CN115165070A - Optical fiber vector hydrophone and array attitude calibration method and system thereof - Google Patents

Abstract

The invention provides an optical fiber vector hydrophone and an array attitude calibration method and system thereof, wherein the attitude calibration method comprises the following steps: the sound source emits signals and rotates for a circle around the optical fiber vector hydrophone; acquiring an azimuth angle theta of the optical fiber vector hydrophone corresponding to the sound source by adopting an acoustic energy flow method; determining the X + axis direction of the optical fiber vector hydrophone according to the obtained azimuth angle; determining the attitude heading of the current hydrophone and the deviation angle delta theta of the X + axis direction according to an attitude sensor in the optical fiber vector hydrophone, and carrying out attitude calibration on the optical fiber vector hydrophone to ensure that the X + axis direction of the optical fiber vector hydrophone is coincident with the attitude heading. The problem that the prior art can not ensure that the X-axis of the fiber vector hydrophone is consistent with the course angle of the attitude sensor in the navigation process is solved, the application capability of the fiber vector hydrophone array in target azimuth measurement is further improved, and the array azimuth estimation precision is improved.

Description

A fiber optic vector hydrophone and its array attitude calibration method and system

technical field

The invention relates to the technical field of attitude calibration of hydrophone arrays, in particular to an optical fiber vector hydrophone and a method and system for calibrating its array attitude.

Background technique

With the continuous development of science and technology, in order to meet the needs of the construction of shore stations, serve the coastal early warning sonar system, and realize remote detection and identification, the ability of hydrophones to play in it is increasingly important. The fiber-optic vector hydrophone converts the measured signal into an optical signal through the high-sensitivity fiber-optic coherent detection technology, and transmits it to the signal processing system through the fiber to extract the information. It has many characteristics such as high sensitivity and easy multiplexing. Combining multiple fiber-optic vector hydrophones according to a certain spacing to form a fiber-optic vector hydrophone array has good array gain.

Each fiber-optic vector hydrophone in the fiber-optic vector hydrophone array corresponds to an attitude sensor, and the orientation angle of the vector hydrophone is estimated by correcting the heading angle of the attitude sensor. Since the vector hydrophone is fixed by spring suspension, the state of each fiber-optic vector hydrophone after suspension is different, resulting in azimuth estimation error; the attitude sensor is installed in a pressure-resistant and watertight sealed cavity, through the mechanical structure The way of limiting makes the heading angle consistent with the zero degree direction of the fiber optic vector hydrophone (that is, the X+ axis of the fiber optic vector hydrophone), but there is an engineering deviation when the two are assembled together, resulting in the direction of the X﹢ axis of the vector hydrophone It is not completely coincident with the heading angle direction of the attitude sensor, resulting in inaccurate azimuth estimation; the fiber-optic vector hydrophones in the array are connected through soft connections. During the actual assembly process, the X+ axis direction of each vector hydrophone The deviation from the heading angle is not a fixed value, which leads to the weakening of the array gain during the azimuth estimation of the array. In severe cases, the array azimuth estimation cannot be performed. According to the sound intensity signals received by the X-axis and Y-axis of the fiber optic vector hydrophone, the heading angle of the attitude sensor is corrected, so that the deviation between the X+-axis direction of the vector hydrophone and the heading angle of the attitude sensor is within the error range, The accuracy of each heading sensor in the fiber optic vector hydrophone array is achieved, thereby improving the accuracy of the array orientation estimation. However, at this stage, the correction of the heading angle of the attitude sensor in the fiber-optic vector hydrophone array is mostly the correction of the hydrophone itself during non-navigation. Therefore, a method that can actually correct the heading angle of the attitude sensor during sailing is urgently needed. As an alternative or supplement, the accuracy of each heading sensor in the fiber-optic vector hydrophone array is achieved, thereby improving the array orientation estimation accuracy.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an optical fiber vector hydrophone and its array attitude calibration method and system, so as to solve the problem that the X﹢ axis of the optical fiber vector hydrophone cannot be guaranteed to be consistent with the heading angle of the attitude sensor during the navigation process in the prior art. Therefore, the application ability of the fiber-optic vector hydrophone array in the target azimuth measurement will be improved, and the azimuth estimation accuracy of the array will be improved.

In the first aspect, the present invention provides a method for calibrating the attitude of an optical fiber vector hydrophone, comprising:

The sound source emits a signal and rotates around the fiber optic vector hydrophone;

The acoustic energy flow method is used to obtain the azimuth angle θ of the fiber-optic vector hydrophone corresponding to the sound source;

Determine the X+ axis direction of the fiber optic vector hydrophone through the obtained azimuth;

According to the attitude sensor in the fiber optic vector hydrophone, determine the current attitude heading of the hydrophone and the deviation angle Δθ of the X+ axis direction, and calibrate the attitude of the fiber optic vector hydrophone to make the X+ axis direction of the fiber optic vector hydrophone and the attitude heading. coincide.

Further, before the sound source transmits the signal, the method further includes: placing the fiber optic vector hydrophone vertically in the water under far-field conditions.

Preferably, the vertical placement of the optical fiber vector hydrophone is that the optical fiber vector hydrophone is in a straight state by means of a counterweight and a floating ball.

Preferably, the sound source is rotated around the fiber optic vector hydrophone by a rotating stage.

Further, the sound source revolves around the fiber optic vector hydrophone at a fixed preset speed.

Further, the acoustic energy flow method includes:

According to the received signal information of the sound source, the estimation of the azimuth angle of the fiber-optic vector hydrophone is realized, wherein the X-axis and Y-axis signals of the fiber-optic vector hydrophone are received as:

where s(t) represents the sound intensity at the position of the fiber optic vector hydrophone at time t; v _x represents the received sound intensity signal on the X axis; v _y represents the received sound intensity signal on the Y axis; θ is the sound source The azimuth of the signal in the XOY plane of the vector sphere;

The azimuth angle θ of the sound source signal on the XOY plane of the vector sphere is:

In the second aspect, the present invention provides a method for calibrating the attitude of an optical fiber vector hydrophone array, comprising:

The sound source emits a signal and rotates around the fiber optic vector hydrophone array;

The acoustic energy flow method is used to obtain the azimuth angle θ of the sound source corresponding to each fiber-optic vector hydrophone in the fiber-optic vector hydrophone array;

Determine the X+ axis direction of each fiber-optic vector hydrophone through the obtained azimuth;

According to the attitude sensor in each fiber optic vector hydrophone, determine the current attitude heading of the hydrophone and the deviation angle Δθ of the X+ axis direction, and perform attitude calibration on each fiber optic vector hydrophone, so that the The X+ axis direction coincides with the attitude heading.

Further, the sound source revolves around the fiber optic vector hydrophone array at a fixed preset speed.

Further, the acoustic energy flow method includes:

According to the sound source signal information received by each fiber-optic hydrophone in the fiber-optic vector hydrophone array, the azimuth angle estimation of each fiber-optic vector hydrophone is realized, wherein the X-axis and Y-axis signals of the fiber-optic vector hydrophone are Receive as:

where s(t) represents the sound intensity at the position of the fiber optic vector hydrophone at time t; v _x represents the received sound intensity signal on the X axis; v _y represents the received sound intensity signal on the Y axis; θ is the sound source The azimuth of the signal in the XOY plane of the vector sphere;

The azimuth angle θ of the sound source signal on the XOY plane of the vector sphere is:

In a third aspect, the present invention provides an optical fiber vector hydrophone array attitude calibration system, comprising: a sound source signal transmitting module, a sound source signal receiving module, a data processing module, and an attitude calibration module;

Sound source signal emission module: used for sound source emission signal, and rotates around the fiber optic vector hydrophone array at a preset speed;

Sound source signal acquisition module: used to acquire the sound source signal received by each fiber optic vector hydrophone in the fiber optic vector hydrophone array, and send it to the data processing module;

Data processing module: used to receive the sound source signal sent by the sound source signal acquisition module, and use the sound energy flow method to obtain the azimuth angle of the sound source corresponding to each fiber optic vector hydrophone in the fiber optic vector hydrophone array; Determine all the azimuth angles of each fiber optic vector hydrophone; determine the deviation angle between the attitude heading of the current hydrophone and its corresponding X+ axis direction according to the attitude sensor in each fiber optic vector hydrophone;

Attitude calibration module: used to calibrate the attitude of each fiber optic vector hydrophone in the fiber optic vector hydrophone array, so that the X+ axis direction of each fiber optic vector hydrophone in the array coincides with the attitude heading.

beneficial effect

The invention provides an optical fiber vector hydrophone and its array attitude calibration method and system. Under far-field conditions, the optical fiber vector hydrophone is vertically placed in water, the sound source emits broadband signals, and surrounds each optical fiber vector hydrophone. The hydrophone rotates once, and the X﹢ axis direction of each fiber-optic vector hydrophone is found by using the method of sound energy flow. At the same time, according to the heading angle of the attitude sensor, the deviation angle between the X﹢ axis of the optical fiber vector hydrophone and the heading angle of the attitude sensor is calculated, and the deviation angle is calibrated so that the X﹢ axis direction of the optical fiber vector hydrophone coincides with the heading of the attitude sensor. . Testing in water ensures that the fiber optic vector hydrophone can also perform attitude calibration during sailing.

The fiber-optic vector hydrophones in the fiber-optic vector hydrophone array are connected through soft connections. During the actual assembly process, the deviation between the X+ axis direction and the attitude heading of each fiber-optic vector hydrophone in the array is not a fixed value. The calibration method provided by the invention can ensure that the X﹢ axis direction of the fiber optic vector hydrophone in the array is coincident with the heading of the attitude sensor, so as to ensure the efficient use of the array gain; The attitude calibration of each fiber optic vector hydrophone can make the array attitude achieve high consistency. application.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

Fig. 1 is the calibration structure schematic diagram of the optical fiber vector hydrophone provided by the present invention;

Fig. 2 is an azimuth estimation diagram of the fiber optic vector hydrophone array provided by the present invention.

In the figure: 1-fiber-optic vector hydrophone; 2-attitude sensor; 3-attitude heading; 4-axis direction of fiber-optic vector hydrophone; 5-vector sphere XOY plane; 6-sound source; 7-fiber-optic vector water Listener array.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Example 1

The fiber optic vector hydrophone 1 is shown in Figure 1. The top of the fiber optic vector hydrophone 1 is provided with an attitude sensor 2, and the direction of the arrow in the attitude sensor 2 indicates the attitude heading 3; There is a vector sphere XOY plane 5 inside the vector sphere, wherein the dotted lines in the vector sphere XOY plane 5 represent the X and Y axes of the fiber optic vector hydrophone 1, and the direction of the solid arrows represents the X+ axis direction 4 of the fiber optic vector hydrophone.

As shown in Figure 1-2, this case provides a fiber-optic vector hydrophone attitude calibration method, including:

Step 1: Under far-field conditions, the fiber optic vector hydrophone 1 is placed vertically in the water, and the fiber optic vector hydrophone 1 is straightened by means of a counterweight and a floating ball.

Step 2: Set the rotating stage so that the sound source 6 can rotate around the fiber optic vector hydrophone 1, and the distance between the sound source 6 and the fiber optic vector hydrophone 1 remains unchanged.

Step 3: The sound source 6 transmits a broadband signal, and rotates around the fiber optic vector hydrophone 1 once, and the time for one rotation is about 1 minute;

Step 4: Using the sound energy flow method, obtain the azimuth angle θ of the fiber optic vector hydrophone 1 corresponding to the sound source 6;

The acoustic energy flow method includes:

According to the sound source signal information received by the fiber-optic vector hydrophone 1, the estimation of the azimuth angle of the sound source 6 by the fiber-optic vector hydrophone 1 is realized, wherein the X-axis and Y-axis signals of the fiber-optic vector hydrophone 1 are received as:

where s(t) represents the sound intensity at the position of the fiber-optic vector hydrophone 1 at time t; _vx represents the received sound intensity signal on the X axis; _vy represents the received sound intensity signal on the Y axis; θ is the sound intensity The azimuth angle of the source signal in the vector sphere XOY plane 5;

The azimuth angle θ of the sound source signal on the vector sphere XOY plane 5 is:

Step 5: Determine the X+ axis direction 4 of the fiber optic vector hydrophone through the obtained azimuth angle. Wherein, by obtaining the azimuth angle of the sound source 6 after one rotation, the position of the sound source 6 when the azimuth angle is zero degrees is determined, that is, the X+ axis direction 4 of the fiber optic vector hydrophone.

Step 6: Determine the attitude heading 3 of the current hydrophone and the deviation angle Δθ of the X+ axis direction according to the attitude sensor 2 in the optical fiber vector hydrophone 1, and perform attitude calibration on the optical fiber vector hydrophone 1, so that the optical fiber vector hydrophone The X+ axis direction 4 of , coincides with the attitude heading 3. The deviation angle Δθ is the angle value of the azimuth angle measured by the fiber optic vector hydrophone 1 when the sound source 6 rotates to the position where the heading angle of the attitude sensor is 0 degrees.

Example 2

As shown in Figure 1-2, this case provides a method for calibrating the attitude of a fiber optic vector hydrophone array. The method in Embodiment 1 is used to calibrate the attitude of each fiber optic vector hydrophone 1 in the fiber optic vector hydrophone array 7. , so that the X+ axis direction 4 of each fiber-optic vector hydrophone in the array coincides with the attitude heading 3, wherein the difference between the calibration method in Embodiment 2 and Embodiment 1 is that the light source 6 surrounds the entire fiber at a fixed preset speed with an appropriate amount of water. The receiver array 7 makes one revolution. The fiber vector hydrophone array 7 is composed of a plurality of fiber vector hydrophones 1 arranged in a row, and the number of the fiber vector hydrophones 1 in the fiber vector hydrophone array 7 can be set according to actual requirements. FIG. 2 is an example of a fiber-optic vector hydrophone array 7 composed of 16 fiber-optic vector hydrophones 1 . When the attitude of each fiber-optic vector hydrophone 1 in the array is highly consistent, the larger the array gain, the larger the range of the array to estimate the target orientation, and the higher the accuracy.

Example 3

As shown in Figure 1-2, this case provides an optical fiber vector hydrophone array attitude calibration system, including: a sound source signal transmitting module, a sound source signal receiving module, a data processing module, and an attitude calibration module;

Sound source signal transmitting module: used for sound source 6 to transmit broadband signal, and rotate around fiber optic vector hydrophone array 7 at a preset speed, and the duration of one rotation is 1 minute;

Sound source signal acquisition module: used to acquire the sound source signal received by each fiber optic vector hydrophone 1 in the fiber optic vector hydrophone array 7, and send it to the data processing module;

Data processing module: used to receive the sound source signal sent by the sound source signal acquisition module, and use the sound energy flow method to obtain the azimuth angle of the sound source corresponding to each fiber optic vector hydrophone 1 in the fiber optic vector hydrophone array 7; Through all the obtained azimuth angles, determine the X+ axis direction 4 of each fiber optic vector hydrophone; determine the current attitude heading 3 of the hydrophone and its corresponding X+ axis direction according to the attitude sensor 2 in each fiber optic vector hydrophone 1 deviation angle;

Attitude calibration module: used to calibrate the attitude of each fiber optic vector hydrophone 1 in the fiber optic vector hydrophone array 7, so that the X+ axis direction 4 of each fiber optic vector hydrophone in the array coincides with the attitude heading 3 .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A method for calibrating the attitude of a fiber vector hydrophone, comprising:

a sound source emits a signal and rotates for a circle around the optical fiber vector hydrophone;

acquiring an azimuth angle theta of the optical fiber vector hydrophone corresponding to the sound source by adopting an acoustic energy flow method;

determining the X + axis direction of the optical fiber vector hydrophone according to the obtained azimuth angle;

and determining the deviation angle delta theta between the attitude heading of the current hydrophone and the X + axis direction according to an attitude sensor in the optical fiber vector hydrophone, and performing attitude calibration on the optical fiber vector hydrophone to ensure that the X + axis direction of the optical fiber vector hydrophone coincides with the attitude heading.

2. The method of claim 1, further comprising, before the acoustic source emits the signal:

under far-field conditions, a fiber-vector hydrophone is placed vertically in the water.

3. The method as claimed in claim 2, wherein the vertical placement of the fiber vector hydrophone is achieved by a weight and a floating ball to keep the fiber vector hydrophone in a straightened state.

4. The method of claim 1, wherein the acoustic source is rotated around the fiber-vector hydrophone by a rotating stage.

5. The method of claim 1, wherein the acoustic source rotates around the fiber vector hydrophone at a fixed predetermined speed.

6. The method of claim 1, wherein the method of acoustic power streaming comprises:

according to the received sound source signal information, the estimation of the azimuth angle of the optical fiber vector hydrophone is realized, wherein the X-axis and Y-axis signal reception of the optical fiber vector hydrophone is as follows:

wherein s (t) represents the sound intensity of the position of the optical fiber vector hydrophone at the time t; v. of _x Representing the X-axis received sound intensity signal; v. of _y Representing the sound intensity signal received by the Y axis; theta is the azimuth angle of the sound source signal on the XOY plane of the vector ball;

the azimuth angle theta of the sound source signal on the vector sphere XOY plane is as follows:

7. a method for calibrating the attitude of an optical fiber vector hydrophone array is characterized by comprising the following steps:

the sound source transmits signals and rotates for a circle around the optical fiber vector hydrophone array;

acquiring the azimuth angle theta of each optical fiber vector hydrophone in the optical fiber vector hydrophone array corresponding to the sound source by adopting an acoustic energy flow method;

determining the X + axis direction of each optical fiber vector hydrophone according to the obtained azimuth angle;

and determining the attitude heading of the current hydrophone and the deviation angle delta theta of the X + axis direction according to the attitude sensor in each optical fiber vector hydrophone, and performing attitude calibration on each optical fiber vector hydrophone to ensure that the X + axis direction of each optical fiber vector hydrophone is coincident with the attitude heading.

8. The method of claim 6, wherein the sound source rotates around the fiber-optic vector hydrophone array at a fixed preset speed.

9. The method for calibrating the attitude of the fiber vector hydrophone array according to claim 6, wherein the acoustic energy flow method comprises the following steps:

according to sound source signal information received by each optical fiber proper hydrophone in the optical fiber vector hydrophone array, the azimuth angle of each optical fiber vector hydrophone is estimated, wherein the X-axis signal reception and the Y-axis signal reception of the optical fiber vector hydrophones are as follows:

wherein s (t) represents the sound intensity of the position of the optical fiber vector hydrophone at the time t; v. of _x Representing the X-axis received sound intensity signal; v. of _y Representing the sound intensity signal received by the Y axis; theta is the azimuth angle of the sound source signal on the XOY plane of the vector ball;

the azimuth angle theta of the sound source signal on the vector sphere XOY plane is as follows:

10. an optical fiber vector hydrophone array attitude calibration system, comprising: the system comprises a sound source signal transmitting module, a sound source signal receiving module, a data processing module and an attitude calibration module;

the sound source signal transmitting module: the device is used for transmitting signals by a sound source and rotating around the optical fiber vector hydrophone array for a circle at a preset speed;

a sound source signal acquisition module: the system is used for acquiring a sound source signal received by each optical fiber vector hydrophone in the optical fiber vector hydrophone array and sending the sound source signal to the data processing module;

a data processing module: the system is used for receiving a sound source signal sent by a sound source signal acquisition module and acquiring the azimuth angle of each optical fiber vector hydrophone in the optical fiber vector hydrophone array corresponding to the sound source by adopting an acoustic energy flow method; determining the X + axis direction of each optical fiber vector hydrophone through all the obtained azimuth angles; determining a deviation angle between the attitude heading of the current hydrophone and the X + axis direction corresponding to the attitude heading according to an attitude sensor in each optical fiber vector hydrophone;

an attitude calibration module: the attitude calibration method is used for calibrating the attitude of each optical fiber vector hydrophone in the optical fiber vector hydrophone array, so that the X + axis direction of each optical fiber vector hydrophone in the array is coincident with the attitude heading.

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