Autonomous underwater navigation device

Abstract

FIELD: underwater navigation.SUBSTANCE: invention relates to devices designed for precise positioning under water, including in conditions of limited visibility or in the absence of communication with the surface. The autonomous underwater navigation device includes a sealed housing comprising a Doppler hydroacoustic log, an information display module, and a strapdown inertial navigation system with a microelectromechanical inertial sensor board comprising a three-axis gyroscope, accelerometer, and magnetometer. The device also includes a satellite navigation system receiver located in the buoy, hydroacoustic transducers of the Doppler hydroacoustic log, and a battery pack. The battery pack is placed inside the sealed housing of the device, the hydroacoustic transducers of the Doppler hydroacoustic log are placed on the rod outside the sealed housing of the device, the device additionally comprises a hydroacoustic communication module consisting of a computer and two hydroacoustic piezoelectric emitters, one of which is configured only to receive a signal, the other to receive and emit a signal.EFFECT: increasing the accuracy of navigation of the device in real time, ensuring the possibility of placing the device on underwater carriers.1 cl, 5 dwg

Description

[0001] The invention relates to underwater navigation means intended for precise positioning under water, including in conditions of limited visibility or in the absence of communication with the surface.

[0002] The Cobra-Tac system, developed by Teledyne RD Instruments, is well-known and is positioned as a revolutionary platform for autonomous navigation. Its key feature is the integration of data from a Doppler velocity meter (DVL), compass, and pressure sensor, enabling the creation of bathymetric maps and navigation to points with specified geodetic coordinates without the use of external devices. The disadvantages of this system include its large size, black-and-white display, and poor information content, the lack of connectivity for additional equipment to improve local navigation accuracy, and the inability to install it on underwater diver propulsion systems.

[0003] The DiNIS™ (Diver Navigation and Imaging System) from Kenautics Inc. is a well-known high-tech solution for underwater navigation, exploration, and data analysis. DiNIS™ integrates inertial navigation, multi-frequency sonar, and other sensors into a compact, ruggedized enclosure. The system provides autonomous positioning, data collection, and storage. The main drawbacks include the accumulation of gyroscope errors (drift), reduced sensor performance in conditions of high interference or poor visibility, and the device's significant weight.

[0004] Patent RU 2439602 C2 (published January 10, 2012) describes a device for determining the direction of a sound source without relying on shipboard equipment or beacons. However, this device has a low bearing accuracy of 10–15 degrees and lacks a function for determining the distance to the sound source, making it ineffective for navigation.

[0005] An alternative approach is implemented in the solution described in patent RU 172196 U1 (published June 30, 2017), adopted as a prototype, relating to an autonomous diver navigation device containing a navigation unit and a battery pack connected to the housing. The device includes a Doppler hydroacoustic log with hydroacoustic transducers, a data display module, a strapdown inertial navigation system (INS) comprising a microelectromechanical inertial sensor board housing a three-axis gyroscope, accelerometer, and magnetometer, a battery pack housed in a separate housing, and a sealed buoy with a satellite navigation system (SNS) receiver, all housed in a robust housing. The known device is constructed from two sealed housings and the buoy, connected by a cable. The information display module provides the user with an intuitive interface with the ability to flexibly configure route parameters.However, the prototype lacks the ability to install the device on underwater carriers. It also lacks the ability to adjust the navigation solution based on SNS data while moving, as the buoy is designed exclusively for operation at zero speed. A separate sealed battery pack housing, connected to the navigation device, complicates its operation and increases its weight. Furthermore, the navigation algorithms do not account for the systematic drift error of gyroscope readings, which reduces the accuracy of determining the device's angular coordinates. Absolute navigation is ensured at a distance of no more than 30 meters from the bottom.

[0006] The objective of the present invention is to eliminate the disadvantages inherent in the prototype, improve the performance characteristics and expand the functionality of the device.

[0007] The technical result consists in increasing the accuracy of navigation of the device in real time, ensuring the possibility of placing the device on underwater carriers.

[0008] The stated technical result is achieved by an autonomous underwater navigation device comprising a sealed housing containing a Doppler hydroacoustic log, a data display module, and a strapdown inertial navigation system with a microelectromechanical inertial sensor board containing a three-axis gyroscope, accelerometer, and magnetometer. The device also includes a satellite navigation system receiver housed in a buoy, hydroacoustic transducers of the Doppler hydroacoustic log, and a battery pack. The battery pack is housed within the sealed housing of the device, the hydroacoustic transducers of the Doppler hydroacoustic log are mounted on a rod outside the sealed housing of the device, and the device additionally contains a hydroacoustic communication module consisting of a computer and two hydroacoustic piezoelectric emitters, one of which is configured to receive only a signal, the other to receive and transmit a signal.

[0009] The essence of the invention is explained by the following figures:

[0010] Fig. 1 - structural and functional diagram of the autonomous navigation device for a diver;

[0011] Fig. 2 - view of the autonomous underwater navigation device from the front panel;

[0012] Fig. 3 - view of the autonomous underwater navigation device from the rear panel;

[0013] Fig. 4 – view of a “float” type buoy;

[0014] Fig. 5 – view of a fish-type buoy.

[0015] The figures indicate:

[0016] 1 - navigation device;

[0017] 2 - navigation system computer;

[0018] 3 - strapdown inertial navigation system (SINS);

[0019] 4 – three-axis gyroscope;

[0020] 5 - three-axis accelerometer;

[0021] 6 - three-axis magnetometer;

[0022] 7 - pressure sensor;

[0023] 8 - GPS / GJIOHACC SNS receiver;

[0024] 9 - Doppler hydroacoustic log (DGL);

[0025] 10 - DGL calculator;

[0026] 11 - hydroacoustic transducers DGL;

[0027] 12 - communication module;

[0028] 13 - communication module calculator;

[0029] 14 - hydroacoustic piezoelectric emitters of the communication module;

[0030] 15 - information display module;

[0031] 16 - information display module calculator;

[0032] 17 - liquid crystal display;

[0033] 18 – battery pack;

[0034] 19 - battery controller;

[0035] 20 - battery;

[0036] 21 - sealed connector for connecting the navigation device to the charger;

[0037] 22 - charger;

[0038] 23 - sealed case;

[0039] 24 - piezoelectric control buttons;

[0040] 25 - handles for holding the device by a diver;

[0041] 26 - safety ring;

[0042] 27 - buoy;

[0043] 28 - connecting cable;

[0044] 29 - SNS antenna cable holder;

[0045] 30 - sensor block (water sensor and temperature sensor);

[0046] 31 - guides for fastening to the carrier.

[0047] The structural and functional diagram of the autonomous navigation device is shown in Fig. 1.

[0048] The navigation device 1 includes a navigation system computer 2, a strapdown inertial navigation system (SINS) 3, which includes a three-axis gyroscope 4, an accelerometer 5 and a magnetometer 6, manufactured using microelectromechanical systems (MEMS) technology.

[0049] The navigation device 1 also includes a pressure sensor 7, a SNS receiver 8, a DGL 9 developed on the basis of a DGL computer 10 and four DGL hydroacoustic transducers 11. The navigation device 1 includes a hydroacoustic communication module 12, consisting of a communication module computer 13 and hydroacoustic piezoelectric emitters of the communication module 14, one of which is configured only to receive a signal, the other to receive and transmit a signal. The navigation device 1 contains an information display module 15, consisting of an information display module computer 16 and a liquid crystal screen 17. In addition, the navigation device 1 includes a battery pack 18, consisting of a battery controller 19 and a battery 20, as well as a sealed connector 21, necessary for connecting an external charger 22.In this case, the BINS 3, the pressure sensor 7, the DGL computer 10, the communication module computer 13, the information display module computer 16, the battery controller 19, the battery 20 are located inside the sealed housing 23 of the device.

[0050] On the front panel of the navigation device (Fig. 2) there is a liquid crystal display 17, piezoelectric control buttons 24, handles for holding the device by the diver 25, safety rings 26. Above the handles for holding the device by the diver 25 there is a buoy 27 with a SNS receiver 8, connected to the device via a connecting cable 28, secured to the cable holder.

[0051] On the rear panel of the device (Fig. 3), DGL 11 hydroacoustic transducers are mounted on a rod, paired on each side. The DGL 11 hydroacoustic transducers are connected to the DGL 10 computer (located inside the sealed device) via a cable through a sealed cable entry and a sealed connector. The rod length is adjustable, allowing the autonomous underwater navigation device to be mounted on underwater vehicles.

[0052] The rear panel of the device (Fig. 3) houses the sensor unit 30 and mounting guides for the device to the carrier. Sensor unit 30 includes a water sensor and a temperature sensor. The water sensor ensures the device operates exclusively in the working (aquatic) environment, preventing damage to the antennas and reducing power consumption. Readings from the temperature sensor are used to correct the device's readings. Mounting guides 31 are used when mounting the autonomous underwater navigation device on underwater carriers. The autonomous navigation device is secured using a universal mount—a bracket.

[0053] On the rear panel of the device, near buoy 27, are two hydroacoustic piezoelectric emitters 14 of the hydroacoustic communication module 12. One is configured for signal reception only, and the other for both reception and transmission. The piezoelectric emitters operate based on the piezoelectric effect. The transmission signal, as well as the received signals, are generated and processed in the computer of the communication module 13 (located inside the device's sealed housing).

[0054] The autonomous underwater navigation device operates in three modes:

[0055] 1. Compass mode;

[0056] 2. Map mode;

[0057] 3. Settings mode.

[0058] In Compass mode, the LCD screen 17 displays all navigation information. It also displays the active waypoint and the direction to the selected waypoint. The Compass page menu allows you to add, select, and adjust waypoint coordinates, adjust the compass when used with an underwater vehicle, set the operating depth and screen brightness, and switch to the product setup mode.

[0059] In the Map mode, the page menu contains a fixed set of basic commands, allowing you to add, select, adjust and delete route point coordinates, zoom in or out, determine the distance between two points on the map, switch to the viewing mode to configure the working map, move between control points, return to the map navigation mode, determine the type of working map, change the screen brightness, and switch to the product configuration mode.

[0060] The “Settings” mode contains a fixed set of basic commands that allow you to work with route checkpoints, configure the depth sensor, set a password for the autonomous underwater navigation device, calibrate the compass, set the sound speed value depending on the operating conditions, perform device diagnostics, set the address for hydroacoustic communication, and turn on and off the receiver of the satellite navigation system 8.

[0061] The device operates as follows.

[0062] In the underwater research area, the autonomous underwater navigation device is removed from the transport container. Pressing control buttons 24 turns on the autonomous underwater navigation device, and the charge level of battery 20 is checked on the "Compass" or "Map" pages. If the charge level is less than 80%, charge battery 20 using external charger 22, connected to sealed connector 21. Battery controller 19 protects battery 20 from overcharging. A map of the underwater research area is downloaded using the data cable. The autonomous underwater navigation device is configured on the "Settings" page according to the specified route.

[0063] To correct geographic coordinates at route points without the diver / underwater vehicle surfacing, buoy 27 with GPS / GLONASS SNS receiver 8 is released by unwinding connecting cable 28. The "float" type buoy (Fig. 4) is used for autonomous diver movement. The "fish" type buoy (Fig. 5) is used for installation on mobile vehicles; the buoy has a hydrodynamic shape and can receive SNS signals when towed at a speed of up to 2 m / s. GPS / GLONASS SNS receiver 8 provides correction information about the coordinates of the autonomous underwater navigation device to the computer of the navigation system 3.

[0064] The "Compass" or "Map" work page displays data from the SNS 8 receiver. If no data is available, it is necessary to establish the known coordinates of the device, after which you can begin moving, ensuring the "horizontal" orientation of the device according to the readings of the roll and trim indicator.

[0065] When using the device on underwater vehicles, it is necessary to mount the autonomous underwater navigation device using a bracket and turn on the device. At the same time, the length of the rod with the DGL 11 hydroacoustic transducers attached to it must be adjusted so that the underwater vehicle does not interfere with the transmission of signals from the hydroacoustic transducers.

[0066] Operating modes are controlled by 24 piezoelectric control buttons, which provide a quick response and are resistant to mechanical stress. The 24 piezoelectric control buttons are sealed, preventing water penetration. The absence of moving mechanical parts increases their reliability and extends their service life, which is important for use in aggressive aquatic environments.

[0067] The pairing of all devices and sensors, as well as control of operating modes, is provided by the software part of the autonomous navigation device.

[0068] The calculation of the current coordinates is carried out by the computer of the navigation system 2 on the basis of the data received from the DGL 9, the communication module 12, the pressure sensor 7, the gyroscope 4, the accelerometer 5 and the magnetometer 6. The navigation solution is also adjusted on the basis of the information received from the GPS / GLONASS receiver 8 and the communication module 12, which makes it possible to increase the accuracy of determining the coordinates.

[0069] Real-time dead reckoning in latitude-longitude-depth coordinates, in the absence of SNS signals, is performed using data from the SINS 3, DGL 9, and pressure sensor 7. The SINS 3 data provides information on angular rates, linear accelerations, and magnetic field vector components. Based on this data, the navigation system computer 2 determines the angular orientation of the autonomous underwater navigation device, namely, the heading, roll, and pitch angles. This is combined with data from the Doppler hydroacoustic log 9, which provides information on the speed and direction of movement and the distance to the bottom, with data from the communication module 12, which corrects the coordinates and azimuth using the hydroacoustic beacon, and pressure sensor 7, which provides information on the dive depth. Data from sensor unit 30, including a temperature sensor, is used to calculate the speed of sound.The integration of data from various sensors included in the autonomous underwater navigation device ensures high accuracy of autonomous navigation while moving underwater.

[0070] The device also provides local navigation relative to a hydroacoustic beacon or similar device. In this mode, the device operates by exchanging 12 signals from the communication module with the communication module of another device or beacon. The communication module allows for the transmission of up to 15 coded messages. Beacons can be installed on stationary and mobile underwater objects and can also be transported by divers. Each beacon contains a power amplifier, which provides a range of up to 1 km. Each beacon is assigned a number, which serves as an address when sending messages.

[0071] To conserve power, the beacons are in sleep mode. When navigation by beacons is required, the autonomous underwater navigation device sends a hydroacoustic signal to wake the beacons. The transmitted messages contain encrypted information (device number, command number, etc.). The beacons filter the signal according to the identifier and process the incoming commands.

[0072] The autonomous underwater navigation device according to the present invention is up to 40% lighter than the prior art. This is achieved by eliminating the external sealed battery housing and placing it inside the device, as well as by upgrading the internal circuit boards to reduce their size and weight.

[0073] Also, using the guides for mounting to the carrier 31, the autonomous underwater navigation device can be placed on underwater carriers.

[0074] Navigation accuracy is improved by integrating the autonomous underwater navigation device with the hydroacoustic navigation and communication system, as well as implementing a gyroscope calibration algorithm during operation. Gyroscope calibration reduces systematic error while increasing accuracy.

[0075] Thus, this device allows you to calculate and display the trajectory of movement, the current navigation data of the device in real time with reference to electronic marine charts, indicating geographic coordinates, speed of movement, orientation angles, immersion depth, distance to the bottom, distance to lighthouses and direction of movement.

Claims

An autonomous underwater navigation device comprising a sealed housing, a navigation system computer, an information display module, a strapdown inertial navigation system with a microelectromechanical inertial sensor board on which a three-axis gyroscope, accelerometer and magnetometer are placed, a satellite navigation system receiver placed in a buoy, a Doppler hydroacoustic log containing a Doppler hydroacoustic log computer and hydroacoustic transducers of a Doppler hydroacoustic log, as well as a battery unit, characterized in that the navigation system computer is configured to determine the current coordinates of the device based on data received from the strapdown inertial navigation system, the Doppler hydroacoustic log, the hydroacoustic communication module and the satellite navigation system receiver,the Doppler hydroacoustic log computer and the battery pack are located inside the sealed housing of the device, the hydroacoustic transducers of the Doppler hydroacoustic log are located on a rod adjustable in length outside the sealed housing of the device and are connected to the Doppler hydroacoustic log computer by a cable through a sealed cable entry and a sealed connector, the device is provided with guides for attachment to an underwater carrier, and also additionally contains a hydroacoustic communication module consisting of a communication module computer and two hydroacoustic piezoelectric emitters, one of which is configured to only receive a signal, and the other - to receive and emit a signal, wherein the hydroacoustic communication module is configured to exchange signals with a hydroacoustic beacon or a similar device for correcting the coordinates and / or azimuth of the autonomous underwater navigation device.

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