Double-resonance cavity solid acoustic sensor device

Abstract

The present invention relates to a dual-resonance cavity solid acoustic sensor device, including a dual-resonance cavity solid acoustic sensor, the dual-resonance cavity solid acoustic sensor includes an outer resonant cavity and an inner resonant cavity, the outer resonant cavity is sleeved on the outer side of the inner resonant cavity, a plurality of side ejectors are fixed at equal intervals on the side wall of the outer resonant cavity, the heads of the side ejectors are in contact with the outer surface of the side wall of the inner resonant cavity; an ultra-low frequency vibrator and a medium-high frequency vibrator are arranged in the inner resonant cavity; the ultra-low frequency vibrator includes a first piezoelectric ceramic sheet and a single cantilever spring, the first piezoelectric ceramic sheet is fixed in the inner resonant cavity at a single point through the cantilever spring; the medium-high frequency vibrator includes a second piezoelectric ceramic sheet, an ejector and a plurality of vibration conduction springs, the second piezoelectric ceramic sheet is fixed in the inner resonant cavity at multiple points through the vibration conduction spring, and the needle head of the ejector passes through the inner resonant cavity and pushes on the second piezoelectric ceramic sheet. The present invention can effectively pick up space and solid propagation sound, has a wide frequency response range, and has extremely high sensitivity to sound signals in low, medium and high frequency bands.

Description

Technical Field

[0001] The invention belongs to the technical field of spatial sound detection, and in particular relates to a double-resonance cavity solid acoustic sensor device. Background Art

[0002] Sound waves are vibrations of the sound source that cause the surrounding air to oscillate, and that type of oscillation is sound waves; sound propagates in the form of waves, which we call sound waves; sound waves propagate in all directions with the help of air; in the air of open spaces, that type of propagation is like a soap bubble that gradually grows, a spherical surface wave; to be able to hear sound there must be a medium to propagate the sound; in addition to air, water, metal, wood, etc. can also transmit sound waves, and they are all good media for sound waves.

[0003] Existing spatial sound detectors rely on air transmission to pick up spatial sound. If they are buried underground or in solid bodies such as walls, the received spatial sound intensity is very weak due to the sound barrier formed by the solid medium, and the sound outside the surface or wall cannot be heard.

[0004] In view of this, there is a need for a spatial sound detection device that can be concealed in a solid medium such as underground or a wall to pick up spatial sound. Summary of the invention

[0005] The object of the present invention is to provide a dual-resonance cavity solid acoustic sensor device, which can effectively pick up space and solid propagation sound by being concealed in solid media such as underground and walls.

[0006] The present invention provides a dual-resonance cavity solid acoustic sensor device, comprising a dual-resonance cavity solid acoustic sensor, the dual-resonance cavity solid acoustic sensor comprising an outer resonant cavity and an inner resonant cavity, the outer resonant cavity is sleeved on the outer side of the inner resonant cavity, a plurality of side ejector pins are fixed at equal intervals on the side wall of the outer resonant cavity, the heads of the side ejector pins are in contact with the outer surface of the side wall of the inner resonant cavity; an ultra-low frequency vibrator for picking up an ultra-low frequency sound signal propagated by a solid medium, and a mid-high frequency vibrator for picking up a mid-high frequency sound signal propagated by a solid medium are arranged in the inner resonant cavity;

[0007] The ultra-low frequency vibrator comprises a first piezoelectric ceramic sheet and a single cantilever spring, wherein the first piezoelectric ceramic sheet is fixed in the inner resonant cavity by being suspended at a single point by the cantilever spring;

[0008] The medium and high frequency vibrator includes a second piezoelectric ceramic sheet, a pin and a plurality of vibration conducting springs. The second piezoelectric ceramic sheet is suspended and fixed in the inner resonant cavity at multiple points through the vibration conducting springs. The tip of the pin passes through the inner resonant cavity and presses against the second piezoelectric ceramic sheet.

[0009] Furthermore, the inner resonant cavity is a cylindrical structure made of thin-walled metal, and the outer resonant cavity is a cylindrical structure made of thin-walled metal.

[0010] Furthermore, the top surfaces of the outer resonant cavity and the inner resonant cavity are in a connected state in the same horizontal plane, and the bottom surfaces are in different horizontal planes and are separated and not in contact.

[0011] Furthermore, it also includes a signal processing device, which includes a summing amplifier circuit, an automatic gain control circuit and a filtering amplifier circuit connected in sequence;

[0012] The summing amplifier circuit is used to sum and amplify the picked-up ultra-low frequency sound signal and the medium and high frequency sound signal; the automatic gain control circuit is used to perform automatic gain control on the sound signal; and the filtering amplifier circuit is used to filter and amplify the sound signal.

[0013] Furthermore, it also includes an optical fiber transmission device, which is connected to the filtering and amplifying circuit and is used to convert the sound electrical signal into an optical signal for output.

[0014] Furthermore, the signal processing device is provided with an AC power supply interface.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention utilizes a dual-resonance cavity structure to conduct the vibration signal received by the outer resonant cavity through the side ejector to produce a physical amplification effect. After the amplified vibration signal is conducted to the inner resonant cavity, the inner resonant cavity utilizes a dual-oscillator structure to form an extremely sensitive, wide-band solid acoustic sensor as a whole. The sensor can be concealed in solid media such as underground and walls. Through the principles of solid sound transmission and cavity resonance, geological layers, walls and other solids are used as sound pickup and propagation media. Since solid sound transmission has a fast propagation speed and low attenuation, and the built-in dual-resonance cavity structure and dual-oscillator pickup structure of the present invention, the acoustic sensor has a wide frequency response range and is extremely sensitive to sound signals in the low, medium and high frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a dual-resonance cavity solid acoustic sensor device of the present invention;

[0018] Figure 2 It is a cross-sectional schematic diagram of the dual-resonance cavity solid acoustic sensor device of the present invention. DETAILED DESCRIPTION

[0019] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0020] Embodiment 1

[0021] See also Figure 1 , Figure 2 The present embodiment provides a dual-resonance cavity solid acoustic sensor device, including a dual-resonance cavity solid acoustic sensor, the dual-resonance cavity solid acoustic sensor includes an outer resonant cavity 2 and an inner resonant cavity 1, the outer resonant cavity 2 is sleeved on the outside of the inner resonant cavity 1, four side ejector pins 3 are fixed on the side wall of the outer resonant cavity 2 at equal intervals, and the heads of the side ejector pins 3 are in contact with the outer surface of the side wall of the inner resonant cavity 1; the inner resonant cavity 1 is provided with an ultra-low frequency vibrator for picking up ultra-low frequency sound signals propagated by a solid medium, and a medium-high frequency vibrator for picking up medium-high frequency sound signals propagated by a solid medium.

[0022] The ultra-low frequency vibrator includes a first piezoelectric ceramic sheet 11 and a single cantilever spring 12. The first piezoelectric ceramic sheet 11 is fixed in the inner resonant cavity 1 by the cantilever spring 12 at a single point. When the inner resonant cavity 1 resonates with the vibration signal of the attached solid, the vibration signal is transmitted to the first piezoelectric ceramic sheet 11 through the cantilever spring 12, causing the first piezoelectric ceramic sheet 11 to vibrate and displace, generating a sound signal. The ultra-low frequency vibrator structure is sensitive to ultra-low frequency sound signals such as footsteps, digging and smashing. Ultra-low frequency sound signals refer to sound signals between 10Hz and 500Hz.

[0023] The mid-high frequency vibrator includes a second piezoelectric ceramic sheet 13, a pin 14 and a plurality of vibration transmission springs 15. The second piezoelectric ceramic sheet 13 is suspended and fixed in the inner resonant cavity 1 at multiple points through the vibration transmission springs 15. The tip of the pin 14 passes through the inner resonant cavity 1 and is pressed against the second piezoelectric ceramic sheet 13. When the inner resonant cavity 1 resonates with the vibration signal of the attached solid, the pin 14 applies a pressure corresponding to the vibration signal to the second piezoelectric ceramic sheet 13 to generate a sound signal. The mid-high frequency vibrator structure is sensitive to mid-high frequency environmental sound signals such as speech and motor vehicles. Mid-high frequency sound signals refer to sound signals between 500Hz and 5KHz.

[0024] In the dual-resonance cavity solid acoustic sensor, a wide-frequency response solid acoustic sensor composed of dual vibrators can be concealedly buried in solid media such as underground and walls. Through the principles of solid sound transmission and cavity resonance, geological layers, walls and other solids are used as sound pickup and propagation media. Since solid sound transmission has a fast propagation speed and low attenuation, and the built-in dual-vibrator pickup structure of the present invention, the acoustic sensor has a wide frequency response range and is extremely sensitive to sound signals in the low, medium and high frequency bands.

[0025] In this embodiment, the inner resonant cavity 1 is a cylindrical structure made of thin-walled metal, with an ultra-low frequency vibrator and a medium-high frequency vibrator built in, buried in the ground, wall and other solids. Through the principle of solid sound transmission and cavity resonance, the inner resonant cavity resonates with the vibration signal of the attached solid, and the vibration signal is applied to the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet inside the inner resonant cavity through the cantilever spring and the ejector pin in the inner resonant cavity, respectively, to generate a sound signal. The ultra-low frequency vibrator focuses on picking up ultra-low frequency sound signals such as footsteps, digging and smashing, and the medium-high frequency vibrator focuses on picking up medium-high frequency environmental sound signals such as speaking and motor vehicles. The outer resonant cavity 2 is a cylindrical structure made of thin-walled metal. The top surface of the outer resonant cavity 2 and the inner resonant cavity 1 are connected in the same horizontal plane, and the bottom surface is a different horizontal plane, separated and not in contact.

[0026] See also Figure 1 The dual-resonance cavity solid acoustic sensor device also includes a signal processing device, which includes a summing amplifier circuit 21, an automatic gain control circuit 22 and a filtering amplifier circuit 23 connected in sequence, and is used to receive two sound signals picked up by the dual-resonance cavity solid acoustic sensor, perform summing amplification, automatic gain control, filtering and amplification, and output a complete sound signal in a low, medium and high wide frequency range.

[0027] Specifically, the summing amplifier circuit 21 sums and amplifies the two sound signals picked up by the sound pickup structure in the inner resonant cavity, and outputs the sound signal. Since the two sound pickup structures in the inner resonant cavity have different sensitivities to sound signals in different frequency bands, the pin-type sound pickup structure is sensitive to medium and high frequency environmental sound signals such as speech and motor vehicles, and the cantilever-type sound pickup structure is sensitive to low frequency sound signals such as footsteps and digging, the two signals are summed and amplified by the summing amplifier circuit, so that the acoustic sensor has a wide frequency response range and has extremely high sensitivity to sound signals in low, medium and high frequency bands.

[0028] The automatic gain control circuit 22 performs automatic gain control on the sound signal. In order to improve the sensitivity of picking up weak sound at the far end, the sound signal needs to be amplified at a high multiple. By adding an automatic gain control circuit to the signal processing device, when the sound signal picked up at the near end is too strong, the automatic gain control circuit automatically reduces the amplification factor to keep the sound signal strength within a reasonable range, thereby avoiding distortion caused by too strong sound.

[0029] The filter amplifier circuit 23 filters and amplifies the sound signal to improve the sound quality.

[0030] In this embodiment, the dual-resonance cavity solid acoustic sensor device also includes an optical fiber transmission device 4, which is connected to the filter amplifier circuit 23 and is used to convert the sound electrical signal into an optical signal for output. The optical fiber transmission device is composed of an optical modulation circuit and an optical transmission module, which converts the electrical signal into an optical signal for output. Due to the serious problem of lightning strikes in the wild, optical fiber transmission signals can be used for field deployment, and the electrical signal is converted into an optical signal through the optical modulation circuit, and the signal is output through the optical fiber transmission module.

[0031] In this embodiment, the signal processing device is provided with an AC power supply interface. In order to ensure long-distance power transmission in the field and prevent damage caused by lightning strikes in the field, the signal processing device can be powered by an AC power supply.

[0032] The present invention utilizes a dual-resonance cavity structure to conduct the vibration signal received by the outer resonant cavity through the side ejector to produce a physical amplification effect. After the amplified vibration signal is conducted to the inner resonant cavity, the inner resonant cavity utilizes a dual-oscillator structure to form an extremely sensitive, wide-band solid acoustic sensor as a whole. The sensor can be concealed in solid media such as underground and walls. Through the principles of solid sound transmission and cavity resonance, geological layers, walls and other solids are used as sound pickup and propagation media. Since solid sound transmission has a fast propagation speed and low attenuation, and the built-in dual-resonance cavity structure and dual-oscillator pickup structure of the present invention, the acoustic sensor has a wide frequency response range and is extremely sensitive to sound signals in the low, medium and high frequency bands.

[0033] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0034] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A dual-resonance cavity solid acoustic sensor device, characterized in that: The invention comprises a dual-resonance cavity solid acoustic sensor, the dual-resonance cavity solid acoustic sensor comprising an outer resonant cavity (2) and an inner resonant cavity (1), the outer resonant cavity (2) being sleeved on the outer side of the inner resonant cavity (1), a plurality of side ejector pins (3) being fixed at equal intervals on the side wall of the outer resonant cavity (2), the heads of the side ejector pins (3) being in contact with the outer surface of the side wall of the inner resonant cavity (1); an ultra-low frequency vibrator for picking up an ultra-low frequency sound signal propagated by a solid medium, and a mid-high frequency vibrator for picking up a mid-high frequency sound signal propagated by a solid medium are arranged in the inner resonant cavity (1); The ultra-low frequency vibrator comprises a first piezoelectric ceramic sheet (11) and a single cantilever spring (12); the first piezoelectric ceramic sheet (11) is fixed in the inner resonant cavity (1) by being suspended at a single point via the cantilever spring (12); The medium and high frequency vibrator comprises a second piezoelectric ceramic sheet (13), a pin (14) and a plurality of vibration transmission springs (15); the second piezoelectric ceramic sheet (13) is suspended and fixed in the inner resonant cavity (1) at multiple points via the vibration transmission springs (15); the tip of the pin (14) passes through the inner resonant cavity (1) and is pressed against the second piezoelectric ceramic sheet (13); The top surfaces of the outer resonant cavity (2) and the inner resonant cavity (1) are connected in the same horizontal plane, and the bottom surfaces are in different horizontal planes and are separated and not in contact; The inner resonant cavity (1) is a cylindrical structure made of thin-walled metal, and the outer resonant cavity (2) is a cylindrical structure made of thin-walled metal.

2. The dual-resonance cavity solid-state acoustic sensor device according to claim 1, characterized in that: It also includes a signal processing device, which includes a summing amplifier circuit (21), an automatic gain control circuit (22) and a filtering amplifier circuit (23) connected in sequence; The summing amplifier circuit (21) is used to sum and amplify the picked-up ultra-low frequency sound signal and the medium and high frequency sound signal; the automatic gain control circuit (22) is used to perform automatic gain control on the sound signal after summing and amplification; and the filtering amplifier circuit (23) is used to filter and amplify the sound signal after automatic gain control.

3. The dual-resonance cavity solid-state acoustic sensor device according to claim 2, characterized in that: It also comprises an optical fiber transmission device (4), which is connected to the filtering and amplifying circuit (23) and is used to convert the filtered and amplified sound signal into an optical signal for output.

4. The dual-resonance cavity solid-state acoustic sensor device according to claim 2, characterized in that: The signal processing device is provided with an AC power supply interface.

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