Underwater searching and positioning method, device and equipment for wrecked ship and medium

Abstract

The invention relates to an underwater searching and positioning method, device and equipment for a wrecked ship and a medium, and the method comprises the steps that an autonomous underwater vehicle determines a third searching direction angle according to the chemical molecule concentration difference between a second searching position point and a first searching position point and a second searching direction angle, continuing to search on the second search position point according to a third search direction angle and a preset first search step length, and updating the second search position point according to the third search direction angle based on a position calculation formula to determine a third search position point; the autonomous underwater vehicle updates the third search position point based on a position calculation formula until the difference value between the chemical molecule concentration detected by the autonomous underwater vehicle at the current search position point and the chemical molecule concentration of a certain position point in a preset space range in the chemical molecule concentration distribution field is smaller than a preset concentration threshold value; if so, determining that the ship approaches the to-be-searched wrecked ship. According to the invention, the detectable time and the positioning precision of the wrecked ship are greatly prolonged.

Description

Technical Field

[0001] The present application relates to the field of molecular communication, and in particular to a method for underwater search and positioning of a wrecked ship, a corresponding device, an electronic device, and a computer-readable storage medium. Background Art

[0002] Due to the dynamic and uncertain nature of the ocean environment, underwater target search and positioning are technically demanding. Acoustic communication remains the primary technology for underwater positioning due to its ability to transmit signals over long distances. However, acoustic waves suffer from severe energy attenuation, multipath propagation, and limited signal duration. Especially in deep-sea environments, signal synchronization is difficult to achieve and power resources are limited. Given these limitations, molecular communication has been developed as a bio-inspired and energy-efficient alternative for communication and sensing.

[0003] After sinking, a shipwreck often faces power shortages, such as battery depletion and equipment damage. Traditional acoustic communications rely on actively transmitting acoustic signals, which consumes a lot of energy. If the power is insufficient, the signal will be interrupted, shortening the search window. Furthermore, the dynamic nature of the ocean environment (such as water currents and temperature fluctuations) and uncertainties (such as high pressure and turbid water in the deep sea) can seriously interfere with acoustic signals. Sound waves are susceptible to energy attenuation, resulting in weak signals after long-distance propagation. Furthermore, acoustic signals reflect off the water, generating interfering multipath propagation, leading to large positioning errors or even signal loss. This problem is particularly prominent in the deep sea.

[0004] To sum up, in order to adapt to the problems in the existing technology where traditional acoustic communication relies on active emission of sound wave signals, which has high energy consumption, and once the power is insufficient, the signal will be interrupted, resulting in a shortened search window, and sound waves are easily affected by energy attenuation and multipath propagation, resulting in large positioning errors or even signal loss, the applicant has made corresponding explorations to solve these problems. Summary of the Invention

[0005] The purpose of this application is to solve the above problems and provide a method for underwater search and positioning of a wrecked ship, a corresponding device, an electronic device and a computer-readable storage medium.

[0006] In order to meet the various objectives of this application, this application adopts the following technical solutions:

[0007] A method for underwater search and positioning of a wrecked ship, which is proposed to meet one of the purposes of this application, comprises:

[0008] Determine a chemical molecule concentration distribution field formed by chemical molecules released underwater by a wreck to be searched that is equipped with a chemical emitter, and calculate, based on a preset Fick's diffusion model, the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times, wherein the greater the distance between the position point and the wreck to be searched, the smaller the corresponding chemical molecule concentration;

[0009] An underwater autonomous vehicle equipped with a high-precision molecular concentration sensor moves vertically downward to the bottom of the to-be-searched area to determine an initial search location point, randomly selects any search direction angle as a first search direction angle of the initial search location point, searches according to the first search direction angle at a preset first search step length to determine the first search location point, and adds a preset turning angle to the first search direction angle as a second search direction angle to continue searching to determine the second search location point;

[0010] The underwater autonomous vehicle determines the third search direction angle based on the chemical molecule concentration difference between the second search location point and the first search location point and the second search direction angle, continues searching at the second search location point according to the third search direction angle and a preset first search step size, and updates the second search location point according to the third search direction angle based on a preset position calculation formula to determine a third search location point;

[0011] The underwater autonomous vehicle updates the third search position point based on the position calculation formula until the difference between the chemical molecule concentration detected by the underwater autonomous vehicle at the current search position point and the chemical molecule concentration at a certain position point within a preset spatial range in the chemical molecule concentration distribution field is less than a preset concentration threshold, and then determines that it has approached the wreck to be searched, thereby completing the search and positioning of the underwater wreck.

[0012] Optionally, the step of calculating and determining the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times according to a preset Fick diffusion model includes:

[0013] Obtaining the position coordinates, the first diffusion coefficient in the horizontal axis direction, the second diffusion coefficient in the vertical axis direction, and the third diffusion coefficient in the vertical axis direction of the chemical molecule within a preset spatial range in the chemical molecule concentration distribution field corresponding to the current position point;

[0014] The position point coordinates corresponding to the current position point, the first diffusion coefficient, the second diffusion coefficient and the third diffusion coefficient are input into a preset Fick diffusion model to calculate and determine the hit probability density of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times.

[0015] Optionally, the step of calculating and determining the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times according to a preset Fick diffusion model includes:

[0016] Obtaining the position coordinates, the first diffusion coefficient in the horizontal axis direction, the second diffusion coefficient in the vertical axis direction, and the third diffusion coefficient in the vertical axis direction corresponding to the current position point of the chemical molecule in the chemical molecule concentration distribution field within a preset spatial range;

[0017] calculating and determining an equivalent diffusion coefficient of the chemical molecule according to the first diffusion coefficient, the second diffusion coefficient, and the third diffusion coefficient, and calculating and determining an equivalent molecular propagation distance of the chemical molecule according to the equivalent diffusion coefficient, the coordinates of the position point corresponding to the current position point, the first diffusion coefficient, the second diffusion coefficient, and the third diffusion coefficient;

[0018] The equivalent diffusion coefficient and the equivalent molecular propagation distance are input into a preset molecular concentration calculation model to determine the chemical molecule concentration of each position point within a preset underwater space at different times.

[0019] Optionally, the step of determining, by the underwater autonomous vehicle, the third search direction angle according to the chemical molecule concentration difference between the second search location point and the first search location point and the second search direction angle includes:

[0020] Determining a first chemical molecule concentration corresponding to the first search location and a second chemical molecule concentration corresponding to the second search location based on detection by a high-precision molecule concentration sensor of the underwater autonomous vehicle, and determining a chemical molecule concentration difference between the second search location and the first search location based on a difference between the second chemical molecule concentration and the first chemical molecule concentration;

[0021] If it is detected that the chemical molecule concentration difference is greater than zero and the second search direction angle is clockwise, or if it is detected that the chemical molecule concentration difference is less than or equal to zero and the second search direction angle is counterclockwise, the sum of the second search direction angle and the preset turning angle is used as the third search direction angle;

[0022] In other cases, the difference between the second search direction angle and the preset turning angle is used as the third search direction angle.

[0023] Optionally, the step of updating the second search position point according to the third search direction angle based on a preset position calculation formula to determine the third search position point includes:

[0024] Obtaining the position coordinates corresponding to the second search position point, the third search direction angle, and the preset first search step size;

[0025] Calculate and determine the first product between the preset first search step and the displacement components in various directions of the third search direction angle, and determine the third search position point based on the first sum of the first product and the position coordinates corresponding to the second search position point, wherein the displacement components in various directions include the displacement component in the horizontal axis direction, the displacement component in the vertical axis direction, and the displacement component in the vertical axis direction, the displacement component in the horizontal axis direction is the cosine value of the third search direction angle, the displacement component in the vertical axis direction is the sine value of the third search direction angle, and the displacement component in the vertical axis direction is zero.

[0026] Optionally, after the step of the underwater autonomous vehicle updating the third search position point based on the position calculation formula, the method further comprises:

[0027] If the difference in chemical molecule concentration between a certain search position point of the underwater autonomous vehicle and a previous search position point is zero, driving the underwater autonomous vehicle to escape from the zero gradient concentration state;

[0028] If the search position point is located at the bottom of the water, it drives the underwater autonomous vehicle to move upward to a preset height; otherwise, it drives the underwater autonomous vehicle to move downward to the preset height. At the same time, the first search step is updated to a preset multiple of the first search step to determine the second search step, and the search for the underwater wrecked ship is continued according to the second search step until the underwater autonomous vehicle escapes from the zero gradient concentration state, wherein the preset height includes 50 meters or 100 meters, the second search step is not less than the preset search step threshold, and the zero gradient concentration state indicates that the difference in chemical molecule concentration between the current search position point and the previous search position point is zero.

[0029] Optionally, the chemical molecule concentration distribution field is formed by specific chemical molecules continuously released by the wrecked vessel to be searched equipped with a chemical emitter at an unknown underwater location, through diffusion and convection in the underwater environment;

[0030] The hit probability density represents the probability distribution of chemical molecules released by the wrecked ship to be searched at each location within a preset spatial range at different times;

[0031] The chemical molecule concentration represents the chemical molecule concentration received at different times at each position point within a preset spatial range of the chemical molecules released by the wreck to be searched.

[0032] A device for underwater searching and locating a wrecked ship provided for another purpose of the present application comprises:

[0033] a molecular concentration calculation module configured to determine a chemical molecule concentration distribution field formed by chemical molecules released underwater by a wreck to be searched that is equipped with a chemical emitter, and to calculate, based on a preset Fick diffusion model, a hit probability density and a chemical molecule concentration of chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times, wherein the greater the distance between the position point and the wreck to be searched, the smaller the corresponding chemical molecule concentration;

[0034] a second search point determination module, configured to include an underwater autonomous vehicle equipped with a high-precision molecular concentration sensor moving vertically downward to the bottom of the to-be-searched area to determine an initial search position point, randomly selecting any search direction angle as a first search direction angle of the initial search position point, searching according to the first search direction angle and a preset first search step length to determine the first search position point, and adding a preset turning angle to the first search direction angle as a second search direction angle to continue searching to determine the second search position point;

[0035] a third search point determination module, configured for the underwater autonomous vehicle to determine a third search direction angle based on a chemical molecule concentration difference between the second search position point and the first search position point and the second search direction angle, continue searching at the second search position point according to the third search direction angle and a preset first search step size, and update the second search position point according to the third search direction angle based on a preset position calculation formula to determine a third search position point;

[0036] The search position point updating module is configured so that the underwater autonomous vehicle updates the third search position point based on the position calculation formula until the difference between the chemical molecule concentration detected by the underwater autonomous vehicle at the current search position point and the chemical molecule concentration at a certain position point within a preset spatial range in the chemical molecule concentration distribution field is less than a preset concentration threshold, and then it is determined that the underwater autonomous vehicle has approached the wreck to be searched, so as to complete the search and positioning of the underwater wreck.

[0037] An electronic device provided to meet another purpose of the present application includes a central processing unit and a memory, wherein the central processing unit is used to call and run a computer program stored in the memory to execute the steps of the underwater search and positioning method for a wrecked ship described in the present application.

[0038] A computer-readable storage medium is provided to meet another purpose of the present application, which stores a computer program implemented according to the underwater search and positioning method for a wrecked ship in the form of computer-readable instructions. When the computer program is called and executed by a computer, the steps included in the corresponding method are executed.

[0039] Compared with the existing technology, this application addresses the problems in the existing technology that traditional acoustic communication relies on active transmission of sound wave signals, which has high energy consumption. Once the power is insufficient, the signal will be interrupted, resulting in a shortened search window, and the sound waves are easily affected by energy attenuation and multipath propagation, resulting in large positioning errors or even signal loss. This application includes but is not limited to the following beneficial effects:

[0040] First, in molecular communication, chemical transmitters installed on wrecked ships can be designed with low power consumption. Even in low-power situations, they can still release molecules for a long time, forming a stable concentration distribution field. This means that wrecked ships can still be found by underwater autonomous vehicles by tracking molecular concentration gradients for days or even weeks after sinking, significantly extending the time it can be detected and improving the chances of search and rescue.

[0041] Second, molecular communication relies on the diffusion and convection of chemical molecules to form concentration gradients, and its propagation patterns are more closely aligned with the physical properties of the underwater environment: while the molecular concentration field slowly diffuses over time, its overall distribution is relatively stable (and predictably affected by water currents), and the concentration gradient, characterized by its "higher near, lower far" characteristic (the closer to the wreck, the higher the concentration), has a clear directionality. AUVs use high-precision sensors to capture these gradient variations, enabling stable tracking even in complex environments, reducing search failures caused by signal interference and improving the reliability of locating the wrecked vessel.

[0042] Third, traditional acoustic positioning requires that the acoustic transmitter of the wrecked ship remain intact (such as the antenna, power supply, and signal processing module are working properly), otherwise no signal can be transmitted. However, the wrecked ship may suffer a violent collision during the sinking process, causing damage to the acoustic equipment and directly losing the ability to be detected. The core of molecular communication is "chemical molecule release", and its transmitter structure can be designed to be simpler and stronger, such as a sealed chemical storage tank, which releases molecules through passive penetration or simple mechanical structures, and has low dependence on equipment integrity. Even if the ship is damaged, as long as the chemical transmitter is not completely destroyed, it can continue to release molecules, providing a signal source for the search and increasing the possibility of the wrecked ship being discovered.

[0043] Fourthly, if a wrecked ship sinks in the deep sea, molecular communication can form a concentration field spanning a large range through the continuous release of chemical molecules. Even in a deep-sea environment with weak signals, underwater autonomous vehicles can still gradually approach the target by searching against the concentration gradient, breaking through the bottleneck of traditional acoustic technology in deep-sea search and rescue.

[0044] Furthermore, molecular communication, with its advantages of low power consumption, high stability, and strong environmental adaptability, effectively makes up for the shortcomings of acoustic communication in the search and rescue of wrecked ships, greatly extends the detectable time of wrecked ships, improves the positioning accuracy in complex environments, and ultimately significantly increases the probability of successful search and rescue. It has important practical value for the search and rescue of wrecked ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0046] Figure 1 Schematic diagram of the process of underwater search and positioning of a wrecked vessel in an embodiment of the present application;

[0047] Figure 2 This is an exemplary architecture of the underwater search and positioning method for a wrecked ship in an embodiment of the present application;

[0048] Figure 3 This is a principle block diagram of the underwater search and positioning device for a wrecked ship in an embodiment of the present application;

[0049] Figure 4 Schematic diagram of the structure of the computer device in the embodiment of the present application. DETAILED DESCRIPTION

[0050] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and are not to be construed as limiting the present application.

[0051] It will be understood by those skilled in the art that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, "connected" or "coupled" as used herein may include wireless connections or wireless couplings. The term "and / or" used herein includes all or any units and all combinations of one or more associated listed items.

[0052] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0053] It will be understood by those skilled in the art that the terms "client," "terminal," and "terminal device" as used herein include both devices that are wireless signal receivers, i.e., devices that only have wireless signal receivers without transmission capabilities, and devices that have receiving and transmitting hardware capable of two-way communication over a two-way communication link. Such devices may include: cellular or other communication devices such as personal computers and tablet computers, which have single-line displays, multi-line displays, or cellular or other communication devices without multi-line displays; PCS (Personal Communications Service), which may combine voice, data processing, fax, and / or data communication capabilities; PDA (Personal Digital Assistant), which may include a radio frequency receiver, a pager, Internet / Intranet access, a web browser, a notepad, a calendar, and / or a GPS (Global Positioning System) receiver; and conventional laptop and / or palmtop computers or other devices, which have and / or include a radio frequency receiver. As used herein, the terms "client," "terminal," or "terminal device" may be portable, transportable, or installed in a vehicle (air, sea, and / or land), or may be adapted and / or configured to operate locally and / or in a distributed manner at any other location on Earth and / or in space. As used herein, the terms "client," "terminal," or "terminal device" may also refer to a communication terminal, an Internet terminal, or a music / video playback terminal, such as a PDA, an MID (Mobile Internet Device), and / or a mobile phone with music / video playback capabilities, or may include a smart TV, a set-top box, or other device.

[0054] The hardware referred to by names such as "server", "client", and "service node" in this application is essentially an electronic device with capabilities equivalent to those of a personal computer. It is a hardware device that has the necessary components revealed by the von Neumann principle, such as a central processing unit (including an arithmetic unit and a controller), a memory, an input device, and an output device. Computer programs are stored in its memory, and the central processing unit loads the program stored in the external memory into the internal memory for execution, executes the instructions in the program, and interacts with the input and output devices to complete specific functions.

[0055] It should be noted that the concept of "server" referred to in this application can also be extended to server clusters. Based on the network deployment principles understood by those skilled in the art, the servers described should be logically divided. In physical space, these servers can be independent of each other but callable through interfaces, or integrated into a single physical computer or a computer cluster. Those skilled in the art should understand this flexibility and should not use it to constrain the implementation of the network deployment method of this application.

[0056] Unless expressly specified, one or more technical features of the present application can be deployed on a server for implementation and accessed by a client through a remote call to obtain an online service interface provided by the server, or can be directly deployed and run on a client for implementation.

[0057] Unless expressly specified otherwise, the neural network models referenced or may be referenced in this application may be deployed on a remote server and remotely called on the client, or may be deployed and directly called on a client with sufficient device capabilities. In some embodiments, when it runs on the client, its corresponding intelligence may be obtained through transfer learning to reduce the requirements for the client's hardware operating resources and avoid excessive occupation of the client's hardware operating resources.

[0058] Unless explicitly specified, the various data involved in this application can be stored remotely on a server or on a local terminal device, as long as they are suitable for being called by the technical solution of this application.

[0059] Those skilled in the art should be aware that although the various methods of this application are described based on the same concept and thus exhibit commonality, unless otherwise specified, these methods can be independently executed. Similarly, the various embodiments disclosed in this application are all based on the same inventive concept. Therefore, concepts with the same expression, as well as concepts that are appropriately transformed for convenience despite different expression, should be understood as equivalent.

[0060] Unless expressly stated to be mutually exclusive, the various embodiments disclosed in this application may be cross-combined with the relevant technical features of the various embodiments to flexibly construct new embodiments, as long as such combination does not deviate from the creative spirit of this application and can meet the needs of the prior art or resolve certain deficiencies in the prior art. Those skilled in the art should be aware of such flexibility.

[0061] See also Figure 1 and Figure 2 In one embodiment, the underwater search and positioning method for a wrecked ship of the present application includes:

[0062] Step S10: determining a chemical molecule concentration distribution field formed by chemical molecules released underwater by a wreck to be searched that is equipped with a chemical emitter, and calculating, based on a preset Fick's diffusion model, the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times, wherein the greater the distance between the position point and the wreck to be searched, the smaller the corresponding chemical molecule concentration;

[0063] The underwater search and positioning system for a wrecked vessel can simulate and determine the chemical molecule concentration distribution field formed by the release of chemical molecules underwater by a wrecked vessel equipped with a chemical emitter, and calculate and determine the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times based on a preset Fick diffusion model. The greater the distance between the position point and the wrecked vessel to be searched, the smaller the corresponding chemical molecule concentration.

[0064] In some embodiments, the chemical molecule concentration distribution field is formed by diffusion and convection in the underwater environment by specific chemical molecules continuously released by a wreck ship to be searched equipped with a chemical emitter at an unknown underwater location; the hit probability density represents the probability distribution of the chemical molecules released by the wreck ship to be searched at each position point within a preset spatial range at different times; the chemical molecule concentration represents the chemical molecule concentration received at different times by each position point within the preset spatial range at the chemical molecules released by the wreck ship to be searched.

[0065] In some embodiments, the step of calculating and determining the hit probability density and chemical molecule concentration of each position point in the chemical molecule concentration distribution field at different times within a preset spatial range according to a preset Fick diffusion model includes:

[0066] Step S101, obtaining the position coordinates, the first diffusion coefficient in the horizontal axis direction, the second diffusion coefficient in the vertical axis direction, and the third diffusion coefficient in the vertical axis direction of the chemical molecule within a preset spatial range in the chemical molecule concentration distribution field corresponding to the current position point;

[0067] Step S102: input the position point coordinates corresponding to the current position point, the first diffusion coefficient, the second diffusion coefficient, and the third diffusion coefficient into a preset Fick diffusion model to calculate and determine the hit probability density of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times.

[0068] In a further embodiment, the step of calculating and determining the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times according to a preset Fick diffusion model includes:

[0069] Step S1001, obtaining the position coordinates, the first diffusion coefficient in the horizontal axis direction, the second diffusion coefficient in the vertical axis direction, and the third diffusion coefficient in the vertical axis direction corresponding to the current position point of the chemical molecule in the chemical molecule concentration distribution field within a preset spatial range;

[0070] Step S1002: calculating and determining an equivalent diffusion coefficient of the chemical molecule based on the first diffusion coefficient, the second diffusion coefficient, and the third diffusion coefficient; and calculating and determining an equivalent molecular propagation distance of the chemical molecule based on the equivalent diffusion coefficient, the coordinates of the position point corresponding to the current position point, the first diffusion coefficient, the second diffusion coefficient, and the third diffusion coefficient;

[0071] Step S1003: input the equivalent diffusion coefficient and the equivalent molecular propagation distance into a preset molecular concentration calculation model to determine the chemical molecule concentration of each position point within a preset underwater space at different times.

[0072] Specifically, according to a preset Fick diffusion model, the hit probability density of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times is calculated and determined, wherein the calculation formula of the hit probability density is expressed as:

[0073]

[0074] Where (x, y, z) represents the coordinates of the chemical molecule at the current position; t represents the current time; D x represents the first diffusion coefficient in the horizontal direction (x direction); D y represents the second diffusion coefficient in the vertical direction (y direction); D z represents the third diffusion coefficient in the vertical axis direction; exp() represents the exponential function.

[0075] Furthermore, the chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times is calculated and determined according to a preset Fick diffusion model, wherein the calculation formula of the chemical molecule concentration is expressed as:

[0076]

[0077] Wherein, M is the molecular release intensity, which represents the total amount of chemical molecules released per unit time; the equivalent diffusion coefficient of the chemical molecule is calculated and determined according to the first diffusion coefficient, the second diffusion coefficient and the third diffusion coefficient, and D is the equivalent diffusion coefficient, which is calculated as follows: Comprehensively reflects the influence of diffusion coefficients in different directions;

[0078] The equivalent molecular propagation distance of the chemical molecule is calculated based on the equivalent diffusion coefficient, the coordinates of the position point corresponding to the current position point, the first diffusion coefficient, the second diffusion coefficient, and the third diffusion coefficient. R is the equivalent molecular propagation distance, and its calculation formula is expressed as follows: Used to measure the propagation of molecules in complex three-dimensional space; erfc() is the complementary error function, which is used to describe the concentration distribution attenuation characteristics after molecular diffusion.

[0079] Step S20: The underwater autonomous vehicle equipped with a high-precision molecular concentration sensor moves vertically downward to the bottom of the to-be-searched area to determine an initial search location point, randomly selects any search direction angle as a first search direction angle of the initial search location point, searches according to the first search direction angle and a preset first search step length to determine the first search location point, and adds a preset turning angle to the first search direction angle as a second search direction angle to continue searching to determine the second search location point;

[0080] Determine the chemical molecule concentration distribution field formed by the release of chemical molecules underwater by the wreck ship to be searched that is equipped with a chemical emitter, calculate and determine the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times based on a preset Fick's diffusion model, then an underwater autonomous vehicle equipped with a high-precision molecular concentration sensor moves vertically downward to the bottom of the area to be searched to determine an initial search position point, randomly selects any search direction angle as the first search direction angle of the initial search position point, searches according to the first search direction angle according to a preset first search step length to determine the first search position point, adds a preset turning angle to the first search direction angle as a second search direction angle to continue searching to determine the second search position point, wherein the preset turning angle can be 60°, etc.

[0081] Specifically, an underwater autonomous vehicle equipped with a high-precision molecular concentration sensor moves vertically downward to the bottom of the area to be searched, randomly selects a search starting point as an initial search position point, randomly selects any search direction angle from an initial direction angle set as a first search direction angle θ1 of the initial search position point, and determines a preset first search step size; wherein, the initial direction angle set can be θ∈{-120°,-60°,0°,60°,120°,180°};

[0082] Due to the lack of sufficient historical concentration data, a search is performed according to the first search direction angle according to a preset first search step to determine a first search position point, a preset turning angle is added to the first search direction angle as a second search direction angle to continue searching to determine a second search position point, and the search is continued based on the second search position point, wherein the second search direction angle θ2 is expressed as θ2=θ1+60 ° .

[0083] Step S30: The underwater autonomous vehicle determines the third search direction angle based on the chemical molecule concentration difference between the second search location point and the first search location point and the second search direction angle, continues searching at the second search location point according to the third search direction angle and a preset first search step size, and updates the second search location point according to the third search direction angle based on a preset position calculation formula to determine a third search location point;

[0084] An underwater autonomous vehicle equipped with a high-precision molecular concentration sensor moves vertically downward to the bottom of the area to be searched to determine an initial search position point, randomly selects any search direction angle as the first search direction angle of the initial search position point, searches according to the first search direction angle according to a preset first search step to determine the first search position point, adds a preset turning angle to the first search direction angle as a second search direction angle to continue searching to determine the second search position point, then the underwater autonomous vehicle determines the third search direction angle according to the chemical molecule concentration difference between the second search position point and the first search position point and the second search direction angle, continues searching at the second search position point according to the third search direction angle and the preset first search step, and updates the second search position point according to the third search direction angle based on a preset position calculation formula to determine the third search position point.

[0085] In a specific embodiment, the step of the underwater autonomous vehicle determining the third search direction angle according to the chemical molecule concentration difference between the second search position point and the first search position point and the second search direction angle includes:

[0086] Step S301: Determine a first chemical molecule concentration corresponding to the first search location and a second chemical molecule concentration corresponding to the second search location based on detection by a high-precision molecule concentration sensor of the underwater autonomous vehicle, and determine a chemical molecule concentration difference between the second search location and the first search location based on a difference between the second chemical molecule concentration and the first chemical molecule concentration;

[0087] Step S302: If it is detected that the chemical molecule concentration difference is greater than zero and the second search direction angle is clockwise, or if it is detected that the chemical molecule concentration difference is less than or equal to zero and the second search direction angle is counterclockwise, the sum of the second search direction angle and the preset turning angle is used as the third search direction angle;

[0088] Step S303: In other cases, the difference between the second search direction angle and the preset turning angle is used as the third search direction angle.

[0089] Specifically, the chemical molecule concentration difference between the current search position point and the previous search position point of the underwater autonomous vehicle is calculated and determined, wherein the calculation formula of the chemical molecule concentration difference between the current search position point and the previous search position point of the underwater autonomous vehicle is expressed as:

[0090] ΔC=C n-1 -C n-2 ,

[0091] Among them, C n-1 represents the concentration of chemical molecules at the current search location of the underwater autonomous vehicle; C n-2 represents the chemical molecule concentration at the last search position of the underwater autonomous vehicle; ΔC represents the difference in chemical molecule concentration between the current search position of the underwater autonomous vehicle and the last search position.

[0092] Furthermore, the subsequent moving direction of the underwater autonomous vehicle is determined based on the difference in chemical molecule concentration between the current search position point and the previous search position point of the underwater autonomous vehicle, as well as the previous turning direction of the underwater autonomous vehicle, and the expression is:

[0093]

[0094] Among them, θ nIndicates the search direction angle of the current search position; prev_turn indicates the turn of the underwater autonomous vehicle at the previous search position n-1, where "-" indicates that the turn of the underwater autonomous vehicle at the previous search position n-1 is clockwise; "+" indicates that the turn of the underwater autonomous vehicle at the previous search position n-1 is counterclockwise; this stage ends when the underwater autonomous vehicle finds the wrecked ship or falls into the zero gradient concentration area.

[0095] In a further embodiment, the step of updating the second search position point according to the third search direction angle based on a preset position calculation formula to determine the third search position point includes:

[0096] Step S3001: Obtain the position coordinates corresponding to the second search position point, the third search direction angle, and the preset first search step length;

[0097] Step S3002: Calculate and determine the first product between the preset first search step and the displacement components in each direction of the third search direction angle, and determine the third search position point based on the first sum of the first product and the position coordinates corresponding to the second search position point, wherein the displacement components in each direction include the displacement component in the horizontal axis direction, the displacement component in the vertical axis direction, and the displacement component in the vertical axis direction, the displacement component in the horizontal axis direction is the cosine value of the third search direction angle, the displacement component in the vertical axis direction is the sine value of the third search direction angle, and the displacement component in the vertical axis direction is zero.

[0098] The preset position calculation formula is expressed as:

[0099]

[0100] Among them, P current represents the position coordinates corresponding to the current search position of the underwater autonomous vehicle; P new represents the position coordinates of the next search position point corresponding to the current search position point of the underwater autonomous vehicle; the corresponding position coordinates; cos(θ n ) is the cosine value of the search direction angle of the current search position point, which represents the displacement component in the horizontal axis direction; sin(θ n ) represents the sine value of the search direction angle of the current search position point, which represents the displacement component in the longitudinal direction; the displacement component in the vertical direction is zero; l represents the search step length, which can be 50 meters or 100 meters, etc. Those skilled in the art can determine the value of the search step length as needed according to the actual business scenario, and no limitation is made here.

[0101] Step S40: The underwater autonomous vehicle updates the third search position point based on the position calculation formula until the difference between the chemical molecule concentration detected by the underwater autonomous vehicle at the current search position point and the chemical molecule concentration at a certain position point within the preset spatial range in the chemical molecule concentration distribution field is less than a preset concentration threshold, and then determines that the underwater autonomous vehicle has approached the wreck to be searched, thereby completing the search and positioning of the underwater wreck.

[0102] The underwater autonomous vehicle determines the third search direction angle based on the chemical molecule concentration difference between the second search position point and the first search position point and the second search direction angle, continues searching at the second search position point according to the third search direction angle and the preset first search step, and updates the second search position point according to the third search direction angle based on a preset position calculation formula to determine the third search position point. The underwater autonomous vehicle updates the third search position point based on the position calculation formula until the difference between the chemical molecule concentration detected by the underwater autonomous vehicle at the current search position point and the chemical molecule concentration at a certain position point within a preset spatial range in the chemical molecule concentration distribution field is less than a preset concentration threshold, then it is determined that the underwater autonomous vehicle has approached the wreck to be searched, so as to complete the search and positioning of the underwater wreck. The preset concentration threshold can be determined as needed by those skilled in the art and is not limited here.

[0103] In some embodiments, after the step of updating the third search location point based on the position calculation formula, the underwater autonomous vehicle includes:

[0104] Step S401: If the chemical molecule concentration difference between a certain search position point of the underwater autonomous vehicle and a previous search position point is zero, driving the underwater autonomous vehicle to escape from the zero gradient concentration state;

[0105] Step S402: If the search position point is located at the bottom of the water, the underwater autonomous vehicle is driven to move upward to a preset height; otherwise, the underwater autonomous vehicle is driven to move downward to the preset height. At the same time, the first search step is updated to a preset multiple of the first search step to determine a second search step, and the search for the underwater wrecked ship is continued according to the second search step until the underwater autonomous vehicle escapes from the zero gradient concentration state, wherein the preset height includes 50 meters or 100 meters, the second search step is not less than a preset search step threshold, and the zero gradient concentration state indicates that the difference in chemical molecule concentration between the current search position point and the previous search position point is zero.

[0106] Specifically, once the concentration difference between the current position and the previous position is detected to be zero, the zero gradient concentration state is immediately escaped. Depending on whether the autonomous vehicle is currently at the bottom of the water, it moves in the opposite vertical direction to a preset height h. For example, if it is at the bottom of the water (and cannot continue to move downward), it moves upward by 50 meters or 100 meters;

[0107] If it is not at the bottom of the water, move down 50 or 100 meters. The purpose of this operation is to change the water depth, leaving the current flat area with uniform concentration and try to enter a new space with a concentration gradient.

[0108] The second search step length is determined by updating the original first search step length to a first search step length of a preset multiple α, and the second search step length is limited to not less than a preset search step length threshold τ to avoid inefficient search due to a too small step length. For example, the preset multiple can be 3 or 5 times, and the preset search step length threshold τ can be 30 meters or 50 meters. Those skilled in the art can determine the preset multiple and the preset search step length threshold as needed based on actual needs, and no limitation is made here.

[0109] After completing the vertical movement and step size adjustment, the autonomous vehicle continues to search according to the original inverse concentration gradient search logic with the new step size until it detects that the concentration difference is not zero, that is, it escapes the zero gradient state and resumes the normal inverse concentration gradient tracking mode; until the difference between the chemical molecule concentration detected by the underwater autonomous vehicle at the current search position and the chemical molecule concentration at a certain position point within the preset spatial range in the chemical molecule concentration distribution field is less than the preset concentration threshold, it is determined that it has approached the wreck to be searched, so as to complete the search and positioning of the underwater wreck.

[0110] Compared with the existing technology, this application addresses the problems in the existing technology that traditional acoustic communication relies on active transmission of sound wave signals, which has high energy consumption. Once the power is insufficient, the signal will be interrupted, resulting in a shortened search window, and the sound waves are easily affected by energy attenuation and multipath propagation, resulting in large positioning errors or even signal loss. This application includes but is not limited to the following beneficial effects:

[0111] First, in molecular communication, chemical transmitters installed on wrecked ships can be designed with low power consumption. Even in low-power situations, they can still release molecules for a long time, forming a stable concentration distribution field. This means that wrecked ships can still be found by underwater autonomous vehicles by tracking molecular concentration gradients for days or even weeks after sinking, significantly extending the time it can be detected and improving the chances of search and rescue.

[0112] Second, molecular communication relies on the diffusion and convection of chemical molecules to form concentration gradients, and its propagation patterns are more closely aligned with the physical properties of the underwater environment: while the molecular concentration field slowly diffuses over time, its overall distribution is relatively stable (and predictably affected by water currents), and the concentration gradient, characterized by its "higher near, lower far" characteristic (the closer to the wreck, the higher the concentration), has a clear directionality. AUVs use high-precision sensors to capture these gradient variations, enabling stable tracking even in complex environments, reducing search failures caused by signal interference and improving the reliability of locating the wrecked vessel.

[0113] Third, traditional acoustic positioning requires that the acoustic transmitter of the wrecked ship remain intact (such as the antenna, power supply, and signal processing module are working properly), otherwise no signal can be transmitted. However, the wrecked ship may suffer a violent collision during the sinking process, causing damage to the acoustic equipment and directly losing the ability to be detected. The core of molecular communication is "chemical molecule release", and its transmitter structure can be designed to be simpler and stronger, such as a sealed chemical storage tank, which releases molecules through passive penetration or simple mechanical structures, and has low dependence on equipment integrity. Even if the ship is damaged, as long as the chemical transmitter is not completely destroyed, it can continue to release molecules, providing a signal source for the search and increasing the possibility of the wrecked ship being discovered.

[0114] Fourthly, if a wrecked ship sinks in the deep sea, molecular communication can form a concentration field spanning a large range through the continuous release of chemical molecules. Even in a deep-sea environment with weak signals, underwater autonomous vehicles can still gradually approach the target by searching against the concentration gradient, breaking through the bottleneck of traditional acoustic technology in deep-sea search and rescue.

[0115] Furthermore, molecular communication, with its advantages of low power consumption, high stability, and strong environmental adaptability, effectively makes up for the shortcomings of acoustic communication in the search and rescue of wrecked ships, greatly extends the detectable time of wrecked ships, improves the positioning accuracy in complex environments, and ultimately significantly increases the probability of successful search and rescue. It has important practical value for the search and rescue of wrecked ships.

[0116] See also Figure 3, an underwater search and positioning device for a wrecked ship provided to meet one of the purposes of the present application, includes a molecular concentration calculation module 1100, a second search point determination module 1200, a third search point determination module 1300, and a search position point update module 1400. The molecular concentration calculation module 1100 is configured to determine a chemical molecule concentration distribution field formed by the release of chemical molecules underwater by a wrecked ship to be searched that is equipped with a chemical emitter, and to calculate the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times according to a preset Fick diffusion model, wherein the greater the distance between the position point and the wrecked ship to be searched, the smaller the corresponding chemical molecule concentration; the second search point determination module 1200 is configured to move an underwater autonomous vehicle equipped with a high-precision molecular concentration sensor vertically downward to the bottom of the area to be searched to determine an initial search position point, and randomly select any search direction angle as the first search position point of the initial search position point. a search direction angle, searching according to the first search direction angle and a preset first search step length to determine a first search location point, adding a preset turning angle to the first search direction angle as a second search direction angle to continue searching to determine a second search location point; a third search point determination module 1300, configured such that the underwater autonomous vehicle determines the third search direction angle based on the chemical molecule concentration difference between the second search location point and the first search location point and the second search direction angle, continues searching at the second search location point according to the third search direction angle and the preset first search step length, and updates the second search location point according to the third search direction angle based on a preset position calculation formula to determine a third search location point;

[0117] The search position point update module 1400 is configured to cause the underwater autonomous vehicle to update the third search position point based on the position calculation formula until the difference between the chemical molecule concentration detected by the underwater autonomous vehicle at the current search position point and the chemical molecule concentration at a certain position point within a preset spatial range in the chemical molecule concentration distribution field is less than a preset concentration threshold, and then it is determined that the underwater autonomous vehicle has approached the wreck to be searched, so as to complete the search and positioning of the underwater wreck.

[0118] Based on any embodiment of this application, please refer to Figure 4 Another embodiment of the present application further provides an electronic device, which can be implemented by a computer device, such as Figure 4As shown, a schematic diagram of the internal structure of a computer device. The computer device includes a processor, a computer-readable storage medium, a memory, and a network interface connected via a system bus. Among them, the computer-readable storage medium of the computer device stores an operating system, a database, and computer-readable instructions, and the database may store a control information sequence, and when the computer-readable instructions are executed by the processor, the processor may implement a method for underwater search and positioning of a wrecked ship. The processor of the computer device is used to provide computing and control capabilities to support the operation of the entire computer device. The memory of the computer device may store computer-readable instructions, and when the computer-readable instructions are executed by the processor, the processor may execute the method for underwater search and positioning of a wrecked ship of the present application. The network interface of the computer device is used to connect and communicate with a terminal. Those skilled in the art will understand that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0119] In this embodiment, the processor is used to execute Figure 3 The memory stores the program code and various data required to execute the specific functions of each module in the device. The network interface is used to transmit data between user terminals or servers. The memory in this embodiment stores the program code and data required to execute all modules in the underwater search and location device for a wrecked vessel of this application. The server can call the server's program code and data to execute the functions of all modules.

[0120] The present application also provides a storage medium storing computer-readable instructions. When the computer-readable instructions are executed by one or more processors, the one or more processors execute the steps of the underwater search and positioning method for a wrecked ship described in any embodiment of the present application.

[0121] The present application also provides a computer program product, including a computer program / instruction, which, when executed by one or more processors, implements the steps of the underwater search and positioning method for a wrecked ship described in any embodiment of the present application.

[0122] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments of the present application can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiments of the method. The aforementioned storage medium can be a computer-readable storage medium such as a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0123] The above description is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for underwater search and positioning of a wrecked ship, characterized in that: include: Determine a chemical molecule concentration distribution field formed by chemical molecules released underwater by a wreck to be searched that is equipped with a chemical emitter, and calculate, based on a preset Fick's diffusion model, the hit probability density and chemical molecule concentration of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times, wherein the greater the distance between the position point and the wreck to be searched, the smaller the corresponding chemical molecule concentration; An underwater autonomous vehicle equipped with a high-precision molecular concentration sensor moves vertically downward to the bottom of the to-be-searched area to determine an initial search location point, randomly selects any search direction angle as a first search direction angle of the initial search location point, searches according to the first search direction angle at a preset first search step length to determine the first search location point, and adds a preset turning angle to the first search direction angle as a second search direction angle to continue searching to determine the second search location point; The underwater autonomous vehicle determines the third search direction angle based on the chemical molecule concentration difference between the second search location point and the first search location point and the second search direction angle, continues searching at the second search location point according to the third search direction angle and a preset first search step size, and updates the second search location point according to the third search direction angle based on a preset position calculation formula to determine a third search location point; The underwater autonomous vehicle updates the third search position point based on the position calculation formula until the difference between the chemical molecule concentration detected by the underwater autonomous vehicle at the current search position point and the chemical molecule concentration at a certain position point within a preset spatial range in the chemical molecule concentration distribution field is less than a preset concentration threshold, and then determines that it has approached the wreck to be searched, thereby completing the search and positioning of the underwater wreck.

2. The underwater search and positioning method for a wrecked ship according to claim 1, characterized in that: The step of calculating and determining the hit probability density and chemical molecule concentration of each position point in the chemical molecule concentration distribution field at different times within a preset spatial range according to a preset Fick diffusion model includes: Obtaining the position coordinates, the first diffusion coefficient in the horizontal axis direction, the second diffusion coefficient in the vertical axis direction, and the third diffusion coefficient in the vertical axis direction of the chemical molecule within a preset spatial range in the chemical molecule concentration distribution field corresponding to the current position point; The position point coordinates corresponding to the current position point, the first diffusion coefficient, the second diffusion coefficient and the third diffusion coefficient are input into a preset Fick diffusion model to calculate and determine the hit probability density of the chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times.

3. The underwater search and positioning method for a wrecked ship according to claim 2, characterized in that: The step of calculating and determining the hit probability density and chemical molecule concentration of each position point in the chemical molecule concentration distribution field at different times within a preset spatial range according to a preset Fick diffusion model includes: Obtaining the position coordinates, the first diffusion coefficient in the horizontal axis direction, the second diffusion coefficient in the vertical axis direction, and the third diffusion coefficient in the vertical axis direction corresponding to the current position point of the chemical molecule in the chemical molecule concentration distribution field within a preset spatial range; calculating and determining an equivalent diffusion coefficient of the chemical molecule according to the first diffusion coefficient, the second diffusion coefficient, and the third diffusion coefficient, and calculating and determining an equivalent molecular propagation distance of the chemical molecule according to the equivalent diffusion coefficient, the coordinates of the position point corresponding to the current position point, the first diffusion coefficient, the second diffusion coefficient, and the third diffusion coefficient; The equivalent diffusion coefficient and the equivalent molecular propagation distance are input into a preset molecular concentration calculation model to determine the chemical molecule concentration of each position point within a preset underwater space at different times.

4. The underwater search and positioning method for a wrecked ship according to claim 1, characterized in that: The step of determining, by the underwater autonomous vehicle, the third search direction angle according to the chemical molecule concentration difference between the second search position point and the first search position point and the second search direction angle includes: Determining a first chemical molecule concentration corresponding to the first search location and a second chemical molecule concentration corresponding to the second search location based on detection by a high-precision molecule concentration sensor of the underwater autonomous vehicle, and determining a chemical molecule concentration difference between the second search location and the first search location based on a difference between the second chemical molecule concentration and the first chemical molecule concentration; If it is detected that the chemical molecule concentration difference is greater than zero and the second search direction angle is clockwise, or if it is detected that the chemical molecule concentration difference is less than or equal to zero and the second search direction angle is counterclockwise, the sum of the second search direction angle and the preset turning angle is used as the third search direction angle; In other cases, the difference between the second search direction angle and the preset turning angle is used as the third search direction angle.

5. The underwater search and positioning method for a wrecked ship according to claim 1, characterized in that: The step of updating the second search position point according to the third search direction angle based on a preset position calculation formula to determine a third search position point includes: Obtaining the position coordinates corresponding to the second search position point, the third search direction angle, and the preset first search step size; Calculate and determine the first product between the preset first search step and the displacement components in various directions of the third search direction angle, and determine the third search position point based on the first sum of the first product and the position coordinates corresponding to the second search position point, wherein the displacement components in various directions include the displacement component in the horizontal axis direction, the displacement component in the vertical axis direction, and the displacement component in the vertical axis direction, the displacement component in the horizontal axis direction is the cosine value of the third search direction angle, the displacement component in the vertical axis direction is the sine value of the third search direction angle, and the displacement component in the vertical axis direction is zero.

6. The underwater search and positioning method for a wrecked ship according to claim 1, characterized in that: After the step of updating the third search position point based on the position calculation formula, the method further includes: If the difference in chemical molecule concentration between a certain search position point of the underwater autonomous vehicle and a previous search position point is zero, driving the underwater autonomous vehicle to escape from the zero gradient concentration state; If the search position point is located at the bottom of the water, it drives the underwater autonomous vehicle to move upward to a preset height; otherwise, it drives the underwater autonomous vehicle to move downward to the preset height. At the same time, the first search step is updated to a preset multiple of the first search step to determine the second search step, and the search for the underwater wrecked ship is continued according to the second search step until the underwater autonomous vehicle escapes from the zero gradient concentration state, wherein the preset height includes 50 meters or 100 meters, the second search step is not less than the preset search step threshold, and the zero gradient concentration state indicates that the difference in chemical molecule concentration between the current search position point and the previous search position point is zero.

7. The underwater search and positioning method for a wrecked ship according to any one of claims 1 to 6, characterized in that: The chemical molecule concentration distribution field is formed by the specific chemical molecules continuously released by the wrecked vessel to be searched at an unknown underwater location and is formed by diffusion and convection in the underwater environment; The hit probability density represents the probability distribution of chemical molecules released by the wrecked ship to be searched at each location within a preset spatial range at different times; The chemical molecule concentration represents the chemical molecule concentration received at different times at each position point within a preset spatial range of the chemical molecules released by the wreck to be searched.

8. An underwater search and positioning device for a wrecked ship, characterized in that: include: a molecular concentration calculation module configured to determine a chemical molecule concentration distribution field formed by chemical molecules released underwater by a wreck to be searched that is equipped with a chemical emitter, and to calculate, based on a preset Fick diffusion model, a hit probability density and a chemical molecule concentration of chemical molecules in the chemical molecule concentration distribution field at each position point within a preset spatial range at different times, wherein the greater the distance between the position point and the wreck to be searched, the smaller the corresponding chemical molecule concentration; a second search point determination module, configured to include an underwater autonomous vehicle equipped with a high-precision molecular concentration sensor moving vertically downward to the bottom of the to-be-searched area to determine an initial search position point, randomly selecting any search direction angle as a first search direction angle of the initial search position point, searching according to the first search direction angle and a preset first search step length to determine the first search position point, and adding a preset turning angle to the first search direction angle as a second search direction angle to continue searching to determine the second search position point; a third search point determination module, configured for the underwater autonomous vehicle to determine a third search direction angle based on a chemical molecule concentration difference between the second search position point and the first search position point and the second search direction angle, continue searching at the second search position point according to the third search direction angle and a preset first search step size, and update the second search position point according to the third search direction angle based on a preset position calculation formula to determine a third search position point; The search position point updating module is configured so that the underwater autonomous vehicle updates the third search position point based on the position calculation formula until the difference between the chemical molecule concentration detected by the underwater autonomous vehicle at the current search position point and the chemical molecule concentration at a certain position point within a preset spatial range in the chemical molecule concentration distribution field is less than a preset concentration threshold, and then it is determined that the underwater autonomous vehicle has approached the wreck to be searched, so as to complete the search and positioning of the underwater wreck.

9. An electronic device comprising a central processing unit and a memory, characterized in that: The central processing unit is configured to call and run a computer program stored in the memory to execute the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that It stores a computer program implemented according to the method described in any one of claims 1 to 7 in the form of computer-readable instructions, and when the computer program is called and executed by a computer, the steps included in the corresponding method are executed.

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