Loudspeaker voice coil temperature control method and device, electronic equipment and storage medium

Abstract

The application relates to the field of electronic technology, in particular to a loudspeaker voice coil temperature control method and device, electronic equipment and a storage medium. The voice coil temperature control method comprises the following steps: acquiring a first audio power of a loudspeaker, and a predicted temperature corresponding to the first audio power; acquiring a real-time measured temperature of the loudspeaker at a current moment; fusing the predicted temperature and the real-time measured temperature, inputting a fused temperature value into a temperature feedback processing model, and obtaining an output reference temperature; acquiring a preset maximum set temperature and a power prediction model, inputting the reference temperature and the maximum set temperature value into the power prediction model, obtaining an output target power, and obtaining a control gain value according to the first audio power and the target power; and adjusting a power value of a second audio signal of the loudspeaker at a next moment by using the control gain value, so that the temperature of the loudspeaker voice coil is stabilized below the maximum set temperature, and the sound quality of the loudspeaker voice coil is prevented from being affected by excessively high temperature.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to a method, apparatus, electronic device, and storage medium for controlling the voice coil temperature of a loudspeaker. Background Technology

[0002] A loudspeaker is a transducer that converts electrical signals into sound signals, and it is widely used in electronic devices that need to play audio, such as mobile phones, computers, and tablets. During operation, the temperature of the loudspeaker's voice coil changes depending on the operating time and conditions. If the voice coil operates in a high-temperature environment for extended periods, it will affect the sound quality of the loudspeaker, and frequent operation in such environments can even damage the voice coil. Therefore, temperature regulation and control of the loudspeaker's voice coil is particularly important.

[0003] In related technologies, when controlling the speaker voice coil temperature, the measured temperature of the speaker voice coil is collected, and then a feedback control system is used based on the collected measured temperature to control the maximum output power of the audio signal. This feedback control system uses a fixed feedback control coefficient and adjusts the maximum output power of the audio signal according to the measured voice coil temperature. However, in actual working scenarios, the relationship between the speaker voice coil temperature and the maximum output power is greatly affected by different environmental factors. If the feedback control system uses a fixed feedback control coefficient, the control accuracy of the speaker voice coil temperature will fluctuate greatly in different working environments. Therefore, the speaker voice coil temperature control method provided by related technologies still has certain technical defects. Summary of the Invention

[0004] This application provides a speaker voice coil temperature control method, apparatus, electronic device, and storage medium to solve the technical problem of low control accuracy in the speaker voice coil temperature control methods provided in the related art.

[0005] In a first aspect, this application provides a method for controlling the temperature of a loudspeaker voice coil, the temperature control method comprising:

[0006] The first audio signal input to the speaker at the current moment is obtained, the first audio power corresponding to the first audio signal is determined, and the predicted temperature corresponding to the first audio power is obtained according to the relationship between audio power and temperature.

[0007] Obtain the voltage and current values ​​of the speaker at the current moment of operation, and determine the measured temperature of the speaker at the current moment based on the voltage and current values;

[0008] The predicted temperature and the measured temperature are fused to obtain a fused temperature value, which is then input into a temperature feedback processing model to obtain an output reference temperature. The temperature feedback processing model is used to characterize the correspondence between the fused temperature value and the reference temperature.

[0009] Obtain a preset maximum set temperature and power prediction model, input the reference temperature and the maximum set temperature value into the power prediction model to obtain the output target power, and obtain the control gain value at the next moment based on the first audio power and the target power;

[0010] The power value of the second audio signal input to the speaker at the next moment is adjusted using the control gain value at the next moment.

[0011] In one possible design, obtaining the predicted temperature corresponding to the first audio power based on the relationship between audio power and temperature includes:

[0012] Obtain the control gain value from the previous moment;

[0013] The first audio power at the current moment and the control gain value at the current moment are convolved to obtain the processed intermediate power value;

[0014] The intermediate power value is input into the trained voice coil temperature prediction model to obtain the predicted temperature corresponding to the first audio power.

[0015] The voice coil temperature prediction model is a second-order loudspeaker heat transfer model established based on target thermal parameters. The target thermal parameters include a first target thermal parameter between the loudspeaker's voice coil and the loudspeaker's magnetic circuit, a second target thermal parameter between the loudspeaker's magnetic circuit and the air, and a third target thermal parameter for the convection between the loudspeaker's voice coil and the air. The voice coil temperature prediction model is used to characterize the mapping relationship between the audio power input to the loudspeaker's voice coil and the temperature of the loudspeaker's voice coil.

[0016] In one possible design, the voice coil temperature control method further includes:

[0017] Before adjusting the power value of the second audio signal input to the speaker at the next moment using the control gain value at the next moment, and / or before convolving the first audio power at the current moment with the control gain value at the current moment, the control gain value is smoothed using a preset gain smoothing function.

[0018] In one possible design, the temperature feedback processing model is represented by the following formula:

[0019]

[0020]

[0021] in, Represents the S field, This represents the corresponding feedback coefficient. T Indicates the sampling period. It represents the discrete domain.

[0022] In one possible design, the power prediction model is expressed by the following formula: ;

[0023] in, ; and All represent coefficients of the power prediction model. It represents the discrete domain.

[0024] In one possible design, the voice coil temperature prediction model is expressed by the following formula:

[0025] ;

[0026] Where t represents a discrete time point, Te_pred[ ] represents the predicted temperature output by the voice coil temperature prediction model, and P_in[ ] represents the discrete value of the input power. as well as The coefficients of the voice coil temperature prediction model are obtained by converting the discrete domain transfer function H(z) corresponding to Te_pred[t] and the continuous domain transfer function H... model (s) is transformed and determined;

[0027] The discrete-domain transfer function H(z) corresponding to Te_pred[t] is: ;

[0028] The continuous domain transfer function H model (s) is:

[0029] Wherein, Rca represents the third target RTD value of the voice coil resistor, Rcm represents the first target RTD value of the voice coil resistor, Rma represents the second target RTD value of the magnetic circuit resistor, Cma represents the second target RVC value of the magnetic circuit capacitor, and Ccm represents the first target RVC value of the voice coil capacitor. , , and They represent the equivalent time constants after simplification, and These are the simplified coefficients.

[0030] In one possible design, the voice coil temperature control method further includes:

[0031] The closed-loop transfer function obtained from the gain smoothing function, the temperature feedback processing model, the power prediction model, and the voice coil temperature prediction model is expressed by the following formula:

[0032]

[0033] in,

[0034] in, Represents the closed-loop transfer function. Represents the open-loop transfer function. This represents the gain smoothing function. This represents the transfer function corresponding to the power prediction model. This represents the transfer function corresponding to the voice coil temperature prediction model. This represents the transfer function corresponding to the temperature feedback processing model. , f1 and f1 are both coefficients of the closed-loop transfer function; and They represent the equivalent time constants after simplification, Indicates the smoothing time constant. Represents the S field, and These are the simplified coefficients.

[0035] In one possible design, the dominant pole of the closed-loop transfer function is ;

[0036] in, For the natural frequency, For the damped natural frequency, , The damping ratio;

[0037] The voice coil temperature control method further includes:

[0038] Based on the closed-loop transfer function and the set dominant pole, the coefficients are determined using the phase angle condition equation according to the set set settling time Tss. and The ratio;

[0039] Based on the determined coefficients and The ratio is updated to the damping ratio. And the phase angle condition equation, to determine the value of coefficient f1;

[0040] Construct the amplitude condition equation, and based on the amplitude condition equation and the coefficients... and The ratio of the coefficients is used to determine the coefficients. and The value of .

[0041] Secondly, this application also provides a loudspeaker voice coil temperature control device, the voice coil temperature control device comprising:

[0042] The temperature prediction unit is used to acquire the first audio signal input to the speaker at the current moment, determine the first audio power corresponding to the first audio signal, and acquire the predicted temperature corresponding to the first audio power based on the relationship between audio power and temperature.

[0043] The temperature measurement unit is used to acquire the voltage and current values ​​of the speaker at the current moment of operation, and to determine the measured temperature of the speaker at the current moment based on the voltage and current values.

[0044] A temperature processing unit is used to fuse the predicted temperature and the measured temperature to obtain a fused temperature value, and input the fused temperature value into a temperature feedback processing model to obtain an output reference temperature; the temperature feedback processing model is used to characterize the correspondence between the fused temperature value and the reference temperature;

[0045] The gain processing unit is used to obtain a preset maximum set temperature and power prediction model, input the reference temperature and the maximum set temperature value into the power prediction model to obtain the output target power, and obtain the control gain value at the next moment based on the first audio power and the target power.

[0046] A power control unit is used to adjust the power value of the second audio signal input to the speaker at the next moment using the control gain value at the next moment.

[0047] Thirdly, this application also provides an electronic device, including a memory, a processor, and an audio module, wherein the processor is electrically connected to the memory and the audio module respectively, the audio module includes a speaker, the memory stores a computer program that can run on the processor, and the processor executes the computer program to implement the steps of the speaker voice coil temperature control method as described in any of the above claims.

[0048] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the loudspeaker voice coil temperature control method as described in any of the preceding claims.

[0049] The speaker voice coil temperature control method provided in the first aspect above firstly acquires the first audio signal input to the speaker at the current moment, determines the first audio power corresponding to the first audio signal, and obtains the predicted temperature corresponding to the first audio power based on the correspondence between audio power and temperature. Then, it acquires the voltage and current values ​​of the speaker at the current moment, and determines the measured temperature of the speaker at the current moment based on the voltage and current values. Further, it fuses the predicted temperature and the measured temperature to obtain a fused temperature value, and inputs the fused temperature value into a temperature feedback processing model to obtain the output reference temperature. The temperature feedback processing model is used to characterize the correspondence between the fused temperature value and the reference temperature. It acquires a preset maximum set temperature and a power prediction model, inputs the reference temperature and the maximum set temperature value into the power prediction model to obtain the output target power, and obtains the control gain value for the next moment based on the first audio power and the target power. Finally, it uses the control gain value for the next moment to adjust the power value of the second audio signal input to the speaker at the next moment. As can be seen, the speaker voice coil temperature control method provided in this application obtains a fusion temperature value by fusing the measured temperature of the actual sampled voice coil with the predicted temperature corresponding to the first audio power. Then, based on the temperature feedback processing model and the power prediction model, the corresponding control gain value for the next moment is obtained. Finally, the power value of the second audio signal input to the speaker at the next moment is adjusted using the control gain value, so that the temperature of the speaker voice coil is stabilized below the maximum set temperature, thus avoiding the speaker voice coil from affecting the sound quality due to excessive temperature.

[0050] The beneficial effects provided by the other aspects and the various possible designs of the other aspects can be found in the beneficial effects of the first aspect and the various possible implementations of the first aspect, and will not be repeated here. Attached Figure Description

[0051] Figure 1 This is a schematic flowchart of a loudspeaker voice coil temperature control method provided in an embodiment of this application;

[0052] Figure 2 A schematic diagram of feedback control for a loudspeaker voice coil temperature control method provided in an embodiment of this application;

[0053] Figure 3 A flowchart of the closed-loop transfer function system solution method provided in this application embodiment;

[0054] Figure 4 This is one of the simulation diagrams of the unit step response and zero-pole point of the control method according to an embodiment of this application;

[0055] Figure 5 This is the second simulation diagram of the unit step response and zero-pole point of the control method according to an embodiment of this application.

[0056] Figure 6 This is the third simulation diagram of the unit step response and zero-pole simulation of the control method according to an embodiment of this application;

[0057] Figure 7 This is the fourth simulation diagram of the unit step response and zero-pole simulation of the control method according to an embodiment of this application.

[0058] Figure 8 This is a schematic diagram of the temperature curve of the speaker when it is playing a single frequency point according to an embodiment of this application;

[0059] Figure 9 This is a schematic diagram of the temperature curve of the speaker when playing a song, according to an embodiment of this application.

[0060] Figure 10 A schematic diagram of temperature curves of a loudspeaker operating under three different ambient temperatures, provided for an embodiment of this application;

[0061] Figure 11 A partially enlarged view of the temperature curves of the loudspeaker provided in this application embodiment when it operates under three different ambient temperatures;

[0062] Figure 12 A schematic diagram of the equivalent circuit of the voice coil temperature prediction model provided in the embodiments of this application;

[0063] Figure 13 This is a schematic diagram of the speaker voice coil temperature control device provided in an embodiment of this application. Detailed Implementation

[0064] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c alone can mean: a alone, b alone, c alone, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0065] The terms “center,” “longitudinal,” “lateral,” “up,” “down,” “left,” “right,” “front,” and “rear,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0066] The terms "connected" and "connected" should be interpreted broadly. For example, in circuit structures, "connected" or "connected" can refer not only to physical connections but also to electrical or signal connections. This could be a direct connection (physical connection) or an indirect connection via at least one intermediate component, as long as the circuit is connected. It could also refer to the internal connection between two components. Similarly, a signal connection can refer to a connection via a circuit or a medium, such as radio waves. Those skilled in the art will understand the specific meaning of these terms in this application based on the specific circumstances.

[0067] In related technologies, when controlling the speaker voice coil temperature, the measured temperature of the speaker voice coil is collected, and then a feedback control system is used based on the collected measured temperature to control the maximum output power of the audio signal. This feedback control system uses a fixed feedback control coefficient to adjust the maximum output power of the audio signal according to the measured voice coil temperature. However, in actual working scenarios, the relationship between the speaker voice coil temperature and the maximum output power is greatly affected by different environmental factors. If the feedback control system uses a fixed feedback control coefficient, it is necessary to adjust the feedback control coefficient according to the current environmental factors in different working environments so that the feedback control system can be applied to different working scenarios. This results in the existing feedback control system being applicable only to one suitable environment. When the working environment changes, the control accuracy of the speaker voice coil temperature fluctuates greatly, leading to a decrease in control accuracy. Therefore, the speaker voice coil temperature control method provided by related technologies still has certain technical defects.

[0068] To overcome the deficiencies in the aforementioned related technologies, this application provides a loudspeaker voice coil temperature control method. First, it acquires the first audio signal input to the loudspeaker at the current moment, determines the first audio power corresponding to the first audio signal, and obtains the predicted temperature corresponding to the first audio power based on the correspondence between audio power and temperature. Then, it acquires the voltage and current values ​​of the loudspeaker at the current moment, and determines the measured temperature of the loudspeaker at the current moment based on the voltage and current values. Further, it fuses the predicted temperature and the measured temperature to obtain a fused temperature value, and inputs the fused temperature value into a temperature feedback processing model to obtain an output reference temperature. The temperature feedback processing model is used to characterize the correspondence between the fused temperature value and the reference temperature. It acquires a preset maximum set temperature and a power prediction model, inputs the reference temperature and the maximum set temperature value into the power prediction model to obtain the output target power, and obtains the control gain value for the next moment based on the first audio power and the target power. Finally, it uses the control gain value for the next moment to adjust the power value of the second audio signal input to the loudspeaker at the next moment. As can be seen, the speaker voice coil temperature control method provided in this application obtains a fusion temperature value by fusing the measured temperature of the actual sampled voice coil with the predicted temperature corresponding to the first audio power. Then, based on the temperature feedback processing model and the power prediction model, the corresponding control gain value for the next moment is obtained. Finally, the power value of the second audio signal input to the speaker at the next moment is adjusted using the control gain value, so that the temperature of the speaker voice coil is stabilized below the maximum set temperature, thus avoiding the speaker voice coil from affecting the sound quality due to excessive temperature.

[0069] Figure 1 For a schematic flowchart of the loudspeaker voice coil temperature control method provided in this application embodiment, please refer to [link / reference]. Figure 1 As shown, the speaker voice coil temperature control method provided in this embodiment includes:

[0070] S101. Obtain the first audio signal input to the speaker at the current moment, determine the first audio power corresponding to the first audio signal, and obtain the predicted temperature corresponding to the first audio power based on the relationship between audio power and temperature.

[0071] Figure 2 For a feedback control schematic diagram of the loudspeaker voice coil temperature control method provided in the embodiments of this application, please refer to [link / reference]. Figure 2 As shown, in this embodiment, obtaining the predicted temperature corresponding to the first audio power based on the relationship between audio power and temperature specifically includes:

[0072] First, obtain the control gain value from the previous time step; then, convolve the first audio power and the control gain value at the current time step to obtain the intermediate power value; finally, input the intermediate power value into the trained voice coil temperature prediction model to obtain the predicted temperature corresponding to the first audio power.

[0073] In this embodiment, the voice coil temperature prediction model 204 is a second-order model of loudspeaker heat transfer based on target thermal parameters. The target thermal parameters include a first target thermal parameter between the loudspeaker's voice coil and the loudspeaker's magnetic circuit, a second target thermal parameter between the loudspeaker's magnetic circuit and the air, and a third target thermal parameter between the loudspeaker's voice coil and the air convection. The voice coil temperature prediction model 204 is used to characterize the mapping relationship between the audio power input to the loudspeaker's voice coil and the temperature of the loudspeaker's voice coil.

[0074] In one embodiment of this application, the transfer function corresponding to the voice coil temperature prediction model 204 can be expressed by the following formula:

[0075] ;

[0076] Where t represents a discrete time point, Te_pred[ ] represents the predicted temperature output by the voice coil temperature prediction model, and P_in[ ] represents the discrete value of the input power. and The coefficients of the voice coil temperature prediction model are determined by transforming the discrete domain transfer function H(z) and the continuous domain transfer function H(s) corresponding to Te_pred[t].

[0077] Wherein, the discrete-domain transfer function H(z) corresponding to Te_pred[t] is: ;

[0078] Among them, the continuous domain transfer function H model (s) is:

[0079] Wherein, Rca represents the third target RTD value of the voice coil resistor, Rcm represents the first target RTD value of the voice coil resistor, Rma represents the second target RTD value of the magnetic circuit resistor, Cma represents the second target RVC value of the magnetic circuit capacitor, and Ccm represents the first target RVC value of the voice coil capacitor. , , and They represent the equivalent time constants after simplification, and These are the simplified coefficients.

[0080] Figure 12This is a schematic diagram of the equivalent circuit structure of the voice coil temperature prediction model provided in the embodiments of this application. Figure 12 In the equivalent circuit shown, Tc represents the temperature of the voice coil, Ta represents the temperature of the air, Tm represents the temperature of the magnet, and P... coil P represents the power of the first power branch, which is the sum of the power of the voice coil and the magnetic circuit. con This represents the power of thermal convection. According to... Figure 12 The equivalent circuit shown can be used to determine the temperature of the speaker's voice coil by establishing a mapping relationship between the input power of the voice coil and the temperature of the voice coil.

[0081] Specifically, according to Figure 12 As shown, the continuous domain transfer function H corresponding to the first power branch coil (s) can be expressed as the following formula (1):

[0082] (1)

[0083] Where Tca(s) represents the transfer function of the temperature difference between the voice coil and the air in the continuous domain, P coil (s) represents P coil In the transfer function in the continuous domain, Rcm represents the first target thermal resistance value of the voice coil resistor, Rma represents the second target thermal resistance value of the magnetic circuit resistor, Cma represents the second target thermal capacitance value of the magnetic circuit capacitor, and Ccm represents the first target thermal capacitance value of the voice coil capacitor.

[0084] The continuous domain transfer function H corresponding to the second power branch con (s) can be expressed as the following formula (2):

[0085] (2)

[0086] Where Tca(s) represents the transfer function of the temperature difference between the voice coil and the air in the continuous domain, P con (s) represents P con In the transfer function over the continuous domain, Rca represents the third target thermal resistance value of the voice coil thermal resistor.

[0087] Since the first power branch and the second power branch are connected in parallel, Figure 2 The continuous domain transfer function H(s) of the equivalent circuit shown can be expressed as the following formula (3):

[0088] (3)

[0089] Substituting formulas (1) and (2) into formula (3) for simplification, we obtain the simplified H(s) expressed as formula (4) as follows:

[0090] (4)

[0091] in, , .

[0092] Furthermore, the continuous domain transfer function H(s) can be bilinearly transformed using the bilinear transformation formula shown in formula (5) to obtain the discrete domain transfer function H(z). Formula (5) is as follows:

[0093] (5)

[0094] Where T represents the sampling period, s represents the complex frequency variable in the continuous domain, and z represents the complex variable in the discrete domain.

[0095] The discrete-domain transfer function H(z) can be expressed as follows (6):

[0096] (6)

[0097] Among them, coefficient and The coefficients are determined by transforming the discrete-domain transfer function H(z) and the continuous-domain transfer function H(s) using a bilinear transform. Based on the above derivation, it can be understood that the coefficients... and This can be represented by thermal parameters Rcm, Rma, Cma, Ccm, and Rca. By adjusting these thermal parameters, the coefficients can be adjusted. and .

[0098] Furthermore, the voice coil temperature prediction model can be represented by the difference equation corresponding to the discrete domain transfer function H(z). Specifically, the voice coil temperature prediction model can be expressed as the following formula (7):

[0099] (7)

[0100] Where t represents a discrete time point, Te_pred[ ] represents the predicted temperature output by the voice coil temperature prediction model, and P_in[ ] represents the discrete value of the input power.

[0101] When using the voice coil temperature prediction model to detect the temperature of the loudspeaker's voice coil, the current input power P_in of the loudspeaker's voice coil can be discretized and used as the input of formula (7) to the voice coil temperature prediction model, so that the predicted temperature Te_pred output by the voice coil temperature prediction model can be obtained.

[0102] S102. Obtain the voltage and current values ​​of the speaker at the current moment of operation, and determine the measured temperature of the speaker at the current moment based on the voltage and current values.

[0103] Please continue reading Figure 2 As shown, for a speaker voice coil, the voltage and current values ​​of the speaker voice coil can be sampled by a voltage sampling circuit and a current sampling circuit, respectively. Then, the internal resistance of the voice coil can be calculated based on the sampled voltage and current values. Based on the calculated internal resistance of the voice coil, the measured temperature of the voice coil can be calculated according to the relationship between internal resistance and temperature.

[0104] For example, the input power of the voice coil can be calculated using U... 2 / R is calculated, where U is the voltage of the first input audio signal after passing through an amplifier, and R is the real-time sampling impedance Re Measured calculated through the voltage and current signal (IVsignal) fed back by the voice coil. The measured temperature value TeMeasured can be obtained by the relationship between temperature rise and impedance.

[0105] S103. The predicted temperature and the measured temperature are fused to obtain a fused temperature value. The fused temperature value is then input into the temperature feedback processing model to obtain the output reference temperature. The temperature feedback processing model is used to characterize the correspondence between the fused temperature value and the reference temperature.

[0106] In one embodiment of this application, the fusion of predicted temperature and measured temperature can be achieved by methods such as Kalman filtering and low-pass filtering. Specifically, both predicted temperature and measured temperature are input into temperature fusion module 201, which stores Kalman filtering algorithm or low-pass filtering algorithm to fuse predicted temperature and measured temperature.

[0107] For example, in this embodiment, a low-pass filter is used to fuse the predicted temperature and the measured temperature. Assuming that the temperature model deviates under different ambient temperatures, the fused temperature value Tefusion can be calculated using the following formula:

[0108] (8)

[0109] In the above formula (1), To determine the fusion temperature value, For actual measured temperature, To predict temperature, This is a low-pass filter function.

[0110] As can be seen from the above formula (1), the difference between the measured temperature and the predicted temperature is first processed by low-pass filtering, and then the predicted temperature value is added back. This ensures that even if the predicted temperature rise deviates (due to model deviation) or the ambient temperature deviates, the fused temperature value can quickly approach the real temperature, so that the fused temperature value is closer to the real temperature.

[0111] In one embodiment of this application, the transfer function corresponding to the temperature feedback processing model 202 is expressed by the following formula:

[0112] (9)

[0113] (10)

[0114] in, Represents the S field, This represents the corresponding feedback coefficient. T Indicates the sampling period. It represents the discrete domain.

[0115] It is understood that in this embodiment Figure 2 The medium temperature feedback processing model 202 is equipped with the transfer function shown in the above formula (9). The above transfer function is used to process the fusion temperature value Tefusion to obtain the reference temperature Tefb.

[0116] S104. Obtain the preset maximum set temperature and power prediction model, input the reference temperature and maximum set temperature values ​​into the power prediction model to obtain the output target power, and obtain the control gain value for the next moment based on the first audio power and the target power.

[0117] In one embodiment of this application, a power prediction model 203 is used to characterize the correspondence between temperature values ​​and the power of the audio signal input by the voice coil. The power prediction model 203 can be trained in advance using multiple sets of temperature values ​​and audio signal power values. When training the power prediction model 203, the maximum set temperature can be used as a limiting condition.

[0118] In one embodiment of this application, the transfer function corresponding to the power prediction model is expressed by the following formula:

[0119] (11)

[0120] in, ; and All represent coefficients of the power prediction model. It represents the discrete domain.

[0121] It is understandable that the function model in the power prediction model is the transfer function shown in formula (11), and the target power corresponding to the reference temperature is obtained based on the reference temperature and the maximum set temperature value using this transfer function.

[0122] In one embodiment, the above formula (11) for the continuous domain can be obtained through a bilinear transformation. The power prediction transfer function H1(s) above is transformed from the continuous domain into the discrete domain transfer function H(z) shown below, where T is the sampling period and Z represents the discrete domain.

[0123] (12)

[0124] Formula (4) above is a first-order expression, and formula (12) above is a second-order expression. In practical applications, the power prediction transfer function H1(s) can be selected as first-order or multi-order depending on the situation. In this embodiment, the first-order expression shown in formula (11) is determined to be the optimal choice after simulation test.

[0125] For the transfer function of the second-order discrete domain shown in the above formula (12), the input and output can be correlated by the difference equation to obtain the following expression:

[0126] (13)

[0127] Where x[n] is the input of the digital field and y[n] is the output of the digital field, in this embodiment, we still use H... model For example, in [z], the input is the smoothed sampling power, and the output is the predicted temperature of the speaker at that sampling power.

[0128] In this system, after the feedback system obtains the target power, the ratio of the target power to the first audio power input at the current moment is the target gain. After the target gain is smoothed by the gain smoothing module 205, one path applies to the input signal, and the other path applies to the input power. This power is then processed by the voice coil temperature prediction model H. model (z) The predicted temperature is obtained, and this predicted temperature and the real-time sampled measured temperature Te Measured are subjected to a temperature fusion process. For details, please refer to the method shown in formula (8) to obtain the input temperature of the temperature feedback processing model 202. After passing through the temperature feedback transfer function H fb (z) Obtain the reference temperature value Tefb. The difference between the reference temperature value Tefb and the preset maximum set temperature value Tmax is used as the input of the power prediction model 203 to obtain the target power.

[0129] When Te Measured (actual temperature) is large, the reference temperature value Tefb will also be relatively large. At this time, after the difference is made with the preset maximum set temperature value Tmax, the output target power will be very small after passing through the power prediction model 203. The small target power ensures that the negative gain (absolute value) of the main channel signal increases. This is equivalent to suppressing the signal of the main channel, preventing the speaker's voice coil temperature from rising and causing the speaker to burn out.

[0130] S105. Adjust the power value of the second audio signal input to the speaker at the next moment using the control gain value at the next moment.

[0131] In one embodiment of this application, the control gain value is smoothed before adjusting the power value of the second audio signal input to the speaker at the next moment using the control gain value at the next moment, and / or before convolving the first audio power at the current moment with the control gain value at the current moment.

[0132] Specifically, this embodiment employs a gain smoothing function. The control gain value is smoothed.

[0133] In this process, after obtaining the target power corresponding to the voice coil through the above steps, the ratio of the target power to the input first audio power is used as the control gain (i.e., target gain) of the previous moment. The power of the second audio signal input at the next moment is adjusted using the control gain of the previous moment to obtain the adjusted second audio signal. Then, the second audio signal is output to the voice coil for playback.

[0134] As can be seen, the speaker voice coil temperature control method provided in this application obtains a fusion temperature value by fusing the measured temperature of the actual sampled voice coil with the predicted temperature corresponding to the first audio power. Then, based on the temperature feedback processing model and the power prediction model, the corresponding control gain value for the next moment is obtained. Finally, the power value of the second audio signal input to the speaker at the next moment is adjusted using the control gain value, so that the temperature of the speaker voice coil is stabilized below the maximum set temperature, thus avoiding the speaker voice coil from affecting the sound quality due to excessive temperature.

[0135] It is understood that the loudspeaker voice coil temperature control method provided in this application is essentially a feedback control method for voice coil temperature, which is based on... Figure 2 The feedback control system shown Figure 2The feedback control system shown essentially obtains a closed-loop transfer function based on the temperature feedback processing model 202, the power prediction model 203, and the voice coil temperature prediction model 204. The audio signal power of the voice coil is adjusted according to this closed-loop transfer function to obtain the power value of the second audio signal input at the next moment.

[0136] In one embodiment of this application, the closed-loop transfer function obtained based on the gain smoothing function, the temperature feedback processing model, the power prediction model, and the voice coil temperature prediction model can be expressed by the following formula:

[0137] (14)

[0138] in, (15)

[0139] in, Represents the closed-loop transfer function. Represents the open-loop transfer function. This represents the gain smoothing function. This represents the transfer function corresponding to power prediction model 203. This represents the transfer function corresponding to voice coil temperature prediction model 204. This represents the transfer function corresponding to temperature feedback processing model 202. , Both f1 and f2 are coefficients of the closed-loop transfer function; and They represent the equivalent time constants after simplification, Indicates the smoothing time constant. Represents the S field, and These are the simplified coefficients.

[0140] Understandably, after determining the optimal functional forms of each of the above transfer functions, the thermal resistance values ​​are then calculated using the magnetic circuit thermal resistance model of the voice coil. Finally, the closed-loop transfer function is determined using the phase angle condition equation and the amplitude condition equation. The values ​​of each coefficient are determined, and then the optimal closed-loop transfer function can be determined. This optimal closed-loop transfer function is used to control the temperature of the speaker voice coil to ensure that the temperature of the speaker voice coil does not exceed the preset maximum temperature value.

[0141] In one embodiment of this application, the above-mentioned closed-loop transfer function The dominant pole is ;

[0142] in, For the natural frequency, For the damped natural frequency, , The damping ratio is denoted as .

[0143] Figure 3 For a flowchart of the closed-loop transfer function system solution method provided in this application embodiment, please refer to [link / reference]. Figure 3 As shown, in one embodiment of this application, the voice coil temperature control method further includes a pole placement method, specifically comprising:

[0144] S301. Set the initial damping ratio. Based on the closed-loop transfer function and the set dominant pole, determine the correlation coefficient using the phase angle condition equation according to the set settling time Tss. and The ratio of .

[0145] First, assume the feedback transfer function is unity feedback, and that the dominant pole is... Assuming the system's settling time to steady state at 2% is Tss, then... At this point, the ratio of k1 to k0 can be determined using the phase angle condition:

[0146] (16)

[0147] S302, based on the determined coefficients and The ratio of the damping ratio is updated. The phase angle condition equation is used to determine the value of the coefficient f1.

[0148] Transform the feedback transfer function into a first-order transfer function: At this point, the zeros of the closed-loop function will not change, therefore k1 and k0 The ratio can be the value obtained in the previous step, and the damping ratio is updated as follows: (At this point, the damping ratio can be configured to be larger, for example, 0.99, so that the system has almost no overshoot), and updates are performed simultaneously. And other parameters, substituting them again into the phase angle condition to determine f1:

[0149] (17)

[0150] S303. Construct the amplitude condition equation, based on the amplitude condition equation and coefficients. and The ratio, determine the coefficient and The value of .

[0151] In this embodiment, the following amplitude conditions are used:

[0152] (18)

[0153] Among them, the model parameters in the above formula , , , All of these can be obtained through modeling, and the other parameters are those known to industry professionals.

[0154] Based on the closed-loop transfer function provided in this application, configuring the controller parameters is a challenge. System controllers in related technologies are generally quite complex and cannot accurately determine the temperature-power transfer function and power-gain transfer function based on system performance (these two transfer functions are usually empirical functions). Furthermore, multiple sets of different transfer functions are required for different ambient temperatures.

[0155] To ensure the closed-loop transfer function adapts to various environments, the transfer function corresponding to a well-known voice coil temperature prediction model is adopted. and gain smoothing function Then, the transfer function corresponding to the power prediction model is simulated using the following method. Transfer function corresponding to temperature feedback processing model Conduct simulation tests.

[0156] In one embodiment, the gain smoothing function Choose the first-order smoothing as shown below:

[0157] (19)

[0158] in, This is the corresponding RC time constant, which can be dynamically configured. This gain smoothing function is mainly used to smooth the gain and ensure that the output signal does not fluctuate in sound. If there are fluctuations, this parameter can be increased.

[0159] In this embodiment, to estimate the speaker's voice coil temperature, it is necessary to construct a mapping relationship between the speaker's input power and the voice coil temperature, using a voice coil temperature prediction function. The transfer function for the continuous domain is as follows:

[0160] (20)

[0161] in, Rca represents the third target RTD value of the voice coil RTD, Rcm represents the first target RTD value of the voice coil RTD, Rma represents the second target RTD value of the magnetic circuit RTD, Cma represents the second target RTD value of the magnetic circuit RVC, and Ccm represents the first target RTD value of the voice coil RVC. and They represent the equivalent time constants after simplification, Represents the S field, and These are the simplified coefficients.

[0162] Among them, the aforementioned voice coil temperature prediction function The voice coil temperature prediction function is used to represent the inherent properties of a loudspeaker. It can be obtained through modeling.

[0163] The following assumes Hfb(s) = H1(s) = 1, and the stability and performance of the control system are analyzed based on this assumption.

[0164] The open-loop transfer function H can be obtained. open (s) can be expressed as:

[0165] (twenty one)

[0166] Closed-loop transfer function H close (s) can be expressed as:

[0167] (twenty two)

[0168] In the closed-loop transfer function mentioned above, at different H... sm (s) and H model Under (s), the performance of the closed-loop transfer function varies considerably.

[0169] In one embodiment of this application, based on the form of the closed-loop transfer function provided above, this embodiment can set Rcm=10.9, Ccm=0.5, Rma=20.9, Cma=0.1. .

[0170] Figure 4 For one of the simulation diagrams of the unit step response and zero-pole points of the control method according to the embodiments of this application, please refer to [link / reference]. Figure 4 As shown, Figure 4 In this context, Amplitude represents the amplitude, closed-loop Step Response represents the unit step response of the closed-loop transfer function, and closed-loop Pole-Zero Map represents the distribution of zeros and poles.

[0171] Please continue reading Figure 4 It can be seen that the control system has obvious overshoot, and the overshoot is 12%, which cannot meet the requirements of the speaker voice coil temperature protection. At this time, the dominant pole of the system is p1,2=-2.72±5.15i, the natural frequency of the conjugate pole pair is 5.83, the damping ratio is 0.466, the system is an underdamped system, and therefore there is a large overshoot.

[0172] In one embodiment of this application, based on the form of the closed-loop transfer function provided above, this embodiment can set Rcm=20.9, Ccm=0.5, Rma=10.9, Cma=0.1. .

[0173] Based on the closed-loop transfer function and parameter settings described above, a simulation experiment is conducted in this embodiment. Figure 5 For the second simulation diagram of the unit step response and zero-pole points of the control method according to the embodiments of this application, please refer to [link / reference]. Figure 5 As shown, based on the above parameter settings, the voice coil temperature control system does not overshoot, but the control system takes too long to reach steady state, which cannot meet the requirements of speaker voice coil temperature protection. At this time, the dominant pole is p=-2.22, which is on the real axis and has a damping ratio of 1, so there is no overshoot. Moreover, the pole is too close to the imaginary axis, resulting in an excessively long adjustment time.

[0174] Please combine Figure 4 and Figure 5 It can be seen that the performance of the control system varies greatly for different gain smoothing processing functions and power prediction transfer functions. This difference is caused by the dominant pole of the closed-loop transfer function. Therefore, it is necessary to reconfigure the dominant pole to improve the system performance. Reconfiguring the dominant pole is equivalent to selecting appropriate power prediction transfer function H1(s) and temperature feedback processing transfer function Hfb(s).

[0175] To overcome the aforementioned technical deficiencies, in one embodiment of this application, the general form for determining the power prediction transfer function H1(s) can be expressed as:

[0176] (twenty three)

[0177] Based on the power prediction transfer function H1(s) shown in the above formula, the closed-loop transfer function Hclose(s) of the control system can be expressed as follows:

[0178] (twenty four)

[0179] Using the dominant pole placement method, we assume the conjugate dominant poles are p1 and p2, and then assume other non-dominant poles based on the orders of M and N. We then substitute all poles into the closed-loop transfer function H. close (s), solving the equation will give the coefficient a. k and b k Finally, a k and b k Bring back the closed-loop transfer function H close (s) to verify whether its stability and dynamic performance meet the requirements.

[0180] Simulation tests show that when the orders of N and M are high, the complexity of the entire system increases, the equations become more complex to solve, and instability is more likely to occur. Furthermore, compared to lower orders, the performance of the control system is still determined by the dominant poles. Therefore, choosing a lower-order power prediction transfer function H1(s) is a better choice.

[0181] In one embodiment, based on the general form of the power prediction transfer function H1(s) given by the above formula, when M=1, N=0, b0=1, the power prediction transfer function H1(s) can be expressed as follows:

[0182] (25)

[0183] In one embodiment, based on the general form of the power prediction transfer function H1(s) given by the above formula, when M=1, N=1, b0=1, the power prediction transfer function H1(s) can be expressed as follows:

[0184] (26)

[0185] In one embodiment, based on the general form of the power prediction transfer function H1(s) given by the above formula, when M=1, N=1, b0=k1, b1=k0, a0=1, a1=1, the power prediction transfer function H1(s) can be expressed as follows:

[0186] (27)

[0187] Closed-loop transfer function H close (s) can be expressed in the following form:

[0188] (28)

[0189] In this embodiment, Rcm=10.9, Ccm=0.5, Rma=20.9, Cma=0.1 can be set. Taking the power prediction transfer function H1(s) shown in the above formula (27) as an example, the steady-state adjustment time Tss of the control system is set to 2.4s, and the damping ratio ζ is adjusted from 0.466 to 0.99. At this time, the natural frequency ω=1.68, and the dominant pole can be obtained as p1,2=-1.67±0.237i.

[0190] Simulation tests were performed on the control system composed of the above closed-loop transfer function. Figure 6 For the third simulation diagram of the unit step response and zero-pole points of the control method according to the embodiments of this application, please refer to [link / reference]. Figure 6As shown, although the damping ratio ζ has been adjusted to 0.99, the system still has a large overshoot (12%). This is because a new zero point z = -0.782 has been introduced (compared to...). Figure 4 and Figure 5 , Figure 6 There is clearly an additional zero point (z=-0.782), the existence of which will speed up the response of the control system, thus leading to a larger overshoot.

[0191] To overcome the effects of introducing a new zero point, this embodiment further improves the temperature feedback transfer function. This reduces the overshoot of the control system.

[0192] To overcome the aforementioned technical deficiencies, in one embodiment of this application, a temperature feedback transfer function is determined. The general form can be expressed as:

[0193] (29)

[0194] In the above temperature feedback transfer function Based on this, the closed-loop transfer function Hclose(s) in this embodiment can be expressed as follows:

[0195] (30)

[0196] By comparing and analyzing the closed-loop transfer functions shown in formula (28) and formula (30), it can be seen that if the denominator of the temperature feedback transfer function Hfb(s) is not 1, more zeros will be introduced to affect the system performance. In addition, when the order of the numerator of the temperature feedback transfer function Hfb(s) is high, the feedback system is very sensitive to high-frequency noise, which will cause the system to be unstable. In summary, the temperature feedback transfer function with a first-order denominator of 1 is the optimal choice.

[0197] Based on the above analysis and considerations, the temperature feedback transfer function Hfb(s) selected in this embodiment can be expressed in the following form:

[0198]

[0199] In the above temperature feedback transfer function Based on this, the closed-loop transfer function Hclose(s) in this embodiment can be expressed as follows:

[0200] (31)

[0201] In this embodiment, Rcm=10.9, Ccm=0.5, Rma=20.9, Cma=0.1 can be set. Taking the power prediction transfer function H1(s) shown in the above formula (27) as an example, the steady-state adjustment time Tss of the control system is set to 2.4s, and the damping ratio of the dominant pole is still 0.99. Figure 7 For the fourth simulation diagram of the unit step response and zero-pole points of the control method according to the embodiments of this application, please refer to [link / reference]. Figure 7 As shown, the overshoot of the control system is very small at this time (overshoot is 3%). Compared to Figure 6 This is equivalent to correcting the original zero point z=-0.782 to z=-1.13 under the condition that the damping ratio remains unchanged. The increase in the magnitude of the zero point makes the response speed of the control system slower, thus resulting in a smaller overshoot.

[0202] Furthermore, embodiments of this application also provide the following pole configuration method, specifically including: first, setting an initial damping ratio; based on the closed-loop transfer function and the set dominant poles, determining the coefficients through the phase angle condition equation according to the set settling time Tss. and The ratio, and then based on the determined coefficients. and The ratio is updated to the damping ratio. And the phase angle condition equation, to determine the value of the coefficient f1, finally construct the amplitude condition equation, based on the amplitude condition equation and the coefficients and The ratio, determine the coefficient and The ratio; after determining the specific values ​​of each coefficient in the closed-loop transfer function, the specific values ​​of each coefficient are substituted into the optimal closed-loop transfer function described above to determine the transfer function in the final control system, so as to adjust the power of the speaker voice coil. Furthermore, the specific method for determining the coefficients can be found in the detailed description in the above embodiments, and will not be repeated here.

[0203] Based on the pole placement method provided in this embodiment, the system is theoretically analyzed according to the control system transfer function, the dynamic performance of the system is set, and the optimal control parameters of the closed-loop transfer function (including the controller and feedback transfer function) are obtained using the pole placement method and the amplitude and phase angle conditions, thereby determining the closed-loop transfer function to realize the above-mentioned control system.

[0204] Based on the closed-loop transfer function shown in formula (31) provided in the above embodiments, the above voice coil temperature control method is simulated and tested in a specific environment.

[0205] In this embodiment, with an ambient temperature of 25°C, the maximum temperature threshold is set to 100°C. The speaker is controlled to operate at a single frequency and during a song, respectively, to verify the effectiveness of the above-mentioned voice coil temperature control method in temperature control.

[0206] Figure 8 This is a schematic diagram of the temperature curve of the speaker when it is playing a single frequency point, according to an embodiment of this application. Figure 9 For a schematic diagram of the temperature curve of the speaker when playing music according to an embodiment of this application, please refer to [link / reference]. Figure 8 and Figure 9 As shown, in an environment of 25℃, with a maximum temperature threshold set to 100℃, using the voice coil temperature control method provided in this embodiment, the speaker did not overshoot in temperature when playing single-frequency sounds and songs, and the highest temperature value was always less than the maximum set temperature threshold of 100℃. Therefore, it can be determined that the above-mentioned voice coil temperature control method has high accuracy in voice coil temperature control. Figure 8 and Figure 9 The horizontal axis represents time (in seconds). Figure 8 and Figure 9 The horizontal axis represents temperature (in degrees Celsius).

[0207] To test the control effect of the voice coil temperature control method provided in this embodiment at different temperatures, this embodiment sets a maximum temperature threshold of 100℃ and compares the control temperature when playing a single frequency point at different ambient temperatures. Specifically, this embodiment can set the environment to three environments with different ambient temperatures: high temperature of 60℃, normal temperature of 25℃, and low temperature of -20℃, and compare and analyze the control effect of the voice coil temperature.

[0208] Figure 10 This is a schematic diagram of the temperature curves of a loudspeaker operating under three different ambient temperatures, provided as an embodiment of this application. Figure 11 For a partial enlarged view of the temperature profile of the loudspeaker provided in this application embodiment operating under three different ambient temperatures, please refer to [link / reference]. Figure 10 As shown, from Figure 10 and Figure 11 As can be seen, under three environments—high temperature (60℃), normal temperature (25℃), and low temperature (-20℃)—when the speaker plays a single frequency point, the control method provided in this embodiment ensures that the speaker's voice coil temperature is always below the maximum temperature threshold of 100℃, and the temperature deviation under different ambient temperatures is within 2℃. Therefore, it can be determined that the above-mentioned voice coil temperature control method has high accuracy in controlling the voice coil temperature. Figure 10 and Figure 11 The horizontal axis represents time (in seconds). Figure 8 and Figure 9 The horizontal axis represents temperature (in degrees Celsius).

[0209] As can be seen, based on the above-mentioned optimal transfer function design, by fusing measured and predicted temperature data, more accurate temperature data can be obtained. Thus, a set of control schemes and parameters can protect and control different temperature rise states under different ambient temperatures, ensuring that the maximum temperature of the voice coil does not exceed the maximum set temperature Tmax, and that the voice coil does not have a significant temperature exceeding the temperature threshold, thereby achieving precise control of the voice coil temperature.

[0210] The following provides a speaker voice coil temperature control device, which can be referred to in conjunction with the speaker voice coil temperature control methods provided in the above embodiments.

[0211] Figure 13 For a schematic diagram of the speaker voice coil temperature control device provided in the embodiments of this application, please refer to [link / reference]. Figure 13 As shown, the voice coil temperature control device provided in this embodiment includes:

[0212] The temperature prediction unit 1301 is used to acquire the first audio signal input to the speaker at the current moment, determine the first audio power corresponding to the first audio signal, and acquire the predicted temperature corresponding to the first audio power based on the relationship between audio power and temperature.

[0213] The temperature measurement unit 1302 is used to acquire the voltage and current values ​​of the speaker at the current moment of operation, and to determine the measured temperature of the speaker at the current moment based on the voltage and current values.

[0214] The temperature processing unit 1303 is used to fuse the predicted temperature and the measured temperature to obtain a fused temperature value, and input the fused temperature value into the temperature feedback processing model to obtain the output reference temperature; the temperature feedback processing model is used to characterize the correspondence between the fused temperature value and the reference temperature.

[0215] The gain processing unit 1304 is used to obtain a preset maximum set temperature and power prediction model, input the reference temperature and maximum set temperature values ​​into the power prediction model to obtain the output target power, and obtain the control gain value at the next moment based on the first audio power and the target power.

[0216] The power control unit 1305 is used to adjust the power value of the second audio signal input to the speaker at the next moment using the control gain value at the next moment.

[0217] In one embodiment of this application, the temperature prediction unit 1301 is specifically used for:

[0218] Obtain the control gain value from the previous time step; convolve the first audio power value and the control gain value at the current time step to obtain the processed intermediate power value; input the intermediate power value into the trained voice coil temperature prediction model to obtain the predicted temperature corresponding to the first audio power; wherein, the voice coil temperature prediction model is a second-order model of loudspeaker heat transfer based on target thermal parameters, the target thermal parameters include the first target thermal parameter between the loudspeaker's voice coil and the loudspeaker's magnetic circuit, the second target thermal parameter between the loudspeaker's magnetic circuit and the air, and the third target thermal parameter between the loudspeaker's voice coil and the air convection; the voice coil temperature prediction model is used to characterize the mapping relationship between the audio power input to the loudspeaker's voice coil and the temperature of the loudspeaker's voice coil.

[0219] In one embodiment of this application, the temperature prediction unit 1301 is specifically used for:

[0220] The first audio power corresponding to the first audio signal is determined using the following formula. Based on the relationship between audio power and temperature, the predicted temperature corresponding to the first audio power is obtained:

[0221] ;

[0222] Where t represents a discrete time point, Te_pred[ ] represents the predicted temperature output by the voice coil temperature prediction model, and P_in[ ] represents the discrete value of the input power. and The coefficients of the voice coil temperature prediction model are determined by transforming the discrete domain transfer function H(z) and the continuous domain transfer function H(s) corresponding to Te_pred[t].

[0223] The discrete-domain transfer function H(z) corresponding to Te_pred[t] is: ;

[0224] Continuous domain transfer function H model (s) is:

[0225] Wherein, Rca represents the third target RTD value of the voice coil RTD, Rcm represents the first target RTD value of the voice coil RTD, Rma represents the second target RTD value of the magnetic circuit RTD, Cma represents the second target RTD value of the magnetic circuit RVC, and Ccm represents the first target RTD value of the voice coil RVC. , . and They represent the equivalent time constants after simplification, Represents the S field, and These are the simplified coefficients.

[0226] In one embodiment of this application, the gain processing unit 1304 is further configured to:

[0227] Before adjusting the power value of the second audio signal input to the speaker at the next moment using the control gain value at the next moment, and / or before convolving the first audio power at the current moment with the control gain value at the current moment, the control gain value is smoothed using a preset gain smoothing function.

[0228] In one embodiment of this application, the temperature processing unit 1303 is specifically used for:

[0229] The fusion temperature value is processed using the following formula to obtain the output reference temperature:

[0230]

[0231]

[0232] Among them, S Let S represent the domain, and f1 represent the corresponding feedback coefficient. T Z represents the sampling period. It represents the discrete domain.

[0233] In one embodiment of this application, the gain processing unit 1304 is further configured to:

[0234] The target output power is obtained by processing the preset maximum set temperature and reference temperature using the following formula:

[0235]

[0236] in, ; and All represent coefficients of the power prediction model. It represents the discrete domain.

[0237] In one embodiment of this application, the loudspeaker voice coil temperature control device is expressed by the following formula based on the gain smoothing processing function, the temperature feedback processing model, the power prediction model, and the closed-loop transfer function obtained from the voice coil temperature prediction model:

[0238]

[0239] in,

[0240] in, Represents the closed-loop transfer function. Represents the open-loop transfer function. This represents the gain smoothing function. This represents the transfer function corresponding to the power prediction model. This represents the transfer function corresponding to the voice coil temperature prediction model. This represents the transfer function corresponding to the temperature feedback processing model. , Both f1 and f2 are coefficients of the closed-loop transfer function; and They represent the equivalent time constants after simplification, Represents the discrete time constant. Represents the S field, and These are the simplified coefficients.

[0241] In one embodiment of this application, the dominant pole of the closed-loop transfer function in the loudspeaker voice coil temperature control device is ;

[0242] in, For the natural frequency, For the damped natural frequency, , The damping ratio;

[0243] In one embodiment of this application, the loudspeaker voice coil temperature control device further includes a parameter determination unit, which is specifically used to: determine coefficients based on the closed-loop transfer function and the set dominant pole, according to the set settling time Tss, through the phase angle condition equation. and The ratio; based on the determined coefficients. and The ratio of the damping ratio is updated. And the phase angle condition equation, to determine the value of coefficient f1; construct the amplitude condition equation, and based on the amplitude condition equation and coefficients and The ratio, determine the coefficient and The ratio of .

[0244] This application also provides an electronic device, which includes a memory, a processor, and an audio module. The processor is electrically connected to both the memory and the audio module. In this embodiment, the audio module includes at least a speaker. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements the steps of the speaker voice coil temperature control method described above, thereby controlling the operation of the audio module. Specifically, it can control the power of the audio signal input to the speaker to avoid excessive audio signal power, which could cause the speaker voice coil to overheat and affect the sound quality. For the specific control process, please refer to the above embodiments, which will not be repeated here. The electronic device provided in this embodiment can be any one of a mobile phone, laptop computer, tablet computer, or smart wearable device.

[0245] In other embodiments, the audio module also includes a microphone and a voice processing module, and the processor controls the microphone and voice processing module to receive and play voice signals.

[0246] This application also provides a computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the steps of the speaker voice coil temperature control method described in any of the preceding claims, which will not be repeated here. The computer-readable storage medium can be any of the following, for example, a non-transitory computer-readable storage medium can be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, magnetic tape, a floppy disk, and an optical data storage device, etc.

[0247] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing related hardware to implement them. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0248] Finally, it should be noted that the above embodiments are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for controlling the voice coil temperature of a loudspeaker, characterized in that, The temperature control method includes: The first audio signal input to the speaker at the current moment is obtained, the first audio power corresponding to the first audio signal is determined, and the predicted temperature corresponding to the first audio power is obtained according to the relationship between audio power and temperature. Obtain the voltage and current values ​​of the speaker at the current moment of operation, and determine the measured temperature of the speaker at the current moment based on the voltage and current values; The predicted temperature and the measured temperature are fused to obtain a fused temperature value, which is then input into a temperature feedback processing model to obtain an output reference temperature. The temperature feedback processing model is used to characterize the correspondence between the fused temperature value and the reference temperature. Obtain the preset maximum set temperature and power prediction model, input the reference temperature and the maximum set temperature value into the power prediction model to obtain the output target power, and obtain the control gain value at the next moment based on the first audio power and the target power; The power value of the second audio signal input to the speaker at the next moment is adjusted using the control gain value at the next moment.

2. The loudspeaker voice coil temperature control method according to claim 1, characterized in that, The step of obtaining the predicted temperature corresponding to the first audio power based on the relationship between audio power and temperature includes: Obtain the control gain value from the previous moment; The first audio power at the current moment and the control gain value at the current moment are convolved to obtain the processed intermediate power value; The intermediate power value is input into the trained voice coil temperature prediction model to obtain the predicted temperature corresponding to the first audio power. The voice coil temperature prediction model is a second-order loudspeaker heat transfer model established based on target thermal parameters. The target thermal parameters include a first target thermal parameter between the loudspeaker's voice coil and the loudspeaker's magnetic circuit, a second target thermal parameter between the loudspeaker's magnetic circuit and the air, and a third target thermal parameter for the convection between the loudspeaker's voice coil and the air. The voice coil temperature prediction model is used to characterize the mapping relationship between the audio power input to the loudspeaker's voice coil and the temperature of the loudspeaker's voice coil.

3. The loudspeaker voice coil temperature control method according to claim 2, characterized in that, The voice coil temperature control method further includes: Before adjusting the power value of the second audio signal input to the speaker at the next moment using the control gain value at the next moment, and / or before convolving the first audio power at the current moment with the control gain value at the current moment, the control gain value is smoothed using a preset gain smoothing function.

4. The loudspeaker voice coil temperature control method according to claim 1, characterized in that, The temperature feedback processing model is expressed by the following formula: in, Represents the S field, This represents the corresponding feedback coefficient. T Indicates the sampling period. Represents the discrete domain.

5. The loudspeaker voice coil temperature control method according to claim 4, characterized in that, The power prediction model is expressed by the following formula: ; in, ; and All represent coefficients of the power prediction model. Represents the discrete domain.

6. The loudspeaker voice coil temperature control method according to claim 5, characterized in that, The voice coil temperature prediction model is expressed by the following formula: ； Where t represents a discrete time point, Te_pred[ ] represents the predicted temperature output by the voice coil temperature prediction model, and P_in[ ] represents the discrete value of the input power. as well as The coefficients of the voice coil temperature prediction model are obtained by converting the discrete domain transfer function H(z) corresponding to Te_pred[t] and the continuous domain transfer function H... model (s) is transformed and determined; The discrete-domain transfer function H(z) corresponding to Te_pred[t] is: ; The continuous domain transfer function H model (s) is: Wherein, Rca represents the third target RTD value of the voice coil RTD, Rcm represents the first target RTD value of the voice coil RTD, Rma represents the second target RTD value of the magnetic circuit RTD, Cma represents the second target RVC value of the magnetic circuit RVC, and Ccm represents the first target RVC value of the voice coil RVC. , , and They represent the equivalent time constants after simplification, and These are the simplified coefficients.

7. The loudspeaker voice coil temperature control method according to claim 3, characterized in that, The voice coil temperature control method further includes: The closed-loop transfer function obtained from the gain smoothing function, the temperature feedback processing model, the power prediction model, and the voice coil temperature prediction model is expressed by the following formula: in, in, Represents the closed-loop transfer function. Represents the open-loop transfer function. This represents the gain smoothing function. This represents the transfer function corresponding to the power prediction model. This represents the transfer function corresponding to the voice coil temperature prediction model. This represents the transfer function corresponding to the temperature feedback processing model. , f1 and f1 are both coefficients of the closed-loop transfer function. and They represent the equivalent time constants after simplification, Indicates the smoothing time constant. Represents the S field, and These are the simplified coefficients.

8. The loudspeaker voice coil temperature control method according to claim 7, characterized in that, The dominant pole of the closed-loop transfer function is ; in, For the natural frequency, For the damped natural frequency, , The damping ratio; The voice coil temperature control method further includes: Based on the closed-loop transfer function and the set dominant pole, the coefficients are determined using the phase angle condition equation according to the set set settling time Tss. and The ratio; Based on the determined coefficients and The ratio is updated to the damping ratio. And the phase angle condition equation, to determine the value of coefficient f1; Construct the amplitude condition equation, and based on the amplitude condition equation and the coefficients... and The ratio of the coefficients is used to determine the coefficients. and The value of .

9. A loudspeaker voice coil temperature control device, characterized in that, The voice coil temperature control device includes: The temperature prediction unit is used to acquire the first audio signal input to the speaker at the current moment, determine the first audio power corresponding to the first audio signal, and acquire the predicted temperature corresponding to the first audio power based on the relationship between audio power and temperature. The temperature measurement unit is used to acquire the voltage and current values ​​of the speaker at the current moment of operation, and to determine the measured temperature of the speaker at the current moment based on the voltage and current values. A temperature processing unit is used to fuse the predicted temperature and the measured temperature to obtain a fused temperature value, and input the fused temperature value into a temperature feedback processing model to obtain an output reference temperature; the temperature feedback processing model is used to characterize the correspondence between the fused temperature value and the reference temperature; The gain processing unit is used to obtain a preset maximum set temperature and power prediction model, input the reference temperature and the maximum set temperature value into the power prediction model to obtain the output target power, and obtain the control gain value at the next moment based on the first audio power and the target power. A power control unit is used to adjust the power value of the second audio signal input to the speaker at the next moment using the control gain value at the next moment.

10. An electronic device comprising a memory, a processor, and an audio module, wherein the processor is electrically connected to both the memory and the audio module, the audio module includes a speaker, and the memory stores a computer program executable on the processor, characterized in that... When the processor executes the computer program, it implements the steps of the loudspeaker voice coil temperature control method as described in any one of claims 1 to 8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the loudspeaker voice coil temperature control method as described in any one of claims 1 to 8.

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