CN101806884B - Absolute position precise positioning method of deep-sea beacon based on ultra-short baseline - Google Patents

Abstract

The invention provides a method for accurately positioning the absolute position of a deep-sea beacon based on an ultra short base line, which comprises the following steps that: (1) respectively receiving beacon signals at a measurement point by ultra short base line acoustic arrays to measure the bearing of the beacon; (2) using a GPS to measure the absolute position of the measurement point; (3) changing the position of the measurement point based on the last obtained bearing and the received signals to obtain a measurement point having a larger bearing difference; (4) repeating step (2) and step (3) to obtain enough measurement point data; (5) carrying out the field measurement on the sound velocity distribution in a sea area near the position of the beacon; (6) calculating the horizontal coordinate of the beacon based on the position of the measurement point and the horizontal bearing; and (7) calculating the depth of the beacon based on the calculated horizontal coordinate of the beacon, the sound velocity profile and the elevation bearing of acoustic signals at each measurement point. The method has extensive application prospects in the aspects of black box rescue and underwater beacon navigation in deep sea.

Description

Absolute position precise positioning method of deep-sea beacon based on ultra-short baseline

technical field

The invention belongs to the field of underwater acoustic positioning, and mainly relates to a positioning method of a seabed beacon.

Background technique

When the beacon machine works underwater, because it only emits sound pulses independently and periodically, the surface positioning system can only obtain the target's azimuth information, but not the distance information, so the long baseline method with high positioning accuracy is invalid. Only azimuth-only positioning methods can be used. Most of the existing azimuth-only positioning methods focus on the research of using the two-dimensional horizontal azimuth of the target to locate the target.

In the CNKI of Chinese Academic Literature Network Publishing General Database, the public reports related to the application of the present invention that can be retrieved mainly include: 1. Acoustic Beacon Design of Underwater Acoustic Active and Passive Positioning System (Chinese Dissertation/Harbin Engineering University/2008/Xu Zhiheng ). This document introduces the design scheme of the underwater acoustic beacon system, not the positioning method of the beacon; 2. Research on positioning and navigation technology of deep sea acoustic transponders (Chinese dissertation/Harbin Engineering University/2008/Lan Hualin). This document provides an azimuth-only positioning method for submarine transponders based on an ultra-short baseline, which is highly relevant to the application of the present invention. However, this document does not give the selection method of the measuring point, and does not introduce the method of sound ray bending correction in detail; 3. An acoustic beacon positioning method based on an ultra-short baseline (High Technology Communication 2009 No. 5 / Li think). This document presents a method for determining the position of a beacon using only target azimuth information. The azimuth information is obtained through multiple measurements, the relationship between the azimuth information and the target position is established, and the position of the beacon in the geodetic coordinate system is obtained by using the least square method. But no sound ray bending correction is given.

For the precise positioning of deep-sea submarine beacons, the existing azimuth-only positioning methods have at least two shortcomings: one is that the position of the beacon is unknown, and the position of the measuring point directly affects the accuracy of the positioning of the beacon, and the existing method does not give the position of the measuring point Second, when using the three-dimensional azimuth of the acoustic signal to locate the beacon, although the sound velocity distribution in shallow seas has little influence on the positioning accuracy, it can be solved directly, but in the deep sea where the sound velocity distribution has a greater impact on the positioning accuracy, it is no longer necessary. Be applicable. Aiming at the deficiencies of the prior art, a method for accurately calibrating the absolute position of the deep-sea subsea transponder is needed.

Contents of the invention

The purpose of the present invention is to provide an ultra-short baseline-based precise positioning method for the absolute position of a deep-sea beacon that can realize precise calibration of the absolute position of a deep-sea subsea transponder.

The purpose of the present invention is achieved like this:

(1) The ultra-short baseline acoustic matrix receives beacon signals at a measurement point and measures the beacon azimuth;

(2) Change the position of the measuring point according to the azimuth obtained last time and the received signal, and obtain the measuring point with a large difference in azimuth;

(3) Use GPS to measure the absolute position of the measuring point;

(4) repeat step (2) and step (3) to obtain enough measuring point data;

(5) On-site measurement of the sound velocity distribution in the sea area near the beacon position;

(6) Calculate the horizontal coordinates of the beacon according to the position of the measuring point and the horizontal orientation;

(7) Calculate the depth of the beacon according to the horizontal coordinates of the beacon, the sound velocity profile and the pitch and azimuth of the sound signals of each measuring point.

In order to realize the purpose of the present invention, it is necessary to use the ultra-short baseline to detect the beacon acoustic signal and measure the orientation of the acoustic signal in the geodetic coordinate system.

In order to realize the purpose of the present invention, it is necessary to use the beacon horizontal azimuth value of the current survey point to guide the course of the surface ship to select the next survey point.

In order to realize the purpose of the present invention, it is necessary to use GPS to determine the absolute geodetic coordinates of the measuring point and to use a sound velocity profiler to measure the sound velocity distribution in the sea area near the beacon position.

In order to achieve the purpose of the present invention, the azimuth of the acoustic signal needs to be decomposed into horizontal azimuth and elevation azimuth, and the horizontal coordinates of the beacon can be calculated by combining the horizontal and azimuth.

In order to achieve the purpose of the present invention, it is necessary to correct the sound ray bending according to the horizontal coordinates of the measuring point and the beacon, and the pitch and azimuth of the acoustic signal, so as to obtain the depth coordinate of the beacon.

The present invention is characterized in that the ultra-short baseline of the surface ship is used to accurately locate the deep-sea beacon, the position of the measuring point is determined through the guidance of the ultra-short baseline, and the absolute position coordinates of the high-precision deep-sea beacon are obtained by sound ray bending correction. This method has broad application prospects in black box search and rescue and underwater beacon navigation under deep sea conditions.

Description of drawings

Figure 1 is a schematic diagram of the geometric configuration of deep-sea beacons for precise positioning.

Figure 2 is a top view of the selection of measuring points for precise positioning of deep-sea beacons.

Fig. 3 is a schematic diagram of the principle of horizontal azimuth intersection of points on both sides.

Fig. 4 is a flow chart of the implementation of the method for precise positioning of the absolute position of the deep-sea beacon based on the ultra-short baseline.

Detailed ways

The present invention is described in more detail below in conjunction with accompanying drawing example:

其中θ_i定义为第i测点测得信标声信号水平方向与正北方向夹角；

定义为第i测点测得信标声信号的掠射角。In the present invention, as shown in Fig. 1, the beacon 1 is anchored on the seabed, and the position is X _b ; the acoustic pulse signal is periodically emitted at a time interval T; the ultra-short baseline acoustic matrix 2 is installed on the surface ship, and the high-precision GPS3 is installed on the ship . The ultra-short baseline acoustic matrix detects the acoustic signal of the beacon at different measuring point X _Gi and finds its direction, and combines the installation error calibration results of the ultra-short baseline and the ship attitude data of the measuring point to obtain the position of the beacon in the geodetic coordinate system position

Where _θi is defined as the angle between the horizontal direction of the beacon acoustic signal measured at the i-th measuring point and the true north direction;

Defined as the grazing angle of the beacon acoustic signal measured at the i-th measuring point.

The selection method of the measuring point is shown in Figure 2. Assuming that the position of measuring point 1 is X _G1 , the horizontal orientation of the beacon is measured θ ₁ ; then the course of the surface ship is selected as θ ₁ -60°, and it stops after sailing for a certain distance, and proceeds to the second Point measurement to obtain the horizontal orientation θ _{2 of} the beacon; then select the heading of the surface ship as θ ₂ -60°, stop after sailing distance r ₀ , and perform the third point measurement to obtain the horizontal orientation θ ₃ of the beacon; and so on, to obtain N measurement points and the corresponding measurement results. This method utilizes the direction-finding ability of the ultra-short baseline to guide the surface ship azimuth, and can ensure that the distance between the measuring point and the submarine beacon is getting closer.

Assuming that the beacon coordinates X _b = (x _b , y _b , z _b ), and the measuring point position coordinates X _G1 = (x _Gi , y _Gi , z _Gi ), then the relationship is as follows:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; Gi</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; ai</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; Gi</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; ai</span>}}\mathrm{<span\; class="notranslate">\; sin</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula

${\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; ai</span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; Gi</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; Gi</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Indicates the horizontal distance between each measuring point and the beacon position. Figure 3 shows a schematic diagram of the intersection of horizontal azimuths taking points on both sides as examples.

Equation (1) is a non-linear equation. Newton's method is used to solve the horizontal coordinates of the beacon, and the result is substituted into equation (2) to obtain the horizontal distance r _ai between each measuring point and the beacon.

Since the water depth of the ultra-short baseline acoustic array is known, the depth coordinates of the beacon position can be obtained according to the horizontal distance, grazing angle and sound velocity distribution. There are two ways to achieve this.

出发进行声线跟踪，当水平距离为r_ai时停止，此时对应的深度即为信标的深度估计

然后对多个测点的深度估计

求平均，得到信标的最终深度估计

the first method. For each survey point, from the glancing angle

Start sound ray tracking, stop when the horizontal distance is r _ai , and the corresponding depth at this time is the depth estimation of the beacon

Then the depth estimation of multiple survey points

averaged to get the final depth estimate for the beacon

$\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; z</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; z</span>}}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

This method requires a sound ray tracing for each measurement point, which requires a large amount of calculation, especially in the case of many measurement points.

在深度一定、声速分布一定的条件下，声传播的水平距离与掠射角有固定的函数关系，如下式：The second method. For any measuring point, the initial value of the beacon depth is obtained by the first method

Under the conditions of constant depth and constant sound velocity distribution, the horizontal distance of sound propagation has a fixed functional relationship with the grazing angle, as follows:

是声信号在超短基线声学基阵位置处的掠射角。where r is the slant distance, and f(·) is a function determined by the sea depth and the corresponding sound velocity distribution, which can be approximated by numerical calculation according to Snell's law.

is the grazing angle of the acoustic signal at the position of the ultra-short baseline acoustic array.

The horizontal distance r _ai ⁽¹⁾ between each measuring point and the beacon can be obtained according to the sound propagation time delay of each measuring point. Define the error e:

$\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; ai</span>}}^{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; ai</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

进行搜索，当e足够小时对应的信标深度即为信标深度估计。搜索的方法可以采用二分法。change depth

Search, when e is small enough, the corresponding beacon depth is the beacon depth estimate. The search method can adopt dichotomy.

Claims (4)

1. A deep-sea beacon absolute position precise positioning method based on an ultra-short baseline, characterized in that: (1) The ultra-short baseline acoustic matrix receives beacon signals at a measurement point and measures the beacon azimuth; (2) Use GPS to measure the absolute position of the measuring point; (3) Change the position of the measuring point according to the azimuth obtained last time and the received signal, and obtain the measuring point with a large difference in azimuth; (4) Repeat steps (2) (3) to obtain enough measuring point data; The method for obtaining enough measuring point data is that the first measuring point position is X _G1 , and the horizontal orientation θ ₁ of the beacon is recorded; Then choose the heading of the surface ship as θ ₁ -60°, stop after sailing for a certain distance, measure the second measuring point, and obtain the horizontal position θ _{2 of} the beacon; then choose the heading of the surface ship as θ ₂ -60°, and sail the distance Stop after r ₀ , measure the third measuring point, and obtain the horizontal orientation θ ₃ of the beacon; and so on, obtain N measuring points and corresponding measurement results; (5) On-site measurement of the sound velocity distribution in the sea area near the beacon position; (6) Calculate the horizontal coordinates of the beacon according to the position of the measuring point and the horizontal orientation; (7) Calculate the depth of the beacon according to the horizontal coordinates of the beacon, the sound velocity profile and the pitch and azimuth of the sound signals of each measuring point. 2. the deep-sea beacon absolute position precise positioning method based on ultra-short baseline according to claim 1, is characterized in that: the method that described beacon orientation is recorded is that beacon is anchored on the seabed, and position is X _b ; With The time interval T periodically emits acoustic pulse signals; the ultra-short baseline acoustic array is installed on the surface ship, and the high-precision GPS is installed on the ship; the ultra-short baseline acoustic array detects the acoustic signal of the beacon at different measuring point positions X _Gi and compares Direction finding, combined with the ultra-short baseline installation error calibration results and the ship attitude data of the measuring point to obtain the orientation of the beacon in the geodetic coordinate system

Where _θi is the angle between the horizontal direction of the beacon sound signal measured at the i-th measuring point and the true north direction;

is the glancing angle of the beacon acoustic signal measured at the i-th measuring point. 3. The ultra-short baseline-based deep-sea beacon absolute position precise positioning method according to claim 1 or 2, characterized in that the horizontal coordinates of the beacon obtained according to the solution, the sound velocity profile and the pitch and azimuth of the acoustic signals of each measuring point The method to calculate the depth of the beacon is: for each measuring point, from the grazing angle Start sound ray tracking, stop when the horizontal distance is r _ai , and the corresponding depth at this time is the depth estimation of the beacon Then the depth estimation of multiple survey points

averaged to get the final depth estimate for the beacon

4. The ultra-short baseline-based method for precise positioning of the absolute position of deep-sea beacons according to claim 1 or 2, characterized in that the horizontal coordinates of the beacons obtained according to the solution, the sound velocity profile, and the pitch and azimuth of the acoustic signals of each measuring point The method to calculate the depth of the beacon is as follows: under the conditions of constant depth and constant sound velocity distribution, the horizontal distance of sound propagation has a fixed functional relationship with the grazing angle.

where r is the horizontal distance of sound propagation, f( ) is a function determined by the sea depth and the corresponding sound velocity distribution, and can be approximated by numerical calculation according to Snell's law,

is the grazing angle of the acoustic signal at the position of the ultra-short baseline acoustic array; Calculate the horizontal distance between each measuring point and the beacon according to the sound propagation delay of each measuring point

Define the error e:

Among them, r _ai is the horizontal distance obtained according to the coordinates of each measuring point and the horizontal coordinates of the beacon, change depth

Search, when e is small enough, the corresponding beacon depth is the beacon depth estimate, and the search method adopts the dichotomy method.

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