A broadband infrasound calibrator with adjustable amplitude

Abstract

The present invention discloses a broadband infrasound calibrator with adjustable amplitude, comprising a sound mouth, a sinusoidal small piston, a pressure-regulating large piston, a sinusoidal driver, a pressure-regulating driver, a cam, a small piston connecting rod, a pressure chamber, a controller, and a displacement sensor; the sinusoidal driver is used to drive the cam, which is connected to the sinusoidal small piston via the small piston connecting rod and is used to drive the sinusoidal small piston to vibrate up and down, thereby generating a single-frequency sinusoidal sound wave in the pressure chamber and outputting a pressure sound wave from the sound mouth; the displacement sensor is installed at the bottom of the sinusoidal small piston and is used to monitor the amplitude of the sinusoidal small piston vibration; the pressure-regulating driver is used to drive the pressure-regulating large piston to move up and down, which can change the volume of the pressure chamber, thereby changing the pressure amplitude of the generated sinusoidal sound wave; the controller is connected to the sinusoidal driver and the pressure-regulating driver and is used to control the sinusoidal driver and the pressure-regulating driver. The present invention can generate broadband sinusoidal sound waves with adjustable amplitude.

Description

Technical Field

[0001] The invention belongs to the technical field of acoustic sensor calibration, and in particular relates to a wide-band infrasound calibrator with adjustable amplitude. Background Art

[0002] A sine wave sound generator used as a calibrator for infrasound sensors typically uses a paper cone electric speaker as a piston in a cavity. This requires a standard signal source and an amplifier driver. However, due to the thin cone, sound insulation is poor and susceptible to interference. Furthermore, it is susceptible to electromagnetic interference, which reduces the signal-to-noise ratio. Complex signal source operations are required each time the generator is turned on, making it impossible to achieve constant output. Conventional mechanical piston sine wave generators are simple to use and can circumvent these issues. The resulting sine wave is of good quality, but the amplitude cannot be adjusted. Summary of the Invention

[0003] The purpose of the present invention is to provide a broadband infrasound calibrator with adjustable amplitude, which can generate broadband sinusoidal sound waves with adjustable amplitude.

[0004] To achieve the above-mentioned object, one aspect of the present invention provides a broadband infrasound calibrator with adjustable amplitude, comprising a sound mouth, a sinusoidal small piston, a pressure-regulating large piston, a sinusoidal driver, a pressure-regulating driver, a cam, a small piston connecting rod, a pressure chamber, a controller, and a displacement sensor;

[0005] The small sine piston and the large pressure regulating piston can move up and down in their respective piston cylinders. The piston cylinders below the small sine piston and the large pressure regulating piston are connected to form a pressure chamber. The sound mouth is installed on the pressure chamber and is connected to the pressure chamber.

[0006] The sinusoidal driver is used to drive the cam, which is connected to the sinusoidal piston via a small piston connecting rod. It is used to drive the sinusoidal piston to vibrate up and down, thereby generating a single-frequency sinusoidal sound wave in the pressure chamber and outputting a pressure sound wave from the sound nozzle. By changing the up and down vibration rate of the sinusoidal piston, the frequency of the sinusoidal sound wave can be changed. The displacement sensor is installed at the bottom of the sinusoidal piston to monitor the amplitude of the sinusoidal piston vibration.

[0007] The pressure regulating driver is used to drive the pressure regulating large piston to move up and down. The up and down movement of the pressure regulating large piston can change the volume of the pressure chamber, thereby changing the pressure amplitude of the generated sinusoidal sound wave; the controller is connected to the sinusoidal driver and the pressure regulating driver, and is used to control the sinusoidal driver and the pressure regulating driver.

[0008] Another aspect of the present invention provides a broadband infrasound calibrator with adjustable amplitude, characterized in that it includes a sound mouth, a sinusoidal small piston, a pressure-regulating large piston, a sinusoidal driver, a pressure-regulating driver, a cam, a small piston connecting rod, a pressure chamber, a controller, and a displacement sensor;

[0009] The sine small piston and the pressure regulating large piston can move left and right in their respective piston cylinders. The piston cylinders on the left side of the sine small piston and the right side of the pressure regulating large piston are connected to form a pressure chamber. The sound mouth is installed on the pressure chamber and is connected to the pressure chamber.

[0010] The sinusoidal driver is used to drive the cam, which is connected to the sinusoidal piston via a small piston connecting rod. It is used to drive the sinusoidal piston to vibrate left and right, thereby generating a single-frequency sinusoidal sound wave in the pressure chamber and outputting a pressure sound wave from the sound nozzle. By changing the left and right vibration rate of the sinusoidal piston, the frequency of the sinusoidal sound wave can be changed. The displacement sensor is installed at the bottom of the sinusoidal piston to monitor the amplitude of the sinusoidal piston vibration.

[0011] The pressure regulating driver is used to drive the pressure regulating large piston to move left and right. The left and right movement of the pressure regulating large piston can change the volume of the pressure chamber, thereby changing the pressure amplitude of the generated sinusoidal sound wave; the controller is connected to the sinusoidal driver and the pressure regulating driver, and is used to control the sinusoidal driver and the pressure regulating driver.

[0012] Preferably, the infrasonic calibrator further includes a main body and an instrument cabin, the pressure chamber is installed in the main body and a certain distance is set between the main body for vibration reduction and heat insulation, the instrument cabin is fixed on the main body, and the signal line of the displacement sensor is installed in the instrument cabin.

[0013] Preferably, the voltage regulating driver adopts a linear motor and the sinusoidal driver adopts a servo motor. By changing the rotation speed of the servo motor of the sinusoidal driver, the frequency of the sinusoidal sound wave generated by the sinusoidal small piston can be changed.

[0014] Preferably, the area of ​​the large pressure-regulating piston is much larger than the area of ​​the small sinusoidal piston, so that the influence of the large pressure-regulating piston on the distortion when changing the pressure amplitude of the sinusoidal sound wave through movement is less than 0.3%.

[0015] The broadband infrasound calibrator with adjustable amplitude according to the above aspect of the present invention can generate broadband sinusoidal sound waves with adjustable amplitude. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] Figure 1 is a side view of a broadband infrasound calibrator with adjustable amplitude according to an embodiment of the present invention;

[0018] Figure 2 1 is a front view of a broadband infrasound calibrator with adjustable amplitude according to an embodiment of the present invention;

[0019] Figure 3 1 is a cross-sectional view of the structure of a broadband infrasound calibrator with adjustable amplitude according to an embodiment of the present invention;

[0020] Figure 4 Schematic diagram of the installation position of a sinusoidal driver according to one embodiment of the present invention;

[0021] Figure 5 Schematic diagram of the relationship between the sinusoidal small piston, the pressure-regulating large piston, and the sound mouthpiece according to one embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of a vertical double-cylinder structure according to an embodiment of the present invention;

[0023] Figure 7 It is a schematic diagram of a horizontal transverse double-cylinder structure of another embodiment of the present invention.

[0024] Description of reference numerals:

[0025] 1-nozzle, 2-sine small piston, 3-pressure regulating large piston, 4-sine drive, 5-pressure regulating drive, 6-cam, 7-small piston connecting rod, 8-pressure chamber, 9-main body, 10-controller, 11-instrument cabin, 12-displacement sensor. DETAILED DESCRIPTION

[0026] 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.

[0027] One embodiment of the present invention provides a broadband infrasound calibrator with adjustable amplitude, such as Figure 1-5 As shown, the amplitude-adjustable wide-band infrasound calibrator of an embodiment of the present invention includes a sound mouth 1, a sinusoidal small piston 2, a pressure-regulating large piston 3, a sinusoidal driver 4, a pressure-regulating driver 5, a cam 6, a small piston connecting rod 7, a pressure chamber 8, a main body 9, a controller 10, an instrument cabin 11 and a displacement sensor 12.

[0028] The sinusoidal small piston 2 and the pressure-regulating large piston 3 are each capable of moving up and down within their respective piston cylinders. The piston cylinders below the sinusoidal small piston and the pressure-regulating large piston are connected to form a pressure chamber 8. The acoustic nozzle 1 is mounted on and connected to the pressure chamber 8. The sinusoidal small piston 2, the pressure-regulating large piston 3, and the pressure chamber 8 form a vibration system. The cam 6 is used to drive the sinusoidal small piston 2 to vibrate up and down. When the drive is provided to the sinusoidal small piston 2, a single-frequency sinusoidal sound wave is generated within the pressure chamber 8, and a pressure sound wave is output from the acoustic nozzle 1. A displacement sensor 12 is mounted at the bottom of the sinusoidal small piston 2 to monitor the amplitude of the vibration of the sinusoidal small piston 2.

[0029] Controller 10 connects to and controls sinusoidal driver 4 and pressure-regulating driver 5. Sine driver 4 drives cam 6, which connects to small sinusoidal piston 2 via small piston connecting rod 7. Pressure-regulating driver 5 drives large pressure-regulating piston 3. As large pressure-regulating piston 3 moves up and down, changing the volume of pressure chamber 8, the pressure amplitude of the generated sinusoidal sound wave varies.

[0030] The broadband infrasound calibrator with adjustable amplitude according to an embodiment of the present invention may further include a main body 9 and an instrument cabin 11. The pressure chamber 8 is mounted within the main body 9 and spaced apart for vibration reduction and heat insulation. The instrument cabin 11 is fixed to the main body 9. The signal lines of the displacement sensor 12 and other sensors are also mounted within the instrument cabin 11.

[0031] The sinusoidal small piston 2 and sinusoidal driver 4 form a sinusoidal pressure oscillation system, while the large pressure-regulating piston 3 and pressure-regulating driver 5 form a pressure regulation system. In one embodiment, the 44mm diameter sinusoidal small piston 2 has an upward stroke of ±5mm with an accuracy of 0.2‰, while the large pressure-regulating piston 3 has a stroke of 0-300mm with an accuracy of mm. The pressure-regulating driver 5 uses a linear motor to drive the 315mm diameter pressure-regulating large piston 3 up and down. It has an 80% compression ratio, a length of 200mm, a stroke range of 80-320mm (maximum 40mm-360mm), and a maximum to minimum volume ratio of 63:1, corresponding to a pressure of 1Pa:63Pa. The sinusoidal driver 4 uses a servo motor to drive the sinusoidal small piston 2, and the displacement sensor 12 uses a laser displacement sensor. Changing the speed of the servo motor in the sinusoidal driver 4 can change the frequency of the sound waves generated by the sinusoidal small piston 2.

[0032] The broadband infrasound calibrator with adjustable amplitude according to the above embodiment of the present invention has the following characteristics and positive effects:

[0033] 1. The sinusoidal driver 4 and the pressure-regulating driver 5 are jointly controlled by the controller 10. The reciprocating vibration rate of the sinusoidal small piston 2 determines the frequency of the sinusoidal wave. Changing the volume under the pressure-regulating large piston 3 can change the amplitude of the sinusoidal wave. The larger the volume under the pressure-regulating large piston 3, the smaller the amplitude of the sinusoidal wave. When the cam 6 drives the sinusoidal small piston 2 to vibrate up and down, a single-frequency sinusoidal sound wave is generated in the pressure chamber 8, and a pressure sound wave is output from the sound nozzle 1. A displacement sensor 12 is installed at the bottom of the sinusoidal small piston 2 to monitor the amplitude of the sinusoidal small piston 2 vibration for tracing the source.

[0034] 2. The sinusoidal small piston 2, the pressure-regulating large piston 3, and the pressure chamber 8 ensure the sealing of the vibration system, so that the cam 6 drives the small piston connecting rod 7 to drive the sinusoidal small piston 2 to move up and down to change the volume, and the amplitude remains unchanged. The -3dB lower limit frequency can reach 0.001Hz.

[0035] 3. The frequency of the sound wave in the pressure chamber 8 is determined by the velocity of the sinusoidal small piston 2, while the amplitude of the sound pressure is determined by the volume connected between the two piston cylinders.

[0036] 4. The area of ​​the large pressure-regulating piston 3 is much larger than that of the small sinusoidal piston 2, so that the influence of the large pressure-regulating piston 3 on the distortion when changing the sound pressure amplitude by moving up and down is less than 0.3% and can be ignored. Moreover, the larger the area of ​​the large pressure-regulating piston 3, the larger the pressure-regulating range.

[0037] 5. The sinusoidal small piston 2 and the pressure-regulating large piston 3 are connected to the pressure chamber 8 and the sound mouth 1. Their shape has no effect on the waveform of the sound wave, and their sealing determines the lower limit frequency of the sound that can be produced.

[0038] 6. The smoother the movement of the sinusoidal small piston 2, the lower the waveform distortion of the generated sound wave. The higher the accuracy of the cam 6, the more accurate the sound pressure waveform. The greater the stroke of the pressure-regulating large piston 3, the greater the sound pressure multiple that can be adjusted.

[0039] Another embodiment of the present invention provides a broadband infrasound calibrator with adjustable amplitude, which has the same components as the previous embodiment, and most of the components are installed in the same manner, except that the sine small piston 2 and the pressure regulating large piston 3 in the previous embodiment are as follows: Figure 6 The vertical double cylinder structure is shown. Figure 7 The structure shown is a horizontal double-cylinder structure.

[0040] like Figure 7As shown, the sinusoidal small piston 2 is installed on the right side of the pressure chamber 8, the pressure-regulating large piston 3 is installed on the left side of the pressure chamber 8, and the sound nozzle 1 is installed at any position of the pressure chamber 8. The sinusoidal small piston and the pressure-regulating large piston can move left and right in their respective piston cylinders. The piston cylinders on the left side of the sinusoidal small piston and the right side of the pressure-regulating large piston are connected to form the pressure chamber 8. The sound nozzle 1 is installed on the pressure chamber 8 and is connected to the pressure chamber 8. The sinusoidal driver 4 is used to drive the cam 6. The cam 6 is connected to the sinusoidal small piston 2 through the small piston connecting rod 7 and is used to drive the sinusoidal small piston 2 to vibrate left and right, thereby generating a single-frequency sinusoidal sound wave in the pressure chamber 8 and outputting a pressure sound wave from the sound nozzle 1. By changing the left and right vibration rate of the sinusoidal small piston 2, the frequency of the sinusoidal sound wave can be changed. The displacement sensor 12 is installed at the bottom of the sinusoidal small piston 2 and is used to monitor the amplitude of the vibration of the sinusoidal small piston 2. The pressure-regulating driver 5 is used to drive the pressure-regulating large piston 3 to move left and right. The left and right movement of the pressure-regulating large piston 3 can change the volume of the pressure chamber 8, thereby changing the pressure amplitude of the generated sinusoidal sound wave; the controller 10 is connected to the sinusoidal driver 4 and the pressure-regulating driver 5, and is used to control the sinusoidal driver 4 and the pressure-regulating driver 5.

[0041] The horizontal transverse double-cylinder structure of this embodiment can reduce the overall size compared with the vertical double-cylinder structure of the previous embodiment. The pressure regulation and sinusoidal wave production effects are the same. The cam 6 drives the sinusoidal small piston 2 through the small piston connecting rod 7, and the pressure regulation driver 5 drives the pressure regulation large piston 3.

[0042] In summary, the wide-band infrasound calibrator with adjustable amplitude in the embodiment of the present invention adopts a dual-piston solution, namely, a large-sized pressure-regulating piston and a small-sized sinusoidal pressure piston. The stroke of the pressure-regulating piston is used to maintain and determine the volume of the piston cylinder to adjust the amplitude. A cam is used to drive the sinusoidal pressure piston to generate a sinusoidal sound wave, and a displacement sensor is used to monitor the vibration process of the sinusoidal pressure piston to achieve traceability. It has reached a metrological level and can be used as a standard instrument for infrasound sensors.

[0043] The broadband infrasound calibrator with adjustable amplitude in the embodiment of the present invention can generate broadband sinusoidal sound waves with adjustable amplitude, with a frequency range of 0.001Hz to 50Hz, an adjustable pressure range of 1Pa to 63Pa, a distortion of ≤0.3%, and an uncertainty of ≤0.3%, with performance surpassing all current similar products.

[0044] 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 broadband infrasound calibrator with adjustable amplitude, characterized in that: It includes a sound mouth, a sinusoidal small piston, a pressure regulating large piston, a sinusoidal driver, a pressure regulating driver, a cam, a small piston connecting rod, a pressure chamber, a controller and a displacement sensor; The small sine piston and the large pressure regulating piston can move up and down in their respective piston cylinders. The piston cylinders below the small sine piston and the large pressure regulating piston are connected to form a pressure chamber. The sound mouth is installed on the pressure chamber and is connected to the pressure chamber. The sinusoidal driver is used to drive the cam, which is connected to the sinusoidal piston via a small piston connecting rod. It is used to drive the sinusoidal piston to vibrate up and down, thereby generating a single-frequency sinusoidal sound wave in the pressure chamber and outputting a pressure sound wave from the sound nozzle. By changing the up and down vibration rate of the sinusoidal piston, the frequency of the sinusoidal sound wave can be changed. The displacement sensor is installed at the bottom of the sinusoidal piston to monitor the amplitude of the sinusoidal piston vibration. The pressure regulating driver is used to drive the pressure regulating large piston to move up and down. The up and down movement of the pressure regulating large piston can change the volume of the pressure chamber, thereby changing the pressure amplitude of the generated sinusoidal sound wave. The controller is connected to the sinusoidal driver and the pressure regulating driver and is used to control the sinusoidal driver and the pressure regulating driver. The area of ​​the large pressure regulating piston is much larger than that of the small sinusoidal piston, so that the influence of the large pressure regulating piston on the distortion when changing the pressure amplitude of the sinusoidal sound wave through movement is less than 0.3%.

2. A broadband infrasound calibrator with adjustable amplitude, characterized in that: It includes a sound mouth, a sinusoidal small piston, a pressure regulating large piston, a sinusoidal driver, a pressure regulating driver, a cam, a small piston connecting rod, a pressure chamber, a controller and a displacement sensor; The sine small piston and the pressure regulating large piston can move left and right in their respective piston cylinders. The piston cylinders on the left side of the sine small piston and the right side of the pressure regulating large piston are connected to form a pressure chamber. The sound mouth is installed on the pressure chamber and is connected to the pressure chamber. The sinusoidal driver is used to drive the cam, which is connected to the sinusoidal piston via a small piston connecting rod. It is used to drive the sinusoidal piston to vibrate left and right, thereby generating a single-frequency sinusoidal sound wave in the pressure chamber and outputting a pressure sound wave from the sound nozzle. By changing the left and right vibration rate of the sinusoidal piston, the frequency of the sinusoidal sound wave can be changed. The displacement sensor is installed at the bottom of the sinusoidal piston to monitor the amplitude of the sinusoidal piston vibration. The pressure regulating driver is used to drive the pressure regulating large piston to move left and right. The left and right movement of the pressure regulating large piston can change the volume of the pressure chamber, thereby changing the pressure amplitude of the generated sinusoidal sound wave. The controller is connected to the sinusoidal driver and the pressure regulating driver and is used to control the sinusoidal driver and the pressure regulating driver. The area of ​​the large pressure regulating piston is much larger than that of the small sinusoidal piston, so that the influence of the large pressure regulating piston on the distortion when changing the pressure amplitude of the sinusoidal sound wave through movement is less than 0.3%.

3. The amplitude-adjustable broadband infrasound calibrator according to claim 1 or 2, characterized in that: It also includes a main body and an instrument cabin. The pressure chamber is installed in the main body and a certain distance is set between the main body and the instrument cabin for vibration reduction and heat insulation. The instrument cabin is fixed on the main body, and the signal line of the displacement sensor is installed in the instrument cabin.

4. The wide-band infrasound calibrator with adjustable amplitude according to claim 1 or 2, characterized in that: The voltage regulating driver adopts a linear motor, and the sinusoidal driver adopts a servo motor. By changing the speed of the servo motor of the sinusoidal driver, the frequency of the sinusoidal sound wave generated by the sinusoidal small piston can be changed.

Images