Device and method for adjusting sensitivity of infrasound sensor

Abstract

The present invention discloses a device and method for adjusting the sensitivity of an infrasound sensor, wherein the infrasound sensor comprises: a shell, a partition plate for dividing the space inside the shell into a front cavity and a rear cavity, the partition plate is provided with a pressure equalizing hole, the front cavity is connected to the outside, and the diaphragm and the back plate are arranged in the front cavity; the adjusting device comprises: a measuring and calculating unit for measuring the temperature T1 of the front cavity, the temperature T2 of the rear cavity and the temperature change rate dT of the rear cavity, and calculating the current compensation amount △I based on T1, T2 and dT; an adjusting unit, which is arranged in the front cavity and arranged relative to the diaphragm, and the adjusting unit is connected in communication with the measuring and calculating unit to obtain △I and adjust the tension of the diaphragm based on △I. By adopting the technical solution of the present invention, by calculating the current value of the adjusting unit, the suction force of the adjusting unit on the diaphragm is changed, thereby adjusting the tension of the diaphragm to achieve the effect of maintaining the sensitivity of the infrasound sensor, thereby improving the detection accuracy.

Description

Technical Field

[0001] The invention relates to the field of infrasound wave detection, and in particular to a device and method for adjusting the sensitivity of an infrasound sensor. Background Art

[0002] Infrasound sensors are devices that can receive infrasound signals in the air. They can be used for earthquake precursor infrasound waves, atmospheric gravity wave measurements, and monitoring and early warning of various natural disasters such as volcanoes and tsunamis. Existing infrasound sensor products can be divided into two categories according to their working principles: capacitive type and dynamic type. For capacitive infrasound sensors, their acoustic sensitive structure is a variable capacitor composed of a circular fixed metal film (diaphragm) and a back plate. The diaphragm will vibrate under the action of infrasound waves, and the capacitance value will change accordingly. Then, a voltage signal is generated through an impedance conversion circuit. The lower limit of the frequency response of the infrasound sensor can reach 0.003Hz. In order to achieve such a low frequency detection limit, the infrasound sensor has a nearly closed back cavity. When the ambient temperature changes, the air pressure in the back cavity will also change, causing the diaphragm tension to change, resulting in a drift in the output voltage of the infrasound sensor, and also causing a change in sensitivity. Infrasound sensors are usually used in arrays with long distances between each sensor. At this time, the voltage drift and sensitivity fluctuations of each sensor caused by changes in environmental factors are inconsistent, resulting in poor amplitude consistency of the sensor array, which has a serious impact on the accuracy of infrasound monitoring and cannot meet the needs of long-distance infrasound detection. Summary of the invention

[0003] The present invention provides an infrasound sensor sensitivity adjustment device and method, which are used to at least solve the problem of poor detection accuracy caused by the change of infrasound sensor sensitivity caused by ambient temperature in the prior art.

[0004] According to a first aspect of the present invention, an infrasound sensor sensitivity adjustment device is provided, wherein the infrasound sensor comprises:

[0005] A shell, provided with a partition for dividing the space inside the shell into a front cavity and a rear cavity, the partition is provided with a pressure equalizing hole, the front cavity is communicated with the outside, and the diaphragm and the back plate are arranged in the front cavity;

[0006] The regulating device comprises:

[0007] A measuring and calculating unit, used for measuring the temperature T1 of the front cavity, the temperature T2 of the rear cavity and the temperature change rate dT of the rear cavity, and calculating the current compensation amount ΔI based on the T1, the T2 and the dT;

[0008] An adjustment unit is disposed in the front cavity and arranged opposite to the diaphragm. The adjustment unit is communicatively connected with the measurement and calculation unit to obtain the ΔI and adjust the tension of the diaphragm based on the ΔI.

[0009] According to some embodiments of the present invention, the adjustment unit is an electromagnetic coil.

[0010] According to some embodiments of the present invention, the distance between the electromagnetic coil and the diaphragm is 0.3 mm-0.7 mm.

[0011] According to some embodiments of the present invention, the measurement calculation unit comprises:

[0012] A front cavity temperature measurement module, arranged in the front cavity;

[0013] A rear cavity temperature measurement module, disposed in the rear cavity;

[0014] A calculation module is communicatively connected with the front cavity temperature measurement module and the rear cavity temperature measurement module, and the calculation module is used to:

[0015] Determine the size relationship between T1 and T2;

[0016] If T1 is greater than T2, ΔI is calculated by formula 1:

[0017]

[0018] If T1 is equal to T2, then ΔI is zero;

[0019] If T1 is less than T2, ΔI is calculated by formula 2:

[0020]

[0021] Among them, I 0 It represents the initial current value of the adjustment unit, n represents the molar amount of gas in the back cavity, R and K represent constants, S represents the effective area of ​​the diaphragm, and V represents the volume of the back cavity.

[0022] According to some embodiments of the present invention, a mounting plate having a plurality of through holes is disposed in the front cavity, and the adjustment unit is embedded in the mounting plate.

[0023] According to some embodiments of the present invention, a first support plate is disposed in the front cavity, and the front cavity temperature measurement module and the calculation module are respectively disposed on two sides of the first support plate.

[0024] According to some embodiments of the present invention, the front cavity temperature measurement module is disposed close to one side of the diaphragm.

[0025] According to some embodiments of the present invention, a second support plate is disposed in the rear cavity, and the rear cavity temperature measurement module is disposed on the second support plate.

[0026] According to some embodiments of the present invention, the rear cavity temperature measurement module is disposed close to one side of the diaphragm.

[0027] According to a second aspect of the present invention, a method for adjusting the sensitivity of an infrasound sensor implemented based on the device for adjusting the sensitivity of an infrasound sensor as described in any one of the embodiments of the first aspect includes:

[0028] The measuring and calculating unit obtains the front cavity temperature T1, the rear cavity temperature T2 and the rear cavity temperature change rate dT, and calculates the current compensation amount ΔI based on the T1, the T2 and the dT;

[0029] The adjusting unit obtains the ΔI and adjusts the tension of the diaphragm based on the ΔI.

[0030] By adopting the embodiment of the present invention, the current value of the adjustment unit is calculated based on measuring the temperatures of the front cavity and the rear cavity, and the suction force of the adjustment unit on the diaphragm is changed, thereby adjusting the tension of the diaphragm to achieve the effect of maintaining the sensitivity of the infrasound sensor, thereby improving the detection accuracy.

[0031] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various other advantages and benefits will become apparent to those skilled in the art by reading the detailed description of the embodiments below. The accompanying drawings are only used to illustrate the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings:

[0033] Figure 1 is a schematic diagram of the structure of an infrasound sensor including an adjustment device in an embodiment of the present invention;

[0034] Figure 2 It is a schematic diagram of the process of adjusting the current of the adjustment unit in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0036] The first embodiment of the present invention provides a device for adjusting the sensitivity of an infrasound sensor, referring to Figure 1 , the infrasound sensor comprises:

[0037] The shell 14 is provided with a partition 10 for dividing the space inside the shell 14 into a front cavity 1 and a rear cavity 15. The partition 10 is provided with a pressure equalizing hole 11. The front cavity 1 is connected to the outside. The diaphragm 8 and the back pole plate 9 are arranged in the front cavity 1. The back pole plate 9 is arranged on the partition 10. The diaphragm 8 is arranged on the side of the back pole plate 9 away from the partition 10.

[0038] The regulating device comprises:

[0039] The measuring and calculating unit is used to measure the temperature T1 of the front cavity 1, the temperature T2 of the rear cavity 15 and the temperature change rate dT of the rear cavity 15. The current compensation amount ΔI is calculated based on T1, T2 and dT. The measuring and calculating unit can be arranged in the housing 14 or outside the housing 14.

[0040] Adjustment unit 7, reference Figure 1 , which is arranged in the front cavity 1 and opposite to the diaphragm 8, the adjustment unit 7 is connected to the measurement and calculation unit for communication to obtain ΔI and adjust the tension of the diaphragm 8 based on ΔI. For example, the suction force of the adjustment unit 7 on the diaphragm 8 is changed by the change of ΔI to adjust the tension of the diaphragm 8, so that the diaphragm 8 reaches a balanced state.

[0041] By adopting the embodiment of the present invention, the current value of the adjustment unit is calculated based on measuring the temperatures of the front cavity and the rear cavity and the temperature change rate of the rear cavity, and the suction force of the adjustment unit on the diaphragm is changed, thereby adjusting the tension of the diaphragm to achieve the effect of maintaining the sensitivity of the infrasound sensor, thereby improving the detection accuracy.

[0042] On the basis of the above-mentioned embodiments, various variant embodiments are further proposed. It should be noted that, in order to make the description concise, only the differences from the above-mentioned embodiments are described in each variant embodiment.

[0043] For example, it is arranged on the inner wall surface of the shell 14 or is arranged in the space of the shell 14 away from the inner wall through the support rod, so that the measured temperature is more accurate.

[0044] According to some embodiments of the present invention, the adjustment unit is an electromagnetic coil.

[0045] According to some embodiments of the present invention, the distance between the electromagnetic coil and the diaphragm is 0.3 mm-0.7 mm, for example, 0.5 mm.

[0046] According to some embodiments of the present invention, reference Figure 1 , the measurement calculation unit comprises:

[0047] The front cavity temperature measurement module 3 is arranged in the front cavity 1. The front cavity 1 temperature measurement module can be a temperature sensor or a thermometer.

[0048] The rear cavity temperature measurement module 12 is disposed in the rear cavity 15. The rear cavity 15 temperature measurement module 12 may be a temperature sensor or a thermometer.

[0049] The calculation module 2 is communicatively connected or electrically connected to the front cavity temperature measurement module 3, the rear cavity temperature measurement module 12 and the adjustment unit 7. The calculation module 2 is used to:

[0050] Determine the size relationship between T1 and T2;

[0051] If T1 is greater than T2, ΔI is calculated by formula 1:

[0052]

[0053] If T1 is equal to T2, then ΔI is zero;

[0054] If T1 is less than T2, ΔI is calculated by formula 2:

[0055]

[0056] Among them, I 0 It represents the initial current value of the adjustment unit, n represents the molar amount of gas in the back cavity, R and K represent constants, S represents the effective area of ​​the diaphragm, and V represents the volume of the back cavity.

[0057] According to some embodiments of the present invention, the front cavity temperature measurement module is disposed on the inner cavity wall of the front cavity, and the rear cavity temperature measurement module is disposed on the inner cavity wall of the rear cavity.

[0058] According to some embodiments of the present invention, the computing module is a microprocessor or a micro computing chip.

[0059] According to some embodiments of the present invention, a mounting plate having a plurality of through holes is provided in the front cavity, and the adjustment unit is embedded in the mounting plate. Figure 1 A mounting plate 6 is provided in the front cavity 1, and a plurality of through holes are provided on the mounting plate 6 for air circulation to keep the temperature of each space in the cavity consistent. The mounting plate 6 is provided with a groove matching the adjustment unit 7, the opening of the groove faces the diaphragm 8, and the adjustment unit 7 is embedded in the groove.

[0060] According to some embodiments of the present invention, the mounting plate is provided with screw holes, and the adjustment unit is mounted on a side of the mounting plate facing the diaphragm by means of screws.

[0061] According to some embodiments of the present invention, the adjustment unit is fixed to a side of the mounting plate facing the diaphragm by bonding.

[0062] According to some embodiments of the present invention, the electromagnetic coil suction force F=KI 2, where K represents the constant after the sensor and electromagnetic coil parameters are fixed, I is the current value in the electromagnetic coil, and F∝I 2 .

[0063] When T1 is greater than T2, the temperature rise period begins. dT represents the temperature change rate of the rear cavity, dP represents the pressure change rate of the rear cavity, n represents the molar amount of gas in the rear cavity, and V represents the volume of the rear cavity.

[0064] dP=(nR / V)·dT Formula 3,

[0065] Since the effective area S of the diaphragm is fixed, the suction force of the electromagnetic coil needs to change ΔF to keep the diaphragm tension balanced. At this time:

[0066]

[0067] The change of suction force is determined by the change of current, I 0 Indicates the initial current value of the electromagnetic coil, at this time:

[0068]

[0069] From formula 4 and 5, we can get:

[0070]

[0071] Similarly, when T1 is less than T2;

[0072]

[0073] According to some embodiments of the present invention, a first support plate is disposed in the front cavity, and the front cavity temperature measurement module and the calculation module are respectively disposed on two sides of the first support plate.

[0074] For example, refer to Figure 1 A first support plate 4 is provided in the front cavity 1, and a plurality of through holes are provided in the first support plate 4. The cross section of the first support plate 4 matches the cross section of the front cavity 1, and the first support plate 4 is detachably connected to the front cavity 1, and the connection method can be bonding, clamping or screwing. The front cavity temperature measurement module 3 is provided on the side of the first support plate 4 close to the diaphragm 8, and can be fixed to the first support plate 4 by bonding, clamping or screwing. The calculation module 2 is provided on the other side of the first support plate 4.

[0075] According to some embodiments of the present invention, a first support rod is provided in the front cavity, and the length of the first support rod is less than the diameter or the longest side length of the front cavity. One end of the first support rod is detachably connected to the inner surface wall of the front cavity, and the connection method can be bonding, clamping or screwing. The other end of the first support rod is detachably connected to the front cavity temperature measurement module, and the connection method can be bonding, clamping or screwing.

[0076] According to some embodiments of the present invention, the front cavity temperature measurement module is disposed on the side of the first support plate close to the diaphragm, so as to better obtain the temperature near the diaphragm, thereby ensuring the sensitivity of the infrasound sensor.

[0077] According to some embodiments of the present invention, a second support plate is disposed in the rear cavity, and the rear cavity temperature measurement module is disposed on the second support plate.

[0078] For example, refer to Figure 1 A second support plate 13 is disposed in the rear cavity 15, and the second support plate 13 is provided with a plurality of through holes. The cross section of the second support plate 13 matches the cross section of the rear cavity 15, and the second support plate 13 is detachably connected to the rear cavity 15, and the connection method can be bonding, clamping or screwing. The rear cavity temperature measurement module 12 is disposed on the second support plate 13.

[0079] According to some embodiments of the present invention, a second support rod is provided in the rear cavity, and the length of the second support rod is less than the diameter or the longest side length of the rear cavity. One end of the second support rod is detachably connected to the inner surface wall of the rear cavity, and the connection method can be bonding, clamping or screwing. The other end of the first support rod is detachably connected to the rear cavity temperature measurement module, and the connection method can be bonding, clamping or screwing.

[0080] According to some embodiments of the present invention, the rear cavity temperature measurement module is disposed on the side of the second support plate close to the diaphragm, so as to better obtain the temperature near the diaphragm, thereby ensuring the sensitivity of the infrasound sensor.

[0081] A second aspect of the present invention provides a method for adjusting the sensitivity of an infrasound sensor based on the device for adjusting the sensitivity of an infrasound sensor as described in any one of the first aspect of the present invention, comprising:

[0082] The measuring and calculating unit obtains the front cavity temperature T1, the rear cavity temperature T2 and the rear cavity temperature change rate dT, and calculates the current compensation amount ΔI based on T1, T2 and dT;

[0083] The adjusting unit obtains the ΔI and adjusts the tension of the diaphragm based on the ΔI.

[0084] For example, refer to Figure 2, the initial current value of the adjustment unit is I0. When the external ambient temperature of the infrasound sensor changes, the front cavity temperature T1, the rear cavity temperature T2 and the rear cavity temperature change rate dT are obtained by the measurement and calculation unit. ΔT represents the difference between T1 and T2. If ΔT is greater than 0, the measurement and calculation unit calculates the current compensation amount △I=f(dT) and adjusts the current of the adjustment unit to: I=I0+f(dT); if ΔT is less than 0, the measurement and calculation unit calculates the current compensation amount △I=g(dT) and adjusts the current of the adjustment unit to: I=I0+g(dT); if ΔT is equal to 0, the current value I0 remains unchanged. When the external ambient temperature changes again, the current value of the adjustment unit is adjusted again according to the above method to keep the diaphragm balanced.

[0085] By adopting the embodiment of the present invention, the current value of the adjustment unit is calculated based on measuring the temperatures of the front cavity and the rear cavity and the temperature change rate of the rear cavity, and the suction force of the adjustment unit on the diaphragm is changed, thereby adjusting the tension of the diaphragm to achieve the effect of maintaining the sensitivity of the infrasound sensor. When the ambient temperature change rate is 5°C / h, the output voltage is less than 0.1V, the sensitivity fluctuation is less than 0.1db, and the detection accuracy is improved.

[0086] It should be noted that, in the description of this specification, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this specification.

[0087] The following is a detailed description of a sensitivity adjustment device for an infrasound sensor using a specific embodiment. It is worth noting that the following description is only an exemplary description and is not a specific limitation of the present invention. All similar structures and similar variations of the present invention should be included in the protection scope of the present invention.

[0088] The infrasound sensor involved in this embodiment includes: a shell, provided with a partition for dividing the space inside the shell into a front cavity and a rear cavity, the partition is provided with a pressure equalizing hole, the front cavity is connected to the outside, and the diaphragm and the back plate are arranged on the partition. The regulating device in this embodiment includes: a front cavity temperature sensor, installed on the side of the first support plate with a through hole in the front cavity facing the diaphragm, for measuring the front cavity temperature. A rear cavity temperature sensor, installed on the side of the second support plate with a through hole in the rear cavity facing the diaphragm, for measuring the rear cavity temperature T2 and the rear cavity temperature change rate dT. A microprocessor, installed on the first support plate with a through hole in the front cavity, for obtaining T1, T2, dT and calculating the current compensation amount △I. An electromagnetic coil, installed on a mounting plate with a through hole in the front cavity. The mounting plate is bonded to the inner wall of the front cavity, and the mounting plate is provided with a groove facing the diaphragm and matching the electromagnetic coil, and the electromagnetic coil is clamped in the groove. The distance between the electromagnetic coil and the diaphragm is 0.5mm. The front cavity temperature sensor, the rear cavity temperature sensor, the microprocessor and the electromagnetic coil are electrically connected.

[0089] When the infrasound sensor with an adjustment device is used for detection, when the external ambient temperature of the infrasound sensor changes, the front cavity connected to the outside is first exchanged with the outside air, resulting in inconsistent temperatures between the front cavity and the rear cavity, causing the diaphragm to deform, resulting in changes in the output voltage and sensitivity of the infrasound sensor. At this time, the front cavity temperature sensor and the rear cavity temperature sensor measure the front cavity temperature T1, the rear cavity temperature T2 and the rear cavity temperature change rate dT, and the microprocessor obtains T1, T2 and dT, and determines the size of T1 and T2.

[0090] If T1 is greater than T2, use the following formula to calculate the current compensation △I of the electromagnetic coil:

[0091]

[0092] If T1 is equal to T2, the current compensation amount △I=0;

[0093] If T1 is less than T2, use the following formula to calculate the current compensation △I of the electromagnetic coil:

[0094]

[0095] Among them, I 0 represents the initial current value of the electromagnetic coil, n represents the molar amount of gas in the back cavity, R and K represent constants, S represents the effective area of ​​the diaphragm, and V represents the volume of the back cavity.

[0096] The microprocessor controls the current of the electromagnetic coil by calculating the current compensation amount to control the suction force on the diaphragm, thereby keeping the diaphragm tension balanced, thereby allowing the infrasound sensor to maintain sensitivity and output voltage.

[0097] The front cavity and the rear cavity exchange air through the pressure equalizing hole, so the temperature of the front cavity and the rear cavity is constantly changing. The microprocessor continuously obtains the data measured by the front cavity temperature sensor and the rear cavity temperature sensor, calculates the current compensation amount and controls the adjustment of the suction force of the electromagnetic coil in real time to keep the sensitivity of the infrasound sensor until the front cavity temperature, the rear cavity temperature and the external environment temperature are kept consistent through air exchange.

[0098] By adopting the embodiment of the present invention, when the external ambient temperature of the infrasound sensor changes, the real-time temperature of the front cavity and the rear cavity and the temperature change rate of the rear cavity are obtained, and the suction force of the electromagnetic coil on the diaphragm of the infrasound sensor is calculated, so that the diaphragm is always kept balanced, and the output voltage and sensitivity of the infrasound sensor are kept unchanged, thereby effectively improving the detection accuracy of the infrasound sensor.

[0099] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations, and the various embodiments may be freely combined in different ways. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for adjusting the sensitivity of an infrasound sensor, characterized in that: The infrasound sensor comprises: A shell, provided with a partition for dividing the space inside the shell into a front cavity and a rear cavity, the partition being provided with a pressure equalizing hole, the front cavity being communicated with the outside, and the diaphragm and the back plate being arranged in the front cavity; The regulating device comprises: A measuring and calculating unit, used for measuring the temperature T1 of the front cavity, the temperature T2 of the rear cavity and the temperature change rate dT of the rear cavity, and calculating the current compensation amount ΔI based on the T1, the T2 and the dT; An adjustment unit is disposed in the front cavity and arranged opposite to the diaphragm. The adjustment unit is communicatively connected with the measurement and calculation unit to obtain the ΔI and adjust the tension of the diaphragm based on the ΔI.

2. The device for adjusting the sensitivity of an infrasound sensor according to claim 1, characterized in that: The adjustment unit is an electromagnetic coil.

3. The device for adjusting the sensitivity of an infrasound sensor according to claim 2, characterized in that: The distance between the electromagnetic coil and the diaphragm is 0.3mm-0.7mm.

4. The device for adjusting the sensitivity of an infrasound sensor according to claim 2, characterized in that: The measurement calculation unit comprises: A front cavity temperature measurement module, arranged in the front cavity; A rear cavity temperature measurement module, disposed in the rear cavity; A calculation module is communicatively connected with the front cavity temperature measurement module and the rear cavity temperature measurement module, and the calculation module is used to: Determine the size relationship between T1 and T2; If T1 is greater than T2, ΔI is calculated by formula 1: If T1 is equal to T2, then ΔI is zero; If T1 is less than T2, ΔI is calculated by formula 2: Wherein, I0 represents the initial current value of the adjustment unit, n represents the molar amount of gas in the back cavity, R and K represent constants, S represents the effective area of ​​the diaphragm, and V represents the volume of the back cavity.

5. The device for adjusting the sensitivity of an infrasound sensor according to claim 4, characterized in that: A first supporting plate is arranged in the front cavity, and the front cavity temperature measuring module and the calculating module are arranged on two sides of the first supporting plate respectively.

6. The device for adjusting the sensitivity of an infrasound sensor according to claim 5, characterized in that: The front cavity temperature measurement module is arranged close to one side of the diaphragm.

7. The device for adjusting the sensitivity of an infrasound sensor according to claim 4, characterized in that: A second supporting plate is arranged in the rear cavity, and the rear cavity temperature measuring module is arranged on the second supporting plate.

8. The device for adjusting the sensitivity of an infrasound sensor according to claim 7, characterized in that: The rear cavity temperature measurement module is arranged close to one side of the diaphragm.

9. The device for adjusting the sensitivity of an infrasound sensor according to claim 1, characterized in that: A mounting plate with a plurality of through holes is arranged in the front cavity, and the adjustment unit is embedded in the mounting plate.

10. A method for adjusting the sensitivity of an infrasound sensor based on the device for adjusting the sensitivity of an infrasound sensor according to any one of claims 1 to 9, characterized in that: include: The measuring and calculating unit obtains the front cavity temperature T1, the rear cavity temperature T2 and the rear cavity temperature change rate dT, and calculates the current compensation amount ΔI based on the T1, the T2 and the dT; The adjustment unit obtains the ΔI and adjusts the tension of the diaphragm based on the ΔI.

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