RU2529207C1 - Navigation system for towed underwater vehicle - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: navigation system for a towed underwater vehicle comprises, installed on a towing vessel, a GPS receiver, a control system, multibeam echo sounder, a shipborne sonar unit, an underwater navigation antenna and, installed on the towed underwater vehicle, side-scanning sonar, a control device and an underwater navigation transponder. Coordinates of the towed underwater vehicle relative to the position of the antenna of the GPS receiver on the towing vessel are determined by phase-based direction-finding. The control system then corrects coordinates of the towed underwater vehicle via cross-correlation processing of images of the bottom topography obtained using the side-scanning sonar and the multibeam echo sounder. The corrected coordinates of the towed underwater vehicle are converted to geographic coordinates.

EFFECT: reducing errors in determining coordinates of a towed underwater vehicle while simultaneously reducing labour costs when conducting underwater exploration.

5 dwg

Description

The invention relates to sonar navigation systems, and in particular to navigation systems for underwater vehicles relative to the support vessel, and can be used to determine the coordinates of a towed underwater vehicle performing sonar bottom relief.

To study the geomorphological structure of the seabed, for example, to identify patterns of distribution of gas hydrates in oceanic sediments, towed underwater vehicles (BPA) are used, on which such measuring equipment as side-scan sonar (HBO), chirp (linear frequency modulation) profilographs are installed etc. In this case, the problem of navigating the underwater vehicle with the aim of bringing into unambiguous correspondence the objects of the obtained bottom map with their exact geographical coordinates arises.

Placing the measuring equipment on a towed underwater vehicle allows not only to expand the measurement area (as compared with the case when the measuring equipment is installed on an autonomous underwater vehicle), but also to increase the resolution of the bottom image (compared to the case when the measuring equipment is installed on a ship). Since the bottom image is built relative to the position of the BPA, it is necessary to create a system for determining the geographic coordinates of the BPA in real time. This problem can be solved with the help of various sonar navigation systems.

Known sonar synchronous rangefinder long-range navigation system [patent for invention RU No. 228914; IPC G01S 15/08, author Kasatkin B.A .; published December 10, 2006] containing a bottom navigation base of M hydroacoustic responder beacons with different response frequencies, in which the underwater object generates acoustic pulses at the request frequency, which are then received by the responder beacons and re-emitted back at the response frequency. The time period between the emission of the request pulse and the reception of the re-emitted pulse for each transponder beacon is determined using counters. Recalculation of the obtained time values into the range between the transponder beacons and the underwater object is carried out by the unit for converting time intervals into distances, the output values of which are transmitted to the inputs of the object coordinate calculator.

The design features of the analogue, which coincide with the essential features of the claimed system, are: an underwater vehicle, the coordinates of which must be determined, antennas for underwater navigation, a sonar transceiver.

However, the well-known analogue has a number of drawbacks, the main of which can be considered that it is necessary to have a section of the water area in advance equipped with respondent beacons, where it is planned to conduct exploratory work, while the spatial coordinates of the respondent beacons should be precisely linked to the terrain, and on beacons The defendants and the underwater object must have a precision watch. All this leads to a rise in the cost of exploration and delay the timing of their implementation.

Also known is a system for determining the location of an underwater vehicle [patent for invention RU No. 2062482; IPC G01S 15/06; authors Chernikov V.N., Kotyashkin S.I .; published on June 20, 1996]. In the system under consideration, the coordinates of the underwater vehicle are determined through the integrated use of the measurement results of the time and phase characteristics of the signals received by the antenna system installed under the bottom of the vessel, in which the receiving elements are distributed at distances that are multiples of half the length of the acoustic wave.

The design features of the analogue, which coincide with the essential features of the claimed device, are: an underwater navigation antenna mounted on the bottom of the vessel, a sonar receiver and a receiving antenna mounted on the underwater vehicle,

However, the known analogue has drawbacks, the main of which is the low speed of the vessel and the underwater vehicle, which does not allow to obtain a large map of the bottom topography, limits the area of underwater observations and increases the timing of the study of a given section of the bottom.

A known system for determining the coordinates of underwater objects [patent for the invention RU No. 2004124358; IPC G01S 5/00; authors Lisitsyn E.D., Kuzmin Yu.I., Leikin F.I .; published on January 27, 2006], adopted as a prototype and containing a towing object, a towed underwater vehicle and a towed buoy system, in which each buoy is equipped with a Global Positioning System (GPS) receiver, a highly stable GPS-synchronized clock, a hydroacoustic receiving system, and a time-measuring controller . All the listed objects are presented in the form of a single towed system, which keeps the parameters of the long and short measuring bases constant, and the towed object is equipped with a highly stable clock and a device for determining the immersion depth of the towed object.

The design features of the analogue, which coincide with the essential features of the claimed device, which we adopted as a prototype, are the presence of a towing vessel and a towed underwater vehicle, the coordinates of which are determined relative to the coordinates of the towing vessel, the presence of a GPS receiver, the equipment of the towed vehicle with a sonar navigation system and a device for measuring the immersion depth of the towed vehicle .

However, the known analogue has drawbacks, among which it is necessary to note the complexity of constructing and adjusting the towed system of buoys that form the measuring base of the navigation system of the underwater vehicle. Each buoy should be equipped with means for determining its own coordinates by satellite navigation systems and a high-precision underwater navigation system for determining the coordinates of an underwater object.

The disadvantages of the prototype are eliminated by the claimed navigation system towed underwater vehicle.

The technical result of the invention is to reduce the error in determining the coordinates of the towed underwater vehicle while reducing labor costs when performing underwater research.

The technical result is achieved by the fact that the navigation system of the towed underwater vehicle contains a GPS receiver installed on the towing vessel, a control system, a multi-beam echo sounder (MBE), an on-board sonar unit, an underwater navigation antenna and a side-scan sonar (HBO) installed on the towed underwater vehicle (BPA) , control device and transponder underwater navigation.

In this case, the GPS receiver is connected to the first port of the control system, to the second port of which a multipath echo sounder is connected, and to the third port of the control system the first port of the onboard sonar unit is connected, the second port of which is connected to the underwater navigation antenna, while the third port of the onboard sonar unit is connected through cable with a control device located on an underwater towed vehicle connected to an underwater navigation transponder and side-scan sonar.

Distinctive features proving the novelty of the claimed navigation system for a towed underwater vehicle are those that first determine the coordinates of the PSU in the system (X, Y, Z), at the origin of which the location of the GPS antenna on the towing vessel was selected by phase direction finding of the PSU using on-board sonar unit, underwater navigation antenna and underwater navigation transponder, and then the control system corrects the received coordinates of the control panel by digital processing according to the standard cross the correlation algorithm for bottom topography images obtained using a side-scan sonar and a multi-beam echo sounder. The corrected coordinates of the BPA based on the GPS receiver data are converted into geographical coordinates.

Thus, the prior art does not know the influence of features similar to the distinguishing features of the claimed navigation system for a towed underwater vehicle on the achievement of the claimed technical result, namely: reducing the error in determining the coordinates of a towed underwater vehicle while reducing labor costs when performing underwater research.

Obtaining a new technical result when using a new set of distinctive features indicates the compliance of the claimed invention with the criterion of "inventive step".

The invention is illustrated by drawings, where

Figure 1 shows a structural diagram of a navigation system for a towed underwater vehicle.

Figure 2 presents an illustration of a method for determining the coordinates of a towed underwater vehicle in the horizontal plane (top view).

Figure 3 shows an illustration of a method for determining the coordinates of a towed underwater vehicle (BPA) in a vertical plane (side view).

Figure 4 shows an illustration of a method for determining the coordinates of a BPA in a vertical plane with the indicated angles, coordinates and distances, which are used in mathematical expressions.

Figure 5 shows a three-dimensional illustration of the method for determining the coordinates of the elements of the navigation system of the towed underwater vehicle in the coordinate system X, Y, Z.

In the figures illustrating the invention, the following notation is introduced:

1 - GPS (Global Positioning System) receiver;

2 - control system;

3 - multi-beam echo sounder;

4 - on-board sonar unit;

5 - antenna underwater navigation;

6 - side-scan sonar;

7 - control device;

8 - transponder underwater navigation;

9 - towing vessel;

10 - cable cable;

11 - towed underwater vehicle (BPA).

12 - transponder antenna for underwater navigation;

13 - side-scan sonar antenna.

Figure 1 shows a structural diagram of a navigation system for a towed underwater vehicle.

The towed underwater vehicle navigation system comprises a GPS receiver 1 installed on the towing vessel, a control system 2, a multi-beam echo sounder 3, an on-board sonar unit 4, an underwater navigation antenna 5 and a towed underwater vehicle containing a side-scan sonar 6, a control device 7 and an underwater navigation transponder 8 .

The GPS receiver 1 is connected to the first port of the control system 2. At the same time, a multi-beam echo sounder 3 is connected to the second port of the control system 2, and the first port of the onboard sonar unit 4 is connected to the third port of the control system 2, the second port of which is connected to the underwater navigation antenna 5.

In addition, the third port of the on-board sonar unit 4 is connected via a cable to a control device 7 connected to an underwater navigation transponder 8 and a side-scan sonar 6.

Moreover, the location on the towing vessel 9 of the GPS antenna of the receiver 1 (point O in FIG. 2, FIG. 3, FIG. 4 and FIG. 5), the multi-beam echo sounder 3 and the underwater navigation antenna 5 is fixed, the distances of their relative positions are measured and set in database management system 2.

The navigation system towed underwater vehicle operates as follows.

The GPS receiver 1 in real time determines the coordinates of the GPS antenna, which are then transmitted via a digital bus to the control system 2. At the same time, the multi-beam echo sounder 3 performs three-dimensional scanning of the bottom with narrow beams of a fixed width and transmits the measured data to the control system 2, which compares the received multi-beam with a fishfinder 3 a three-dimensional map of distances to underwater objects with coordinates received from GPS receiver 1.

A side-scan sonar 6 scans the bottom with a narrow beam, resulting in a detailed picture of the bottom topography, the objects of which are located relative to the path of the BPA 11. These data (bottom map), as well as the depth of the BPA 11 measured by the side-scan sonar 6 and the distance from the BPA 11 to the bottom, are transmitted through the control device 7 via a cable-cable 10 to the on-board sonar unit 4, which then transfers this data to the control system 2.

In this case, to determine the position of the control unit 11, an underwater navigation system is used that works on the principle of phase direction finding and includes an onboard sonar unit 4, an underwater navigation antenna 5 and an underwater navigation transponder 8. The onboard sonar unit 4 sends a request signal through the transmitting hydrophone of the underwater navigation antenna 5 and simultaneously and starts the counter available in its structure. The hydroacoustic signal emitted in response to the antenna of the underwater navigation transponder 12 is recorded by two receiving hydrophones of the underwater navigation antenna 5, which are located in a horizontal plane.

According to the phase difference of the hydroacoustic signal recorded by the receiving hydrophones of the underwater navigation antenna 5, the on-board sonar unit 4 determines the angle of arrival of the signal in the horizontal plane (angle α in FIG. 5). The return time of the hydroacoustic signal t _s, measured by the counter, as well as the value of the angle α are transmitted to the control system 2.

The control system 2 performs the calculation of the coordinates of the BPA 11, the processing of information about the topography of the bottom, the adjustment of the coordinates of the BPA 11 and writes the entire set of information received to a file.

To determine the coordinates {x ', y', z ') BPA 11 control system 2 performs the following calculations.

The speed of sound in water is determined by the Leroy formula:

$$\begin{array}{l}c(T,S,z)=1492.9+3(T-10)-0.006{(}^T-0.04{(}^T+\\ +\mathrm{1,2}(S-35)-0.01(T-\mathrm{eighteen})(S-35)+z/\mathrm{61,}(\mathrm{one})\end{array}$$

where c = c (T, S, z) is the speed of sound in water, m / s;

T - water temperature, ° C;

S is the salinity of the water,%;

z - depth, m.

The average value of the speed of sound in water for the depth to which BPA 11 has descended is determined by integrating expression (1):

$$\overline{c}=\frac{\mathrm{one}}{D-d}{\displaystyle \underset{d}{\overset{D}{\int }}c(T,S,z)dz,(2)}$$

- средняя скорость звука в воде, м/с;Where $$\overline{c}$$

- the average speed of sound in water, m / s;

D - deepening of BPA 11, m;

d - deepening of the antenna of underwater navigation 5, m.

From the measured propagation time of the hydroacoustic signal, the distance L between the antenna of underwater navigation 5 and the antenna of the transponder of underwater navigation 12 is calculated:

$$L=\frac{\mathrm{one}}{2}\overline{c}{t}_s,(3)$$

where L is the distance between the antenna of underwater navigation 5 and the antenna of the transponder of underwater navigation 12, m;

- средняя скорость звука в воде для заданного заглубления БПА 11, м/с; $$\overline{c}$$

- the average speed of sound in water for a given depth of BPA 11, m / s;

t _s - the return time of the hydroacoustic signal, s.

For reference, the location of the antenna of the GPS receiver 1 (point O in figure 4) is selected. The coordinate of the side-scan sonar antenna 13 along the Oz axis relative to the selected reference point is determined by the formula:

$$z\text{'}\text{'}=z_0-d+D,(\mathrm{four})$$

where z 'is the coordinate of the side-scan sonar antenna 13 along the Oz axis, m;

z ₀ - coordinate of the antenna of underwater navigation 5 along the axis Oz, m;

d - deepening of the antenna of underwater navigation 5, m.

The angle of arrival β of the hydroacoustic signal to the underwater navigation antenna 5 (shown in FIG. 5) in the vertical plane is

$$\beta =\arccos \frac{z\text{'}\text{'}-z_0}{L},(5)$$

where β is the angle of arrival of the hydroacoustic signal to the antenna of underwater navigation 5 in a vertical plane relative to the axis Oz, degrees.

The coordinate of the side-scan sonar antenna 13 along the Ox axis relative to the selected reference point is found by the formula:

$$x\text{'}\text{'}=x_{\mathrm{one}}+l=x_0+L\sin \beta \cos \alpha +l,(6)$$

where x 'is the coordinate of the side-scan sonar antenna 13 along the Ox axis, m;

x ₁ - coordinate of the antenna of the transponder of underwater navigation 12 along the axis Ox, m;

l is the distance between the antenna of the transponder underwater navigation 12 and the antenna of the side-scan sonar 13, m;

x ₀ - coordinate of the antenna of underwater navigation 5 along the axis Oh, m;

α is the angle of arrival of the hydroacoustic signal to the antenna of underwater navigation 5 in the horizontal plane relative to the axis Ox, degrees.

Then, the coordinate of the side-scan sonar antenna 13 is calculated along the Oy axis relative to the selected reference point:

$$y\text{'}\text{'}={\mathrm{<figure-callout\; id="0"\; label="y"\; filenames="00000016.png"\; state="\{\{state\}\}">y</figure-callout>}}_0+L\sin \beta \cos \alpha ,(7)$$

where y 'is the coordinate of the side-scan sonar antenna 13 along the Oy axis, m;

y ₀ ^- coordinate of the antenna of underwater navigation 5 along the Oy axis, m

To adjust the coordinates (x ', y', z ') of an underwater towed vehicle, the control system 2 according to the standard cross-correlation algorithm (described, for example, in [Tokarev MP Adaptive algorithms for processing particle images to calculate instantaneous velocity fields / Tokarev MP ., Markovich DM, Bilsky AV // Computational technologies. - 2007. - Volume 12. - No. 3. - P.109-131]) digitally processes images of the bottom topography obtained using a side-scan sonar. 6 and a multi-beam echo sounder 3. The found displacement of the position of the underwater volume that at the bottom of the map, the resulting side-scan sonar 6, relative to the position of the same object on the map of the underwater bottom, obtained by the multibeam 3 is used to refine the FHT 11 coordinates.

БПА 11 на основании данных GPS приемника пересчитываются в географические координаты (φ, λ, $$\hat{x}\text{'}$$

) где φ - географическая широта, градусов; λ - географическая долгота, градусов.Received adjusted coordinates $$(\hat{x}\text{'}\text{'},\hat{y}\text{'}\text{'},\hat{z}\text{'}\text{'})$$

BPA 11 on the basis of GPS receiver data are converted into geographical coordinates (φ, λ, $$\hat{x}\text{'}\text{'}$$

) where φ is the geographical latitude, degrees; λ - geographical longitude, degrees.

Thus, the goal has been achieved, namely: reducing the error in determining the coordinates of the towed underwater vehicle while reducing labor costs when performing underwater research. Moreover, the accuracy of the coordinates of the location of objects on a detailed map of the bottom topography obtained using the BPA 11 is improved by correcting the coordinates of the PBA 11 through cross-correlation processing of bottom images obtained using MBE 3 and HBO 6.

As the GPS receiver 1, NovAtel DL-V3 can be used, which has a coordinate accuracy of up to 10 cm.

As a control system 2, National Instruments equipment can be used: a PXI-1062Q basket with a PXIe-8133 controller and PXI-8432/4 and PXI-8234 interface expansion modules. The control program of such a system is written in the Lab VIEW language.

As the MBE 3 can be used multi-beam echo sounder "Corvette-MLE-250" (JSC Concern "Okeanpribor").

As a BPA 11, the SONIK-ZD side-scan sonar (VNIIOkeangeologiya) can be used, which already has its own on-board sonar unit, a control device and optionally an underwater navigation antenna and an underwater navigation transponder.

Claims (1)

A towed underwater vehicle navigation system comprising a towing vessel, a towed underwater vehicle, a GPS receiver, a sonar navigation system, characterized in that the GPS receiver is located on a towing vessel, which additionally has a multi-beam echo sounder, underwater navigation antenna, control system, on-board sonar unit, and the towed underwater vehicle contains a side-scan sonar, a control device and a transponder for underwater navigation, while the GPS receiver is connected to the first the control system, to the second port of which a multipath echo sounder is connected, and the first port of the onboard sonar unit is connected to the third port of the control system, the second port of which is connected to the underwater navigation antenna, and the third port of the onboard sonar unit is connected via a cable-cable to the towed submarine apparatus by a control device connected to a transponder for underwater navigation and a side-scan sonar.

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