Method, equipment and chip for controlling output power of loudspeaker

Abstract

The invention relates to the technical field of loudspeakers, and provides a method, equipment and a chip for controlling the output power of a loudspeaker. In the method, temperature states of a loudspeaker are fed back to a controller, and gain processing is performed on each temperature state, for example, gain processing is performed on a difference value between a first temperature of a voice coil at a first moment and a temperature threshold value based on a first gain; the fourth temperature is obtained by performing gain processing on the first decrease amount of the temperature of the voice coil from the first moment to the second moment based on the second gain, and the fifth temperature is obtained by performing gain processing on the second decrease amount of the temperature of the magnetic steel from the first moment to the second moment based on the third gain, so that the output power is obtained. And burning of the voice coil caused by the fact that the temperature of the loudspeaker exceeds the temperature threshold can be avoided.

Description

Technical Field

[0001] This application relates to the field of loudspeaker technology, and in particular to a method, apparatus and chip for controlling the output power of a loudspeaker. Background Technology

[0002] A loudspeaker is a device that converts electrical signals into sound signals and is widely used in a wide variety of electronic devices. To increase the loudness of the audio output by a loudspeaker, its output power can be increased. However, when the loudspeaker's output power is too high, the current through the voice coil increases significantly. This causes the voice coil to generate a large amount of heat, resulting in its temperature rising rapidly above its corresponding temperature threshold. This can burn out the voice coil, ultimately damaging the loudspeaker. Summary of the Invention

[0003] To address the problem of controlling the output power of a loudspeaker, embodiments of this application provide a method, apparatus, and chip for controlling the output power of a loudspeaker, including:

[0004] In a first aspect, embodiments of this application provide a method for controlling the output power of a loudspeaker. The controller acquires a first temperature of the voice coil in the loudspeaker at a first moment; determines a first difference between the first temperature and a temperature threshold; superimposes the temperature threshold and a second difference obtained by gain processing the first difference based on a first gain to obtain a second temperature of the voice coil at a second moment, the second moment being the next moment after the first moment; determines a third temperature; wherein the third temperature includes a fourth temperature obtained by gain processing the first decrease in the voice coil temperature from the first moment to the second moment based on a second gain when there is no power input, and / or a fifth temperature obtained by gain processing the second decrease in the magnet temperature from the first moment to the second moment based on a third gain when there is no functional input; determines a sixth temperature based on the difference between the second and third temperatures; and determines the output power based on the sixth temperature.

[0005] In this embodiment, by feeding back the speaker temperature to the controller and performing gain processing at each temperature to obtain the output power threshold, the speaker temperature can be prevented from exceeding the temperature threshold, which could lead to the voice coil burning out.

[0006] In some implementations of the first aspect, gain processing is performed on the first difference based on the first gain, including: multiplying the first difference by the first gain, wherein the first gain is:

[0007]

[0008] Where K1 represents the first gain, t s τ represents the sampling time. cm α represents the temperature rise time constant of the voice coil.T This indicates user-configurable parameters.

[0009] In some implementations of the first aspect, the third temperature includes a fourth temperature. Determining the third temperature includes: determining a first decrease based on the difference between the first temperature and the seventh temperature of the magnet at the first moment; and performing gain processing on the first decrease based on a second gain to obtain the fourth temperature.

[0010] In some implementations of the first aspect, the fourth temperature is obtained by performing gain processing on the first drop amount based on the second gain, including: multiplying the second gain by the first drop amount to obtain the fourth temperature, wherein the second gain is:

[0011]

[0012] Among them, K cm Indicates the second gain, t s τ represents the sampling time. cm This represents the temperature rise time constant of the voice coil.

[0013] In some implementations of the first aspect, the third temperature includes the fifth temperature. Determining the third temperature includes: determining the second decrease based on the difference between the seventh temperature of the magnet at the first moment and the ambient temperature; and performing gain processing on the second decrease based on the third gain to obtain the fifth temperature.

[0014] In some implementations of the first aspect, the fifth temperature is obtained by performing gain processing on the second decrease based on the third gain, including: multiplying the third gain by the second decrease to obtain the fifth temperature, wherein the third gain is:

[0015]

[0016] Among them, K ma Indicates the third gain, t s τ represents the sampling time. ma This represents the temperature rise time constant of the magnet.

[0017] In some implementations of the first aspect, the third temperature is determined by: taking the sum of the fourth and fifth temperatures as the third temperature.

[0018] In some implementations of the first aspect, the output power is determined based on the sixth temperature, including: performing gain processing on the sixth temperature based on the fourth gain to obtain the output power.

[0019] In some implementations of the first aspect, the output power is obtained by performing gain processing on the sixth temperature based on the fourth gain, including: multiplying the fourth gain by the sixth temperature to obtain the output power, wherein the fourth gain is:

[0020]

[0021] Where K2 represents the fourth gain, R cm K represents the thermal resistance between the magnet and the voice coil. cm R represents the voice coil temperature rise coefficient. ma K represents the thermal resistance between the magnet and the environment. ma This indicates the temperature rise coefficient of the magnet.

[0022] In some implementations of the first aspect, obtaining the first temperature of the voice coil in the loudspeaker at a first moment includes: acquiring audio data, determining the predicted temperature of the voice coil at the first moment based on the audio data, and determining the first temperature of the voice coil at the first moment based on the predicted temperature and the measured temperature of the voice coil at the first moment.

[0023] In some implementations of the first aspect, the first temperature of the voice coil at the first moment is determined based on the predicted temperature and the measured temperature of the voice coil at the first moment, including: performing Kalman filtering on the predicted temperature of the voice coil based on the measured temperature of the voice coil at the first moment to obtain the first temperature.

[0024] In some implementations of the first aspect, determining the predicted temperature of the voice coil at a first moment based on audio data includes: determining the input power based on multiple sampled audio data points in the audio data and the DC impedance of the speaker; and determining the predicted temperature of the voice coil at the first moment based on the input power.

[0025] In some implementations of the first aspect, the temperature threshold is preset in the speaker.

[0026] In a second aspect, this application provides an electronic device, comprising: a memory for storing instructions executed by one or more processors of the electronic device, and a processor, one of the one or more processors of the electronic device, for executing the method of controlling the output power of a speaker mentioned in the first aspect or any one of the first aspects of this application.

[0027] Thirdly, this application provides a chip including a processor and a data interface. The processor reads instructions stored in a memory through the data interface to execute a method for controlling the output power of a speaker as mentioned in the first aspect or any one of the first aspects of this application.

[0028] Fourthly, this application provides a readable storage medium storing instructions that, when executed on an electronic device, cause the electronic device to perform the method for controlling the output power of a speaker mentioned in the first aspect or any one of the first aspects of this application.

[0029] Fifthly, embodiments of this application provide a computer program product, which includes computer instructions that, when executed by an electronic device, enable the electronic device to execute computer program code of the method for controlling the output power of a speaker mentioned in the first aspect or any one of the first aspects of this application.

[0030] It is understood that the specific implementation methods and beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the method for controlling the output power of the loudspeaker in the first aspect or any of the various implementation methods provided by the first aspect, and will not be repeated here. Attached Figure Description

[0031] Figure 1 According to some embodiments of this application, a schematic diagram of a speaker temperature protection system is shown;

[0032] Figure 2 According to some embodiments of this application, a flowchart of a method for controlling the output power of a loudspeaker is shown;

[0033] Figure 3 According to some embodiments of this application, a schematic diagram of a method for controlling the output power of a loudspeaker is shown;

[0034] Figure 4 According to some embodiments of this application, a flowchart of a method for determining a fourth temperature is shown;

[0035] Figure 5 According to some embodiments of this application, a flowchart of a method for determining a fifth temperature is shown;

[0036] Figure 6 According to some embodiments of this application, a flowchart illustrating another method for controlling the output power of a loudspeaker is shown;

[0037] Figure 7 According to some embodiments of this application, a schematic diagram of another method for controlling the output power of a loudspeaker is shown;

[0038] Figure 8 A schematic diagram of an excitation signal is shown according to some embodiments of this application;

[0039] Figure 9 A schematic diagram of an excitation response is shown according to some embodiments of this application;

[0040] Figure 10 According to some embodiments of this application, a schematic diagram of the hardware structure of an electronic device is shown. Detailed Implementation

[0041] It is understood that the embodiments of this application include, but are not limited to, a method, apparatus, medium, and product for controlling the output power of a loudspeaker.

[0042] It is understood that the method for controlling the output power of a speaker mentioned in the embodiments of this application can be applied to electronic devices, such as smartphones, headphones, and speakers.

[0043] It is understandable that when the temperature of a speaker's voice coil exceeds a certain temperature threshold, the voice coil will burn out, thus damaging the speaker. To control the voice coil temperature below this threshold, some implementations utilize a speaker protection system to determine the speaker's output power. This output power is used to control the voice coil temperature below the threshold, and then, based on the determined output power, the speaker's operation is controlled.

[0044] The following section describes the speaker's temperature protection system. For example... Figure 1 The diagram shows a schematic of a speaker temperature protection system. The speaker temperature protection system may include a power detection module 110, a gain calculation module 120, and a gain smoothing module 130.

[0045] The power detection module 110 can perform root mean square (RMS) detection on the input power of the input speaker to determine the corresponding RMS value, which is the average power of the actual work done in the input power. Since RMS detection can convert the positive and negative fluctuations of the input power (voltage) into effective values, it accurately reflects the amount of energy actually consumed by the input power in the speaker, avoiding misjudgment of the energy level due to instantaneous changes in the peak value of the input power.

[0046] The gain calculation module 120 can determine the gain based on a preset power threshold and the root mean square value corresponding to the input power. In some implementations, the gain calculation module 120 can obtain the gain by taking the square root of the ratio of the power threshold to the root mean square value.

[0047] The gain smoothing module 130 can process the gain through a low-pass filter to obtain a smoothed gain, thus avoiding high-frequency noise caused by sudden gain changes.

[0048] After determining the smoothed gain, the smoothed gain is amplified to obtain the output signal. This output signal can be input to a loudspeaker to drive it to produce sound. Figure 1 In the example shown, the amplitude of the output signal can be limited based on a power threshold to control the speaker's output power, thereby controlling the speaker's temperature.

[0049] Understandable, based on Figure 1The key to the speaker's temperature protection system lies in setting the power threshold. The method for setting the power threshold is described below.

[0050] In some implementations, the power threshold can be configured to the rated power in the speaker manufacturer's specifications. Throughout the speaker's operation, the power threshold remains constant.

[0051] However, when the power threshold is constant, it can only guarantee that the speaker can continue to operate at the power threshold when playing pink noise (i.e., noise whose power spectral density is inversely proportional to the frequency), but it cannot guarantee that the speaker can continue to operate at the power threshold under any circumstances.

[0052] In other implementations, the controller can also determine the power threshold based on a mathematical relationship between the speaker's historical input power and the power threshold. Generally, the higher the speaker's historical input power, the lower the power threshold.

[0053] However, the power threshold depends on the accuracy of the mathematical relationship between the speaker's historical input power and the power threshold. If the accuracy of this mathematical relationship is low, the accuracy of the power threshold determined by the controller will also be low. Furthermore, obtaining the mathematical relationship between the speaker's historical input power and the power threshold requires significant effort.

[0054] In other implementations, the controller can determine the power threshold based on the voice coil temperature. For example, the controller can superimpose a low-frequency component, which is insensitive to the human ear, onto the input power and determine the speaker's DC impedance by measuring the voltage and current across the voice coil. Then, the controller can determine the voice coil temperature based on the linear relationship between the coil temperature and the DC impedance. Finally, the controller can output the power threshold based on the voice coil temperature.

[0055] However, in determining the power threshold based on the voice coil temperature, the differential element is a crucial component of the controller. Its function is to calculate the rate of temperature change (i.e., the speed at which temperature changes over time). However, the differential element is significantly affected by measurement noise, resulting in relatively low accuracy of the power threshold determined by the controller.

[0056] Therefore, the above-mentioned method of protecting the speaker's temperature based on the speaker's temperature protection system cannot accurately control the speaker's output power, which can easily burn out the voice coil and thus damage the speaker.

[0057] To address the aforementioned problems, this application provides a method for controlling the output power of a loudspeaker. In this method, based on input audio data, a first temperature of the voice coil in the loudspeaker at a first moment is determined; a first difference between the first temperature and a temperature threshold is determined; the temperature threshold and a second difference (after a first proportional amplification of the first difference) are superimposed to obtain a second temperature of the voice coil at a second moment, where the second moment is the next moment after the first moment; a third temperature is determined, wherein the third temperature includes a first decrease in the voice coil temperature from the first moment to the second moment when there is no power input, and / or a second decrease in the loudspeaker magnet temperature from the first moment to the second moment when there is no power input; a fourth temperature is determined based on the difference between the second and third temperatures; and the output power is determined based on the fourth temperature. Thus, accurate temperature control of the loudspeaker is achieved through proportional control, preventing the loudspeaker temperature from exceeding the temperature threshold and causing the voice coil to burn out.

[0058] The following is combined Figure 2 and Figure 3 The method for controlling the output power of a loudspeaker mentioned in the embodiments of this application will be described.

[0059] like Figure 2 The diagram illustrates a flowchart of a method for controlling the output power of a loudspeaker according to an embodiment of this application. Figure 3 The diagram illustrates a schematic representation of a method for controlling the output power of a loudspeaker according to an embodiment of this application. In some implementations, this method for controlling the output power of a loudspeaker may include:

[0060] S201: Obtain the first temperature T of the voice coil in the speaker at the first moment. c (t).

[0061] It's understandable that "first moment" can refer to the current moment. In some implementations, the first moment can be denoted as t.

[0062] It's understandable that the operating state of a loudspeaker can be completely implicit, meaning the temperature of the voice coil and the magnet cannot be measured. However, in the loudspeaker's temperature rise model, the transfer function represents the relationship between the loudspeaker's input power and the voice coil's temperature. Therefore, the controller in the loudspeaker can determine the voice coil's temperature at any given time based on the loudspeaker's temperature rise model and the input power; for example, the first temperature T of the voice coil at time t. c (t).

[0063] In some implementations, since audio data can be input to the speaker as a voltage signal, and root mean square (RMS) detection can accurately represent the actual energy consumed by the voltage signal on the speaker, the speaker can first acquire the audio data input to the speaker and perform RMS processing on the voltage signal corresponding to the audio data to obtain the input power (also known as the RMS value) corresponding to the audio data. Then, the speaker can use a temperature rise model to determine the first temperature of the voice coil at the first moment based on the input power corresponding to the audio data.

[0064] It is understandable that after determining the predicted temperature of the voice coil at the first time t using the temperature rise model, the controller in the loudspeaker can modify the loudspeaker's temperature rise model to improve accuracy, such as through linear modification, nonlinear modification, or Kalman filtering modification. Among these, Kalman filtering is relatively simple in principle and offers high accuracy. Therefore, in this embodiment, the controller in the loudspeaker can perform Kalman filtering modification on the temperature rise model.

[0065] It's understandable that the speaker's operation can be partially implicit, meaning that while the voice coil temperature can be detected by a built-in sensor, the speaker's magnet temperature cannot be measured. Therefore, in some implementations, the controller in the speaker can determine the predicted temperature of the voice coil at the first time t based on audio data, and determine the first temperature T of the voice coil at the first time t based on the predicted temperature and the measured temperature of the voice coil at the first time t. c (t). That is, the controller in the loudspeaker can use a built-in sensor to measure the actual temperature of the voice coil at the first time t, and based on the loudspeaker's temperature rise model and input power, determine the predicted temperature of the voice coil at the first time t. Then, the actual temperature of the voice coil at the first time t is used to correct the predicted temperature of the voice coil at the first time t. For example, the predicted temperature of the voice coil at the first time t can be processed by Kalman filtering to obtain the first temperature T of the voice coil at the first time t. c (t).

[0066] In some methods of determining the first preset temperature of the voice coil at the first time t based on audio data, the controller in the speaker can determine the input power based on multiple sampled audio data points in the audio data and the DC impedance of the speaker, and determine the predicted temperature of the voice coil at the first time t based on the input power.

[0067] For example, the controller in the speaker can determine the input power using formula (0):

[0068]

[0069] Where P represents the input power, Re represents the DC impedance of the speaker (which has a linear relationship with the voice coil temperature), N is the number of sampled audio data points, and v i It can represent sampled audio data points.

[0070] Therefore, by using Kalman filtering to correct the measured temperature of the voice coil at the first time t predicted by the temperature rise model, the predicted first temperature T can be improved. c The accuracy of (t) can be improved, thereby increasing the accuracy of the subsequently determined output power P. th The accuracy.

[0071] In this embodiment of the application, the first temperature T of the voice coil at the first moment t is obtained. c (t), that is, by replacing the differential element in the method of temperature protection for the speaker with state feedback, the temperature protection system can have stronger noise immunity.

[0072] S202: Determine the first temperature T c (t) and temperature threshold T max The first difference.

[0073] In some implementations, the temperature threshold T max This can be preset in the speaker and can also be called the limiting temperature threshold of the voice coil. The first temperature T of the voice coil at the first moment t is determined. c (t) after, such as Figure 3 As shown, the controller in the speaker can control the first temperature T c (t) and temperature threshold T max The difference is defined as the first difference ΔT1. For example, the controller in the speaker can determine the first difference ΔT1 using formula (1):

[0074] ΔT1=T c (t)-T max (1)

[0075] Where ΔT1 can represent the first difference, T c (t) can represent the first temperature of the voice coil at the first moment, T max It can represent a temperature threshold.

[0076] S203: Set the temperature threshold T max The second difference ΔT2, obtained by performing gain processing on the first difference ΔT1 based on the first gain, is superimposed to obtain the second temperature T of the voice coil at the second time t+1. c (t+1), the second time point is the time point following the first time point.

[0077] It is understandable that after determining the first difference ΔT1, the process continues as follows: Figure 3 As shown, the controller in the loudspeaker can perform gain processing on the first difference ΔT1 based on the first gain to obtain the second difference ΔT2. In some implementations, the controller in the loudspeaker can multiply the first difference ΔT1 by the first gain K1 to perform gain processing on the first difference ΔT1 to obtain the second difference ΔT2. For example, the controller in the loudspeaker can determine the second difference ΔT2 using formula (2):

[0078] ΔT2=ΔT1×K1(2)

[0079] Where ΔT2 can represent the second difference, ΔT1 can represent the first difference, and K1 can represent the first gain. Furthermore, the first gain K1 can take the form shown in formula (3):

[0080]

[0081] Where K1 can represent the first gain, t s It can represent the sampling time, τ cm It can represent the temperature rise time constant of the voice coil, and τ cm =R cm ×C cm α T This can represent user-configurable parameters. In some implementations, the first gain can be obtained based on the time constant of the speaker's temperature rise model.

[0082] It is understandable that after determining the second difference ΔT2, the process continues as follows: Figure 3 As shown, the controller in the speaker can control the temperature threshold T. max The second temperature T is obtained by superimposing the second difference ΔT2. c (t+1). Wherein, the second temperature T c (t+1) can represent the temperature of the voice coil at the second time t+1. Here, the first time t and the second time t+1 are two consecutive times of temperature sampling.

[0083] For example, the controller in the speaker can determine the second temperature T using formula (4). c (t+1):

[0084] T c (t+1)=T max +ΔT2 (4)

[0085] Among them, T c (t+1) can represent the second temperature, T max ΔT2 can represent the temperature threshold, and ΔT2 can represent the second difference.

[0086] S204: Determine the third temperature ΔT7; wherein, the third temperature ΔT7 includes the first decrease T of the voice coil temperature from the first time t to the second time t+1 based on the second gain when there is no power input. cm The fourth temperature ΔT4 obtained after gain processing, and the second temperature drop T of the speaker magnet from the first time t to the second time t+1 based on the third gain when there is no power input. ma The fifth temperature ΔT6 is obtained by performing gain processing.

[0087] In some embodiments, the third temperature ΔT7 may include a fourth temperature T4. In other embodiments, the third temperature ΔT7 may include a fifth temperature ΔT6. In still other embodiments, the third temperature ΔT7 may be equal to the sum of the fourth temperature ΔT4 and the fifth temperature ΔT6.

[0088] For the sake of narrative coherence, the methods for determining the fourth temperature ΔT4 and the fifth temperature ΔT6 will be described below.

[0089] S205: Based on the second temperature T c The difference between (t+1) and the third temperature ΔT7 determines the sixth temperature ΔT8.

[0090] Continue as Figure 3 As shown, the sixth temperature ΔT8 can be the second temperature T. c The difference between (t+1) and the third temperature ΔT7. For example, the loudspeaker can determine the sixth temperature ΔT8 using formula (5):

[0091] ΔT8=T c (t+1)-ΔT7 (5)

[0092] Where ΔT8 can represent the sixth temperature, T c (t+1) can represent the second temperature, and ΔT7 can represent the third temperature.

[0093] S206: Determine the output power P based on the sixth temperature ΔT8. th .

[0094] In some implementations, the fourth gain in the speaker's temperature rise model can represent the amplification factor of the transfer function by temperature at a specific frequency or operating condition. Therefore, the speaker can perform gain processing on the sixth temperature ΔT8 based on the fourth gain to obtain the output power P. th In some implementations, the controller in the speaker can perform gain processing on the fourth temperature ΔT8 based on the fourth gain to obtain the output power P. th For example, the controller in the speaker can determine the output power P using formula (6). th :

[0095] P th =K2*ΔT8

[0096] Among them, P th K2 can represent the output power, K2 can represent the fourth gain, and ΔT8 can represent the fourth temperature. Furthermore, the fourth gain can be expressed in the form shown in formula (7):

[0097]

[0098] Where K2 can represent the fourth gain, R cm K can represent the thermal resistance between the magnet and the voice coil. cm R can represent the voice coil temperature rise coefficient. ma The thermal resistance between the magnet and the environment can be represented by Kma, which represents the temperature rise coefficient of the magnet. The input signal of the proportional controller can be configured as the inverse of the error signal.

[0099] In this embodiment, the gain setting method in the method for controlling the output power of the loudspeaker ensures that the loudspeaker protection system has no steady-state error. Furthermore, by feeding back the loudspeaker's operating state (i.e., the first temperature, first drop, and second drop of the voice coil at the first moment) to the controller, and applying appropriate gain at each state value, accurate temperature control of the loudspeaker can be achieved through proportional control to prevent the loudspeaker temperature from exceeding the temperature threshold and causing the voice coil to burn out. The configuration method of the loudspeaker's state feedback loop, feedforward loop, and proportional control coefficient determines that the system's characteristic root is a real number, the system's damping ratio is greater than 1, and the system has no overshoot. Moreover, the controller only has proportional control; the user can control the system's settling time simply by adjusting the proportional control coefficient, making parameter tuning simpler compared to traditional PID control.

[0100] To make it easier to understand, the heat transfer process of the voice coil will be introduced first.

[0101] like Figure 4 As shown, an equivalent circuit diagram of the heat transfer process of a voice coil is illustrated. Wherein, C... cm R can represent the heat capacity between the magnet and the voice coil. cm C can represent the thermal resistance between the magnet and the voice coil. ma R can represent the heat capacity between the magnet and the environment. ma T can represent the thermal resistance between the magnet and the environment. c (t) can represent the first temperature of the voice coil at the first moment, T m (t) can represent the fourth temperature of the magnet at the first moment t, T a P(t) can represent the ambient temperature, and P(t) can represent the input power of the speaker at the first moment.

[0102] During heat transfer, the voice coil generates heat as current flows through the resistor. This heat is conducted to the magnet through the air or structural components (such as the frame, yoke, etc.). As a physical component, the magnet dissipates heat to the ambient temperature until its temperature is the same as the ambient temperature.

[0103] Furthermore, because the voice coil and magnet are relatively close together in the loudspeaker, the voice coil generates heat when current flows through the resistor during operation. This heat is conducted to the magnet through the air or structural components (such as the frame, yoke, etc.), thus lowering the voice coil temperature. Therefore, when there is no power input, the third temperature ΔT7 is mainly affected by the temperature drop of the voice coil from the first time t to the second time t+1 and / or the temperature drop of the magnet from the first time t to the second time t+1.

[0104] Therefore, in some implementations, the third temperature ΔT7 may include a fourth temperature ΔT4. The method for determining the fourth temperature ΔT4 is described below. For example... Figure 5 The diagram shows a flowchart illustrating a method for determining a fourth temperature ΔT4. Figure 5 As shown, the method for determining the fourth temperature ΔT4 may include:

[0105] S204a1: Determine the first temperature T c (t) and the seventh temperature T of the magnet at the first moment m The first decrease T of (t) cm .

[0106] It is understandable that the first decrease T cm The first temperature T of the voice coil at the first moment t is given. c (t) and the seventh temperature T of the magnet at the first moment t. m The difference (t) is the temperature difference between the voice coil temperature and the magnet temperature at the first moment t. For example, the loudspeaker can determine the first drop T using the following formula (8). cm :

[0107] ΔT3=T cm =T c (t)-T m (t) (8)

[0108] Among them, ΔT3 and T cm Both can represent the first decrease, T c (t) can represent the first temperature of the voice coil at the first moment, T m (t) can represent the seventh temperature of the magnet at the first moment t.

[0109] S204a2: Based on the second gain K cm For the first descent T cmGain processing is performed to obtain the fourth temperature ΔT4.

[0110] It is understandable that the fourth temperature ΔT4 can be considered as the second gain K. cm and the first drop T cm The product of. For example, the fourth temperature ΔT4 of the loudspeaker can be determined using the following formula (9):

[0111] ΔT4=K cm ×T cm (9)

[0112] Where ΔT4 can represent the fourth temperature, K cm This can represent the second gain, T. cm This can represent the first decrease. And, the second gain K... cm It can be expressed in the form shown in formula (10):

[0113]

[0114] Among them, K cm This can represent the second gain, t s It can represent the sampling time, τ cm It can represent the temperature rise time constant of the voice coil, and τ cm =R cm ×C cm .

[0115] In some implementations, the third temperature ΔT7 may include a fifth temperature ΔT6. The determination of the fifth temperature ΔT6 is described below. Figure 6 The diagram shows a flowchart illustrating a method for determining the fifth temperature ΔT6. Figure 6 As shown, the method for determining the fifth temperature ΔT6 may include:

[0116] S204b1: Determine the seventh temperature T of the magnet at the first moment t. m (t) and ambient temperature T a The second drop T ma .

[0117] It is understandable that the second decrease T ma The seventh temperature T of the magnet at the first moment t m (t) and ambient temperature T a The difference, that is, the temperature difference between the magnet's temperature and the ambient temperature at the first moment t. For example, the loudspeaker can determine the second drop T using the following formula (11). ma :

[0118] ΔT5=T ma =T m (t)-Ta (11)

[0119] Among them, ΔT5 and T ma Both can represent the second decrease, T m (t) can represent the seventh temperature of the magnet at the first moment t, T a It can represent ambient temperature.

[0120] S204b2: Based on the third gain K ma Second descent T ma Gain processing was performed to obtain the fifth temperature ΔT6.

[0121] It is understandable that the fifth temperature ΔT7 can be considered as the third gain K. ma Second descent T ma The product of. For example, the loudspeaker can determine the fifth temperature ΔT6 using the following formula (12):

[0122] ΔT6=K ma ×T ma (12)

[0123] Where ΔT6 can represent the fifth temperature, K ma It can represent the third gain, T ma This can represent the fourth difference. Furthermore, the third gain K... ma It can be expressed in the form shown in formula (13):

[0124]

[0125] Among them, K ma It can represent the third gain, t s It can represent the sampling time, τ ma The temperature rise time constant of the magnet can be represented by τ. ma =R ma ×C ma .

[0126] In other implementations, the third temperature ΔT7 can be the sum of the fourth temperature ΔT4 and the fifth temperature ΔT6. For example, the loudspeaker can determine the third temperature ΔT7 using formula (14):

[0127] ΔT7=ΔT4+ΔT6(14)

[0128] Among them, ΔT7 can represent the third temperature, ΔT4 can represent the fourth temperature, and ΔT6 can represent the fifth temperature.

[0129] It is understandable that the sixth temperature ΔT8 is equal to the second temperature T. c The difference between (t+1) and the third temperature ΔT7, therefore, as Figure 7 As shown, when the third temperature ΔT7 can be equal to the sum of the fourth temperature ΔT4 and the fifth temperature ΔT6, the sixth temperature ΔT8 can be equal to the second temperature T. c (t+1), the difference between the fourth temperature ΔT4 and the fifth temperature ΔT6.

[0130] Furthermore, since the transfer function in the loudspeaker temperature rise model can represent the relationship between the loudspeaker's input power and the voice coil temperature, therefore, continuing as follows... Figure 7 As shown, after determining the output power, the decrease in voice coil temperature T from the first moment to the third moment can be determined based on the transfer function and the output power. cm And the temperature drop T of the magnet from the first moment to the third moment. ma The data is then fed back to the controller in the speaker. The third time point can be denoted as t+2. The first time point t, the second time point t+1, and the third time point t+2 can be two consecutive time points for temperature sampling, with the third time point t+2 being the next time point after the second time point t+1.

[0131] In some implementations, the transfer function can take the form shown in formula (15):

[0132]

[0133] Where T(s) represents the Laplace transform of temperature, and P(s) represents the Laplace transform of power.

[0134] R ma C can represent the thermal resistance between the magnet and the environment. ma R can represent the heat capacity between the magnet and the environment. cm C can represent the thermal resistance between the magnet and the voice coil. ma It can represent the heat capacity between the magnet and the environment.

[0135] The following is combined Figure 8 and Figure 9 The effects of the method for controlling the output power of a loudspeaker mentioned in the embodiments of this application will be explained.

[0136] like Figure 8 The diagram illustrates an input audio data sample, which can be in the form of an impulse signal. The horizontal axis represents the real axis, and the unit is seconds. -1 The vertical axis can represent the imaginary axis, and the unit can be seconds. -1 Under the influence of this audio data, the speaker's output power can be... Figure 9The excitation response is shown in the form shown, where the horizontal axis represents time, in seconds. -1 The vertical axis represents amplitude, and the unit is amplitude. Figure 8 As can be seen, the amplitude gradually increases to the temperature threshold (i.e., 1). In this way, the voice coil temperature can be slowly increased to the temperature threshold, preventing the voice coil from burning out.

[0137] It is understood that the method for controlling the output power of a speaker provided in this application embodiment can be applied to electronic devices. The hardware structure of the electronic device to which the speaker output power control method provided in this application embodiment is applicable will be described exemplarily below.

[0138] like Figure 10 As shown, the electronic device 1000 may include a processor 1010, an external memory interface 1020, an internal memory 1021, a universal serial bus (USB) interface 1030, a charging management module 1040, a power management module 1041, a battery 1042, an antenna, a wireless communication module 1050, an audio module 1060, a speaker 1060A, a receiver 1060B, a microphone 1060C, a headphone jack 1060D, a camera 1070, a display screen 1080, etc.

[0139] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on the electronic device 1000. In other embodiments of this application, the electronic device 1000 may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0140] The processor 1010 may include one or more processing units, such as an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). These different processing units may be independent devices or integrated into one or more processors.

[0141] The controller can generate operation control signals based on the instruction opcode and timing signals to control instruction fetching and execution. The processor 1010 can control instruction fetching and execution through the controller to implement the method for controlling the output power of a speaker provided in this embodiment. For example, the processor 1010 can control instruction fetching and execution through the controller to implement the above-described method. Figure 2 , Figure 5 and Figure 6 The steps to be implemented in the process shown are as follows.

[0142] The processor 1010 may also include a memory for storing instructions and data. In some embodiments, the memory in the processor 1010 is a cache memory. This memory can store instructions or data that the processor 1010 has just used or that are used repeatedly. If the processor 1010 needs to use the instruction or data again, it can retrieve it directly from the memory. This avoids repeated accesses, reduces the waiting time of the processor 1010, and thus improves the efficiency of the system.

[0143] Wireless communication functionality in electronic devices can be achieved through antennas, wireless communication modules 1050, modem processors, and baseband processors.

[0144] Antennas are used to transmit and receive electromagnetic wave signals. Each antenna in an electronic device can be used to cover one or more communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, antennas can be reused as diversity antennas for a wireless local area network. In some other embodiments, antennas can be used in conjunction with tuning switches.

[0145] The wireless communication module 1050 can provide solutions for wireless communication applications in electronic devices, including wireless local area networks (WLANs) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), and infrared (IR) technologies. The wireless communication module 1050 can be one or more devices integrating at least one communication processing module. The wireless communication module 1050 receives electromagnetic waves via an antenna, performs frequency modulation and filtering of the electromagnetic wave signals, and sends the processed signal to the processor 1010. The wireless communication module 1050 can also receive signals to be transmitted from the processor 1010, perform frequency modulation and amplification, and convert them into electromagnetic waves for radiation via the antenna.

[0146] Electronic devices implement display functions through GPUs, display screens 1080, and application processors. A GPU is a microprocessor for image processing, connecting the display screen 1080 and the application processor. The GPU performs mathematical and geometric calculations and is used for graphics rendering. Processor 1010 may include one or more GPUs, which execute program instructions to generate or modify display information.

[0147] The display screen 1080 is used to display images, videos, etc. The display screen 1080 includes a display panel. The display panel can be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), a Mini-LED, a MicroLED, a Micro-OLED, a quantum dot light-emitting diode (QLED), etc. In some embodiments, the electronic device may include one or N displays 1080, where N is a positive integer greater than 1.

[0148] Electronic device 1000 can implement audio functions, such as music playback and recording, through audio module 1060, speaker 1060A, receiver 1060B, microphone 1060C, headphone jack 1060D, and application processor.

[0149] The audio module 1060 is used to convert digital audio information into analog audio signals for output, and also to convert analog audio input into digital audio signals. The audio module 1060 can also be used for encoding and decoding audio signals. In some embodiments, the audio module 1060 may be located in the processor 10100, or some functional modules of the audio module 1060 may be located in the processor 10100.

[0150] The speaker 1070A, also known as a "loudspeaker," is used to convert audio electrical signals into sound signals. Electronic device 1000 can listen to music or make hands-free calls through the speaker 1070A.

[0151] The loudspeaker 1070A may include a voice coil and a magnet. During heat transfer, the voice coil generates heat as current flows through the resistor. This heat is conducted to the magnet through the air or structural components (such as the frame, yoke, etc.). As a physical component, the magnet dissipates heat to the ambient temperature until its temperature is the same as the ambient temperature.

[0152] The receiver 1070B, also known as the "earpiece," is used to convert audio electrical signals into sound signals. When the electronic device 1000 answers a phone call or voice message, the receiver 1070B can be brought close to the ear to listen to the voice.

[0153] Microphone 1070C, also known as a "microphone" or "voice transducer," is used to convert sound signals into electrical signals. When making a phone call or sending a voice message, the user can speak by bringing their mouth close to microphone 1070C, inputting the sound signal into microphone 1070C. Electronic device 1000 may have at least one microphone 1070C. In some embodiments, electronic device 1000 may have two microphones 1070C, which, in addition to collecting sound signals, can also perform noise reduction. In other embodiments, electronic device 1000 may have three, four, or more microphones 1070C, which can collect sound signals, reduce noise, identify the sound source, and perform directional recording, etc.

[0154] The 1070D headphone jack is used to connect wired headphones. The 1070D headphone jack can be a USB 1030 interface or a 3.5mm Open Mobile Terminal Platform (OMTP) standard interface, a CTIA (Cellular Telecommunications Industry Association of the USA) standard interface.

[0155] In some cases, the embodiments disclosed in this application may be implemented in hardware, firmware, software, or any combination thereof.

[0156] The embodiments disclosed in this application can also be implemented as instructions carried or stored thereon on one or more temporary or non-temporary machine-readable (e.g., computer-readable) storage media, which can be read and executed by one or more processors. For example, the instructions can be distributed via a network or via other computer-readable media. Therefore, machine-readable media can include any mechanism for storing or transmitting information in a machine-readable (e.g., computer-readable) form, including but not limited to floppy disks, optical disks, magnetic disks, magneto-optical disks, read-only memory (ROM), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic cards or optical cards, flash memory, or tangible machine-readable storage for transmitting information (e.g., carrier waves, infrared signals, digital signals, etc.) using the Internet in the form of electrical, optical, acoustic, or other propagation signals. Therefore, machine-readable media includes any type of machine-readable medium suitable for storing or transmitting electronic instructions or information in a machine-readable (e.g., computer-readable) form.

[0157] Embodiments of this application can be implemented as computer programs or program code that execute on a programmable system, the programmable system including at least one processor, a storage system (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device.

[0158] Program code can be applied to input instructions to execute the functions described in this application and generate output information. The output information can be applied to one or more output devices in a known manner. For the purposes of this application, the processing system includes any system having a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application-specific integrated circuit (ASIC), or a microprocessor.

[0159] The program code can be implemented using a high-level procedural language or an object-oriented programming language to communicate with the processing system. Assembly language or machine language can also be used when needed. In fact, the mechanisms described in this application are not limited to any particular programming language. In either case, the language can be a compiled language or an interpreted language.

[0160] The above describes the possible hardware structures of electronic devices. It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the electronic device. In other embodiments of this application, the electronic device may include more or fewer components than illustrated, or combine certain components, or split certain components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of both.

[0161] In the accompanying drawings, some structural or methodological 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 necessary. Rather, in some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. Furthermore, the inclusion of structural or methodological features in a particular figure does not imply that such features are required in all embodiments, and in some embodiments, these features may be omitted or may be combined with other features.

[0162] It should be noted that in the examples and description of this patent, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0163] Although this application has been illustrated and described with reference to certain embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made thereto without departing from the scope of this application.

Claims

1. A method for controlling the output power of a loudspeaker, characterized in that, include: Obtain the first temperature of the voice coil in the loudspeaker at the first moment; Determine the first difference between the first temperature and the temperature threshold; The temperature threshold and the second difference after gain processing of the first difference based on the first gain are superimposed to obtain the second temperature of the voice coil at the second time, which is the next time after the first time. A third temperature is determined; wherein the third temperature includes a fourth temperature obtained by amplifying the temperature of the voice coil from the first moment to the second moment based on a second gain when there is no power input, and / or a fifth temperature obtained by amplifying the temperature of the magnet of the loudspeaker from the first moment to the second moment based on a third gain when there is no functional input. The sixth temperature is determined based on the difference between the second temperature and the third temperature; The output power is determined based on the sixth temperature.

2. The method according to claim 1, characterized in that, The gain processing of the first difference based on the first gain includes: Multiply the first difference by the first gain, where the first gain is: Where K1 represents the first gain, t s τ represents the sampling time. cm α represents the temperature rise time constant of the voice coil. T This indicates user-configurable parameters.

3. The method according to claim 1, characterized in that, The third temperature includes the fourth temperature. The determination of the third temperature includes: The first descent amount is determined based on the difference between the first temperature and the seventh temperature of the magnet at the first moment; The first decrease is amplified based on the second gain to obtain the fourth temperature.

4. The method according to claim 3, characterized in that, The step of performing gain processing on the first decrease amount based on the second gain to obtain the fourth temperature includes: Multiplying the second gain by the first decrease amount yields the fourth temperature, wherein the second gain is: Among them, K cm Indicates the second gain, t s τ represents the sampling time. cm This represents the temperature rise time constant of the voice coil.

5. The method according to claim 1, characterized in that, The third temperature includes the fifth temperature. The determination of the third temperature includes: The second descent amount is determined based on the difference between the seventh temperature of the magnet at the first moment and the ambient temperature. The second decrease is amplified based on the third gain to obtain the fifth temperature.

6. The method according to claim 5, characterized in that, The step of performing gain processing on the second decrease amount based on the third gain to obtain the fifth temperature includes: Multiplying the third gain by the second decrease amount yields the fifth temperature, wherein the third gain is: Among them, K ma The third gain is represented by t. s τ represents the sampling time. ma This represents the temperature rise time constant of the magnet.

7. The method according to claim 3, characterized in that, The determination of the third temperature includes: The sum of the fourth temperature and the fifth temperature is taken as the third temperature.

8. The method according to claim 1, characterized in that, The step of determining the output power based on the sixth temperature includes: The sixth temperature is then processed based on the fourth gain to obtain the output power.

9. The method according to claim 8, characterized in that, The step of performing gain processing on the sixth temperature based on the fourth gain to obtain the output power includes: Multiplying the fourth gain by the sixth temperature yields the output power, wherein the fourth gain is: Where K2 represents the fourth gain, R cm K represents the thermal resistance between the magnet and the voice coil. cm R represents the voice coil temperature rise coefficient. ma K represents the thermal resistance between the magnet and the environment. ma This indicates the temperature rise coefficient of the magnet.

10. The method according to any one of claims 1 to 9, characterized in that, The step of obtaining the first temperature of the voice coil in the loudspeaker at a first moment includes: Acquire audio data, and determine the predicted temperature of the voice coil at the first moment based on the audio data; Based on the predicted temperature and the measured temperature of the voice coil at the first moment, the first temperature of the voice coil at the first moment is determined.

11. The method according to claim 10, characterized in that, Determining the first temperature of the voice coil at the first moment based on the predicted temperature and the measured temperature of the voice coil at the first moment includes: The predicted temperature of the voice coil is obtained by performing Kalman filtering on the measured temperature of the voice coil at the first moment.

12. The method according to claim 10, characterized in that, Determining the predicted temperature of the voice coil at the first moment based on the audio data includes: The input power is determined based on multiple sampled audio data points in the audio data and the DC impedance of the speaker; The predicted temperature of the voice coil at the first moment is determined based on the input power.

13. The method according to claim 1, characterized in that, The temperature threshold is preset in the speaker.

14. An electronic device, characterized in that, include: A memory for storing instructions executed by one or more processors of the electronic device, and a processor, one of one or more processors of the electronic device, for performing the method of controlling the output power of a speaker as claimed in any one of claims 1 to 13.

15. A chip, characterized in that, The chip includes a processor and a data interface, wherein the processor reads instructions stored in a memory through the data interface to execute a method for controlling the output power of a speaker as described in any one of claims 1 to 13.

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