A resonant broadband high sound pressure calibration device

Abstract

The present invention discloses a resonant broadband high sound pressure calibration device, comprising a base, a fixed cavity, a loudspeaker, a mobile cavity, a microphone, a mobile end plug, a microphone fixture, a power amplifier, a large displacement mechanism, and a small displacement mechanism. The fixed cavity, the mobile cavity, the mobile end plug, and the microphone fixture constitute an adjustable resonant cavity with a variable cross-section. By regulating the volume of the mobile cavity and the fixed cavity, the resonant frequency of the adjustable resonant cavity can be changed, and high sound pressure signals of different frequencies can be output. The small displacement mechanism is used to control the relative displacement of the mobile end plug and the mobile cavity, thereby regulating the volume of the mobile cavity. The large displacement mechanism is used to control the relative displacement of the mobile cavity and the fixed cavity, thereby regulating the volume of the fixed cavity. The loudspeaker is placed at the closed end of the fixed cavity and is connected to the power amplifier via a cable. The power amplifier is used to amplify the signal power and drive the loudspeaker to excite sound waves. The present invention has a broadband high sound pressure calibration function and can achieve low-frequency and medium-high-frequency high sound pressure calibration.

Description

Technical Field

[0001] The invention belongs to the field of high sound pressure microphone calibration, and in particular relates to a resonant broadband high sound pressure calibration device. Background Art

[0002] High sound pressure microphones are widely used in many high-noise test scenarios in fields such as aerospace, defense, and military. Broadening the calibration frequency band of high sound pressure microphones plays an important role in improving their test accuracy. At present, the calibration methods for high sound pressure microphones mainly include the piston method and the resonance method. The piston method generates a large amplitude sound wave by compressing a limited cavity with a piston. Due to problems such as control, leakage, and heat generation in mid- and high-frequency calibration, it is mainly suitable for low-frequency and high-sound pressure calibration and is difficult to apply to the mid- and high-frequency range. The resonance method excites high-intensity sound waves based on the principle of acoustic resonance, and designs its calibration frequency (resonance frequency) through the structural dimensions of the resonant cavity. It can be applied to low-frequency and mid- and high-frequency high-sound pressure calibration. However, after the structural dimensions of the resonant cavity are determined, its high-sound pressure calibration frequency is fixed and unchanged. It is limited to single-frequency high-sound pressure calibration and cannot achieve broadband high-sound pressure calibration. Summary of the Invention

[0003] The purpose of the present invention is to provide a resonant broadband high sound pressure calibration device, which has a broadband high sound pressure calibration function and can realize low-frequency and medium-high-frequency high sound pressure calibration.

[0004] In order to achieve the above-mentioned object, the present invention provides a resonant broadband high sound pressure calibration device, comprising a base, a fixed cavity, a loudspeaker, a movable cavity, a microphone, a movable end plug, a microphone fixing device, a power amplifier, a large displacement mechanism and a small displacement mechanism;

[0005] The base is used to support the entire fixing device; the fixed cavity is cylindrical, one end of which is closed and the other end is open, the closed end is fixed to the base, and the open end is embedded in the movable cavity; the movable cavity is cylindrical, both ends are open, one end is embedded in the fixed cavity, and the other end is embedded in the movable end plug, the outer wall of the movable cavity is in contact and sealed with the interior of the fixed cavity, and can slide axially relative to the fixed cavity, thereby changing the volume of the fixed cavity; the movable end plug is cylindrical, and a microphone mounting hole is provided inside, the outer wall of the movable end plug is in contact and sealed with the inner wall of the movable cavity, and can slide axially relative to the movable cavity, thereby changing the volume of the movable cavity; the microphone fixing device is cylindrical and fixed to the movable end plug; the microphone is placed in the microphone mounting hole of the movable end plug for collecting sound signals, and is fastened and sealed by the microphone fixing device;

[0006] The fixed cavity, movable cavity, movable end plug, and microphone fixing device constitute an adjustable resonant cavity with a variable cross-section. By regulating the volumes of the movable cavity and the fixed cavity, the resonant frequency of the adjustable resonant cavity can be changed, thereby outputting high sound pressure signals of different frequencies. The small displacement mechanism is used to control the relative displacement of the movable end plug and the movable cavity, thereby regulating the volume of the movable cavity; the large displacement mechanism is used to control the relative displacement of the movable cavity and the fixed cavity, thereby regulating the volume of the fixed cavity.

[0007] The loudspeaker is placed at the closed end of the fixed cavity and is connected to the power amplifier via a cable; the power amplifier is used to amplify signal power and drive the loudspeaker to excite sound waves.

[0008] Preferably, the large displacement mechanism includes a large connecting member, a large slider, a large lead screw, a large motor, and a large lead screw bracket;

[0009] One end of the large connecting piece is fixedly connected to the moving cavity, and the other end is fixedly connected to the large slider; a threaded through hole is opened in the center of the large slider, and the side is fixedly connected to the large connecting piece, and the center is penetrated by a large lead screw, and the internal thread of the large slider and the external thread of the large lead screw are screwed together;

[0010] The surface of the large lead screw has an external thread, one end of which is mounted on the large lead screw bracket and can rotate relative to the large lead screw bracket, and the other end is connected to the large motor; the large motor is fixed to the upper end of the large lead screw bracket and is used to accurately control the rotation of the large lead screw;

[0011] The side surface of the large lead screw bracket is fixed to the base, supporting the large motor and the large lead screw.

[0012] Preferably, the external thread of the large lead screw is tightly screwed with the internal thread of the large slider, and the change in the relative displacement of the large slider and the large lead screw is linearly related to the change in the rotation angle of the large lead screw. The large motor controls the rotation of the large lead screw to drive the large slider, large connecting part, and mobile cavity, so that the volume of the fixed cavity can be accurately controlled.

[0013] Preferably, the small displacement mechanism includes a small connecting member, a small slider, a small lead screw, a small motor, and a small lead screw bracket;

[0014] One end of the small connector is fixedly connected to the movable end plug, and the other end is fixedly connected to the small slider; a threaded through hole is opened in the center of the small slider, and the side is fixedly connected to the small connector, and the center is penetrated by a small screw, and the internal thread of the small slider and the external thread of the small screw are screwed together;

[0015] The surface of the small screw has an external thread, one end of which is mounted on the small screw bracket and can rotate relative to the small screw bracket, and the other end is connected to the small motor;

[0016] The small motor is fixed to the upper end of the small screw bracket for accurately controlling the rotation of the small screw; the lower end of the small screw bracket is fixed to the upper surface of the large connecting piece for supporting the small motor and the small screw, driving the small motor, the small screw and the small slider to move synchronously with the large connecting piece.

[0017] Preferably, the external thread of the small lead screw is tightly screwed with the internal thread of the small slider, and the change in the relative displacement of the small slider and the small lead screw is linearly related to the change in the rotation angle of the small lead screw. The small motor controls the rotation of the small lead screw to drive the small slider, small connector, and mobile end plug, so that the volume of the mobile cavity can be accurately controlled.

[0018] Preferably, it also includes a controller, a signal transceiver module, and a host computer;

[0019] The host computer is connected to the signal transceiver module, and is used to send the rotation control signal and the acoustic excitation signal of the large motor and the small motor, receive the acoustic signal collected by the microphone, and calibrate the microphone according to the acoustic signal;

[0020] The signal transceiver module is connected to the microphone, controller, power amplifier, and host computer, and is used to perform signal transmission and reception, receive the rotation control signal and the acoustic excitation signal, and send the rotation control signal to the controller, send the acoustic excitation signal to the power amplifier, and send the acoustic signal collected by the microphone to the host computer;

[0021] The controller is connected to the large motor and the small motor, and is used for driving and controlling the large motor and the small motor to rotate according to a rotation control signal.

[0022] According to the resonant broadband high sound pressure calibration device of the present invention, a high sound pressure calibration signal is excited by a dual-degree-of-freedom adjustable resonant cavity. The resonant frequency of the dual-degree-of-freedom adjustable resonant cavity can cover the low frequency and medium and high frequency ranges, and can realize a broadband high sound pressure calibration function. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0024] Figure 1 It is a structural schematic diagram of a resonant broadband high sound pressure calibration device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0026] The embodiment of the present invention provides a resonant broadband high sound pressure calibration device, such as Figure 1 As shown, the resonant broadband high sound pressure calibration device of the embodiment of the present invention includes a base 1, a fixed cavity 2, a speaker 3, a movable cavity 4, a microphone 5, a movable end plug 6, a microphone fixing device 7, a power amplifier 21, a large displacement mechanism and a small displacement mechanism.

[0027] The base 1 is used to support and fix the structure of the entire device; the fixed cavity 2 is cylindrical, one end of which is closed and the other end is open, the closed end is fixed to the base 1, and the open end is embedded in the movable cavity 4; the movable cavity 4 is cylindrical, both ends are open, one end is embedded in the fixed cavity 2, and the other end is embedded with a movable end plug 6, the outer wall of the movable cavity 4 is in contact and sealed with the interior of the fixed cavity 2, and can slide axially relative to the fixed cavity 2, and can change the volume of the fixed cavity 2; the movable end plug 6 is cylindrical, and a microphone mounting hole is provided inside. The outer wall of the movable end plug 6 is in contact and sealed with the inner wall of the movable cavity 4, and can slide axially relative to the movable cavity 4, and can change the volume of the movable cavity 4; the microphone fixing device 7 is cylindrical and fixed to the movable end plug 6; the microphone 5 is placed in the microphone mounting hole of the movable end plug 6 for collecting sound signals, and is fastened and sealed by the microphone fixing device 7, and can be loaded and unloaded according to calibration requirements.

[0028] The fixed cavity 2, the movable cavity 4, the movable end plug 6, and the microphone fixing device 7 constitute an adjustable resonant cavity with a variable cross-section. The adjustable resonant cavity has dual control degrees of freedom. The two volumes of the adjustable resonant cavity can be adjusted independently. By adjusting the movable cavity 4 and the movable end plug 6 to change the resonant frequency of the adjustable resonant cavity, high sound pressure signals of different frequencies can be output.

[0029] The small displacement mechanism includes a small connecting part 8, a small slider 12, a small screw 13, a small motor 10, and a small screw bracket 11, which is used to control the relative displacement between the mobile end plug 6 and the mobile cavity 4 and can regulate the volume of the mobile cavity 4. One end of the small connecting member 8 is fixedly connected to the movable end plug 6, and the other end is fixedly connected to the small slider 12; a threaded through hole is opened in the center of the small slider 12, and the side is fixedly connected to the small connecting member 8, and the center is penetrated by a small lead screw 13, and the internal thread of the small slider 12 and the external thread of the small lead screw 13 are screwed together; the surface of the small lead screw 13 has an external thread, one end of which is mounted on the small lead screw bracket 11 and can rotate relative to the small lead screw bracket 11, and the other end is connected to the small motor 10; the small motor 10 is fixed to the upper end of the small lead screw bracket 11 for accurately controlling the rotation of the small lead screw 13; the lower end of the small lead screw bracket 11 is fixed to the upper surface of the large connecting member 9 for supporting the small motor 10 and the small lead screw 13, driving the small motor 10, the small lead screw 13, and the small slider 12 to move synchronously with the large connecting member 9;

[0030] Preferably, the external thread of the small lead screw 13 is tightly screwed with the internal thread of the small slider 12, and the change in the relative displacement between the small slider 12 and the small lead screw 13 is linearly related to the change in the rotation angle of the small lead screw 13. The small motor 10 controls the rotation of the small lead screw 13 to drive the small slider 12, the small connecting piece 8, and the movable end plug 6, so that the volume of the movable cavity 4 can be accurately controlled.

[0031] The large displacement mechanism includes a large connector 9, a large slider 16, a large lead screw 17, a large motor 14, and a large lead screw bracket 15, which are used to control the relative displacement of the movable chamber 4 and the fixed chamber 2, and can adjust the volume of the fixed chamber 2. The large connector 9 is fixedly connected to the movable chamber 4 at one end and fixedly connected to the large slider 16 at the other end; the large slider 16 has a threaded through hole in the center, and is fixedly connected to the large connector 9 on the side. The center is penetrated by the large lead screw 17, and the internal thread of the large slider 16 and the external thread of the large lead screw 17 are screwed together; the surface of the large lead screw 17 has an external thread, one end of which is mounted on the large lead screw bracket 15 and can rotate relative to the large lead screw bracket 15, and the other end is connected to the large motor 14; the large motor 14 is fixed to the upper end of the large lead screw bracket 15, and is used to accurately control the rotation of the large lead screw 17; the side of the large lead screw bracket 15 is fixed to the base 1, supporting the large motor 14 and the large lead screw 17.

[0032] Preferably, the external thread of the large lead screw 17 is tightly screwed with the internal thread of the large slider 16, and the change in the relative displacement between the large slider 16 and the large lead screw 17 is linearly related to the change in the rotation angle of the large lead screw 17. The large motor 14 controls the rotation of the large lead screw 17 to drive the large slider 16, the large connecting piece 9, and the movable cavity 4, so that the volume of the fixed cavity 2 can be accurately controlled.

[0033] The large displacement mechanism and the small displacement mechanism together constitute a displacement control module, which is used to realize independent control of the two sections of the adjustable resonant cavity; the large displacement mechanism moves alone to independently control the volume of the fixed cavity 2, and the small displacement mechanism moves synchronously with the large displacement mechanism to independently control the volume of the movable cavity 4. The large and small displacement mechanisms in the displacement control module decouple the two cavities of the adjustable resonant cavity.

[0034] The loudspeaker 3 is placed at the closed end of the fixed cavity 2 and is connected to the power amplifier 21 via a cable; the power amplifier 21 is used to amplify signal power, drive the loudspeaker 3 to work, and excite sound waves.

[0035] Preferably, the resonant broadband high sound pressure calibration device of the embodiment of the present invention further includes a controller 18, a signal transceiver module 19, and a host computer 20. The controller 18 is separately connected to the large motor 14 and the small motor 10, and is used to drive and control the rotation of the two motors to achieve decoupling control of the two cavities of the adjustable resonant cavity; the signal transceiver module 19 is used for overall signal transmission and reception of the calibration device, and is connected to the microphone 5, the controller 18, the power amplifier 21, and the host computer 20; the host computer 20 is connected to the signal transceiver module 19 to complete the signal excitation, acquisition, processing and analysis of the high sound pressure calibration process.

[0036] Specifically, the host computer 20 is connected to the signal transceiver module 19, and is used to send rotation control signals and sound excitation signals of the large motor 14 and the small motor 10, receive the sound signals collected by the microphone 5, and calibrate the microphone according to the sound signals; the signal transceiver module 19 is connected to the microphone 5, the controller 18, the power amplifier 21, and the host computer 20, and is used to perform signal transmission and reception, receive rotation control signals and sound excitation signals, and send the rotation control signal to the controller 18, send the sound excitation signal to the power amplifier 21, and send the sound signal collected by the microphone 5 to the host computer; the controller 18 is connected to the large motor 14 and the small motor 10, and is used to drive and control the rotation of the large motor 14 and the small motor 10 according to the rotation control signal.

[0037] The working process of the resonant broadband high sound pressure calibration device according to the embodiment of the present invention is described in detail below through a specific embodiment.

[0038] The desired calibration frequency f is input to the host computer 20, which automatically determines the required rotation angles θ1 and θ2 of the large motor 14 and the small motor 10 based on the calibration frequency, so that the resonant frequency of the resonant cavity is equal to the desired calibration frequency. First, the host computer 20 sends a rotation control signal for the large motor 14 to the signal transceiver module 19. The signal transceiver module 19 transmits the rotation control signal to the controller 18. The controller 18 drives the large motor 14 to rotate by an angle θ1. The large motor 14 drives the large lead screw 17 to rotate synchronously. The large lead screw 17 drives the large slider 16 to move linearly along the axial direction. The displacement L1 of the large slider 16 is proportional to the rotation angle θ1 of the large lead screw 17. The large slider 16 drives the large connector 9 and the movable cavity 4 to move synchronously, completing the volume adjustment of the fixed cavity 2, and then remains stationary. The host computer 20 then sends a rotation control signal for the small motor 10 to the signal transceiver module 19. The signal transceiver module 19 transmits the rotation control signal to the controller 18. The controller 18 drives the small motor 10 to rotate by an angle θ2. The small motor 10 drives the small lead screw 13 to rotate synchronously. The small lead screw 13 drives the small slider 12 to move linearly along the axial direction. The displacement L2 of the small slider 12 is proportional to the rotation angle θ2 of the small lead screw 13. The small slider 12 drives the small connector 8 and the movable end plug 6 to move synchronously, completing the volume adjustment of the movable cavity 4, and then remains stationary. The host computer 20 then sends an acoustic excitation signal to the signal transceiver module 19. The signal transceiver module 19 sends the acoustic excitation signal to the power amplifier 21. The power amplifier 21 amplifies the signal and sends it to the speaker 3, driving the speaker 3 to excite a sound wave with a frequency f. The sound wave resonates in the resonant cavity, and the sound signal is sampled by the standard microphone and the signal transceiver module 19. The sound signal is then transmitted to the host computer 20 to obtain the sound signal of the standard microphone. Next, the standard microphone is replaced with the microphone to be calibrated. The host computer 20 sends the same acoustic excitation signal to the signal transceiver module 19. This signal is then sent to the power amplifier 21, which amplifies the signal and sends it to the speaker 3, driving the speaker 3 to generate a sound wave at a frequency of f. The acoustic signal is sampled by the microphone to be calibrated and the signal transceiver module 19, and then transmitted to the host computer 20, obtaining the acoustic signal of the microphone to be calibrated. The host computer 20 then controls the large motor 14 and the small motor 10 to return to their initial rotation angles. The host computer 20 then calibrates the microphone to be calibrated using a comparison method.

[0039] In summary, the resonant broadband high sound pressure calibration device of the embodiment of the present invention realizes high sound pressure calibration based on the resonance principle and the comparison method, and its core lies in the designed dual-degree-of-freedom adjustable resonant cavity and displacement control module. The designed dual-degree-of-freedom adjustable resonant cavity includes two independent adjustable cavities, and has dual control degrees of freedom. By controlling the resonant frequency of the adjustable resonant cavity with dual degrees of freedom, it can output high sound pressure calibration signals in the low frequency and medium and high frequency ranges; the designed displacement control module is composed of two large and small displacement mechanisms. The large displacement mechanism can move independently, and the small displacement mechanism and the large displacement mechanism move synchronously. The large displacement mechanism and the small displacement mechanism are decoupled and controlled for the two cavities of the adjustable resonant cavity, and can adjust the resonant frequency of the adjustable resonant cavity in the low frequency and medium and high frequency ranges. Furthermore, broadband high sound pressure calibration is realized based on the designed dual-degree-of-freedom adjustable resonant cavity and the displacement control module.

[0040] The resonant broadband high sound pressure calibration device of the embodiment of the present invention has the advantages of a wide calibration frequency band, good controllability, high stability, etc., and has great application value in the calibration of high-voltage microphones.

[0041] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A resonant broadband high sound pressure calibration device, characterized in that: It includes a base, a fixed cavity, a speaker, a movable cavity, a microphone, a movable end plug, a microphone fixing device, a power amplifier, a large displacement mechanism and a small displacement mechanism; The base is used to support the entire fixing device; the fixed cavity is cylindrical, one end of which is closed and the other end is open, the closed end is fixed to the base, and the open end is embedded in the movable cavity; the movable cavity is cylindrical, both ends are open, one end is embedded in the fixed cavity, and the other end is embedded in the movable end plug, the outer wall of the movable cavity is in contact and sealed with the interior of the fixed cavity, and can slide axially relative to the fixed cavity, thereby changing the volume of the fixed cavity; the movable end plug is cylindrical, and a microphone mounting hole is provided inside, the outer wall of the movable end plug is in contact and sealed with the inner wall of the movable cavity, and can slide axially relative to the movable cavity, thereby changing the volume of the movable cavity; the microphone fixing device is cylindrical and fixed to the movable end plug; the microphone is placed in the microphone mounting hole of the movable end plug for collecting sound signals, and is fastened and sealed by the microphone fixing device; The fixed cavity, movable cavity, movable end plug, and microphone fixing device constitute an adjustable resonant cavity with a variable cross-section. By regulating the volumes of the movable cavity and the fixed cavity, the resonant frequency of the adjustable resonant cavity can be changed, thereby outputting high sound pressure signals of different frequencies. The small displacement mechanism is used to control the relative displacement of the movable end plug and the movable cavity, thereby regulating the volume of the movable cavity; the large displacement mechanism is used to control the relative displacement of the movable cavity and the fixed cavity, thereby regulating the volume of the fixed cavity. The loudspeaker is placed at the closed end of the fixed cavity and is connected to the power amplifier via a cable; the power amplifier is used to amplify signal power and drive the loudspeaker to excite sound waves.

2. The resonant broadband high sound pressure calibration device according to claim 1, wherein: The large displacement mechanism includes a large connecting piece, a large slider, a large lead screw, a large motor, and a large lead screw bracket; One end of the large connecting piece is fixedly connected to the moving cavity, and the other end is fixedly connected to the large slider; a threaded through hole is opened in the center of the large slider, and the side is fixedly connected to the large connecting piece, and the center is penetrated by a large lead screw, and the internal thread of the large slider and the external thread of the large lead screw are screwed together; The surface of the large lead screw has an external thread, one end of which is mounted on the large lead screw bracket and can rotate relative to the large lead screw bracket, and the other end is connected to the large motor; the large motor is fixed to the upper end of the large lead screw bracket and is used to accurately control the rotation of the large lead screw; The side surface of the large lead screw bracket is fixed to the base, supporting the large motor and the large lead screw.

3. The resonant broadband high sound pressure calibration device according to claim 2, wherein: The external thread of the large lead screw is tightly screwed with the internal thread of the large slider. The change in the relative displacement of the large slider and the large lead screw is linearly related to the change in the rotation angle of the large lead screw. The large motor controls the rotation of the large lead screw to drive the large slider, the large connecting part, and the mobile cavity, so that the volume of the fixed cavity can be accurately controlled.

4. The resonant broadband high sound pressure calibration device according to claim 2 or 3, characterized in that: The small displacement mechanism includes a small connecting piece, a small slider, a small lead screw, a small motor, and a small lead screw bracket; One end of the small connector is fixedly connected to the movable end plug, and the other end is fixedly connected to the small slider; a threaded through hole is opened in the center of the small slider, and the side is fixedly connected to the small connector, and the center is penetrated by a small screw, and the internal thread of the small slider and the external thread of the small screw are screwed together; The surface of the small screw has an external thread, one end of which is mounted on the small screw bracket and can rotate relative to the small screw bracket, and the other end is connected to the small motor; The small motor is fixed to the upper end of the small screw bracket for accurately controlling the rotation of the small screw; the lower end of the small screw bracket is fixed to the upper surface of the large connecting piece for supporting the small motor and the small screw, driving the small motor, the small screw and the small slider to move synchronously with the large connecting piece.

5. The resonant broadband high sound pressure calibration device according to claim 4, characterized in that: The external thread of the small lead screw is tightly screwed with the internal thread of the small slider. The change in relative displacement between the small slider and the small lead screw is linearly related to the change in the rotation angle of the small lead screw. The small motor controls the rotation of the small lead screw to drive the small slider, small connector, and mobile end plug, thereby accurately controlling the volume of the mobile cavity.

6. The resonant broadband high sound pressure calibration device according to claim 4, characterized in that: It also includes a controller, a signal transceiver module, and a host computer; The host computer is connected to the signal transceiver module, and is used to send the rotation control signal and the acoustic excitation signal of the large motor and the small motor, receive the acoustic signal collected by the microphone, and calibrate the microphone according to the acoustic signal; The signal transceiver module is connected to the microphone, controller, power amplifier, and host computer, and is used to perform signal transmission and reception, receive the rotation control signal and the acoustic excitation signal, and send the rotation control signal to the controller, send the acoustic excitation signal to the power amplifier, and send the acoustic signal collected by the microphone to the host computer; The controller is connected to the large motor and the small motor, and is used for driving and controlling the large motor and the small motor to rotate according to a rotation control signal.

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