A metrological calibration system for a hydroacoustic positioner

Abstract

The application discloses a kind of hydroacoustic locator's measurement calibration system, and the application belongs to the field of hydroacoustic locator calibration, comprising: geometric parameter calibration device, the hydroacoustic locator to be detected and acoustic parameter calibration device;Wherein geometric parameter calibration device, the hydroacoustic locator to be detected and acoustic parameter calibration device are connected;The hydroacoustic locator to be detected includes: transducer array and transponder;Geometric parameter calibration device is used to measure the accuracy index and the action distance index of the hydroacoustic locator to be detected, and the test site of geometric parameter calibration device is deep water harbor basin;Acoustic parameter calibration device is used to measure the sound source level, operating frequency, directivity and full range index of the transducer array;The test site of acoustic parameter calibration device is six side sound-absorbing pool.The application can effectively avoid the error introduced by sound velocity profile, swell posture and other multi-source factors in river, lake and sea environment, and can measure and test the geometric parameters of ultra-short baseline hydroacoustic positioning system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hydroacoustic positioning instrument calibration, and particularly relates to a hydroacoustic positioning instrument metrological calibration system. BACKGROUND

[0002] Hydroacoustic positioning technology and equipment have wide applications in the fields of military defense, emergency rescue, ocean investigation, water transportation engineering and underwater archaeology. At present, the existing metrology technology of hydroacoustic positioning instruments usually takes two measuring ships as carriers, respectively carries acoustic array transducers and acoustic beacon transponders, takes GPS receivers and other types of hydroacoustic positioning equipment as reference standards, and adopts the method of comparison measurement to measure the ranging error in rivers, lakes, seas and other environments.

[0003] However, at the present stage, the nominal working distance of hydroacoustic positioning products is ten thousand meters, and the measurement precision is centimeter level, which is usually derived from the performance parameters such as transducer design size, bandwidth, wavelength and radiation sound power, and has not yet been realized in the full-range metrological calibration and comprehensive value evaluation in real water environment. SUMMARY

[0004] The purpose of the present application is to provide a hydroacoustic positioning instrument metrological calibration system to solve the problems existing in the prior art.

[0005] To achieve the above purpose, the present application provides a hydroacoustic positioning instrument metrological calibration system, which comprises a geometric parameter calibration device, a to-be-tested hydroacoustic positioning instrument and an acoustic parameter calibration device; wherein the geometric parameter calibration device, the to-be-tested hydroacoustic positioning instrument and the acoustic parameter calibration device are connected; the to-be-tested hydroacoustic positioning instrument comprises a transducer array and a transponder.

[0006] The geometric parameter calibration device is used to measure the accuracy index and the action distance index of the to-be-tested hydroacoustic positioning instrument, and the test site of the geometric parameter calibration device is a deep water harbor pool.

[0007] The acoustic parameter calibration device is used to measure the sound source level, working frequency, directivity and full-range index of the transducer array, and the test site of the acoustic parameter calibration device is a six-sides anechoic water pool.

[0008] Preferably, the geometric parameter calibration device comprises a first calibration unit and a second calibration unit, wherein the first calibration unit and the second calibration unit are respectively connected with the to-be-tested hydroacoustic positioning instrument.

[0009] The first calibration unit is used to calculate the positioning indication error, and the positioning indication error is used as the accuracy index of the hydroacoustic positioning instrument.

[0010] The second verification unit is configured to calculate an actual effective distance of the underwater acoustic positioning instrument according to a reference standard value, wherein the reference standard value is positioning data of a GNSS-RTK receiver.

[0011] Preferably, the first verification unit comprises an underwater six-degree-of-freedom platform, a standard steel tape measure and a total station laser range finder.

[0012] The underwater six-degree-of-freedom platform is installed on a translation track on one side of a deep water harbor basin, and the underwater six-degree-of-freedom platform is connected to the underwater acoustic positioning instrument to be tested in the deep water harbor basin, and the total station laser range finder is installed outside the translation track.

[0013] The underwater six-degree-of-freedom platform is configured to adjust a positional relationship between the transducer array and the transponder according to a set test point.

[0014] The total station laser range finder is configured to measure a horizontal distance between the transponder and a geometric center of the transducer array based on the positional relationship.

[0015] The standard steel tape measure is configured to measure a first water entry depth and a second water entry depth, respectively, wherein the first water entry depth is a vertical distance between a water surface of the deep water harbor basin and the transponder, and the second water entry depth is a vertical distance between the water surface of the deep water harbor basin and the transducer.

[0016] Preferably, in the first verification unit, a standard slant range and a standard angle are obtained based on the horizontal distance, the first water entry depth and the second water entry depth; a difference between the standard slant range and a slant range measurement value of the underwater acoustic positioning instrument to be tested is calculated, and a difference between the standard angle and an angle measurement value of the underwater acoustic positioning instrument to be tested is calculated to obtain a positioning indication error.

[0017] Preferably, the second verification unit comprises a standard steel tape measure, a sound velocity profiler, a GNSS-RTK receiver and an intelligent unmanned ship.

[0018] The intelligent unmanned ship comprises a first unmanned ship and a second unmanned ship, and the GNSS-RTK receiver comprises a first receiver and a second receiver.

[0019] The first unmanned ship is configured to carry the first receiver and the transducer array, and the second unmanned ship is configured to carry the second receiver and the transponder.

[0020] The sound velocity profiler is configured to correct a sound velocity of the underwater acoustic positioning instrument to be tested.

[0021] Preferably, in the second calibration unit, based on the first unmanned ship, a second unmanned ship is started to obtain a nominal action distance, wherein the update rate of the nominal action distance meets the normal signal receiving of the water acoustic locator to be detected; positioning data of the GNSS-RTK receiver is obtained, and based on the positioning data, an actual action distance of the water acoustic locator to be detected is obtained.

[0022] Preferably, the acoustic parameter calibration device comprises a third calibration unit and a fourth calibration unit, wherein the third calibration unit and the fourth calibration unit are respectively connected with the water acoustic locator to be detected.

[0023] The third calibration unit is used for measuring the sound source level, working frequency and directivity index of the transducer array.

[0024] The fourth calibration unit is used for measuring the full range index of the transducer array.

[0025] Preferably, the third calibration unit comprises a test vehicle, a first standard hydrophone, a display control computer, a signal collector and a preamplifier; the test vehicle comprises a rotating support and a lifting support.

[0026] The transducer array is installed in a six-sided anechoic tank through the rotating support, the standard hydrophone is installed in the six-sided anechoic tank through the lifting support, the display control computer is connected with the test vehicle and the signal collector respectively, and the signal collector is connected with the preamplifier.

[0027] In the third calibration unit, the first standard hydrophone is adjusted, based on the adjustment result, the direct pulse signal emitted by the transducer array is collected through the signal collector, and the direct pulse signal is subjected to Fourier transform to obtain the working frequency and the open circuit voltage, based on the working frequency and the open circuit voltage, the transducer sound source level and the directivity index are obtained.

[0028] Preferably, the fourth calibration unit comprises a second standard hydrophone, a target analog transponder and a sound velocity profiler; wherein the second standard hydrophone, the target analog transponder and the sound velocity profiler are installed in a six-sided anechoic tank, and the transducer array and the target analog transponder have the same distance from the water surface of the six-sided anechoic tank.

[0029] In the fourth calibration unit, the sound velocity profiler is used to measure the transducer array to obtain the water sound velocity, the second standard hydrophone receives the pulse signal generated by the water sound velocity and feeds back to the target analog transponder, and at the same time, based on the target analog sound source, an equivalent sound wave signal is emitted; and the transponder in the water acoustic locator normally receives the echo signal, at this time, the maximum equivalent distance is taken as the full range index of the water acoustic locator to be detected.

[0030] The technical effect of the present application is:

[0031] The present application provides a kind of hydroacoustic locator's measurement calibration system, comprising: geometric parameter calibration device, the hydroacoustic locator to be detected and acoustic parameter calibration device;Wherein geometric parameter calibration device, the hydroacoustic locator to be detected and acoustic parameter calibration device connect;The hydroacoustic locator to be detected includes: transducer array and transponder;By geometric parameter calibration device, the accuracy index and the action distance index of measurement hydroacoustic locator, the test site of geometric parameter calibration device is deep water harbour basin;By acoustic parameter calibration device, the transducer sound source level, operating frequency, directivity and full range index of measurement hydroacoustic locator;The test site of acoustic parameter calibration device is six side sound-absorbing pool.

[0032] The present application proposes calibration device based on deep water harbour basin and six side sound-absorbing pool, effectively avoids the error introduced by multiple source factors such as sound speed profile, swell posture under river, lake and sea environment, can carry out measurement test to the geometric parameter of super short baseline hydroacoustic positioning system.The calibration device based on deep water harbour basin can realize the measurement test to the acoustic parameter such as transducer sound source level, operating frequency, based on six side sound-absorbing pool integrated hydroacoustic measuring system, develops target simulation transponder, proposes a kind of simulation calibration method based on equivalent sound wave time delay feedback, realizes full range simulation calibration of hydroacoustic positioning. DETAILED DESCRIPTION

[0033] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of this application and of the drawings illustrate the application and serve to explain the principles of the present application. In the drawings:

[0034] Figure 1 It is positioning measurement principle schematic diagram in the embodiment of the present application;

[0035] Figure 2 It is acoustic parameter measurement schematic diagram in the embodiment of the present application;

[0036] Figure 3 It is target simulation transponder circuit function block diagram in the embodiment of the present application;

[0037] Figure 4 It is full range simulation calibration principle schematic diagram in the embodiment of the present application. DETAILED DESCRIPTION

[0038] It should be noted that the embodiments and the features in the embodiments in the present application can be combined with each other without conflict.The present application will be described in detail below with reference to the drawings and in combination with embodiments.

[0039] Embodiment one

[0040] The embodiment provides a metrological calibration system of a water acoustic locator, comprising: a geometric parameter calibration device, a water acoustic locator to be detected and an acoustic parameter calibration device; wherein the geometric parameter calibration device, the water acoustic locator to be detected and the acoustic parameter calibration device are connected; the water acoustic locator to be detected comprises a transducer array and a transponder;

[0041] The geometric parameter calibration device is used for measuring the accuracy index and the action distance index of the water acoustic locator to be detected, and a test site of the geometric parameter calibration device is a deep water harbor basin.

[0042] The acoustic parameter calibration device is used for measuring the sound source level, the working frequency, the directivity and the full range index of the transducer array, and a test site of the acoustic parameter calibration device is a six-sides anechoic tank.

[0043] In the embodiment, the calibration device is specifically designed as follows:

[0044] The water acoustic positioning calibration device is divided into a geometric parameter calibration device and an acoustic parameter calibration device 2. Mainly includes test site, supporting equipment, measurement master standard, etc., and the design parameter accuracy should be traced to the upper level national measurement standard.

[0045] 1. Geometric parameter calibration device

[0046] The geometric parameter calibration device is mainly used for measuring the performance indexes such as the water acoustic positioning accuracy and the action distance, and the design requirements are shown in Table 1.

[0047] Table 1

[0048]

[0049]

[0050] 2. Acoustic parameter calibration device

[0051] The acoustic parameter calibration device is mainly used for measuring the performance indexes such as the sound source level, the working frequency, the directivity and the range of the water acoustic positioning transducer, and the design requirements are shown in Table 2.

[0052] Table 2

[0053]

[0054]

[0055] 3. Geometric parameter measurement method

[0056] (1) Positioning indication error

[0057] Measurement methods: (1) Install the underwater acoustic positioning transducer array and transponder to the underwater six-degree-of-freedom platform; (2) Measure the sound velocity in the underwater acoustic propagation channel using a sound velocity profiler as a system correction factor; (3) Adjust the positions of the transducer array and transponder, selecting 5m, 30m, 50m, 100m, and 150m as calibration points; (4) Measure the horizontal distance from the transponder to the geometric center of the transducer array using a total station laser rangefinder, measure the immersion depth using a standard steel tape measure, convert the standard slant distance and angle, and calculate the difference between the slant distance and angle measurements of the underwater acoustic positioning system to calculate the positioning (X, Y, Z) indication error. The measurement principle is as follows: Figure 1 As shown.

[0058] (2) Scope of action

[0059] Measurement methods: (1) Using two intelligent unmanned vessels as platforms, each equipped with a GNSS-RTK receiver, an underwater acoustic positioning array, and a transponder; (2) Using a standard steel tape measure and a sound velocity profiler to correct system installation offset and sound velocity; (3) Controlling unmanned vessel No. 1 to hover in open water and maintain its position, and starting unmanned vessel No. 2 to move away from unmanned vessel No. 1 until the nominal effective distance is reached; (4) Determining whether the underwater acoustic positioning system can receive signals normally at the nominal update rate; (5) Planning the unmanned vessel's trajectory, using the positioning data of the GNSS-RTK receiver as the reference standard value, to measure the actual effective distance of the underwater acoustic positioning equipment under test.

[0060] 4. Acoustic parameter measurement traceability method

[0061] (1) Sound source level, operating frequency and directivity of underwater acoustic transducer

[0062] Measurement method: (1) Install the underwater acoustic positioning transducer array at the bottom of the slewing support of the test trolley in the anechoic pool, and install the standard hydrophone at the bottom of the lifting support. The test distance meets the far-field condition; (2) Adjust the standard hydrophone in 1mm increments to collect the direct pulse signal within the coverage angle range of the transducer array, and perform Fourier transform to obtain the signal frequency and open-circuit voltage; (3) Calculate the transmission voltage response level of each angle detection point according to formula ①.

[0063] S V =20lg(U OC / U X )+20lgd-M ①

[0064] In the formula: S V It is the transmitted voltage response level, dB (reference value: 1uPa·m / V); U OC This is the standard open-circuit voltage of a hydrophone, V; U XV is the voltage applied to the transducer array under test, V; d is the distance between the standard hydrophone and the transducer array under test, m; M is the sensitivity level of the standard hydrophone, dB (reference value: 1V / uPa). (4) Draw the directivity diagram, and convert the sound source level by the maximum response level of the main axis. The measurement schematic diagram is shown in Figure 2 .

[0065] (2) Full-range analog calibration

[0066] Measurement method: (1) According to the Figure 3 Design and develop a target analog transponder; input the sound speed of the water body into the underwater acoustic positioning system, and transmit pulse sound waves; (3) The standard hydrophone receives the pulse signal of the acoustic array and feeds back to the target analog transponder, which accurately calculates the propagation time and attenuation loss of the pulse sound wave according to the sonar equation; (4) According to the upper limit of the nominal measurement range of the underwater acoustic positioning system, the delay and attenuation are processed, and the equivalent sound wave signal is transmitted by the target analog sound source; (5) Determine whether it can be detected by the underwater acoustic positioning system. If the echo signal can be received, the equipment under test can reach the nominal measurement range; (6) Otherwise, adjust the nominal measurement range according to the indication resolution until the system can normally receive the echo signal, and the maximum equivalent distance is taken as the measurement capability of the equipment under test. The principle of full-range analog calibration is shown in Figure 4 .

[0067] 5. Uncertainty evaluation

[0068] Uncertainty is an important indicator to measure the reliability of the measurement standard and the confidence of the calibration result. The main error sources in the calibration process are mainly divided into two categories: ① repeatability of the equipment under test and the measurement standard; ② system error of the equipment under test and the measurement standard. Taking the positioning indication error σ calibration process as an example, assuming that each error source is independent, the measurement model can be represented as:

[0069]

[0070] In the formula: USBL is the measurement repeatability of the equipment under test; TS is the error introduced by the total station; SVP is the error introduced by the sound speed correction; Tape is the error introduced by the standard steel tape measurement; Calibration is the error introduced by the equipment installation.

[0071] According to JJF 1059.1-2019 "Evaluation and Expression of Measurement Uncertainty", the uncertainty of the underwater acoustic positioning measurement calibration device is evaluated, and the results are shown in Table 3.

[0072] Table 3

[0073]

[0074] The embodiment has the following beneficial effects:

[0075] The embodiment develops an underwater six-degree-of-freedom control mechanism based on a large-scale deepwater harbor basin, builds a full-traceability verification comparison platform based on an unmanned ship, realizes the positioning and orientation of a sound-based array and a transponder in a millimeter-level spatial coordinate system, and uses a comparison calibration method to measure and test the geometric parameters of an ultra-short baseline underwater acoustic positioning system with laser ranging and real-time dynamic satellite differential positioning (GNSS-RTK) technology as a reference standard.

[0076] Based on a six-surface anechoic basin integrated with an underwater acoustic measurement system, the acoustic parameters of a water acoustic transducer such as sound source level and working frequency are measured and tested, a target simulation transponder is developed, an analog calibration method based on equivalent sound wave time delay feedback is proposed, and full-range simulation calibration of underwater acoustic positioning is realized.

[0077] Underwater acoustic positioning technology and equipment have wide applications in military defense, emergency rescue, ocean investigation, water transportation engineering, underwater archaeology and other fields. At present, there are few laboratories in China that can carry out performance testing of underwater acoustic positioning equipment. The reason is that the measurement and testing requires the support of large test basins. Due to the limitation of indoor basin size, the measurement range generally does not exceed 50 m, which is far from meeting the measurement needs of underwater acoustic positioning.

[0078] The embodiment proposes a measurement traceability method of key values of underwater acoustic positioning based on the control of measuring instruments, develops a calibration device based on a large-scale deepwater harbor basin and a six-surface anechoic basin, effectively avoids errors introduced by multiple sources such as sound velocity profile and swell attitude in river, lake and sea environments, expands the calibration range to more than 150 m, and through uncertainty evaluation, the measurement capabilities meet the requirements of national standards such as the Hydrographic Survey Specification and the Ocean Investigation Specification for the traceability and transmission of underwater acoustic positioning values, and accumulate certain technical foundation for the next step of formulating national calibration specifications and measurement standards for underwater acoustic positioning.

[0079] The above is only the preferred specific implementation method of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A metrological calibration system for a hydroacoustic positioner, characterized in that, The system comprises: a geometric parameter calibration device, a water acoustic positioning instrument to be tested, and an acoustic parameter calibration device; the geometric parameter calibration device, the water acoustic positioning instrument to be tested, and the acoustic parameter calibration device are connected; the water acoustic positioning instrument to be tested comprises a transducer array and a transponder; the geometric parameter calibration device is used to measure the accuracy index and the effective distance index of the water acoustic positioning instrument to be tested, and the test site of the geometric parameter calibration device is a deep water harbor basin; the geometric parameter calibration device comprises a first calibration unit and a second calibration unit, and the first calibration unit and the second calibration unit are respectively connected with the water acoustic positioning instrument to be tested; the first calibration unit is used to calculate a positioning indication error, and the positioning indication error is used as the accuracy index of the water acoustic positioning instrument; the second calibration unit is used to calculate the actual effective distance of the water acoustic positioning instrument according to a reference standard value, and the reference standard value is the positioning data of a GNSS-RTK receiver; the first calibration unit comprises an underwater six-degree-of-freedom platform, a standard steel tape, and a total station type laser range finder; the underwater six-degree-of-freedom platform is installed on a translation track on one side of the deep water harbor basin, the underwater six-degree-of-freedom platform is connected with the water acoustic positioning instrument to be tested, the water acoustic positioning instrument to be tested is in the deep water harbor basin, and the total station type laser range finder is installed outside the translation track; the underwater six-degree-of-freedom platform is used to adjust the positional relationship between the transducer array and the transponder according to a set test point; the total station type laser range finder is used to measure the horizontal distance between the transponder and the geometric center of the transducer array based on the positional relationship; the standard steel tape is used to measure a first water entry depth and a second water entry depth, respectively, wherein the first water entry depth is the vertical distance between the water surface of the deep water harbor basin and the transponder, and the second water entry depth is the vertical distance between the water surface of the deep water harbor basin and the transducer; the acoustic parameter calibration device is used to measure the sound source level, the working frequency, the directivity, and the full range index of the transducer array, and the test site of the acoustic parameter calibration device is a six-sides anechoic tank.

2. The metrological calibration system of a hydroacoustic positioner according to claim 1, characterized in that, in the first calibration unit, the standard slant range and the standard angle are obtained based on the horizontal distance, the first water entry depth, and the second water entry depth, the standard slant range and the slant range measurement value of the water acoustic positioning instrument to be tested are subjected to difference calculation, the standard angle and the angle measurement value of the water acoustic positioning instrument to be tested are subjected to difference calculation, and the positioning indication error is obtained.

3. The metrological calibration system of a sound navigation and ranging apparatus according to claim 1, characterized in that, the second calibration unit comprises a standard steel tape, a sound velocity profiler, a GNSS-RTK receiver, and an intelligent unmanned ship; the intelligent unmanned ship comprises a first unmanned ship and a second unmanned ship, and the GNSS-RTK receiver comprises a first receiver and a second receiver; the first unmanned ship is used to carry the first receiver and the transducer array, and the second unmanned ship is used to carry the second receiver and the transponder; the sound velocity profiler is used to correct the sound velocity of the water acoustic positioning instrument to be tested.

4. The water acoustic positioning instrument calibration system according to claim 3, wherein The second calibration unit is started based on the first unmanned ship to obtain a nominal action distance, wherein an update rate of the nominal action distance meets normal signal receiving of the water acoustic locator to be detected; Positioning data of the GNSS-RTK receiver is acquired, and actual action distance of the water acoustic locator to be detected is obtained based on the positioning data.

5. The metrological calibration system of a sound navigation and ranging apparatus according to claim 1, characterized in that, The acoustic parameter calibration device comprises a third calibration unit and a fourth calibration unit, wherein the third calibration unit and the fourth calibration unit are connected with the water acoustic locator to be detected respectively; The third calibration unit is used for measuring a sound source level, a working frequency and a directivity index of the transducer array. The fourth calibration unit is used for measuring a full-range index of the transducer array.

6. The metrological calibration system of a sound navigation and ranging apparatus according to claim 5, characterized in that, The third calibration unit comprises a test vehicle, a first standard hydrophone, a display control computer, a signal collector and a preamplifier. The transducer array is installed in a six-sides anechoic tank through the rotating support, and the standard hydrophone is installed in the six-sides anechoic tank through the lifting support. The display control computer is connected with the test vehicle and the signal collector respectively, and the signal collector is connected with the preamplifier.

7. The metrological calibration system of a sound navigation and ranging apparatus according to claim 5, characterized in that, In the third calibration unit, the first standard hydrophone is adjusted, direct pulse signals emitted by the transducer array are collected through the signal collector based on the adjustment result, and the direct pulse signals are subjected to Fourier transform to obtain a working frequency and an open circuit voltage, and a transducer sound source level and a directivity index are obtained based on the working frequency and the open circuit voltage. The fourth calibration unit comprises a second standard hydrophone, a target analog transponder and a sound velocity profiler. The transducer array and the target analog transponder are arranged at the same distance from the water surface of the six-sides anechoic tank. In the fourth calibration unit, the sound velocity profiler is used to measure the transducer array to obtain a water sound velocity, the second standard hydrophone receives pulse signals generated by the water sound velocity and feeds back to the target analog transponder, and an equivalent sound wave signal is emitted based on the target analog sound source at the same time. The transponder in the water acoustic locator normally receives echo signals, and a maximum equivalent distance is taken as a full-range index of the water acoustic locator to be detected.

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