acoustic signal is affected by environmental noise and recording equipment, etc., which may lead to errors in subsequent parameter calculations. The diaphragm displacement signal is more stable than the acoustic signal, and the diaphragm displacement signal collected by the laser rangefinder as the above-mentioned output signal can obtain more accurate results.
[0043] S102, determining a first parameter and a second parameter according to the test data.
[0044] In some embodiments, a first parameter and a second parameter are determined based on test data, wherein the first parameter is related to the physical structure of the target speaker, and the second parameter includes the order corresponding to the first harmonic component in the predicted output signal. The test data can be analyzed first to determine the first harmonic component and the second harmonic component in the predicted output signal, and the order of the first harmonic component is determined as the second parameter, wherein the signal strength of the first harmonic component is greater than the signal strength of the second harmonic component. Then, a nonlinear system model is established, and the first parameter is determined based on the test data and the nonlinear system model.
[0045] The second harmonic component mentioned in the present application represents all harmonic components except the first harmonic component in the predicted output signal, rather than specifically referring to harmonic components of a certain order. The signal strength of the first harmonic component is greater than the signal strength of the second harmonic component, indicating that the first harmonic component is the main harmonic component in the predicted output signal, that is, the harmonic component with the largest signal strength. Specifically, the signal strength of each harmonic component in the output signal in the test data can be determined by analyzing the spectral components through a signal processing method (such as discrete Fourier transform) based on the collected test data, so that the main harmonic components in the predicted output signal can be determined.
[0046] It can be understood that the selection of the nonlinear system model is related to the specific application of the method provided in this application. When applied to a loudspeaker, a simplified Volterra nonlinear filter model can be used, which can well reflect the nonlinear distortion (i.e., harmonic distortion) of the loudspeaker. When the method provided in this application is applied to other nonlinear systems similar to loudspeakers, other nonlinear system models can also be used, and this application does not limit this.
[0047] Specifically, a simplified Volterra nonlinear filter model is used as an example for explanation. The standard Volterra nonlinear filter expression is shown in formula (1):
[0048]
[0049] Among them, x(n) is the input of the nonlinear system, that is, the excitation signal of the speaker; y(n) is the output of the nonlinear system, that is, the output signal of the speaker; h0 is the DC component, h i is the ith-order Volterra kernel function, h i (m1,m2,...,m i ) is an i-order matrix, i is the matrix order, and m is the subscript of the kernel function coefficient.
[0050] It can be understood that in the output of the actual loudspeaker nonlinear system, the proportion of the DC component h0 is relatively small, so the DC component h0 can be ignored. In addition, there are too many parameters in the filter represented by formula (1), and the diagonal elements can be used to represent the harmonic components generated by the loudspeaker system. Therefore, in order to simplify the modeling, the above formula (1) can be simplified, and the simplified filter expression can refer to formula (2):
[0051]
[0052] Wherein, k is the harmonic order, and M is the maximum order of the corresponding kernel function, that is, the maximum order of the filter. M is usually specified manually, for example, it can be 512 or 2048, or other values, which are not limited in this application.
[0053] It should be understood that the order of the linear component (fundamental wave, i.e., the main component that is ultimately desired to be retained) in the output signal is 1st order, and the signal components of the remaining orders are all harmonic components. The main purpose of the harmonic distortion reduction method provided in the embodiment of the present application is to eliminate the main harmonic components in the output signal. Therefore, when modeling a nonlinear system, only the main harmonic components need to be considered, and the above formula (2) can be further simplified to obtain the following formula (3):
[0054]
[0055] Among them, k is the order of the main harmonic components in the output signal, that is, the second parameter.
[0056] It can be understood that the main harmonic component in the output signal of the speaker is determined by the physical structure of the target speaker. In some embodiments, the test data of the target speaker can be obtained, and the harmonic component with the largest signal strength can be found according to the output signal in the test data. Then, the harmonic component is the main harmonic component in the predicted output signal, and its order is the order corresponding to the main harmonic component.
[0057] It can be understood that the nonlinear system model shown in the above formula (3) includes the fundamental wave and the main harmonic components, the coefficient h1 of the fundamental wave (i.e., the first part parameter of the first parameter mentioned in this application) and the coefficient h of the main harmonic component k (i.e., the second part of the first parameter mentioned in this application) are all related to the physical structure of the target speaker. For different speakers, the coefficients h1 and h k The values of may be different. Specifically, the coefficients h1 and h can be determined by measuring the impulse response signal of the nonlinear system. k The value of the first parameter is determined.
[0058] Exemplarily, when it is determined according to the test data that the order of the first harmonic component of the predicted output signal is 2, the order of the second harmonic component is 3, 4, ..., n, and the signal strength of the first harmonic component is greater than that of the second harmonic component, the second parameter is determined to be 2, that is, the order corresponding to the main harmonic component is the second order, and the above formula (3) can be expressed as:
[0059]
[0060] It can be understood that formula (4) indicates that the predicted output signal includes a second harmonic component, which can represent the harmonic distortion of the sound signal output by the target speaker.
[0061] It should be understood that since the distortion of the low-frequency signal output by the speaker is relatively serious, in some embodiments, the second harmonic signal is mainly introduced in the low-frequency band of the excitation signal, such as the frequency band below 300 Hz to 400 Hz.
[0062] S103: Determine a harmonic compensation signal according to the first parameter and the second parameter.
[0063] In some embodiments, a harmonic signal is first determined based on the original excitation signal and the second parameter, and the order of the harmonic signal is equal to the second parameter; then a harmonic compensation signal (i.e., the first compensation signal mentioned in this application) is determined based on the first parameter and the harmonic signal.
[0064] Specifically, the harmonic signal can be obtained by calculating the power of the original excitation signal, as shown in formula (5):
[0065] x k (n) = x(n) k (5)
[0066] Among them, x k (n) represents the harmonic signal, and x(n) represents the original excitation signal. Since the harmonic compensation signal can be generated by the inverse filter, it is necessary to first establish the inverse filter expression, and determine the coefficients in the inverse filter expression according to the first parameter. The inverse filter expression is shown in formula (6):
[0067]
[0068] in, represents the harmonic compensation signal, p k (i k ) represents the k-order harmonic impulse response h k The impulse response of the inverse system cascaded with the fundamental impulse response h0. It can be understood that the coefficients p of the inverse filter expression are k (i k ) is determined by the first parameter, so the coefficient p needs to be determined based on the first parameter k (ik ), please refer to the frequency domain expression (7) for details:
[0069]
[0070] Where P(z) is the transfer function of the harmonic compensation signal, is the inverse transfer function of the fundamental signal, H k (z) is the transfer function of the k-order harmonic signal. According to the first part of the first parameter, it can be determined According to the second part of the first parameter, H can be determined k (z), so that the transfer function P(z) of the harmonic compensation signal can be determined, and the coefficients of the inverse filter expression can be determined by converting the transfer function P(z) of the harmonic compensation signal into the time domain. In this way, the harmonic compensation signal can be determined based on the harmonic signal and the inverse filter expression.
[0071] S104: Determine a target excitation signal according to the harmonic compensation signal and the original excitation signal.
[0072] In some embodiments, the harmonic compensation signal is inverted to obtain a second compensation signal, and the second compensation signal is added to the original excitation signal to determine the target excitation signal, thereby completing the preprocessing of the original excitation signal.
[0073] It can be understood that adding the second compensation signal to the original excitation signal means introducing an anti-phase harmonic component into the original excitation signal, that is, the target excitation signal contains an anti-phase harmonic component.
[0074] S105: Using the target excitation signal to drive the target speaker to generate a target output signal.
[0075] In some embodiments, a target output signal may be generated by driving a target speaker with a target excitation signal.
[0076] It can be understood that the target excitation signal obtained by the method provided in the embodiment of the present application includes the original excitation signal and the signal components have not changed, but there is an additional inverted harmonic component, and the order of the inverted harmonic component is the same as the order corresponding to the main harmonic component in the predicted output signal. It can be considered that the order is the same as the order corresponding to the main harmonic component in the target output signal, such as the second order, third order or fifth order, etc., so the main harmonic component in the target output signal can be offset, thereby reducing the harmonic distortion of the speaker.
[0077] Exemplarily, if the third-order harmonic distortion of the target speaker is obvious, an inverted third-order harmonic component is introduced into the preprocessed target excitation signal; if both the second-order and third-order harmonic distortions of the target speaker are obvious, reverse second-order and third-order harmonic components are simultaneously introduced into the preprocessed target excitation signal.
[0078] In some embodiments, the main goal is to reduce harmonic distortion. The target excitation signal processed by the signal processing method provided in the embodiments of the present application includes components of the original excitation signal. However, in the process of constructing the harmonic signal, some fundamental components may be introduced, thereby increasing the current or voltage of the excitation signal, which may lead to an increase in the gain of the original excitation signal and an increase in the output signal, resulting in an increase in the loudness of the sound output by the target speaker.
[0079] In other embodiments, with the common goal of reducing harmonic distortion and enhancing low frequencies, the fundamental component can be deliberately retained in the process of constructing the harmonic signal, thereby introducing it into the original excitation signal to enhance the signal size of the target excitation signal in the low frequency band (for example, below 300 Hz); or the low-frequency gain can be further released through an equalizer. For example, when the original low-frequency gain is -5dB, the low-frequency gain can be released to -2dB or -1dB through an equalizer, thereby achieving low-frequency enhancement.
[0080] The signal processing method provided in the embodiment of the present application obtains a target excitation signal by preprocessing the original excitation signal of the speaker, and uses the target excitation signal to drive the speaker, thereby eliminating the main harmonic components in the output signal of the speaker and significantly reducing harmonic distortion. In addition, there is no need to change the physical structure of the speaker, and the output volume of the speaker is not limited, so the broadcasting potential of the speaker can be fully utilized. Since only digital signal processing technology is used, the implementation cost is also relatively low.
[0081] Combine the following Figure 2 and Figure 3 A speaker provided in an embodiment of the present application is introduced. Figure 2 A schematic diagram of a speaker provided in an embodiment of the present application is shown; Figure 3 A schematic diagram of a preprocessing unit workflow provided in an embodiment of the present application is shown.
[0082] like Figure 2 As shown, the speaker 10 includes a preprocessing unit 102, a speaker 103 and a sound box (not shown in the figure), wherein the preprocessing unit 102 is designed according to the nonlinear system 101 and can be a preprocessing circuit (integrated circuit) or a preprocessing chip.
[0083] Specifically, before designing the preprocessing unit 102, it is necessary to obtain the test data of the speaker 10 for calculating the relevant parameters of the nonlinear system 101. First, it is necessary to establish a nonlinear system model to characterize the process from the excitation signal to the output sound signal of the speaker 10, including the generation of harmonic components. For details, please refer to the above formula (3). The specific process of nonlinear system modeling can refer to the above description of step S102, which will not be repeated here.
[0084] It can be understood that the nonlinear system model includes the fundamental wave and the main harmonic components. The coefficient h1 of the fundamental wave and the coefficient h of the main harmonic components are k It is related to the physical structure of the speaker 10. Specifically, the coefficients h1 and h2 can be determined by measuring the impulse response signal of the nonlinear system. k The value of the first parameter is determined by the value of the first parameter. The main harmonic component in the output signal of the speaker is determined by the physical structure of the speaker 10. In some embodiments, the test data of the speaker 10 can be obtained, and according to the output signal in the test data, the spectrum components can be analyzed by a signal processing method (such as discrete Fourier transform) to find the strongest harmonic component, that is, the harmonic component with the largest signal strength. Then, the harmonic component is the main harmonic component in the predicted output signal, and its order is the order corresponding to the main harmonic component, so that the value of the second parameter can be determined.
[0085] Reference Figure 3 , the preprocessing unit 102 may include a signal generator 1021, an inverse filter 1022, an inverter 1023 and an adder 1024. The signal generator 1021 is used to generate a harmonic signal; the inverse filter 1022 is used to generate a harmonic compensation signal; the inverter is used to invert the harmonic compensation signal to determine a second harmonic signal; the adder 1024 is used to add the second harmonic signal to the original excitation signal to determine a target excitation signal. Among them, the signal generator 1021 and the inverse filter 1022 need to be designed according to the nonlinear system.
[0086] Understandably, Figure 3 The preprocessing unit 102 shown may also be a software module. The hardware structure of superimposed various devices is only a structural example. The preprocessing unit may include more or fewer components than shown in the figure, or combine certain components, or split certain components, or arrange the components differently. This application does not impose any restrictions on this.
[0087] In some embodiments, after the values of the first parameter and the second parameter are determined according to the test data of the nonlinear system 101 and the speaker 10, the order of the harmonic signal to be generated by the signal generator 1021 can be determined, thereby completing the design of the signal generator 1021. It can be understood that in order to remove the main harmonic components in the target output signal, the order of the harmonic signal needs to be equal to the order corresponding to the main harmonic components in the predicted output signal predicted by the nonlinear system 101, that is, the order of the harmonic signal is equal to the second parameter.
[0088] In some embodiments, the coefficients of the inverse filter 1022 can be determined according to the first parameter, thereby completing the design of the inverse filter 1022. Specifically, the inverse filter expression shown in the aforementioned formula (6) is first established, and the inverse transfer function of the fundamental signal and the transfer function of the k-order harmonic signal are determined according to the first parameter. The transfer function corresponding to the harmonic compensation signal can be determined, and the aforementioned formula (7) can be referred to. For details, please refer to the aforementioned description of formula (6) and formula (7), which will not be repeated here. The transfer function of the harmonic compensation signal is converted to the time domain to obtain the coefficients of the inverse filter 1022, thereby completing the design of the preprocessing unit 1022.
[0089] It can be understood that when establishing a nonlinear system model, the embodiment of the present application only targets the main harmonic components of the output signal, thereby greatly simplifying the modeling of the nonlinear system 101 of the speaker and the subsequent design of the signal generator 1021 and the inverse filter 1022.
[0090] Continue to refer to Figure 2 and Figure 3 When the original excitation signal drives the speaker 10 to work, it can be preprocessed by the preprocessing unit 102 to obtain a target excitation signal. When the target excitation signal drives the speaker 10, the diaphragm in the speaker 103 is displaced, thereby outputting a sound signal, which is the sound signal after eliminating the main order harmonic distortion.
[0091] The speaker provided in the embodiment of the present application only adds a preprocessing unit without changing the original physical structure of the speaker, and will not limit the output volume of the speaker. The speaker's broadcasting potential can be fully utilized to meet the user's needs for high volume and high sound quality.
[0092] An embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the signal processing method mentioned in the present application is implemented.
[0093] An embodiment of the present application also provides an electronic device, comprising the above-mentioned speaker and an excitation source; the excitation source is connected to the speaker and is used to output an original excitation signal to the speaker.
[0094] An embodiment of the present application provides a readable storage medium, on which instructions are stored. When the instructions are executed on an electronic device, the electronic device executes the signal processing method mentioned in the present application.
[0095] An embodiment of the present application provides a program product, which includes computer instructions. When the program product is executed by an electronic device, the electronic device performs the signal processing method mentioned in the present application.
[0096] It should be noted that the units mentioned in the various device embodiments of the present application are all logical units. Physically, a logical unit can be a physical unit, or a part of a physical unit, or can be implemented as a combination of multiple physical units. The physical implementation of these logical units themselves is not the most important. The combination of functions implemented by these logical units is the key to solving the technical problems proposed by the present application. In addition, in order to highlight the innovative part of the present application, the above-mentioned device embodiments of the present application do not introduce units that are not closely related to solving the technical problems proposed by the present application, which does not mean that there are no other units / modules in the above-mentioned device embodiments.
[0097] In some cases, the disclosed embodiments may be implemented in hardware, firmware, software, or any combination thereof. The disclosed embodiments may also be implemented as instructions carried or stored on one or more temporary or non-temporary machine-readable (e.g., computer-readable) storage media, which may be read and executed by one or more processors. For example, the instructions may be distributed over a network or through other computer-readable media. Machine-readable media include any type of machine-readable media suitable for storing or transmitting electronic instructions or information in a form readable by a machine (e.g., a computer).
[0098] In the accompanying drawings, some structural or method features may be shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be required. Instead, in some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. In addition, the inclusion of structural or method features in a particular figure does not mean that such features are required in all embodiments, and in some embodiments, these features may not be included or may be combined with other features.
[0099] It should be noted that, in the examples and description of the present application, relational terms such as first and second, etc. are only used to distinguish one signal or parameter from another signal or parameter, and do not necessarily require or imply any such actual relationship or order between these signals or parameters. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise one" do not exclude the presence of other identical elements in the process, method, article or device including the elements.
[0100] Although the present application has been illustrated and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present application.
Claims
1. A signal processing method, applied to a loudspeaker, characterized in that: The method comprises: Obtain test data and original excitation signal of the target speaker; Determine a first parameter and a second parameter according to the test data, wherein the first parameter is related to the physical structure of the target speaker, and the second parameter includes an order corresponding to a first harmonic component in the predicted output signal; Determining a first compensation signal according to the first parameter and the second parameter; Determining a target excitation signal according to the first compensation signal and the original excitation signal; The target speaker is driven by the target excitation signal to generate a target output signal.
2. The method according to claim 1, characterized in that The determining the first parameter and the second parameter according to the test data comprises: A first harmonic component and a second harmonic component in the predicted output signal are determined, and the order of the first harmonic component is determined as the second parameter, wherein the signal strength of the first harmonic component is greater than the signal strength of the second harmonic component.
3. The method according to claim 1, characterized in that The determining of the first parameter and the second parameter according to the test data further includes: Build nonlinear system models; The first parameter is determined based on the nonlinear system model and the test data.
4. The method according to claim 3, characterized in that The nonlinear system model includes a fundamental wave and the first harmonic component, the coefficient of the fundamental wave is a first part of the parameters of the first parameter, and the coefficient of the first harmonic component is a second part of the parameters of the first parameter.
5. The method according to claim 4, characterized in that The determining the first parameter based on the nonlinear system model and the test data comprises: Determining an impulse response signal of the nonlinear system model according to the test data; The first part of parameters and the second part of parameters are determined according to the impulse response signal.
6. The method according to claim 1, characterized in that The determining a first compensation signal according to the first parameter and the second parameter comprises: Determine a harmonic signal according to the original excitation signal and the second parameter, wherein the order of the harmonic signal is equal to the second parameter; The first compensation signal is determined according to the first parameter and the harmonic signal.
7. The method according to claim 1, characterized in that The step of determining a target excitation signal according to the first compensation signal and the original excitation signal comprises: Inverting the first compensation signal to obtain a second compensation signal; The original excitation signal and the second compensation signal are added to obtain the target excitation signal.
8. A speaker, characterized in that: The speaker comprises a pre-processing unit, The preprocessing unit is used to determine a first compensation signal according to a first parameter and a second parameter, and to determine a target excitation signal according to the first compensation signal and an original excitation signal, wherein: The first parameter is related to the physical structure of the loudspeaker, the second parameter includes an order corresponding to a first harmonic component in the predicted output signal, and the target excitation signal is used to drive the loudspeaker; The speaker is used to generate a target output signal.
9. The loudspeaker according to claim 8, characterized in that The preprocessing unit includes a signal generator and an inverse filter, The signal generator is used to generate a harmonic signal according to the original excitation signal, and the order of the harmonic signal is equal to the second parameter; The coefficient of the inverse filter is related to the first parameter, and the inverse filter is used to determine the first compensation signal according to the harmonic signal.
10. The loudspeaker according to claim 8, characterized in that The pre-processing unit also includes an inverter and an adder. The inverter is used to invert the first compensation signal to determine a second compensation signal; The adder is used to add the original excitation signal and the second compensation signal to determine the target excitation signal.
11. An electronic device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the signal processing method according to any one of claims 1 to 7 when executing the computer program.
12. An electronic device, characterized in that: comprising a loudspeaker and an excitation source as described in any one of claims 8 to 10; The excitation source is connected to the speaker and is used to output an original excitation signal to the speaker.
13. A readable storage medium, characterized in that: The readable storage medium stores instructions, and when the instructions are executed on an electronic device, the electronic device executes the signal processing method according to any one of claims 1 to 7.
14. A program product, characterized in that The program product comprises computer instructions, and when executed by an electronic device, the electronic device performs the signal processing method according to any one of claims 1 to 7.