Underwater vehicle terrain scanning process simulation method and system, and medium

Abstract

The application provides an underwater vehicle terrain scanning process simulation method, system and medium, and the method comprises the following steps: constructing a multi-beam sonar model; constructing an underwater three-dimensional terrain, and determining a navigation scheme of the underwater vehicle; applying the multi-beam sonar model to the navigation scheme to perform imaging operation, and obtaining an underwater vehicle terrain scanning process model; adding multi-source interference to a terrain scanning result of the underwater vehicle terrain scanning process model to generate a comprehensive simulation image; and visualizing a scanning progress of the underwater vehicle terrain scanning process model, and synchronously outputting the scanning result in the scanning progress; the method can simulate an actual process, provide an experimental platform, reduce experimental cost, provide a guidance scheme and verification for actual detection work, improve work efficiency, and the comprehensive simulation image after adding the multi-source interference has a very realistic effect, can provide data support for an image processing algorithm, and can be widely applied to the technical fields of underwater sensing and computer image processing.

Description

Technical Field

[0001] This invention relates to the fields of underwater sensing and computer image processing technology, and in particular to simulation methods, systems and media for underwater vehicle terrain surveying processes. Background Technology

[0002] As one of the main tools for underwater activities, underwater vehicles can be used in civilian applications such as marine mineral exploration, seabed topography surveying, shipwreck salvage, underwater archaeology, and marine biological detection. In the military, they can be used for mine countermeasures, as carriers of self-propelled mines, and for monitoring underwater enemy situations during naval battles, playing a vital role in underwater activities.

[0003] Underwater visual perception technology, as a fundamental component of underwater vehicle research, provides humans with suitable observation channels and is therefore one of the most important aspects of marine technology. Underwater visual perception technology mainly includes optical visual perception technology and acoustic visual perception technology. Optical images acquired using optical visual perception technology can cover rich color information and subtle geometric details within the observation area; however, due to the limited propagation distance of light in the underwater environment, the visibility of optical visual perception is extremely poor, severely limiting the perception range. Compared to optical perception technology, acoustic perception technology uses sound waves with lower absorption rates and longer propagation distances underwater, therefore, acoustic perception technology is currently the primary method used in underwater detection. Sonar is an important detection and perception tool in autonomous underwater vehicles and unmanned vessels. Multibeam sonar, as one of the most commonly used sonar devices, not only has a large measurement range and high speed but also high accuracy and detection efficiency, capable of detecting the shape, size, and elevation changes of hundreds of underwater targets.

[0004] Due to the high cost and long operating cycle of underwater vehicles and sonar equipment, simulation research related to them has developed rapidly in recent years. However, the following problems still exist: Most current underwater sensing simulation methods are limited to sonar models, but they lack consideration for factors such as underwater terrain, vehicle detection schemes, and changes in sonar perspective during actual underwater activities. At the same time, due to the complex and variable underwater environment, the results of sonar sensing are often subject to severe interference, but current simulation methods do not take this into account. As a result, although the obtained sonar images can reflect the characteristics of underwater targets, they are far from real sonar images due to the lack of noise and interference measurements. Summary of the Invention

[0005] In view of this, in order to at least partially solve one of the above-mentioned technical problems or defects, the purpose of this invention is to provide a simulation method for the overall process of underwater exploration activities that can generate realistic sonar images; the technical solution of this application also provides the system and medium corresponding to the method.

[0006] On the one hand, the technical solution of this application provides a simulation method for the terrain surveying process of underwater vehicles, including the following steps:

[0007] Construct a multibeam sonar model;

[0008] Construct an underwater three-dimensional terrain, determine the navigation scheme of the underwater vehicle based on the underwater three-dimensional terrain, apply the multibeam sonar model to the navigation scheme to perform imaging operations, and obtain the underwater vehicle terrain scanning process model.

[0009] Multi-source interference is added to the terrain survey results of the underwater vehicle terrain survey process model to generate a comprehensive simulation image;

[0010] The scanning progress of the underwater vehicle terrain scanning process model is visualized, and the scanning results are output synchronously based on the integrated simulation image in the scanning progress.

[0011] In one feasible embodiment of the present application, the construction of the multibeam sonar model includes:

[0012] By simplifying the sonar detection field of view by replacing the actual three-dimensional field of view with a two-dimensional planar field of view, a simplified sonar detection field of view coordinate system is obtained.

[0013] Within the sonar detection field of view coordinate system, the sonar beam is simulated using a ray tracing method to collect the target point location information within the detection range;

[0014] The collected target point location information is summarized, and a sonar image is drawn based on the summary results to construct the multibeam sonar model.

[0015] In one feasible embodiment of the present application, the step of simulating the sonar beam using a ray tracing method within the sonar detection field of view coordinate system to acquire target point location information within the detection range includes:

[0016] Starting from the origin of the sonar detection field of view coordinate system, draw equally spaced rays within the acquisition and detection range;

[0017] Determine the target point that is closest to each of the equally spaced rays;

[0018] Calculate the first angle between the equally spaced rays and the reference direction, calculate the relative distance between the target point and the origin, and determine the position information of the target point based on the first angle and the relative distance.

[0019] In one feasible embodiment of the present application, the step of summarizing the acquired target point location information, drawing a sonar image based on the summarization result, and constructing the multibeam sonar model includes:

[0020] The target point position information is adjusted according to the target image size, and the adjusted target point position information is then transformed in the coordinate system.

[0021] The transformed target point location information is drawn as bright spots in the background image;

[0022] The sonar image is generated based on the drawn background image. In the sonar image, the target outline is a bright spot, and the area with no information is a dark spot.

[0023] In one feasible embodiment of the present application, the steps of constructing underwater three-dimensional terrain, determining the navigation plan of the underwater vehicle based on the underwater three-dimensional terrain, and applying the multibeam sonar model to the navigation plan for imaging operations to obtain an underwater vehicle terrain scanning process model include:

[0024] The navigation trajectory of the underwater vehicle is determined within the underwater three-dimensional terrain.

[0025] The sonar angle and the location of the scanning point are determined. Based on the sonar angle and the location of the scanning point, the multi-beam sonar model is used to perform a free-view scanning based on the navigation trajectory. Imaging operation is performed based on the scanning results.

[0026] In one feasible embodiment of the present application, adding multi-source interference to the terrain survey results of the underwater vehicle terrain survey process model to generate a comprehensive simulation image includes:

[0027] The modeling process yields structured noise and target outline ghosting in the sonar image.

[0028] The sonar image structured noise and the target contour ghosting model are added to the terrain survey results of the underwater vehicle terrain survey process model to generate the comprehensive simulation image with multi-source interference.

[0029] In one feasible embodiment of the present application, the modeling to obtain structured noise and target contour ghosting in the sonar image includes:

[0030] The real multibeam sonar background image is segmented, and the gray value distribution frequency of the pixels is statistically analyzed in columns.

[0031] The model parameters are determined by fitting the pixel grayscale distribution frequency using a Gaussian mixture model, and then a single-column structured noise grayscale distribution model is determined based on the model parameters.

[0032] The single-column structured noise grayscale distribution model is used to process all columns in the single-beam structured noise to obtain the overall grayscale distribution model of the single-beam structured noise. The sonar image structured noise is then determined based on the overall grayscale distribution model.

[0033] In one feasible embodiment of the present application, the formula for calculating the structured noise of the sonar image is as follows:

[0034]

[0035] Where f(x) represents the image structured noise, K represents the number of peaks in the Gaussian mixture model, and w k σ represents the weight of the k-th Gaussian function. k Let μ represent the variance of the k-th Gaussian function. k Let g(x|μ) represent the mean of the k-th Gaussian function. k ,σ k ) represents the Gaussian function;

[0036] The formula for calculating the ghosting of the target contour is as follows:

[0037] g ij =g0λ -2 (d-λ) 2

[0038] Where d represents the distance between the point and the target contour, g0 represents the gray value of the target contour, and λ represents the ghost width parameter.

[0039] On the other hand, the technical solution of this application also provides a simulation system for the terrain surveying process of underwater vehicles, which includes:

[0040] Sonar modeling unit, used to build multibeam sonar models;

[0041] The free scanning unit is used to construct underwater three-dimensional terrain, determine the navigation scheme of the underwater vehicle based on the underwater three-dimensional terrain, apply the multibeam sonar model to the navigation scheme to perform imaging operations, and obtain the underwater vehicle terrain scanning process model.

[0042] The multi-source interference unit is used to add multi-source interference to the terrain survey results of the underwater vehicle terrain survey process model to generate a comprehensive simulation image.

[0043] The simulation output unit is used to visualize the scanning progress of the underwater vehicle terrain scanning process model and output the scanning results synchronously based on the comprehensive simulation image in the scanning progress.

[0044] On the other hand, the present application also provides a storage medium storing a processor-executable program, which, when executed by a processor, is used to perform the underwater vehicle terrain survey simulation method as described in any one of the first aspects.

[0045] The advantages and beneficial effects of the present invention will be set forth in part in the following description, and the rest will become apparent from the specific embodiments thereof:

[0046] The underwater vehicle terrain scanning simulation method provided in this application can establish a multi-beam sonar simulation model based on ray tracing, construct a three-dimensional underwater scene, formulate a vehicle navigation plan, and enable the underwater vehicle carrying the sonar model to perform free-viewpoint scanning of the underwater terrain in the underwater scene according to a predetermined trajectory. By adding multi-source interference to the sonar image generated by the terrain scanning, a comprehensive simulation image is formed. The terrain scanning process simulation method proposed in this invention can simulate the actual process, provide an experimental platform for related research, reduce experimental costs, and at the same time, the pre-simulation can provide guidance and verification for actual detection work, improve work efficiency. In addition, the comprehensive simulation image after adding multi-source interference has a very realistic effect and can provide data support for image processing algorithms. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating the steps of the underwater vehicle terrain surveying simulation method provided in the technical solution of this application.

[0049] Figure 2 This is a flowchart illustrating the simulation method for the specific underwater vehicle terrain surveying process in the technical solution of this application. Detailed Implementation

[0050] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0051] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0053] In view of the shortcomings of the prior art pointed out in the background technical solution, the technical solution of this application establishes a multi-beam sonar model and applies it to the underwater vehicle terrain scanning process. Then, multi-source interference is added to the scanning results to form an assembly simulation image. This can realize the simulation of the entire underwater vehicle terrain scanning process, fill the gap in the current terrain scanning process simulation method, and generate a simulated sonar image with higher similarity to the real sonar image, thus solving the problem of poor simulation image realism.

[0054] Refer to the instruction manual. Figure 1 The simulation method for underwater vehicle terrain surveying provided in the embodiments of the technical solution of this application is described in detail. The method may include steps S01-S04:

[0055] S01. Construct a multibeam sonar model;

[0056] Specifically, in this embodiment, during one working cycle, the multibeam sonar emits multiple sound waves in a three-dimensional fan-shaped space in front of its beam transceiver array. These sound waves are reflected by a target object and captured by the array. The target object's position is determined based on the beam direction and the time difference between transmission and reception. After data processing, a sonar image is generated. Based on the above working principle of the multibeam sonar, a multibeam sonar model is established in simulation software. In some feasible implementations, the specific modeling process of the multibeam sonar model may include steps S011-S013:

[0057] S011. The sonar detection field of view is simplified by replacing the actual three-dimensional field of view with a two-dimensional planar field of view, resulting in a simplified sonar detection field of view coordinate system.

[0058] Specifically, in this embodiment, to improve computational efficiency, the three-dimensional sonar field of view is replaced by a two-dimensional plane. In three-dimensional space, a Cartesian coordinate system is established with the sonar array as the origin and the sonar center beam as the positive vertical axis. For example... Figure 2As shown, the coordinate system plane is the plane containing the sonar field of view, where the sonar field of view is a circle with the origin as the center, an included angle of α, and a radius of R. max A sector symmetrical about the vertical axis of the coordinate system.

[0059] S012. Within the sonar detection field of view coordinate system, the sonar beam is simulated using a ray tracing method to collect the target point location information within the detection range.

[0060] Specifically, in this embodiment, ray tracing technology is used to simulate the formation, propagation, reflection, and reception process of sonar beams. Starting from the sonar array, equally spaced rays are drawn within the field of view. Each ray searches for the nearest target point in the target point cloud and acquires the direction data of the current ray and the distance data between the target point and the origin. In some feasible implementations, the process of acquiring target point location information within the detection range may include steps S0121-S0123:

[0061] S0121. Starting from the origin of the sonar detection field coordinate system, draw equally spaced rays within the acquisition and detection range;

[0062] S0122. Determine the target point that is closest to each of the equally spaced rays;

[0063] S0123. Calculate the first angle between the equally spaced rays and the reference direction, calculate the relative distance between the target point and the origin, and determine the target point position information based on the first angle and the relative distance.

[0064] Specifically, in this embodiment, equally spaced rays are drawn within the viewport, starting from the origin of the viewport coordinate system. Then, the nearest target point to each ray is sequentially found. The angle θ between the current ray direction and the reference direction, and the relative distance d between the point and the origin, are calculated as the position data of the target point. In this embodiment, the ray direction is represented by the angle θ between the ray and the reference direction, and the expression for θ is:

[0065]

[0066] Where i is the ray number and N is the total number of rays, which is 512 in the example.

[0067] S013. Summarize the collected target point location information, draw a sonar image based on the summarization result and construct the multibeam sonar model.

[0068] Specifically, in this embodiment, after calculating and summarizing the target point information, a sonar image is drawn. Since sonar images typically have two types: polar coordinates and standard coordinates, both representing the same detected target but with different presentations, two types of sonar images are drawn according to different needs. In some feasible implementations, the process of drawing a sonar image may include steps S0131-S0133:

[0069] S0131. Adjust the target point position information according to the target image size, and transform the adjusted target point position information into a coordinate system;

[0070] S0132. The transformed target point position information is drawn as a highlight in the background image;

[0071] S0133. Generate the sonar image based on the drawn background image. In the sonar image, the target outline is a bright spot, and the position with no information is a dark spot.

[0072] Specifically, in this embodiment, the target point is drawn as a bright spot on the background image. The background image has a predefined shape and size based on different shape parameters and requirements, where all pixels have a grayscale value of 0, and the bright spot has a grayscale value of 255. The polar coordinate system image is drawn, and the formula for calculating the position of the target bright spot in the image is:

[0073]

[0074] Where, x i and y i Let L be the coordinates of the i-th target point in the background image, and let L be the height of the polar coordinate image. In this example, L can be 1218.

[0075] In addition, plotting a standard coordinate system image requires an extra coordinate system transformation; the remaining steps are the same as for a polar coordinate system image. The coordinate system transformation formula is:

[0076]

[0077] Based on the coordinate system transformation formula, a multibeam sonar model capable of imaging targets within the field of view was established.

[0078] S02. Construct underwater three-dimensional terrain, determine the navigation scheme of the underwater vehicle based on the underwater three-dimensional terrain, apply the multibeam sonar model to the navigation scheme to perform imaging operation, and obtain the underwater vehicle terrain scanning process model.

[0079] Specifically, in this embodiment, an underwater three-dimensional terrain is established using a specific underwater area in the Yangtze River channel as a prototype. An underwater area with dimensions of 20m in length and width, and an average depth of 10m, is constructed, including underwater shipwrecks, terrain gradients, and other underwater terrain features. Each square meter of terrain contains 100 sampling points. In some feasible implementations, the process of determining the navigation plan of the underwater vehicle may include steps S021-S022:

[0080] S021. Determine the navigation trajectory of the underwater vehicle in the underwater three-dimensional terrain;

[0081] Specifically, in this embodiment, a navigation plan for the underwater vehicle is formulated based on the underwater terrain. Various navigation data are defined, including the vehicle's initial position, timestamp t, yaw angle Cog, instantaneous velocity v of the underwater vehicle, and its depth d. The navigation plan for the entire survey process is obtained by calculating the navigation data; the calculation formula is as follows:

[0082]

[0083] Where, Δx k Δy k Δz k The formula for calculating the distance traveled by the underwater vehicle in each time interval is:

[0084]

[0085] Among them, T n V represents the time interval during the data acquisition process. n The average speed of the underwater vehicle during this time interval is calculated using the following formula:

[0086] T n =t n -t (n-1)

[0087]

[0088] Since the initial coordinates of the underwater vehicle are known, the position data of the underwater vehicle in the underwater terrain at each moment can be calculated using the above method, which serves as the navigation plan for the underwater vehicle.

[0089] S022. Determine the sonar angle and the position of the scanning point. Based on the sonar angle and the position of the scanning point, use the multi-beam sonar model to perform free-view scanning through the navigation trajectory. Perform imaging operation based on the scanning results.

[0090] Specifically, in the embodiments, such as Figure 2As shown, a multibeam sonar model is applied to the current vehicle trajectory and underwater scene to perform imaging operations. During navigation, the vehicle's attitude is varied to achieve a change in the sonar's field of view. The reference direction of the sonar beams is adjusted, causing the sonar field of view to rotate in the vertical coordinate system. After rotation, the angles between each beam and the reference direction remain unchanged, thus enabling the acquisition of underwater target position information outside the original sonar field of view. Subsequent steps remain unchanged, and the sonar image after the change in the sonar field of view is generated.

[0091] Step S021 above establishes a model of the underwater vehicle terrain scanning process, enabling the underwater vehicle equipped with a sonar model to perform free-view scanning of the underwater terrain in a three-dimensional underwater scene according to a predetermined trajectory and generate continuous frame sonar images, which can reflect the complete process of underwater vehicle terrain scanning and visualize it.

[0092] S03. Add multi-source interference to the terrain survey results of the underwater vehicle terrain survey process model to generate a comprehensive simulation image;

[0093] Specifically, in this embodiment, multi-source interference is added to the terrain survey results to generate a comprehensive simulation image. In some feasible implementations, the process of adding multi-source interference may include steps S031-S032:

[0094] S031. Modeling yields structured noise and target outline ghosting in the sonar image;

[0095] S032. Add the sonar image structured noise and the target contour ghosting model to the terrain survey results of the underwater vehicle terrain survey process model to generate the comprehensive simulation image with multi-source interference.

[0096] More specifically, the process of modeling structured noise in sonar images in the embodiments may include steps S0311-S0313:

[0097] S0311. Segment the real multibeam sonar background image and count the frequency distribution of gray values ​​of pixels in columns.

[0098] Specifically, in this embodiment, a real sonar background image without targets is first acquired and segmented into structured noise units. The distribution characteristics of single-beam structured noise in the horizontal direction are then studied. Within the single-beam structured noise, the frequency distribution of grayscale values ​​of pixels in different columns is statistically analyzed, using columns as units. For example... Figure 2 As shown in the example, a Gaussian mixture model (GMM) is used to fit the collected grayscale distribution frequency and determine its parameters to determine a certain column of structured noise model, the expression of which is shown below:

[0099]

[0100] Where f(x) represents the image structured noise, K represents the number of peaks in the Gaussian mixture model, and w k σ represents the weight of the k-th Gaussian function. k Let μ represent the variance of the k-th Gaussian function. k Let g(x|μ) represent the mean of the k-th Gaussian function. k ,σ k ) represents the Gaussian function.

[0101] S0312. Use a Gaussian mixture model to fit the pixel grayscale distribution frequency to determine the model parameters, and determine the single-column structured noise grayscale distribution model based on the model parameters.

[0102] S0313. Process all columns in the single-beam structured noise according to the single-column structured noise gray-scale distribution model to obtain the overall gray-scale distribution model of the single-beam structured noise, and determine the sonar image structured noise according to the overall gray-scale distribution model.

[0103] Step S0311 is performed on all columns of the sonar image to obtain the overall gray-level distribution model of the single-beam structured noise. This model is used as the probability density function for adding structured noise. Pixels at different locations determine their gray levels based on their own probability densities, and these gray-level values ​​are used as the corresponding gray-level values ​​in the original sonar image, thus achieving the purpose of adding structured noise.

[0104] Additionally, the embodiment can also construct a ghost image at the edge of the target outline by changing the grayscale of the pixels around the target outline. The formula for the grayscale change of the pixels around the target outline is:

[0105] g ij =g0λ -2 (d-λ) 2

[0106] Where d represents the distance between the point and the target contour, g0 represents the gray value of the target contour, and λ represents the ghost width parameter, which can be set to 20 in the embodiment. The embodiment adds structured noise and target contour ghosting to the original sonar image, making the simulated sonar image more realistic than the original sonar image.

[0107] S04. Visualize the scanning progress of the underwater vehicle terrain scanning process model, and output the scanning results synchronously in the scanning progress according to the integrated simulation image;

[0108] Specifically, in the embodiment, after completing the underwater vehicle terrain survey process and adding multi-source interference to the sonar image, the navigation process data and the integrated simulation image are output as the results.

[0109] On the other hand, the technical solution of this application also provides a simulation system for the terrain surveying process of underwater vehicles, which includes:

[0110] Sonar modeling unit, used to build multibeam sonar models;

[0111] The free scanning unit is used to construct underwater three-dimensional terrain, determine the navigation scheme of the underwater vehicle based on the underwater three-dimensional terrain, apply the multibeam sonar model to the navigation scheme to perform imaging operations, and obtain the underwater vehicle terrain scanning process model.

[0112] The multi-source interference unit is used to add multi-source interference to the terrain survey results of the underwater vehicle terrain survey process model to generate a comprehensive simulation image.

[0113] The simulation output unit is used to visualize the scanning progress of the underwater vehicle terrain scanning process model and output the scanning results synchronously based on the comprehensive simulation image in the scanning progress.

[0114] On the other hand, the present application also provides a simulation device for underwater vehicle topographic surveying process, the device comprising: at least one processor; at least one memory for storing at least one program; when the at least one program is executed by the at least one processor, the at least one processor runs the underwater vehicle topographic surveying process simulation method as described in the second aspect.

[0115] This invention also provides a storage medium storing a corresponding executable program, which is executed by a processor to implement the underwater vehicle terrain survey simulation method in the first aspect.

[0116] From the above specific implementation process, it can be concluded that the technical solution provided by the present invention has the following advantages or strengths compared with the prior art:

[0117] The terrain surveying simulation method proposed in this application can simulate the actual process, providing an experimental platform for related research, reducing experimental costs, and providing guidance and verification for actual exploration work through pre-simulation, thereby improving work efficiency. Furthermore, the comprehensive simulation image after adding multi-source interference has a very realistic effect and can provide data support for image processing algorithms.

[0118] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0119] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus or device (such as a computer-based system, a processor-included system or other system that can fetch and execute instructions from, an instruction execution system, apparatus or device).

[0120] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0121] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0122] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A simulation method for the terrain surveying process of an underwater vehicle, characterized in that, Includes the following steps: Construct a multibeam sonar model; Construct an underwater three-dimensional terrain, determine the navigation scheme of the underwater vehicle based on the underwater three-dimensional terrain, apply the multibeam sonar model to the navigation scheme to perform imaging operations, and obtain the underwater vehicle terrain scanning process model. Multi-source interference is added to the terrain survey results of the underwater vehicle terrain survey process model to generate a comprehensive simulation image; The scanning progress of the underwater vehicle terrain scanning process model is visualized, and the scanning results are output synchronously in the scanning progress according to the comprehensive simulation image; The construction of the multibeam sonar model includes: By simplifying the sonar detection field of view by replacing the actual three-dimensional field of view with a two-dimensional planar field of view, a simplified sonar detection field of view coordinate system is obtained. Within the sonar detection field of view coordinate system, the sonar beam is simulated using a ray tracing method to collect the target point location information within the detection range; The collected target point location information is summarized, and a sonar image is drawn based on the summary results to construct the multibeam sonar model. The step of simulating the sonar beam using ray tracing within the sonar detection field of view coordinate system to acquire target point location information within the detection range includes: Starting from the origin of the sonar detection field of view coordinate system, draw equally spaced rays within the acquisition and detection range; Determine the target point that is closest to each of the equally spaced rays; Calculate the first angle between the equally spaced rays and the reference direction, calculate the relative distance between the target point and the origin, and determine the position information of the target point based on the first angle and the relative distance; The process of adding multi-source interference to the terrain survey results of the underwater vehicle terrain survey process model to generate a comprehensive simulation image includes: The modeling process yields structured noise and target outline ghosting in the sonar image. The sonar image structured noise and the target contour ghosting model are added to the terrain survey results of the underwater vehicle terrain survey process model to generate the comprehensive simulation image with multi-source interference.

2. The simulation method for underwater vehicle topographic surveying process according to claim 1, characterized in that, The process of summarizing the acquired target point location information, drawing a sonar image based on the summarization results, and constructing the multibeam sonar model includes: The target point position information is adjusted according to the target image size, and the adjusted target point position information is then transformed in the coordinate system. The transformed target point location information is drawn as bright spots in the background image; The sonar image is generated based on the drawn background image. In the sonar image, the target outline is a bright spot, and the area with no information is a dark spot.

3. The simulation method for underwater vehicle topographic surveying process according to claim 1, characterized in that, The process involves constructing an underwater three-dimensional terrain, determining the underwater vehicle's navigation plan based on the underwater three-dimensional terrain, applying the multibeam sonar model to the navigation plan for imaging operations, and obtaining an underwater vehicle terrain scanning process model, including: The navigation trajectory of the underwater vehicle is determined within the underwater three-dimensional terrain. The sonar angle and the location of the scanning point are determined. Based on the sonar angle and the location of the scanning point, the multi-beam sonar model is used to perform a free-view scanning based on the navigation trajectory. Imaging operation is performed based on the scanning results.

4. The simulation method for underwater vehicle topographic surveying process according to claim 1, characterized in that, The modeling process yields structured noise and target contour ghosting in the sonar image, including: The real multibeam sonar background image is segmented, and the gray value distribution frequency of the pixels is statistically analyzed in columns. The model parameters are determined by fitting the pixel grayscale distribution frequency using a Gaussian mixture model, and then a single-column structured noise grayscale distribution model is determined based on the model parameters. The single-column structured noise grayscale distribution model is used to process all columns in the single-beam structured noise to obtain the overall grayscale distribution model of the single-beam structured noise. The sonar image structured noise is then determined based on the overall grayscale distribution model.

5. The simulation method for underwater vehicle topographic surveying process according to claim 4, characterized in that, The formula for calculating the structured noise of the sonar image is as follows: in, This represents structured noise in the image. This represents the number of peaks in a Gaussian mixture model. Indicates the first The weights of a Gaussian function, Indicates the first The variance of a Gaussian function, Indicates the first The mean of a Gaussian function, Represents the Gaussian function; The formula for calculating the ghosting of the target contour is as follows: in, Indicates the distance between the point and the target contour. Indicates the grayscale value of the target outline. This represents the ghost width parameter.

6. A system for implementing the simulation method for the underwater vehicle topographic survey process as described in any one of claims 1-5, characterized in that, include: Sonar modeling unit, used to build multibeam sonar models; The free scanning unit is used to construct underwater three-dimensional terrain, determine the navigation scheme of the underwater vehicle based on the underwater three-dimensional terrain, apply the multibeam sonar model to the navigation scheme to perform imaging operations, and obtain the underwater vehicle terrain scanning process model. The multi-source interference unit is used to add multi-source interference to the terrain survey results of the underwater vehicle terrain survey process model to generate a comprehensive simulation image. The simulation output unit is used to visualize the scanning progress of the underwater vehicle terrain scanning process model and output the scanning results synchronously based on the comprehensive simulation image in the scanning progress.

7. A storage medium storing a processor-executable program, characterized in that, The processor-executable program, when executed by the processor, is used to run the underwater vehicle terrain survey simulation method as described in any one of claims 1-5.

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