Adaptive depth control system for towed sonar stations with dual feedback system

Abstract

FIELD: hydroacoustics.SUBSTANCE: system for controlling the immersion depth of towed hydroacoustic stations comprises at least one carrier vessel with a system for determining position and speed, an SPC cable with a combined carrier and information channel, at least one towed hydroacoustic station with a system for detecting underwater objects, means for measuring the depth under the vessel, an actuator for changing the length of the cable, a bottom relief prediction unit connected to the vessel's cartographic system, a dual control loop unit including an automatic depth control loop and a feedback loop from the hydroacoustic station, a safe maneuver time calculation unit, a group work synchronization unit that ensures data exchange between several hydroacoustic stations in a group.EFFECT: increased accuracy of detection and classification of underwater objects, increased reliability and efficiency of search operations in difficult operating conditions, and reduced response time to the detection of suspicious objects.2 cl, 4 dwg

Description

[0001] Technical field

[0002] The invention relates to the field of hydroacoustics, marine reconnaissance and trawling, namely to devices for automatic depth control and intelligent systems for controlling the position of towed hydroacoustic stations or complexes designed for continuous scanning of the bottom, detection and classification of underwater, near-bottom and bottom objects and synchronized operation of a group of small vessels.

[0003] Technology Level

[0004] Current technological advancements involve the use of stationary hydroacoustic systems, either mounted directly onboard a vessel or installed on the bottom of a water body. However, these approaches have a number of significant drawbacks: limited ability to dynamically adjust the depth of receivers and emitters, which reduces observation accuracy in uneven terrain and vessel motion; a lack of mechanisms for rapid response to changes in the aquatic environment and the geometry of the surveyed area; and difficulties in organizing the joint operation of multiple vessels due to the lack of agreed-upon data exchange methods and protocol compatibility.

[0005] Traditional towed sonar systems are known to passively control the antenna's depth, depending solely on the towing speed and the length of the deployed cable. However, this solution is limited by its ability to automatically adjust depth and is unable to account for changing environmental conditions, reducing the quality of the data obtained and increasing the risk of equipment damage.

[0006] The prior art discloses marine seismic exploration in ice-covered or obstructed waters (see [1] Russian Federation Patent No. 2570428 C2, IPC G01V1 / 38, B63B 21 / 66, published 12 / 10 / 2015), which is a control system for the movement of a deep-sea vehicle, which uses a simple control system for the immersion depth with one control loop.

[0007] A disadvantage of the known solution is the inability to quickly respond to changing situations, i.e., adaptive depth control in real time, in particular the lack of feedback from the towed device itself, which complicates precise positioning of the antenna and increases the likelihood of emergency situations.

[0008] Other existing devices rely on rigidly mounting the sonar to the vessel or mounting it on separate stands, which reduces the device's stability in strong waves and causes data gaps in echograms. Traditional systems with single sonars, controlled by rigid algorithms, also exist, but they have a number of significant drawbacks: poor adaptability to changing conditions (currents, interference, pitching), difficulty coordinating multiple devices, and limited accuracy when processing ambiguous data.

[0009] The closest analogue of the claimed technical solution, selected as a prototype, is a device for launching and raising a towed sonar (see [2] US Patent No. US9751596B2, IPC B63B21 / 66, published 05.09.2017) describing a device for lowering and raising a sonar, including a linear receiving antenna and a volumetric transmitting antenna built into a volumetric body called a fish, wherein said sonar is towed by a surface vessel using a towing rope including a towing cable on which the fish is suspended, the linear antenna is secured to the cable relative to the vessel, said device includes a towing winch including a frame for securing the surface vessel and allowing the towing rope to be wound and unwound around a reel, wherein the reel includes two parts that are rotationally movable around an axis of rotation, means for connecting the two parts, the first part has a cylindrical shape on which the towing rope is intended to be wound, the second part includes a first stop intended for placing the fish.

[0010] The prototype's shortcomings include: It fails to account for pitching and the impact of water surface fluctuations on the stability of the sonar signal, reducing the reliability and information content of bottom images; it also lacks a comprehensive approach to ensuring depth stability, meaning its solution is limited to mechanical adjustments and is insufficiently effective in addressing the problem of collisions with underwater objects, as it does not provide for real-time data processing, which is necessary for the effective interaction of multiple vessels simultaneously.

[0011] Modern hydroacoustic systems are characterized by a number of limitations associated with the lack of automation of decision-making processes for changing the depth of towed elements, unstable operation in sea conditions and complex navigation in a group of vessels.

[0012] Disclosure of the essence of the invention

[0013] The objective of the claimed invention is to create an intelligent system for adaptive control of the immersion depth of towed hydroacoustic stations, ensuring high accuracy and reliability of surveys in difficult marine conditions, promptly responding to changes in the external environment and ensuring the safe and efficient execution of tasks related to the search and classification of underwater objects.

[0014] The technical results of the claimed invention are: increased accuracy of detection and classification of underwater objects; increased reliability and efficiency of search operations in difficult operating conditions, ensuring safety and reducing risks during the survey of marine waters; reduced response time to the detection of suspicious objects.

[0015] The problem is solved and the technical result is achieved thanks to a system for controlling the immersion depth of towed hydroacoustic stations, comprising at least one carrier vessel with a system for determining position and speed; a cable-rope with a combined carrier and information channel; at least one towed hydroacoustic station with a system for detecting underwater objects; means for measuring the depth under the vessel; an actuator for changing the length of the cable, wherein the system additionally comprises a bottom relief prediction unit connected to the vessel's cartographic system; a dual control loop unit; a safe maneuver time calculation unit connected to the bottom relief prediction unit and a second control loop, configured to determine the maximum time of stay at the changed depth without the risk of collision with the bottom;A group synchronization unit that facilitates data exchange between multiple hydroacoustic stations in a group for the joint construction of a 3D model of the underwater environment. The dual-loop control unit includes a first loop for automatic depth control (the hydroacoustic station), linked to the depth measurement system and vessel motion sensors; a second loop for feedback from the hydroacoustic station, capable of generating requests for depth changes upon detection of suspicious objects. The hydroacoustic station is equipped with its own electric propulsion units, driven by a cable, providing an additional degree of freedom of movement relative to the carrier vessel.

[0016] Brief description of drawings

[0017] Fig. 1 – general view of the adaptive control system for the immersion depth of towed hydroacoustic stations (horizontal axis – winch cable extension length, vertical axis – depth).

[0018] Fig. 2 – General view of the system during group towing.

[0019] Fig. 3 – block diagram of the interaction of system elements in operation.

[0020] Fig. 4 - diagram of group underwater monitoring using a complex consisting of several carrier vessels and towed antennas (detection means).

[0021] Implementation of the invention

[0022] The system (Fig. 1) includes the following key components.

[0023] Carrier vessel (1) with a sensor suite including GPS / GNSS, GLONASS, depth sounder (means for measuring the depth beneath the vessel), pressure, speed, acceleration, roll, and pitch sensors. The carrier vessel (1) provides towing, power supply, and data processing.

[0024] Tow cable (2) with an integrated data and power channel, serving as a power support and data highway. The tow cable is designed to accommodate modular mounting of sonars and auxiliary equipment.

[0025] A towed hydroacoustic station (3) with an underwater object detection system, including a hydroacoustic module (locator, profiler, etc.), a data processing and control unit, and an autonomous mobility system (optional). One carrier vessel can tow several stations, for example, 2-5, forming a group of towed hydroacoustic stations (Fig. 2).

[0026] The actuator is a stand-alone towing winch (4) for changing the length of the cable.

[0027] The mother vessel (1) also carries a central control system (CCS) that integrates data from all system components.

[0028] The central control system includes two control circuits:

[0029] • First circuit (vessel → station): control of diving depth based on data from the echo sounder, roll and speed sensors of the vessel;

[0030] • Second circuit (station → vessel): feedback from the hydroacoustic station when anomalies or suspicious objects are detected.

[0031] The central control system also contains:

[0032] • Bottom relief prediction unit integrating with cartographic data;

[0033] • safe maneuver time calculation block, determining the maximum time spent at a changed depth without the risk of collision with an obstacle;

[0034] • a group synchronization unit that supports communication between several hydroacoustic stations in a group for the joint construction of a three-dimensional model of the underwater environment.

[0035] At the same time, the group work synchronization unit as part of a complex of several carrier vessels (for example, when several vessels work together) is also intended for the joint construction of a three-dimensional model of the underwater environment (Fig. 4).

[0036] Fig. 1 shows the different length of the cable-rope depending on the depth of the hydroacoustic station (pos. 3), the speed of the carrier vessel and obstacles in the path of the station.

[0037] Fig. 3 shows a block diagram of the interaction of the system elements with each other, namely:

[0038] Block 1 – Receives and processes data on the course and speed of the towed hydroacoustic station, calculates and measures (checks) the tension force of the cable on the winch, calculates emergency tensions (when snagged), for the command to shoot the cable and transmits data to block 3;

[0039] Block 2 – Receives and processes depth gauge data and transmits data to block 3;

[0040] Block 3 – Receives data from blocks 1 and 2 and processes all data on the state of the cable and winch, and transmits the data to block 4;

[0041] Block 4 – Calculates and issues automated commands to the winch to wind or unwind the cable depending on the parameters of block 3. Transmits and receives signals and data to block 5;

[0042] Block 5 – Central Control System, which carries out decision-making and data exchange between all blocks of the system;

[0043] Block 6 – Records and transmits the recognized signal from the hydroacoustic station (coordinates, speed, type of recognized object). Receives data from Block 5;

[0044] Block 7 – Issues target designations for the use of weapons (including additional electronic, pulse, etc.);

[0045] Block 8 – Performs data exchange (reception and transmission) with ships, vessels, boats, aircraft, and underwater vehicles of the group (order). Transmits and receives data from Block 5;

[0046] Block 9 – Receives and transmits data from the hydroacoustic station (antenna). Receives data from block 5. Transmits data to block 10;

[0047] Block 10 – Processes data received from block 9. Transmits data to blocks 11 and 12;

[0048] Block 11 – Recognizes bottom geometry and relief parameters, classifies atypical objects on the bottom. Transmits data to blocks 12 and 5;

[0049] Block 12. Recognizes and classifies underwater objects (based on convolutional neural network images). Transmits data to Block 5. Receives data from Blocks 10 and 11.

[0050] The system functions as follows .

[0051] In the first stage, data from the vessel (depth, heel angle, wind and current direction) is transmitted to the central control system. Based on this information, the system selects the optimal submersible depth for the station.

[0052] In the second stage, the sonar station continuously monitors the space around it. If it detects an unusual object (such as a rock or other structure), the station transmits a signal to the host vessel to adjust its depth. The central control system calculates the optimal depth and a safe time interval for maintaining the new depth.

[0053] In the third stage, after the object analysis is completed, the system returns the station back to the original depth.

[0054] At the fourth stage, in the case of multiple vessels operating simultaneously, synchronization units support the exchange of information to form a single representation of the space and eliminate duplicate survey areas.

[0055] There are several options for controlling the system.

[0056] Direct control loop (set by the operator or program): setting the target operating algorithm, for example, maintaining a constant distance from the bottom or the water surface; adjusting the position of the cable depending on the current depth data and the speed of the vessel;

[0057] Feedback loop (initiated by the station itself): analysis of primary hydroacoustic information, detection of suspicious objects; request for depth adjustment for further investigation of identified anomalies; the maneuver execution control algorithm is based on the coordinated actions of both loops, taking into account safety constraints and tactical objectives.

[0058] Example of the system operation

[0059] The boat is traveling at 10 knots. The depth gauge registers a depth of 100 meters under the stern. After three minutes of sailing, the depth remains stable (±2-5 meters). A flexible control system lowers the cable to the set depth (80 meters). The sonar covers the bottom at a depth of 80 meters. If the speed or depth suddenly changes, the system instantly compensates for the difference and restores the optimal position. For example, if the depth suddenly increases or an obstacle appears below 50 meters, the winch's automatic system immediately retracts the cable, preventing a collision.

[0060] Thus, the present invention solves the problem of inefficient and unsafe sonar towing by implementing an intelligent adaptive depth control system with a dual feedback loop. This significantly improves the quality of search results and reduces the risk of equipment damage, making possible wide industrial application in ocean research, mineral exploration, rescue operations and environmental assessment. The technical solution is based on the implementation of a dual-loop control system combined with mechanisms for operational assessment of the state of the environment and the implementation of intelligent data processing functions using fuzzy logic and machine learning methods (see [3] neural networks and fuzzy logic systems https: / / ppt-online.org / 115136 ).

[0061] The system's primary purpose is to provide continuous bottom echogram recording in challenging hydrometeorological conditions (sea state 2-4) on small vessels and boats. An additional purpose is to prevent collisions between the sonar and underwater obstacles.

[0062] The claimed invention significantly improves the accuracy and reliability of underwater research, creating a fundamentally new concept for controlling hydroacoustic stations. Its implementation will provide unique opportunities for military, civilian, and research organizations operating in the marine environment.

Claims

1. A system for controlling the immersion depth of towed hydroacoustic stations, comprising: at least one carrier vessel with a position and speed determination system; cable-rope with a combined load-bearing and information channel; at least one towed hydroacoustic station with a system for detecting underwater objects; means for measuring the depth under the vessel; actuator for changing the length of the cable, characterized in that it additionally contains: a bottom relief prediction unit linked to the vessel's mapping system; dual control circuit block including: the first circuit of automatic depth control of the hydroacoustic station, connected to the depth measurement system and vessel motion sensors; a second feedback loop from the hydroacoustic station, designed with the ability to generate requests to change the depth upon detection of suspicious objects; a safe maneuver time calculation unit connected to a bottom relief prediction unit and a second control circuit, configured to determine the maximum time spent at a changed depth without the risk of collision with the bottom; A group synchronization unit that provides data exchange between several hydroacoustic stations in a group for the joint construction of a three-dimensional model of the underwater environment.

2. The system according to paragraph 1, characterized in that the hydroacoustic station is equipped with its own propellers with an electric drive from a cable, providing an additional degree of freedom of movement relative to the carrier vessel.

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