Corrugated tube and method for measuring vibration velocity vector sensor

Abstract

The invention relates to a wave node tube and method for measuring a vibration velocity vector sensor, the wave node tube is composed of a cylindrical tube body, four standard pressure-resistant hydrophones and four high-pressure-resistant transmitting transducers, the four high-pressure-resistant transmitting transducers are of the same batch and the same model and are arranged oppositely in pairs, and the sound axes are perpendicular to each other; the standard pressure-resistant hydrophones are positioned on a sound axis and are arranged in a central symmetry manner; when in use, a measured sensor is in the center of the corrugated tube. The node tube can be used for measuring a vibration velocity vector sensor, and during measurement, the push-pull effect is generated by controlling the vibration phase of the transducer, so that the radiation impedance during vibration of the transducer is greatly reduced; and finally, by controlling the vibration amplitude of the transducer, the direction of a vibration velocity field in the tube can be controlled, and a pressure-resistant rotating device does not need to be developed.

Description

Technical field:

[0001] The present invention belongs to the technical field of computational measurement, and in particular relates to a bellows tube and a method for measuring a vibration velocity vector sensor. Background technology:

[0002] In the field of underwater acoustics, there is a widespread demand for vibration vector sensors that measure velocity in pressure environments, and the measurement frequency is mainly low-frequency.

[0003] The most common device used for underwater low-frequency measurements with vector sensors is a standing wave tube. By comparing the distribution characteristics of the sound pressure and velocity field within the tube, the sensitivity of the sensor under test can be determined. To measure the sensor's vector characteristics, the vector sensor must be rotated during the measurement process. The most common method involves mounting the sensor on a rotating device and rotating it during the measurement. Currently, measurement methods for vector sensors in atmospheric pressure environments are well-established, but measurements in pressure environments still require further improvement.

[0004] First, if you want to create a pressure environment in a standing wave tube, you need to use air pressurization, which carries a high safety risk. If you use water pressurization, the vibration velocity field in the tube is weak, which will affect the signal-to-noise ratio of the measurement and increase the measurement uncertainty.

[0005] Secondly, under pressure, the transducer in the standing wave tube will be subjected to a large radiation impedance, which will affect the vibration of the transducer and still affect the signal-to-noise ratio of the measurement, increasing the uncertainty of the measurement.

[0006] Finally, in a pressure environment, the rotary device needs to be designed to withstand pressure, which is costly and risky. Summary of the invention:

[0007] The technical problem to be solved by the present invention is to provide a bellows and method for measuring a vibration velocity vector sensor. The bellows of the present invention can be used to measure a vibration velocity vector sensor, and a high-pressure environment can be constructed in the bellows by using water pressurization.

[0008] The technical solution of the present invention is to provide a corrugated tube for measuring vibration velocity vector sensor, the corrugated tube consists of a cylindrical tube body, four standard pressure-resistant hydrophones and four high-pressure-resistant transmitting transducers, wherein:

[0009] The four high-pressure resistant transmitting transducers are of the same batch and model, and are placed opposite each other in pairs with their acoustic axes perpendicular to each other; the standard pressure-resistant hydrophone is located on the acoustic axis and is placed in a centrally symmetrical manner; when in use, the sensor under test is at the center of the corrugated tube.

[0010] Preferably, the diameter and height of the tube body are 1 / 5 of the wavelength corresponding to the upper limit of the measurement frequency.

[0011] Preferably, the diameter of the standard pressure-resistant hydrophone should be smaller than 1 / 20 of the wavelength corresponding to the upper limit of the measurement frequency.

[0012] The present invention also provides a method for measuring a corrugated tube of a vibration velocity vector sensor, the steps of which are as follows:

[0013] Step 1: Install the transmitting transducer, standard pressure-resistant hydrophone and the sensor under test in the bellows;

[0014] Step 2: Close the bellows tube and use water pressure to increase the pressure in the bellows tube to the target pressure;

[0015] Step 3: Stimulate the high-voltage emitting transducer to work and record the voltage signal output by the standard pressure-resistant hydrophone;

[0016] Step 4: Calculate the direction of the vibration amplitude according to equations (1) and (2). Taking the x-axis direction as an example, assume that the position of the sensor to be measured is (0, 0), the wave number corresponding to the measurement frequency is k, and the coordinates of the standard pressure-resistant hydrophone on the x-axis are x0 and -x0, and the sound pressure values ​​are p1 and p2.

[0017] Then the x-axis vibration velocity u at the measured sensor is x0 for:

[0018]

[0019] Similarly, the vibration velocity u in the y-axis direction can be obtained y0 , at this time the angle θ between the vibration direction and the x-axis is:

[0020] θ=atan(u x0 / u y0 ) (2)

[0021] Step 5: Depressurize the bellows to complete the measurement.

[0022] Preferably, when the corrugated tube is working, excitation voltages with the same amplitude and opposite directions are applied to the paired high-voltage resistant transmitting transducers, and the amplitudes of the excitation voltages of the two pairs of high-voltage resistant transmitting transducers are controlled to rotate the sound field in the corrugated tube.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] During measurement, the present invention generates a push-pull effect by controlling the vibration phase of the transducer, thereby greatly reducing the radiation impedance of the transducer during vibration; finally, by controlling the vibration amplitude of the transducer, the direction of the vibration velocity field in the tube can be controlled without the need to develop a pressure-resistant rotary device. Description of the drawings:

[0025] Figure 1 Schematic diagram of the bellows tube of the present invention.

[0026] Figure 2 4 is the acoustic field simulation result of the corrugated tube according to the embodiment of the present invention.

[0027] Figure 3 Schematic diagram of sound field calculation according to an embodiment of the present invention. Specific implementation method:

[0028] The present invention will be further described below with reference to the accompanying drawings:

[0029] like Figure 1 As shown, the present invention proposes a corrugated tube for measuring a vibration velocity vector sensor. The corrugated tube consists of a cylindrical tube body 1, four standard pressure-resistant hydrophones 2, and four high-pressure-resistant transmitting transducers 3, wherein:

[0030] The four high-pressure resistant transmitting transducers 3 are of the same batch and model, and are placed opposite each other in pairs with their acoustic axes perpendicular to each other; the standard pressure-resistant hydrophone 2 is located on the acoustic axis and is placed in a centrally symmetrical manner; when in use, the sensor 4 to be measured is at the center of the corrugated tube; the diameter and height of the tube body 1 are 1 / 5 of the wavelength corresponding to the upper limit of the measurement frequency; the diameter of the standard pressure-resistant hydrophone 2 should be less than 1 / 20 of the wavelength corresponding to the upper limit of the measurement frequency.

[0031] The measuring method of the present invention is specifically operated as follows:

[0032] Step 1: Install the transmitting transducer 3, the standard pressure-resistant hydrophone 2 and the sensor under test 4 in the bellows;

[0033] Step 2: Close the bellows tube and use water pressure to increase the pressure in the bellows tube to the target pressure;

[0034] Step 3: Excite the high-voltage emitting transducer and record the voltage signal output by the standard pressure-resistant hydrophone 2. In this step, excitation voltages of the same amplitude and opposite directions are applied to the paired emitting transducers 3. By controlling the amplitude of the excitation voltages of the two pairs of emitting transducers 3, the sound field in the tube can be rotated, as shown in FIG. Figure 2 As shown;

[0035] Step 4: By reading the open-circuit voltage of the standard pressure-resistant hydrophone 2, the vibration velocity amplitude at the center of the corrugated tube can be calculated. In other words, the direction of the vibration velocity amplitude can be calculated according to equations (1) and (2). Taking the x-axis direction as an example, let the position of the sensor 4 under test be (0, 0), the wave number corresponding to the measurement frequency be k, the coordinates of the standard pressure-resistant hydrophone 2 on the x-axis are x0 and -x0, and the sound pressure values ​​are p1 and p2, as shown in the following example: Figure 3 shown.

[0036] Then the x-axis vibration velocity u at the measured sensor is x0 for:

[0037]

[0038] Similarly, the vibration velocity u in the y-axis direction can be obtained y0 , at this time the angle θ between the vibration direction and the x-axis is:

[0039] θ=atan(u x0 / u y0 ) (2)

[0040] Step 5: Depressurize the bellows to complete the measurement.

[0041] The present invention can use water pressurization to construct a high-pressure environment in the corrugated tube; during measurement, a push-pull effect is generated by controlling the vibration phase of the transducer, which greatly reduces the radiation impedance of the transducer during vibration; finally, by controlling the vibration amplitude of the transducer, the direction of the vibration velocity field in the tube can be controlled, without the need to develop a pressure-resistant rotation device.

[0042] The above description is only for the preferred embodiment of the present invention, which should not be understood as limiting the claims. Any equivalent process changes made using the present invention description are included in the patent protection scope of the present invention.

Claims

1. A bellows tube for measuring a vibration velocity vector sensor, characterized in that: The bellows tube consists of a cylindrical tube body, four standard pressure-resistant hydrophones and four high-pressure-resistant transmitting transducers, among which: The four high-pressure resistant transmitting transducers are of the same batch and model, and are placed opposite each other in pairs with their acoustic axes perpendicular to each other; the standard pressure-resistant hydrophone is located on the acoustic axis and is placed in a centrally symmetrical manner; when in use, the sensor under test is at the center of the corrugated tube.

2. The corrugated tube for measuring a vibration velocity vector sensor according to claim 1, characterized in that: The diameter and height of the tube body are 1 / 5 of the wavelength corresponding to the upper limit of the measurement frequency.

3. The corrugated tube for measuring a vibration velocity vector sensor according to claim 1, characterized in that: The diameter of a standard pressure-resistant hydrophone should be less than 1 / 20 of the wavelength corresponding to the upper limit of the measurement frequency.

4. The method for measuring a corrugated tube for a vibration velocity vector sensor according to any one of claims 1 to 3, characterized in that: The steps are as follows, Step 1: Install the transmitting transducer, standard pressure-resistant hydrophone and the sensor under test in the bellows; Step 2: Close the bellows tube and use water pressure to increase the pressure in the bellows tube to the target pressure; Step 3: Stimulate the high-voltage emitting transducer to work and record the voltage signal output by the standard pressure-resistant hydrophone; Step 4: Calculate the direction of the vibration amplitude according to equations (1) and (2). Taking the x-axis direction as an example, assume that the position of the sensor to be measured is (0, 0), the wave number corresponding to the measurement frequency is k, and the coordinates of the standard pressure-resistant hydrophone on the x-axis are x0 and -x0, and the sound pressure values ​​are p1 and p2. Then the x-axis vibration velocity u at the measured sensor is x0 for: Similarly, the vibration velocity u in the y-axis direction can be obtained y0 , at this time the angle θ between the vibration direction and the x-axis is: θ=where(u x0 / the y0 ) (2) Step 5: Depressurize the bellows to complete the measurement.

5. The method for measuring a corrugated tube for a vibration velocity vector sensor according to claim 4, characterized in that: When the corrugated tube is working, excitation voltages of the same amplitude and opposite directions are applied to the paired high-voltage resistant transmitting transducers. By controlling the amplitudes of the excitation voltages of the two pairs of high-voltage resistant transmitting transducers, the sound field in the corrugated tube rotates.

Images