A device and method for measuring the radial acceleration sensitivity of a cylindrical hydrophone

Abstract

The application relates to a kind of radial acceleration sensitivity measuring device and measuring method of circular pipe hydrophone, including base, harf, end cover, to be measured circular pipe hydrophone, slider, preamplifier, accelerometer and exciter;Wherein, the bottom of base is provided with several mounting holes of different sizes, to cooperate with the exciter of different interfaces is installed;The top of base is semicircular pipe with semicircular cross section, semicircular pipe is horizontally arranged, the inner wall of semicircular pipe is provided with two sliding grooves along the length direction of semicircular pipe, a plurality of sliders are respectively slidably connected in each sliding groove, the inner end surface of slider is respectively conformal with sliding groove, the outer end surface of slider is circular arc, and the size is adapted with the outer diameter of to-be-measured circular pipe hydrophone.The application is based on the use of accelerometer method test, through the structural integration design of hydrophone and preamplification circuit, and signal transmission process is all electromagnetic shielding environment, effectively avoids the design drawbacks existing in prior art.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrophone detection and relates to a device and a method for measuring radial acceleration sensitivity of a circular pipe hydrophone. BACKGROUND

[0002] The circular pipe hydrophone is an ideal choice in a towed line array system due to its high sensitivity and wide frequency band response characteristics. However, the hydrophone is disturbed by axial and radial vibration signals during sound detection. Therefore, acceleration sensitivity, as one of the important performance indicators of the circular pipe hydrophone, can reflect the response characteristics of the hydrophone under the action of acceleration. Therefore, measuring the acceleration sensitivity of the hydrophone is crucial to evaluating its performance in water.

[0003] The existing scheme is only suitable for a specific size of the circular pipe hydrophone, and the structure is single. In addition, the preamplifier circuit is generally placed on the outside during testing, and the electromagnetic shielding effect is relatively poor. During the testing process, various interference factors are superimposed, and the data consistency is poor. SUMMARY

[0004] The technical problem to be solved by the application is to provide a device and a method for measuring radial acceleration sensitivity of a circular pipe hydrophone. Based on the acceleration meter method test, the structure of the hydrophone and the preamplifier circuit is designed integrally, and the signal transmission process is in an electromagnetic shielding environment, which effectively avoids the design drawbacks in the existing scheme.

[0005] The technical solution of the application is to provide a device for measuring radial acceleration sensitivity of a circular pipe hydrophone, which comprises a base, a hafu, an end cover, a circular pipe hydrophone to be tested, a slider, a preamplifier, an accelerometer and a vibration exciter. Wherein,

[0006] A plurality of mounting holes of different sizes are formed in the bottom of the base to cooperate with the installation of vibration exciters with different interfaces. The top of the base is a semicircular pipe with a semicircular cross section. The semicircular pipe is horizontally arranged, and two sliding grooves are arranged on the inner wall of the semicircular pipe along the length direction of the semicircular pipe. A plurality of sliders are respectively connected in each sliding groove. The inner end surface of the slider is conformal with the sliding groove, and the outer end surface of the slider is arc-shaped. The size of the slider is adapted to the outer diameter of the circular pipe hydrophone to be tested. A counterbore is further arranged on the slider, and a screw is threadedly connected in the counterbore. After the clamping position of the circular pipe hydrophone to be tested is determined, the slider can be fastened in the corresponding sliding groove through the screw.

[0007] The hafu is a semicircular pipe structure, and the pipe diameter of the hafu is adapted to the semicircular pipe of the base. The hafu and the semicircular pipe are spliced into a cylinder. A second sliding groove is arranged on the inner wall of the hafu along the length direction of the hafu. A second slider is slidably connected on the second sliding groove. The structure of the second slider is consistent with that of the slider on the semicircular pipe. After the clamping position of the circular pipe hydrophone to be tested is determined, the second slider can be fastened in the second sliding groove through the screw.

[0008] The diameter of the end cover is matched with the outer diameter of the semicircular pipe, and the end cover is closed to the two ends of the cylinder through fasteners;

[0009] The measured circular pipe hydrophone is integrally injection molded, and is clamped in the cylinder spliced by the Haofu and the semicircular pipe through the cooperation of the slider and the second slider;

[0010] The preamplifier is externally packaged with a metal shell, and internally has a preamplification circuit, the preamplifier is fixed in the cylinder, the lead of the measured circular pipe hydrophone is connected to the input end of the preamplifier, and the lead wire led out of the output end of the preamplifier penetrates through the end cover and extends outward;

[0011] The exciter is installed on the mounting hole of the base;

[0012] The accelerometer is connected to the exciter, so that the measured circular pipe hydrophone and the accelerometer can maintain the same amplitude during vibration;

[0013] The base, the Haofu and the end cover are all made of metal materials.

[0014] Based on the acceleration meter method test, the application can adapt to circular pipe hydrophones of different sizes through reasonable structural design, the preamplifier is placed in the metal cavity, the acceleration response signal output process is all in the shielding layer, the structure is simple and the test is stable, and the design defects in the prior art can be effectively avoided.

[0015] As preferred, the semicircular pipe and the Haofu are spliced into a cylinder and fastened by screws.

[0016] As preferred, the two sliding grooves and the second sliding groove in the cylinder are uniformly distributed in the circumferential direction.

[0017] As preferred, the diameter and size of the measured circular pipe hydrophone are designed according to the working frequency band and the impedance matching characteristics of the preamplification circuit.

[0018] As preferred, the base, the Haofu and the end cover are made of aluminum alloy materials.

[0019] As preferred, the working frequency band of the preamplification circuit is 10Hz-10kHz, the output is in differential form, and the amplification amount is 40dB.

[0020] As preferred, the sensitivity of the accelerometer 7 is 100mv / g.

[0021] As preferred, the accelerometer is connected to an accelerometer power supply on one side when used, and an analog signal is connected to an oscilloscope.

[0022] As preferred, the size of the connection between the bottom upper plane of the base and the outer arc of the semicircular pipe of the top is not greater than 5cm.

[0023] The application also provides a measuring method of the radial acceleration sensitivity measuring device of the above-mentioned cylindrical hydrophone, fixing the accelerometer and the bottom of the base on the table of the exciter, keeping the radial direction of the to-be-measured cylindrical hydrophone consistent with the vibration direction of the exciter, measuring the radial vibration acceleration of the to-be-measured cylindrical hydrophone by the accelerometer; supplying power to the to-be-measured cylindrical hydrophone and the accelerometer through the low-voltage power supply and the power supply of the accelerometer respectively, keeping the exciter vibrating in the vertical direction, transmitting the specific frequency sine signal from the signal source to the exciter after amplification by the power amplifier; then converting the sound pressure information obtained by the to-be-measured cylindrical hydrophone into an electric signal and inputting the electric signal to the preamplifier and the filter for further processing, and outputting the voltage peak-to-peak value U H and U a of the to-be-measured cylindrical hydrophone and the accelerometer to the oscilloscope; finally, the radial acceleration sensitivity M a of the hydrophone can be obtained according to formula (1)

[0024]

[0025] wherein, M ar is the sensitivity of the standard accelerometer.

[0026] Compared with the prior art, the application has the following advantages:

[0027] The application adopts the accelerometer method to measure the radial acceleration sensitivity of the to-be-measured element, places the to-be-measured hydrophone and the preamplification circuit in the same electromagnetic shielding environment on the premise of simulating the acceleration environment, and the device itself is made of all-metal materials, so that the test process can avoid the introduction of redundant interference and vibration loss, and at the same time, the device can change the shape and clamping position of the clamp according to cylindrical hydrophones of different sizes, thereby improving the flexibility of the whole device. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a partial structure diagram of the application;

[0029] Figure 2 is a schematic diagram of the use of the device of the application;

[0030] Figure 3 is a measurement principle diagram of the application. DETAILED DESCRIPTION

[0031] The application will be further described in combination with the specific embodiments and the accompanying drawings:

[0032] The radial acceleration sensitivity measuring device of the cylindrical hydrophone of the application mainly comprises a base 1, a to-be-measured cylindrical hydrophone 2, a preamplifier 3, a sliding block 4, a Haversine 5, an end cover 6, an exciter 7 and an accelerometer 8.

[0033] AsFigure 1 、 2 In this embodiment, the base 1 is made of aluminum alloy. The bottom of the base 1 is provided with several through holes, and the exciter 7 is connected through the through holes matched with the interface specifications. The top of the base 1 is a semicircular tube, which is horizontally arranged. The inner wall of the semicircular tube is provided with two sliding grooves along the length direction of the semicircular tube. A plurality of sliding blocks 4 are respectively and slidably connected in each sliding groove. The sliding blocks 4 are overall fan-shaped. The inner end faces of the sliding blocks 4 are respectively conformal with the sliding grooves. The outer end faces of the sliding blocks 4 are circular arc-shaped and are matched with the outer diameter of the measured circular tube hydrophone 2. A counterbore is further arranged at the middle of each sliding block 4. Screws are threadedly connected in the counterbores. After the clamping position of the measured circular tube hydrophone 2 is determined, the sliding blocks 4 can be fastened in the corresponding sliding grooves through the screws. The semicircular tube is provided with four threaded holes in the cross section to be screwed with the Hafnium 5. The left and right end faces of the semicircular tube are each provided with two threads to connect the end cover 6. During installation and use, the measured circular tube hydrophone 2 is radially consistent with the vibration direction of the exciter 7.

[0034] In this embodiment, the Hafnium 5 is made of aluminum alloy. The overall shape is semicircular tube. The inner wall of the Hafnium is provided with a second sliding groove. A sliding block 4 is slidably arranged in the second sliding groove. The second sliding block is consistent with the sliding block structure on the semicircular tube. After the clamping position of the measured circular tube hydrophone is determined, the second sliding block can be fastened in the second sliding groove through the screws and cooperate with the sliding block on the semicircular tube to clamp and position the measured circular tube hydrophone. The Hafnium 5 is provided with four through holes in the cross section to be fixed with the base 1 through screws. The left top of the Hafnium 5 is provided with a lead slot to lead out the wires of the preamplifier 3.

[0035] In this embodiment, the end cover 6 is made of aluminum alloy. The overall shape is cylindrical, which is consistent with the cylindrical cross section after the semicircular tube and the Hafnium 5 are spliced. The surface is provided with two through holes to be fixed at the two ends of the cylinder through screws, so that the internal environment of the device is closed.

[0036] In this embodiment, the measured circular tube hydrophone 2 is integrally formed by pouring. The diameter and size of the measured circular tube hydrophone 2 are designed according to the working frequency band and the impedance matching characteristics of the preamplifier circuit. During use, the measured circular tube hydrophone 2 is hard connected inside the base 1 and the Hafnium 5. The base 1 and the Hafnium 5 are both made of metal materials, which form a shielding environment inside to avoid the introduction of external electromagnetic interference. There are two pins on the upper end face of the element, which are the positive and negative electrodes of the measured circular tube hydrophone 2, and are connected to the input end of the preamplifier 3.

[0037] In this embodiment, the preamplifier 3 is externally packaged with a metal shell and internally provided with a preamplifier circuit connected through a pin lead. The working frequency band of the preamplifier circuit is 10 Hz-10 kHz, which is output in differential form. The amplification amount is 40 dB.

[0038] In this embodiment, the sensitivity of the accelerometer 8 is 100mv / g. The accelerometer 8 is hard connected to the exciter 7, which ensures that the to-be-measured hydrophone and the accelerometer have the same amplitude during vibration. During use, the power supply of the accelerometer is connected to one side, and the analog signal is connected to the oscilloscope.

[0039] The measurement principle used in the present application is shown in Figure 3 The measurement system includes a signal source, a power amplifier, a to-be-measured element, an accelerometer, an exciter, a filter, an oscilloscope, an accelerometer power supply, a hydrophone low-voltage power supply, etc. The accelerometer and the bottom of the base are fixed on the table top of the exciter, the radial direction of the to-be-measured cylindrical hydrophone is consistent with the vibration direction of the exciter, and the radial vibration acceleration borne by the to-be-measured cylindrical hydrophone is measured by the accelerometer; the to-be-measured cylindrical hydrophone and the accelerometer are powered by the low-voltage power supply and the accelerometer power supply respectively, the exciter is kept vibrating in the vertical direction, a specific frequency sine signal is sent by the signal source and transmitted to the exciter after being amplified by the power amplifier; then the to-be-measured cylindrical hydrophone converts the acquired sound pressure information into an electrical signal and inputs it to the preamplifier and the filter for further processing, and the peak-to-peak voltage U H of the to-be-measured cylindrical hydrophone and the accelerometer after processing is displayed on the oscilloscope; finally, the radial acceleration sensitivity M a of the hydrophone can be obtained according to formula (1): a

[0040]

[0041] In the formula, M ar is the sensitivity of the standard accelerometer.

[0042] The present application characterizes the radial acceleration sensitivity of the hydrophone element through structural design, and the hydrophone and the exciter are hard connected, which ensures that the vibration transmission has no loss. The preamplification circuit is also placed in an electromagnetic shielding environment on the circuit, which avoids introducing redundant interference. Thus, the radial acceleration response capability of the cylindrical hydrophone at different frequencies can be accurately compared, and the test results provide data reference for performance evaluation of the hydrophone.

[0043] The above only describes the preferred embodiments of the present application, but cannot be understood as a limitation on the claims. Any equivalent process transformation made by using the present application specification is included in the patent protection scope of the present application.​

Claims

1. A radial acceleration sensitivity measuring device for a circular tube hydrophone, characterized in that: Includes a base, a humping chamber, end caps, a hydrophone under test (tube), a slider, a preamplifier, an accelerometer, and a vibrator; among which, The bottom of the base has several mounting holes of different sizes to accommodate vibrators with different interfaces. The top of the base is a semi-circular tube, which is set horizontally. The inner wall of the semi-circular tube has two grooves along its length. Multiple sliders are slidably connected in each groove. The inner end face of the slider is conformal to the groove, and the outer end face of the slider is arc-shaped. The size is adapted to the outer diameter of the hydrophone to be tested. The slider is also provided with a countersunk hole, and a screw is threaded into the countersunk hole. After determining the clamping position of the hydrophone to be tested, the slider can be fastened in the corresponding groove by the screw. The Hafu is a semi-circular tube structure and its diameter is adapted to the semi-circular tube of the base. The Hafu and the semi-circular tube are combined to form a cylinder. The inner wall of the Hafu is provided with a second sliding groove along the length of the Hafu. A second slider is slidably connected to the second sliding groove. The structure of the second slider is the same as that of the slider on the semi-circular tube. After the clamping position of the hydrophone to be tested is determined, the second slider can be fastened in the second sliding groove by screws. The diameter of the end cap is adapted to the outer diameter of the semi-circular tube, and the end cap is sealed at both ends of the cylinder by fasteners; The test cylindrical hydrophone is integrally cast and molded, and is clamped in a cylinder composed of a ferrule and a semi-circular tube by the cooperation of a slider and a second slider. The preamplifier is externally encapsulated in a metal shell, and internally contains the preamplifier circuit. The preamplifier is fixed in a cylinder. The lead wire of the hydrophone under test is connected to the input terminal of the preamplifier. The lead wire of the output terminal of the preamplifier passes through the end cover and extends outward. The vibrator is installed on the mounting holes of the base; The accelerometer is connected to the exciter to ensure that the hydrophone under test and the accelerometer maintain the same amplitude during vibration; The base, hub, and end caps are all made of metal.

2. The radial acceleration sensitivity measuring device for a circular tube hydrophone according to claim 1, characterized in that: The semi-circular tube and the Hafu tube are assembled into a cylinder and then fastened with screws.

3. The radial acceleration sensitivity measuring device for a circular tube hydrophone according to claim 2, characterized in that: The grooves and the second groove inside the cylinder are evenly distributed circumferentially.

4. The radial acceleration sensitivity measuring device for a circular tube hydrophone according to claim 1, characterized in that: The diameter and dimensions of the test tube hydrophone are designed based on the operating frequency band and the impedance matching characteristics of the preamplifier circuit.

5. The radial acceleration sensitivity measuring device for a circular tube hydrophone according to claim 1, characterized in that: The base, hub, and end caps are made of aluminum alloy.

6. The radial acceleration sensitivity measuring device for a circular tube hydrophone according to claim 1, characterized in that: The preamplifier circuit operates in the frequency range of 10Hz to 10kHz, outputs differentially, and has an amplification of 40dB.

7. The radial acceleration sensitivity measuring device for a circular tube hydrophone according to claim 1, characterized in that: The accelerometer 7 has a sensitivity of 100 mv / g.

8. The radial acceleration sensitivity measuring device for a circular tube hydrophone according to claim 7, characterized in that: When using the accelerometer, connect one side to the accelerometer power supply and connect the analog signal to the oscilloscope.

9. The radial acceleration sensitivity measuring device for a circular tube hydrophone according to claim 1, characterized in that: The dimension at the connection between the bottom upper plane of the base and the outer arc of the top semicircular tube is no more than 5cm.

10. The measurement method of the radial acceleration sensitivity measuring device for a circular tube hydrophone as described in any one of claims 1-9, characterized in that: The accelerometer and base are fixed to the exciter's platform, ensuring the radial direction of the test tube hydrophone is aligned with the exciter's vibration direction. The accelerometer measures the radial vibration acceleration experienced by the test tube hydrophone. Power is supplied to the test tube hydrophone and the accelerometer via a low-voltage power supply and an accelerometer power supply, respectively. The exciter maintains vertical vibration. A sinusoidal signal of a specific frequency is emitted from a signal source, amplified by a power amplifier, and then transmitted to the exciter. The test tube hydrophone converts the acquired sound pressure information into an electrical signal, which is then input to a preamplifier and filter for further processing. The peak-to-peak voltage U of the processed test tube hydrophone and the accelerometer is then compared. H with U a The open-circuit voltage at the output terminal is displayed on the oscilloscope; finally, the radial acceleration sensitivity M of the hydrophone can be obtained according to equation (1). a : In the formula, M ar This refers to the sensitivity of a standard accelerometer.

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