Frequency response adjustment system and method for acoustic signal generating device based on multi-sensor data acquisition

Abstract

The present application discloses a frequency response adjustment system and method for an acoustic signal generating device based on multi-sensor data acquisition, relating to the field of acoustic metrology calibration technology. The system solves the problem of excessively high cost of the correction system caused by ensuring that the acoustic signal meets the requirements of a Class 1 acoustic calibrator in the prior art. The system includes a sensor unit, a main control unit, a digital-to-analog converter, an operational amplifier, and a coupling cavity with a speaker inside. The main control unit can control the magnitude of the digital-to-analog converter output signal, generate a pure tone signal of a specified frequency and amplitude, and adjust the frequency response based on a preset sound pressure compensation algorithm according to the air pressure, temperature, and humidity of the operating environment. There is no need to use expensive Class 1 or LS microphones, nor is there a need to design an acquisition circuit and calculate the sound pressure level in the hardware circuit. Therefore, the production cost of the system can be reduced while achieving calibration of multiple frequency points and multiple sound pressure levels.

Description

Technical Field

[0001] The present application relates to the field of acoustic metrology calibration technology, and in particular to a frequency response adjustment system and method for an acoustic signal generating device based on multi-sensor data acquisition. Background Art

[0002] An acoustic signal generator is a type of acoustic calibrator, primarily used for periodic calibration of acoustic measuring instruments such as sound level meters and for testing the frequency response of test microphones. Common acoustic calibration methods include pistonphones and acoustic calibrators with negative feedback.

[0003] Pistonphones: Sound calibrators generate sound pressure in a fixed volume of air through the movement of one or more pistons with known volumetric velocities. The pistons, driven by a motor, reciprocate within the cavity, changing the pressure and producing sound. While the sound pressure is stable and can reach Class 1 or even LS levels, they suffer from the following drawbacks:

[0004] (1) Friction and wear can easily lead to aging of seals and air leakage;

[0005] (2) Nonlinear distortion: When the piston displacement exceeds the linear region, second harmonic distortion is likely to occur, and the rapid movement of the piston causes airflow noise;

[0006] (3) The piston is sensitive to temperature and humidity, which can easily cause distortion and changes in sound pressure level;

[0007] (4) Due to the limitation of motor speed, the frequency can usually only reach 250Hz, and the scope of use is limited.

[0008] The sound calibrator with negative feedback can achieve calibration at multiple sound pressure levels and multiple frequencies, but it has the following defects:

[0009] (1) Inherent defects in the feedback system: Signal processing in the feedback loop, such as analog-to-digital conversion and signal conditioning, introduces a delay of 0.1-5ms, resulting in phase distortion in the high-frequency band.

[0010] (2) Microphone dependency defects: the stability of the reference microphone will directly lead to the deviation of the output sound pressure level. In addition, the microphone is affected by temperature, which will cause the feedback system to misjudge the sound pressure and overshoot;

[0011] (3) Environmental adaptability defects: first, there is no air pressure compensation. When used in plateaus, the air density decreases, causing the acoustic impedance to change, resulting in changes in the output sound pressure level. Second, it is greatly affected by environmental noise. When the signal-to-noise ratio deteriorates, it will cause the feedback system to be misadjusted.

[0012] (4) To realize a Class 1 sound calibrator, a Class 1 or LS microphone needs to be used for negative feedback, which results in excessively high costs and high prices. In addition, the use of a microphone for negative feedback requires the design of a signal acquisition and conditioning circuit, and the analysis and calculation of acoustic measurements on the acquired signals. This is equivalent to realizing the output of the sound signal within the device while also designing a sound level meter, resulting in a complex overall solution and low reliability.

[0013] With the development of noise measurement, it is often necessary to calibrate acoustic measurement instruments such as sound level meters at multiple frequencies and sound pressure levels to ensure measurement accuracy. To achieve this goal, a low-cost and stable frequency response adjustment system with multiple frequencies and sound pressure levels is urgently needed. Summary of the Invention

[0014] The purpose of this application is to overcome the problem of high cost of the correction system in the prior art caused by making the acoustic signal meet the requirements of a Class 1 acoustic calibrator, and to provide a frequency response adjustment system and method for an acoustic signal generating device based on multi-sensor data acquisition.

[0015] In a first aspect, a frequency response adjustment system for an acoustic signal generating device based on multi-sensor data acquisition is provided, comprising:

[0016] The sensor unit is used to detect the air pressure, temperature and humidity of the use environment and transmit them to the main control unit;

[0017] The main control unit is used to control the output signal of the digital-to-analog converter based on the preset sound pressure compensation algorithm according to the air pressure, temperature and humidity of the operating environment, generate a pure tone signal of specified frequency and amplitude, adjust the frequency response, and store the compensation parameters of each frequency point under reference environmental conditions;

[0018] A digital-to-analog converter, used to convert the pure tone signal generated by the main control unit into an analog signal;

[0019] An operational amplifier, configured to control the amplitude of the output signal through a DC signal from a main control unit and to convert the analog signal from a single-ended signal into a differential signal and output it to a speaker in the coupling cavity for outputting an acoustic signal;

[0020] The coupling cavity is used to convert the differential signal into an acoustic signal through the internal speaker.

[0021] In some possible implementations, a power management unit is further included, which includes a first DC-DC boost circuit and a second DC-DC boost circuit, wherein the first DC-DC boost circuit is used to convert the connected power supply into a first specified voltage to power the sensor unit and the main control unit, and the second DC-DC boost circuit is used to convert the connected power supply into a second specified voltage to power the digital-to-analog converter and the operational amplifier.

[0022] In some possible implementations, the power management unit also includes an input protection circuit, which includes a PMOS tube, the source of the PMOS tube is connected to the positive electrode of the power supply through a first resistor, a diode and a membrane switch connected in series in sequence, a second resistor is connected in series between the gate and the source of the PMOS tube, the gate of the PMOS tube is connected to the collector of the NPN transistor through a third resistor, the drain of the PMOS tube is connected to VUSB through a voltage regulator diode, the emitter of the NPN transistor is connected to the negative electrode of the power supply, the base of the NPN transistor is connected to the IO pin of the main control unit through a fourth resistor, and the base of the NPN transistor is also connected to the negative electrode of the power supply through a fifth resistor. A tantalum electrolytic capacitor, a ceramic capacitor and a transient voltage suppression diode are connected in parallel between the drain of the PMOS tube and the negative electrode of the power supply, and the negative electrode of the power supply is grounded.

[0023] In some possible implementations, the preset sound pressure compensation algorithm includes:

[0024] Calculate the gain compensation G under the current usage environment err :

[0025] ;

[0026] Among them, P is the air pressure of the use environment, T is the temperature of the use environment, P ref is the reference ambient pressure, T ref is the temperature of the reference environment, K is the humidity correction factor, , e is the water vapor partial pressure, , RH is the humidity of the operating environment, e sat (T) is the saturated water vapor pressure;

[0027] The output voltage value V after compensation is: , V ref is the output voltage value under the reference environment.

[0028] In some possible implementations, the formula for the main control unit to generate a pure tone signal is:

[0029]

[0030] Among them, A ref is the pure tone signal amplitude under the reference environment, G err is the gain supplement in the current use environment, f is the frequency of the pure tone signal, n is the sampling point index number of the discrete signal, f s is the sampling rate, is the initial phase.

[0031] In some possible implementations, the output amplitude of the pure tone signal output by the main control unit to the digital-to-analog converter is 0-224 -1, the frequency of the pure tone signal is 20Hz~16kHz.

[0032] In some possible implementations, the air fixes the amplitude of the pure tone signal to 2 in a reference environment. 22 The reference environment conditions are: static pressure of 101.325 kPa, air temperature of 23 °C, and relative humidity of 50%.

[0033] In a second aspect, a method for adjusting the frequency response of an acoustic signal generator based on multi-sensor data acquisition is provided. The method is applied to the frequency response adjustment system for an acoustic signal generator based on multi-sensor data acquisition as described in the first aspect. A measurement microphone is inserted into a coupling cavity, and the output voltage values ​​of a digital-to-analog converter at each frequency point under a reference environment are pre-stored to a specified address. The method includes:

[0034] Read the output voltage value of the digital-to-analog converter at each frequency point under the reference environment stored in the specified address;

[0035] Set the frequency of the output signal;

[0036] Set the output voltage value of the digital-to-analog converter at the current frequency;

[0037] Read the air pressure, temperature and humidity measured by the sensor unit in the current usage environment;

[0038] Calculate the gain compensation G under the current use environment according to the air pressure, temperature and humidity err ;

[0039] Set the amplitude of the pure tone signal to G err *A ref , where A ref is the pure tone signal amplitude in the reference environment.

[0040] In some possible implementations, storing the output voltage value of the digital-to-analog converter at each frequency point under a reference environment to a specified address includes:

[0041] S001. Set the amplitude A of the pure tone signal under the reference environment ref ;

[0042] S002. Adjust the frequency of the pure tone signal within the range of 20Hz~16kHz;

[0043] S003. Determine whether the output sound pressure level meets the requirements based on the sound pressure level data measured by the measurement microphone;

[0044] If the judgment result is no, the voltage value output by the digital-to-analog converter is adjusted, and step S003 is executed;

[0045] If the judgment result is yes, then determine whether the frequency of the pure tone signal is within the range of 20 Hz to 16 kHz. If it is within the range of 20 Hz to 16 kHz, execute step S004; otherwise, execute step S002.

[0046] S004. Store the output voltage value of the digital-to-analog converter at each frequency point.

[0047] In a third aspect, a computer-readable storage medium is provided, wherein the computer-readable medium stores program code for execution by a device, the program code including steps for executing the method in any one of the implementations of the first aspect described above.

[0048] This application has the following beneficial effects:

[0049] 1. The system of the present application utilizes a sensor unit to collect information such as air pressure, temperature, and humidity in the operating environment, and designs a sound pressure compensation algorithm based on this information. The system compensates for the output sound pressure level relative to the reference environment and adjusts the size of the sound signal output so that the sound signal meets the requirements of a Class 1 sound calibrator. At the same time, the system of the present application does not require the use of expensive Class 1 or LS microphones, nor does it require the design of acquisition circuits and calculation of sound pressure levels in hardware circuits, thereby simplifying the circuit, reducing costs, and achieving calibration of multiple frequency points and multiple sound pressure levels.

[0050] 2. The method of the present application calculates the gain compensation in the current usage environment based on information such as air pressure, temperature, and humidity, compensates the output sound pressure level relative to the reference environment, and adjusts the size of the sound signal output so that the sound signal meets the requirements of a Class 1 sound calibrator. Secondly, the frequency response adjustment method designed for the reference environment uses a DC voltage-controlled gain amplifier to solve the frequency response of the output signal in the range of 20Hz~16kHz, so that the sound signal meets the requirements of a Class 1 sound calibrator. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings that constitute a part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application.

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0053] Figure 1 1 is a schematic diagram of a frequency response adjustment system for an acoustic signal generating device based on multi-sensor data acquisition according to Example 1 of the present application;

[0054] Figure 2 1 is a schematic diagram of a power management unit in a frequency response adjustment system of an acoustic signal generating device based on multi-sensor data acquisition according to Example 1 of the present application;

[0055] Figure 3 This is a circuit diagram of an input protection circuit in a frequency response adjustment system of an acoustic signal generating device based on multi-sensor data acquisition according to Example 1 of the present application;

[0056] Figure 4 This is a storage area allocation diagram of a storage medium in the frequency response adjustment system of an acoustic signal generating device based on multi-sensor data acquisition according to Example 1 of the present application;

[0057] Figure 5 This is a flow chart of a method for adjusting the frequency response of an acoustic signal generating device based on multi-sensor data acquisition according to Example 2 of the present application;

[0058] Figure 6 This is a flowchart of obtaining the output voltage value of the digital-to-analog converter at each frequency point under a reference environment in Example 2 of the present application.

[0059] Reference numerals:

[0060] 100, sensor unit; 200, main control unit; 300, digital-to-analog converter; 400, operational amplifier; 500, coupling cavity; 501, loudspeaker; 600, power management unit; 601, power supply; 602, first DC-DC boost circuit; 603, second DC-DC boost circuit. DETAILED DESCRIPTION

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0062] Example 1

[0063] like Figure 1 As shown, the frequency response adjustment system of an acoustic signal generating device based on multi-sensor data acquisition involved in Example 1 of the present application includes a sensor unit 100, a main control unit 200, a digital-to-analog converter 300, an operational amplifier 400 and a coupling cavity 500. In order to obtain a suitable voltage for power supply, it also includes a power management unit 600.

[0064] like Figure 2As shown, the power management unit 600 uses two 1.5V carbon batteries LR6 (size 5) as the power supply 601 for power supply. A first DC-DC boost circuit 602 is built through a power chip to convert the input power supply 601 into 3.3V to supply power to devices such as the sensor unit 100 and the main control unit 200. A second DC-DC boost circuit 603 is built through a power chip to convert the input power supply 601 into 5V to supply power to devices such as the digital-to-analog converter and the operational amplifier 400.

[0065] As Figure 3 shown, the power management unit 600 further includes an input protection circuit. The input protection circuit includes a PMOS transistor Q1. The source of the PMOS transistor Q1 is connected to the positive pole of the power supply 601 through a first resistor R1, a diode D1, and a fuse F1 connected in series in sequence. A second resistor R2 is connected in series between the gate and the source of the PMOS transistor Q1. The gate of the PMOS transistor Q1 is connected to the collector of an NPN transistor Q2 through a third resistor R3. The drain of the PMOS transistor Q1 is connected to the VUSB pin of the MiniUSB interface through a zener diode D2. The emitter of the NPN transistor Q2 is connected to the negative pole of the power supply 601. The base of the NPN transistor Q2 is connected to the IO pin of the main control unit through a fourth resistor R4. The main control unit 200 is connected with a membrane switch S1 for controlling the output of the IO pin. The base of the NPN transistor Q2 is also connected to the negative pole of the power supply 601 through a fifth resistor R5. A tantalum electrolytic capacitor C1, a ceramic capacitor C2, and a transient voltage suppression diode D3 are connected in parallel between the drain of the PMOS transistor Q1 and the negative pole of the power supply 601. The negative pole of the power supply 601 is grounded.

[0066] When the membrane switch is pressed at startup, the network POWER is grounded, and the level is 0, that is, the gate level of the PMOS transistor Q1 is 0, Ugs < Ugs(th). At this time, the PMOS transistor Q1 is turned on, and the subsequent circuits (that is, the first DC-DC boost circuit 602 and the second DC-DC boost circuit 603) are powered to work normally. At the same time, the pin IO of the main control unit 200 continuously outputs a high level, causing the NPN transistor Q2 to be turned on, continuously pulling down the gate level of the PMOS transistor Q1. At this time, it is in the startup state.

[0067] When the membrane switch is pressed again, the pin IO of the main control unit 200 outputs a low level. At this time, the NPN transistor Q2 is turned off, and the gate level of the PMOS transistor Q1 is pulled up by the resistor R2, Ugs > Ugs(th). At this time, the PMOS transistor Q1 is turned off, and it is in the shutdown state at this time.

[0068] When the MiniUSB is connected, the 5V VUSB makes VCC continuously maintain at 2.8V through the zener diode D2 (zener voltage value is 2.2V), bypassing the control of the PMOS transistor Q1 to supply power to the subsequent circuits, which is mainly used during program burning.

[0069] The input protection circuit consists of a battery pack connected in series with a 0.25A one-time blow fuse F1 and a current limiting resistor R1.

[0070] In the input protection circuit, diode D1 is a Schottky diode used to prevent the power supply 601 from being reversely connected. D3 is a transient voltage suppressor diode, namely a TVS tube. The decoupling capacitors are a tantalum electrolytic capacitor C1 with a rated voltage of 6.3V and a ceramic capacitor C2 with a rated voltage of 50V.

[0071] In this embodiment, the sensor unit 100 is mainly used to measure the air pressure, temperature and humidity in the environment in which the system is used, and transmit the measured data to the main control unit 200. The main control unit 200 compensates the size of the output signal through a certain algorithm so that the final output sound signal meets the requirements of "JJG 176-2022 Sound Calibrator Verification Procedure".

[0072] According to JJG 176-2022 Sound Calibrator Verification Procedure, the reference environmental conditions used in this system are:

[0073] Static pressure: 101.325kPa;

[0074] Air temperature: 23°C;

[0075] Relative humidity: 50%;

[0076] The relationship between air density and air pressure is: ;

[0077] in, is the air density, P is the air pressure, R is the specific gas constant of air, which is about 287, and T is the absolute temperature of the reference environment, which is 396.15K here.

[0078] The humidity correction factor is:

[0079] Where K is the humidity correction factor, P is the air pressure, and e is the water vapor partial pressure. The calculation formula for e is:

[0080] ;

[0081] Among them, RH is the humidity of the operating environment, e sat (T) is the saturated water vapor pressure, which can be calculated using the Wagner-Pruss equation.

[0082] In the operating environment of air pressure, temperature and humidity, the gain compensation G err for:

[0083]

[0084] Among them, P is the air pressure of the use environment, T is the temperature of the use environment, P ref is the reference ambient pressure, T ref is the temperature of the reference environment, and K is the humidity correction factor.

[0085] The output voltage after compensation is:

[0086]

[0087] Among them, V ref is the output voltage value under the reference environment.

[0088] The sound pressure level change ∆SPL after compensation is: .

[0089] In this embodiment, the main control unit 200 primarily performs the following functions: 1. Acquires the air pressure, temperature, and humidity data of the operating environment detected by the sensor unit 100, designs a sound pressure compensation algorithm, and controls the magnitude of the output signal of the digital-to-analog converter 300; 2. Generates a sinusoidal signal of a specified frequency and amplitude, outputs it through the digital-to-analog converter 300 and operational amplifier 400, and thereby generates an acoustic signal within the coupling cavity 500; 3. Designs a frequency response adjustment method and stores the compensation parameters for each frequency point under reference environmental conditions in a storage module of the main control unit 200; and 4. Controls the output of each power supply voltage of the power management unit 600 via IO pins to conserve power.

[0090] In this embodiment, the pure tone signal is generated by the following formula:

[0091]

[0092] Among them, A ref is the pure tone signal amplitude under the reference environment, G err is the gain supplement in the current use environment, f is the frequency of the pure tone signal, n is the sampling point index number of the discrete signal, f s is the sampling rate, is the initial phase.

[0093] Frequency response conditions under reference environment:

[0094] (1) In this embodiment, the digital-to-analog converter 300 is 24 bits. The main control unit 200 outputs data to the digital-to-analog converter 300 through the I2S interface. The output amplitude of the digital signal (i.e., the pure tone signal generated by the main control unit 200) is 0~2 24 -1, fix the amplitude of the digital signal to 2 at the reference temperature 22 While ensuring the signal-to-noise ratio of the output signal of the digital-to-analog converter 300, a gain compensation space is reserved, with a maximum gain compensation of 12dB.

[0095] (2) In this embodiment, the output frequency range is set to 20 Hz ~ 16 kHz. Due to the influence of the frequency response of the sound-generating device in the coupling cavity 500, when the operational amplifier 400 outputs the same electrical signal, the sound pressure level of the sound signal generated by the sound-generating device will have a large deviation when driving the sound-generating device to emit a sound signal. To solve this problem, the operational amplifier 400 uses a controllable gain amplifier as the main component, and uses the DAC peripheral of the main control unit 200 to output a DC voltage to adjust the amplitude of the output electrical signal.

[0096] (3) The DC voltage value used to adjust the gain of the controllable gain amplifier in the range of 20 Hz to 16 kHz is stored in the storage medium.

[0097] The storage solution of this embodiment is as follows:

[0098] In this embodiment, the storage medium is mainly used to store the software of the system and adjust the DC voltage value of the gain of the controllable gain amplifier. The allocation of the storage area is as follows: Figure 4 As shown:

[0099] BootLoader: used to store the boot program. This program is executed first when the device is powered on or the software is reset to jump to the APP program.

[0100] Upgrade identification area: When all program files are successfully downloaded through the serial port and the total checksum is verified, this area stores the size of the new program file. The boot program determines whether to copy the program file from the "upgrade file storage area" to the "APP running area" by judging the content of this area;

[0101] Instrument information storage area: mainly used to store the instrument's software version number, hardware version, and machine number;

[0102] APP running area: All functional programs of this system are stored in this area;

[0103] Upgrade file storage area: receives bin files transmitted via the serial port for subsequent software version upgrades and maintenance;

[0104] Each frequency point correction value storage area: used to store the DC voltage value set at the reference temperature to adjust the frequency response of this system.

[0105] The digital-to-analog converter (DAC) 300 uses an I2S audio interface to receive pure audio signals from the main control unit 200 and convert them into analog signals for processing by subsequent circuit modules. This system uses a 24-bit DAC with a sampling rate of 48kHz and a 3.3V reference voltage. The DAC's output voltage range is 0-3.3V.

[0106] In this embodiment, the operational amplifier 400 is a controllable gain amplifier, which has the following three purposes:

[0107] (1) The DC signal of the main control unit 200 is used to control the amplitude of the output signal of the operational amplifier 400, thereby adjusting the frequency response of the sound signal output;

[0108] (2) Convert the single-ended signal output by the digital-to-analog converter 300 into a differential signal and output it to the speaker 501 in the coupling cavity 500;

[0109] (3) It has the function of power amplification to ensure that the speaker 501 can output the sound signal normally.

[0110] In this embodiment, in order to realize human-computer interaction, the main control unit 200 is also connected to human-computer interaction devices such as a touch screen, a display + control panel or a display + keyboard + mouse. In order to realize data storage, the main control unit is also configured with a storage medium. The sensor unit 100 is used to collect information such as air pressure, temperature, humidity, etc. in the use environment, and a sound pressure compensation algorithm is designed based on the air pressure, temperature, humidity and other information. The output sound pressure level in the reference environment is compensated and the size of the sound signal output is adjusted so that the sound signal meets the requirements of a Class 1 sound calibrator. At the same time, the system of this embodiment does not need to use expensive Class 1 or LS microphones, nor does it need to design acquisition circuits and calculate sound pressure levels in the hardware circuit, thereby simplifying the circuit, reducing costs, and realizing calibration of multiple frequency points and multiple sound pressure levels.

[0111] Example 2

[0112] like Figure 5 As shown, a method for adjusting the frequency response of an acoustic signal generating device based on multi-sensor data acquisition according to Example 2 of the present application is applied to the frequency response adjustment system for an acoustic signal generating device based on multi-sensor data acquisition as described in the first aspect. Before implementing the method, two preparatory steps are required: 1. Inserting a measurement microphone into a coupling cavity to detect the sound pressure level of the acoustic signal in the coupling cavity; 2. Storing the output voltage value of the digital-to-analog converter at each frequency point under a reference environment to a specified address. The method includes:

[0113] S100, reading the output voltage value of the digital-to-analog converter at each frequency point under the reference environment stored in the specified address;

[0114] S200, setting the frequency of the output signal;

[0115] S300, setting the output voltage value of the digital-to-analog converter at the current frequency;

[0116] S400, reading the air pressure, temperature and humidity measured by the sensor unit in the current use environment;

[0117] S500, calculating the gain compensation G under the current use environment according to the air pressure, temperature and humidity err ;

[0118] S600, set the amplitude of the pure tone signal to G err *A ref , where A ref is the pure tone signal amplitude under the reference environment. In this embodiment, A ref Take 2 22 , that is, the amplitude of the pure tone signal needs to be set to G err *2 22 .

[0119] like Figure 6 As shown, the output voltage value of the digital-to-analog converter at each frequency point under the reference environment is stored in a specified address. The following steps S001-S004 are all performed by placing the frequency response adjustment system in the reference environment, specifically including:

[0120] S001. Set the amplitude A of the pure tone signal under the reference environment ref In this embodiment, A ref Take 2 22 ;

[0121] S002. Adjust the frequency of the pure tone signal within the range of 20Hz~16kHz;

[0122] S003. Determine whether the output sound pressure level meets the requirements based on the sound pressure level data measured by the measurement microphone. In this embodiment, if 93.75 dB ≤ the sound pressure level measured by the measurement microphone ≤ 94.25 dB, the requirements are met.

[0123] If the judgment result is no, the voltage value output by the digital-to-analog converter is adjusted, and step S003 is executed;

[0124] If the judgment result is yes, then determine whether the frequency of the pure tone signal is within the range of 20 Hz to 16 kHz. If it is within the range of 20 Hz to 16 kHz, execute step S004; otherwise, execute step S002.

[0125] S004. Store the output voltage value of the digital-to-analog converter at each frequency point.

[0126] It should be noted that, in this embodiment, the gain compensation in the current usage environment is calculated based on information such as air pressure, temperature, and humidity, and compensation is performed relative to the output sound pressure level in the reference environment to adjust the size of the sound signal output so that the sound signal meets the requirements of a Class 1 sound calibrator. For other specific implementations of the frequency response adjustment method of the sound signal generating device based on multi-sensor data acquisition in this embodiment, please refer to the specific implementation of the frequency response adjustment system of the sound signal generating device based on multi-sensor data acquisition mentioned above. To avoid redundancy, they will not be repeated here.

[0127] Example 3

[0128] A computer-readable storage medium according to embodiment 3 of the present application, wherein the computer-readable storage medium stores program code for execution by a device, the program code including steps for executing the method in any one of the implementations in embodiment 1 of the present application;

[0129] Among them, the computer-readable storage medium can be a read-only memory (ROM), a static storage device, a dynamic storage device or a random access memory (RAM); the computer-readable storage medium can store program code, and when the program stored in the computer-readable storage medium is executed by the processor, the processor is used to execute the steps of the method in any one of the implementation methods in Example 1 of the present application.

[0130] The above are only preferred specific implementations of this application; however, the scope of protection of this application is not limited thereto. Any person skilled in the art who, within the technical scope disclosed in this application, makes equivalent substitutions or modifications based on the technical solutions and improved concepts of this application shall be covered by the scope of protection of this application.

Claims

1. A frequency response adjustment system for an acoustic signal generator based on multi-sensor data acquisition, characterized in that: include: The sensor unit is used to detect the air pressure, temperature and humidity of the use environment and transmit them to the main control unit; The main control unit is used to control the output signal of the digital-to-analog converter based on the preset sound pressure compensation algorithm according to the air pressure, temperature and humidity of the operating environment, generate a pure tone signal of specified frequency and amplitude, adjust the frequency response, and store the compensation parameters of each frequency point under reference environmental conditions; A digital-to-analog converter, used to convert the pure tone signal generated by the main control unit into an analog signal; An operational amplifier, configured to control the amplitude of the output signal through a DC signal from a main control unit and to convert the analog signal from a single-ended signal into a differential signal and output it to a speaker in the coupling cavity for outputting an acoustic signal; A coupling cavity for converting the differential signal into an acoustic signal through an internal speaker; Among them, the preset sound pressure compensation algorithms include: Calculate the gain compensation G under the current usage environment err : Among them, P is the air pressure of the use environment, T is the temperature of the use environment, P ref is the reference ambient pressure, T ref is the temperature of the reference environment, K is the humidity correction factor, e is the water vapor partial pressure, e=RH*e sat (T), RH is the humidity of the operating environment, e sat (T) is the saturated water vapor pressure; The output voltage value V after compensation is: V = V ref *G err , V ref is the output voltage value under the reference environment.

2. The frequency response adjustment system for an acoustic signal generator based on multi-sensor data acquisition according to claim 1, characterized in that: It also includes a power management unit, which includes a first DC-DC boost circuit and a second DC-DC boost circuit, wherein the first DC-DC boost circuit is used to convert the connected power supply into a first specified voltage to power the sensor unit and the main control unit, and the second DC-DC boost circuit is used to convert the connected power supply into a second specified voltage to power the digital-to-analog converter and the operational amplifier.

3. The frequency response adjustment system for an acoustic signal generator based on multi-sensor data acquisition according to claim 2, characterized in that: The power management unit also includes an input protection circuit, which includes a PMOS tube. The source of the PMOS tube is connected to the positive electrode of the power supply through a first resistor, a diode and a fuse connected in series in sequence. A second resistor is connected in series between the gate and the source of the PMOS tube. The gate of the PMOS tube is connected to the collector of the NPN transistor through a third resistor. The drain of the PMOS tube is connected to VUSB through a voltage regulator diode. The emitter of the NPN transistor is connected to the negative electrode of the power supply. The base of the NPN transistor is connected to the IO pin of the main control unit through a fourth resistor. The main control unit is connected to a membrane switch for controlling the output of the IO pin. The base of the NPN transistor is also connected to the negative electrode of the power supply through a fifth resistor. A tantalum electrolytic capacitor, a ceramic capacitor and a transient voltage suppression diode are connected in parallel between the drain of the PMOS tube and the negative electrode of the power supply. The negative electrode of the power supply is grounded.

4. The frequency response adjustment system for an acoustic signal generator based on multi-sensor data acquisition according to claim 1, characterized in that: The formula for the main control unit to generate a pure tone signal is: Among them, A ref is the pure tone signal amplitude under the reference environment, G err is the gain supplement in the current use environment, f is the frequency of the pure tone signal, n is the sampling point index number of the discrete signal, f s is the sampling rate, and φ is the initial phase.

5. The frequency response adjustment system for an acoustic signal generating device based on multi-sensor data acquisition according to any one of claims 1 to 4, characterized in that: The output amplitude of the pure tone signal output by the main control unit to the digital-to-analog converter is 0 to 2 24 -1, the frequency of the pure tone signal is 20Hz~16kHz.

6. The frequency response adjustment system for an acoustic signal generator based on multi-sensor data acquisition according to claim 1 or 4, characterized in that: The air in the reference environment fixes the amplitude of the pure tone signal to 2 22 , the conditions of the reference environment are: static pressure of 101.325kPa, air temperature of 23℃, and relative humidity of 50%.

7. A frequency response adjustment method for an acoustic signal generating device based on multi-sensor data acquisition, characterized in that: The method is applied to the frequency response adjustment system of the acoustic signal generating device based on multi-sensor data acquisition according to any one of claims 1 to 6, wherein a measurement microphone is inserted into a coupling cavity, and the output voltage value of the digital-to-analog converter at each frequency point under a reference environment is pre-stored to a specified address, and the method comprises: Read the output voltage value of the digital-to-analog converter at each frequency point under the reference environment stored in the specified address; Set the frequency of the output signal; Set the output voltage value of the digital-to-analog converter at the current frequency; Read the air pressure, temperature and humidity measured by the sensor unit in the current usage environment; Calculate the gain compensation G under the current use environment according to the air pressure, temperature and humidity err ; Set the amplitude of the pure tone signal to G err *A ref , where A ref is the pure tone signal amplitude in the reference environment.

8. The frequency response adjustment method of the acoustic signal generating device based on multi-sensor data acquisition according to claim 7, characterized in that: Store the output voltage value of the digital-to-analog converter at each frequency point under the reference environment to the specified address, including: S001. Set the amplitude A of the pure tone signal under the reference environment ref ; S002. Adjust the frequency of the pure tone signal within the range of 20Hz to 16kHz; S003. Determine whether the output sound pressure level meets the requirements based on the sound pressure level data measured by the measurement microphone; If the judgment result is no, the voltage value output by the digital-to-analog converter is adjusted, and step S003 is executed; If the judgment result is yes, then determine whether the frequency of the pure tone signal is within the range of 20 Hz to 16 kHz. If it is within the range of 20 Hz to 16 kHz, execute step S004; otherwise, execute step S002. S004. Store the output voltage value of the digital-to-analog converter at each frequency point.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a program code for execution by a device, wherein the program code includes steps for executing the method according to claim 7 or 8.

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