CN110375845B - Electrostatic balance type high-sensitivity hydrophone - Google Patents

Abstract

The invention discloses an electrostatic balance type high sensitivity hydrophone, which comprises a sound pressure sensitive structure, a displacement detection device, an electrostatic drive device and a detection and control circuit. Under the strong background noise, the acoustic elastic body in the sound pressure sensitive structure of the traditional hydrophone exhibits nonlinear characteristics due to excessive deformation, and the sensitivity decreases. The present invention adopts the displacement detection device to detect the deformation amount of the elastic body by means of closed-loop detection, and uses the electrostatic driving device to drive the elastic body, so that the elastic body works in the equilibrium position. The invention makes up for the defect that the elastic body of the hydrophone exhibits nonlinearity under strong background noise and reduces the sensitivity, and is beneficial to improve the sensitivity of the hydrophone.

Description

An electrostatically balanced high-sensitivity hydrophone

technical field

The invention relates to a hydrophone, in particular to an electrostatic balance type high-sensitivity hydrophone, which belongs to the technical field of measuring instruments.

Background technique

The hydrophone is the key device for underwater sound detection. In the probe of the hydrophone, the weak sound pressure signal is generally obtained by detecting the displacement of the acoustic elastic body. In marine environments, hydrophones are often disturbed by strong background noise. Under strong noise, the deformation of the acousto-elastic body is large, and the relationship between the vibration displacement and the sound pressure is nonlinear, resulting in a decrease in the detection sensitivity of the hydrophone. After detecting the large deformation of the elastic body of the hydrophone, the electrostatic balance hydrophone based on closed-loop detection can maintain the elastic body in the equilibrium position through feedback control, which can reduce the nonlinearity of the elastic body and improve the sensitivity of the hydrophone.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is the problem of insufficient sensitivity of the hydrophone under strong background noise, and an electrostatic balance type high-sensitivity hydrophone is provided.

In order to achieve the above object, the present invention adopts the following design scheme: an electrostatic balance type high-sensitivity hydrophone, comprising:

The sound pressure sensitive structure includes an acoustic elastomer and a casing, the acoustic elastomer is installed in the casing, and the edge is fixedly connected to the casing;

a displacement detection device for detecting the deformation amount of the acoustic elastic body;

An electrostatic drive to drive and maintain the sonoelastic body in an equilibrium position;

The detection and control circuit is used to receive and process the signal of the displacement detection device, and output the feedback voltage to the electrostatic driving device.

Further, the acoustic elastomer is a film with a conductor attached to the surface.

Further, the conductor is a metal conductive sheet.

Further, the electrostatic driving device includes an upper driving pole plate and a lower driving pole plate; the upper driving pole plate is located above the acoustic elastic body, and the lower driving pole plate is located below the acoustic elastic body; Both the plate and the lower driving pole plate are fixedly connected with the casing, and both the upper driving pole plate and the lower driving pole plate are connected with the feedback signal output end of the closed-loop control circuit.

Further, the upper driving electrode plate and the lower driving electrode plate are made of conductor material.

Further, the upper driving pole plate and the lower driving pole plate are densely provided with sound-transmitting small holes, so that the pole plates do not hinder the transmission of sound pressure.

Further, the displacement detection device includes a fixed pole plate, a moving pole plate and a connecting piece; the fixed pole plate is electrically connected with the signal processing and control circuit; the moving pole plate is connected with the acoustic elastic body through the connecting piece; the connecting piece passes through the lower drive The small hole in the center of the pole plate makes the moving pole plate below the lower driving pole plate.

Further, the connecting piece is an insulating material; the moving electrode plate and the grading plate are both conductor materials.

Further, both the signal processing and control circuit and the grading board are fixedly connected to the housing.

Further, the signal processing and control circuit includes a capacitance detection module, a processor module and a high-voltage drive module; the capacitance detection module and the high-voltage drive module are both connected to the processor module; the capacitance detection module is connected to the displacement detection device for detecting sound. The displacement of the elastic body; the high-voltage driving module is connected with the electrostatic driving device to control the voltage of the driving plate; the processor module receives the output signal of the capacitance detection module, and processes the output signal through the PID control algorithm to obtain the feedback control signal; The high-voltage driving module applies a feedback voltage to the upper driving electrode plate and the lower driving electrode plate according to the feedback control signal, thereby generating a feedback force to keep the acoustic elasticity in a balanced position; the feedback control signal output by the signal processing and control circuit is also used to characterize the acoustic pressure measurement.

The beneficial effect of the invention is that the acoustic elastic body in the sound pressure sensitive structure of the hydrophone often produces a large displacement under strong background noise. Acoustoelastics exhibit nonlinearity under large deformations, resulting in reduced detection sensitivity of hydrophones. The electrostatic closed-loop control can maintain the acoustic elasticity of the hydrophone in the equilibrium position, and make up for the defect that the hydrophone elastic body deforms greatly and presents nonlinearity under strong background noise, which reduces the sensitivity, which is beneficial to improve the sensitivity of the hydrophone.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of an electrostatically balanced high-sensitivity hydrophone;

Figure 2 is a schematic diagram of an electrostatically balanced high-sensitivity hydrophone acoustic elastomer;

3 is a schematic diagram of an electrostatically balanced high-sensitivity hydrophone in an electrostatic driving device;

FIG. 4 is a schematic diagram of an electrostatic balance type high-sensitivity hydrophone displacement detection device.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in FIG. 1 , the present invention provides an electrostatically balanced high-sensitivity hydrophone, including a sound pressure sensitive structure 1 , a displacement detection device 2 , an electrostatic drive device 3 and a detection and control circuit 4 . The sound pressure sensitive structure includes an acoustic elastic body 11 and a casing 12 , the acoustic elastic body 11 is installed in the casing 12 , and the edge is fixedly connected to the casing 12 ; the displacement detection device 2 is used to detect the acoustic elastic body 11 The electrostatic driving device 3 is used to drive and keep the acoustic elastic body 11 in a balanced position; the detection and control circuit 4 is used to receive and process the signal of the displacement detection device 2, and output a feedback voltage to the electrostatic driving device 3. At the same time, the feedback voltage also characterizes the sound pressure measurement.

As shown in FIG. 2 , the acoustic elastic body 11 is a thin film 111 with a conductor 112 attached to the surface. The conductor 112 is a metal conductive sheet. The shape of the thin film 111 is circular. Since the displacement of the center point of the circular film is larger than that of other shapes under the same sound pressure, the selection of the circular film is beneficial to improve the detection sensitivity.

As shown in FIG. 3 , the electrostatic driving device 3 includes an upper driving electrode plate 31 and a lower driving electrode plate 32 ; the upper driving electrode plate 31 is located above the acoustic elastic body 11 , and the lower driving electrode plate 32 is located at the Below the acoustic elastic body 11 . Both the upper driving pole plate 31 and the lower driving pole plate 32 are fixedly connected to the casing, and are connected to the feedback voltage output terminal of the detection and control circuit 4. The upper driving pole plate 31 and the lower driving pole plate 32 are conductive materials, and are densely formed with sound-transmitting small holes 311, so that the pole plates do not hinder the transmission of sound pressure.

As shown in FIG. 4 , the displacement detection device 2 includes a fixed pole plate 21 , a movable pole plate 22 and a connecting member 23 . The stator plate 21 is electrically connected to the signal processing and control circuit 4 . The signal processing and control circuit 4 and the grading board 21 are fixedly connected to the housing 12 . The moving pole plate 22 is connected to the acoustic elastic body 11 through the connecting member 23 . The connecting piece 23 passes through the small hole in the center of the lower driving pole plate 32 , so that the moving pole plate 22 is located below the lower driving pole plate 32 . The connecting piece 23 is an insulating material; the grading plate 21 and the moving electrode plate 22 are both conductor materials. The fixed electrode plate 21 and the movable electrode plate 22 form a detection capacitor, and the acoustic elastic body 11 is deformed under the action of sound pressure, so that the movable electrode plate 22 is displaced and the detection capacitance changes. However, the displacement detection device is not limited to capacitance detection. The connecting piece 23 is made of light-weight and high-rigidity material, and silicon carbide ceramics are selected, but not limited thereto; the moving pole plate 22 is made of light-weight and high-rigidity material, and aluminum-magnesium alloy is selected, but not limited thereto.

The signal processing and control circuit 4 includes a capacitance detection module, a processor module and a high-voltage drive module. The capacitance detection module and the high-voltage driving module are both connected with the processor module; the capacitance detection module is connected with the displacement detection device 2 for detecting the displacement of the acoustic elastic body 11 ; the high-voltage driving module is connected with the electrostatic driving device 3 for controlling the driving plate The size of the voltage; the processor module receives the output signal of the capacitance detection module, and processes the output signal through the PID control algorithm to obtain a feedback control signal. The feedback control signal drives the electrostatic drive device, so that the high-voltage drive module sends the upper drive plate 31 and the lower The drive plate 32 applies a feedback voltage, thereby generating a feedback force to keep the acoustic elasticity 11 in an equilibrium position. The feedback control signal output by the signal processing and control circuit 4 is used to characterize the sound pressure measurement value. The capacitance detection module adopts, but is not limited to, the MS3110 chip; the processor module adopts, but is not limited to, the STM32F103VB chip; the high-voltage driving module adopts, but is not limited to, the DAC082S085 and OPA187 chips.

In the invention, the deformation amount of the elastic body is detected by the displacement detection device, and the elastic body is driven by the electrostatic driving device to make it work in the equilibrium position. The closed-loop detection makes up for the shortcoming that the elastic body of the hydrophone deforms greatly and presents nonlinearity under strong background noise, which reduces the sensitivity, and improves the sensitivity of the hydrophone.

Those skilled in the art can easily make various changes and modifications without departing from the spirit and scope of the present invention defined by the claims according to the written description, drawings and claims provided by the present invention. Any modifications and equivalent changes made to the above embodiments according to the technical idea and essence of the present invention fall within the protection scope defined by the claims of the present invention.

Claims (7)

1. An electrostatic equilibrium type high sensitivity hydrophone, characterized in that: the method comprises the following steps:

the sound pressure sensitive structure (1) comprises a sound elastic body (11) and a shell (12), wherein the sound elastic body (11) is arranged in the shell (12), and the edge of the sound elastic body is fixedly connected with the shell (12);

displacement detection means (2) for detecting the amount of deformation of the acoustic elastic body (11);

an electrostatic drive device (3) for driving and maintaining the acoustic elastomer (11) in a balanced position;

the detection and control circuit (4) is used for receiving and processing signals of the displacement detection device (2) and outputting feedback voltage to the electrostatic driving device (3);

the electrostatic driving device (3) comprises an upper driving polar plate (31) and a lower driving polar plate (32); the upper driving polar plate (31) is positioned above the acoustic elastomer (11), and the lower driving polar plate (32) is positioned below the acoustic elastomer (11); the upper driving polar plate (31) and the lower driving polar plate (32) are both fixedly connected with the shell (12), and the upper driving polar plate (31) and the lower driving polar plate (32) are both connected with a feedback signal output end of the detection and control circuit (4);

the upper driving polar plate (31) and the lower driving polar plate (32) are both provided with sound-transmitting small holes (311) densely, so that the polar plates do not obstruct sound pressure transmission;

the displacement detection device (2) comprises a fixed polar plate (21), a movable polar plate (22) and a connecting piece (23); the fixed polar plate (21) is electrically connected with the detection and control circuit (4); the movable polar plate (22) is connected with the acoustic elastomer (11) through a connecting piece (23); the connecting piece (23) passes through a small hole in the center of the lower driving pole plate (32), and the movable pole plate (22) is positioned below the lower driving pole plate (32).

2. The electrostatically balanced high sensitivity hydrophone of claim 1, wherein: the acoustic elastomer (11) is a film (111) with a conductor (112) attached to the surface.

3. The electrostatically balanced high sensitivity hydrophone of claim 2, wherein: the conductor (112) is a metal conductive sheet.

4. The electrostatically balanced high sensitivity hydrophone of claim 1, wherein: the upper driving polar plate (31) and the lower driving polar plate (32) are made of conductor materials.

5. The electrostatically balanced high sensitivity hydrophone of claim 1, wherein: the connecting piece (23) is made of insulating materials; the fixed polar plate (21) and the movable polar plate (22) are both made of conductor materials.

6. The electrostatically balanced high sensitivity hydrophone of claim 1, wherein: the detection and control circuit (4) and the fixed pole plate (21) are both fixedly connected with the shell (12).

7. The electrostatically balanced high sensitivity hydrophone of claim 1, wherein: the detection and control circuit (4) comprises a capacitance detection module, a processor module and a high-voltage driving module; the capacitance detection module and the high-voltage driving module are connected with the processor module; the capacitance detection module is connected with the displacement detection device (2) and is used for detecting the displacement of the acoustic elastomer (11); the high-voltage driving module is connected with the electrostatic driving device (3) and is used for controlling the voltage of the driving polar plate; the processor module receives an output signal of the capacitance detection module and processes the output signal through a PID control algorithm to obtain a feedback control signal; the high-voltage driving module applies feedback voltage to the upper driving polar plate (31) and the lower driving polar plate (32) according to the feedback control signal, so that feedback force is generated to keep the acoustic elastomer (11) at a balance position; the feedback control signal output by the detection and control circuit (4) is also used for representing the sound pressure measured value.

Images