A seabed mining area passability map acquisition method

Abstract

The application adopts an acoustic perception device to accurately collect seabed topographic elevation data, calculates the topographic features of a seabed mining area based on the obtained seabed topographic elevation data, obtains a topographic information map of the seabed mining area, processes the topographic information map of the seabed mining area in combination with the geometric passability of a mining vehicle, respectively obtains a risk gradient attenuation map of the seabed mining area and a normalized passability map, fuses the risk gradient attenuation map and the normalized passability map, and obtains a visualized seabed mining area passability map. The seabed mining area passability map is helpful for the mining vehicle to visualize the risk level of an obstacle when operating at the edge of the obstacle, and to display the passability level of the whole map in real time, thereby providing a strong guarantee for safe driving and path planning of the mining vehicle, and greatly improving the passability and operation efficiency of the mining vehicle.

Description

Technical Field

[0001] This invention relates to the technical field of map acquisition methods, specifically to a method for acquiring a map of the navigability of a seabed mining area. Background Technology

[0002] The ocean is the largest treasure trove of resources on Earth, with abundant mineral resources on the seabed and in coastal areas, including metals, non-metals, energy, and rare elements. Marine mineral resources are of great significance to human economic development and technological progress, and countries around the world are stepping up their efforts to explore marine resources. Underwater robots and deep-sea mining vehicles have gradually become research hotspots.

[0003] my country is rich in marine resources. To understand the mineral resources within my country's territorial waters and to better utilize these resources in the future, many domestic researchers have joined the research on deep-sea mining vehicles. Mining vehicles operating in seabed mining areas require path planning and navigation for normal operations. Current technologies typically combine digital elevation model (DEM) data of marine mining areas to provide path planning and navigation for deep-sea mining vehicles. However, marine topography is diverse and geological structures are complex. Under conditions of rapid topographic relief and unstable geology, the basic topographic information from DEMs cannot provide safe and accurate driving strategies for the path planning and passage of deep-sea mining vehicles, and it also reduces the passage and operational efficiency of deep-sea mining vehicles. Summary of the Invention

[0004] To address the technical problems of existing technologies that cannot provide safe and accurate driving strategies for deep-sea mining vehicles based on digital elevation model-based terrain data, and the low efficiency of deep-sea mining vehicle passage and operation, this application provides a method for obtaining seabed mining area accessibility maps, providing safer, more accurate, and more efficient passage strategies and guidance for deep-sea mining vehicles.

[0005] A method for obtaining a seabed mining area accessibility map according to this application includes the following steps:

[0006] Step 1: Acoustic sensing equipment is used to acquire seabed topographic elevation data, and the acquired seabed topographic elevation data is preprocessed.

[0007] Step 2: Based on the processed topographic elevation data, calculate the topographic slope, topographic relief, topographic roughness, and topographic step change values ​​of the seabed mining area to establish a topographic information map of the seabed mining area.

[0008] Step 3: Process the topographic information map of the seabed mining area based on the geometric passability of the deep-sea mining vehicle to obtain a risk gradient attenuation map of the seabed mining area. The risk gradient attenuation map represents the potential collision risk level of each area in the seabed mining area.

[0009] Step 4: Process the topographic information map of the seabed mining area based on the geometric passability of the deep-sea mining vehicle to obtain a normalized passability map of the seabed mining area.

[0010] Step 5: Construct a traversable map of the seabed mining area based on the risk gradient decay map and the normalized traversability map.

[0011] In one embodiment of this application, step one further specifically includes:

[0012] Acquire seabed topographic elevation data collected by multibeam forward-looking sonar, and perform data cleaning on the seabed topographic elevation data to eliminate outlier data points;

[0013] The cleaned data is calibrated, and the calibrated data is then interpolated and smoothed to obtain the processed terrain elevation data.

[0014] In one embodiment of this application, step two extracts the topographic slope information, topographic relief information, topographic roughness information, and topographic step change value of the seabed mining area based on the processed topographic elevation data, and establishes a topographic information map of the seabed mining area. This includes: establishing a 3*3 window, using the topographic elevation data in the 8 neighboring windows to calculate the topographic slope information, topographic relief information, topographic roughness information, and topographic step change value of the seabed mining area, and establishing a topographic information map of the seabed mining area.

[0015] In one embodiment of this application, step two extracts topographic slope information, topographic relief information, topographic roughness information, and topographic step change value of the seabed mining area based on the processed topographic elevation data, and establishes a topographic information map of the seabed mining area, including:

[0016] The terrain slope is calculated using the third-order inverse distance-squared difference method, specifically including: setting the elevation value of the center point as z(i,j), and calculating the terrain slope based on the elevation data of each grid cell within the 8-neighborhood of the center point:

[0017]

[0018]

[0019]

[0020] θ ascepct =arctan(slope) x / slope y );

[0021] Among them, slope x Let slope be the rate of change of slope in the x-direction. y Let θ be the rate of change of slope in the y-direction, d be the grid resolution, and θ be the slope.slope For slope, θ ascepct The slope aspect is defined, with true north as 0° and clockwise as the positive direction, where 0° ≤ θ. ascepct ≤360°.

[0022] In one embodiment of this application, step two extracts topographic slope information, topographic relief information, topographic roughness information, and topographic step change value of the seabed mining area based on the processed topographic elevation data, and establishes a topographic information map of the seabed mining area, including:

[0023] The terrain relief is calculated using the Terrain Relief Index (TRI):

[0024] TRI(i,j)=sqrt(∑((z(i+m,j+n)-z(i,j)) 2 )

[0025] Where TRI(i,j) is the topographic relief index of the cell in the i-th row and j-th column of the topographic elevation data, z(i,j) represents the elevation of the center point of the window, z(i+m,j+n) is the elevation of the 8-neighborhood of the center point, the set of values ​​for m and n is {-1, 0, 1}, and ∑ represents the summation of all 8-neighborhood grids.

[0026] In one embodiment of this application, step two extracts topographic slope information, topographic relief information, topographic roughness information, and topographic step change value of the seabed mining area based on the processed topographic elevation data, and establishes a topographic information map of the seabed mining area, including:

[0027] Terrain roughness information is calculated by the ratio of the standard deviation of the elevation data of the window center point and its 8 neighboring grids to the average elevation within the window:

[0028]

[0029] Among them, z i The elevation values ​​of each grid cell within the 8-neighborhood window of the central grid are given by z. avg This represents the average elevation of each grid cell within the window.

[0030] In one embodiment of this application, step two extracts topographic slope information, topographic relief information, topographic roughness information, and topographic step change value of the seabed mining area based on the processed topographic elevation data, and establishes a topographic information map of the seabed mining area, including:

[0031] The step change in terrain is calculated as the difference between the highest and lowest elevation points within the window:

[0032] h = z max -z min

[0033] Among them, z max z is the maximum elevation value within the window. min This is the minimum elevation value within the window.

[0034] In one embodiment of this application, step three involves processing the seabed mining area topographic information map based on the geometric passability of the deep-sea mining vehicle to obtain a risk gradient attenuation map of the seabed mining area, including:

[0035] Obtain the maximum terrain undulation, maximum terrain slope, maximum terrain roughness, and maximum terrain step difference that the deep-sea mining vehicle can traverse;

[0036] The obtained seabed mining area topographic information map is binarized based on the maximum terrain undulation, maximum terrain slope, maximum terrain roughness, and maximum terrain step difference that the deep-sea mining vehicle can pass through, resulting in a grid map composed of (0, 1), where 1 represents the obstacle area and 0 represents the passable area.

[0037] A risk gradient attenuation map of the deep-sea mining vehicle and obstacles is generated based on the distance between each grid and the obstacle area. The specific formula is as follows:

[0038]

[0039] Where R(c) represents the risk level, different values ​​represent different risk levels, the higher the value, the closer to the obstacle, the higher the risk level, and vice versa, d is the actual distance of the current grid from the edge of the obstacle, S1, S2, S3, S4 are the critical values ​​of the risk gradient level, where S1≤S2≤S3≤S4.

[0040] In one embodiment of this application, step four, which processes the seabed mining area topographic information map based on the geometric passability of the deep-sea mining vehicle to obtain a normalized accessibility map of the seabed mining area, includes:

[0041] Obtain the maximum terrain relief θ that the deep-sea mining vehicle can traverse. max Maximum terrain slope R max Maximum terrain roughness Tri max and the maximum terrain step difference h max ;

[0042] Based on the maximum terrain relief θ that deep-sea mining vehicles can traverse max Maximum terrain slope R max Maximum terrain roughness Tri max and the maximum terrain step difference h max Normalize the topographic relief θ, topographic slope R, topographic roughness Tri, and topographic step difference h of each grid in the topographic information map of the seabed mining area.

[0043] The normalized accessibility T of the seafloor mining area is calculated based on the normalized topographic relief, topographic slope, topographic roughness, and topographic step difference:

[0044]

[0045] Where α1, α2, α3, α4 are non-negative numbers, and satisfy α1 + α2 + α3 + α4 = 1, θ n R n Tri n h n These are the normalized topographic relief, topographic slope, topographic roughness, and topographic step difference, respectively.

[0046] A normalized accessibility map of the seabed mining area is constructed based on the value of the normalized accessibility T. The lower the T value, the higher the accessibility level of the grid, and the higher the safety of deep-sea mining vehicles passing through the area.

[0047] In one embodiment of this application, step five, which involves constructing a traversable map of the seabed mining area based on a risk gradient decay map and a normalized traversability map, includes: fusing the risk gradient decay map and the normalized traversability map to obtain a traversable map of the seabed mining area.

[0048] This application utilizes advanced environmental sensing equipment to accurately collect seabed topographic elevation data. Based on this data, key topographic features of the seabed mining area are calculated, resulting in a topographic information map. This map is then processed using the geometric mobility of mining vehicles to generate a risk gradient attenuation map and a normalized accessibility map. These two maps are then fused to create a visualized seabed mining area accessibility map. This accessibility map helps visualize the risk level of obstacles when mining vehicles approach their edges and displays the overall map's accessibility level in real time. This provides strong support for safe driving and route planning for mining vehicles, significantly improving their accessibility and operational efficiency. Attached Figure Description

[0049] Figure 1 This is a technical flowchart of a method for obtaining accessibility maps of seabed mining areas.

[0050] Figure 2 It is a 3x3 grid window.

[0051] Figure 3 It is a topographic elevation data map of a specific area in a cobalt-rich crust mining area in the central Pacific Ocean.

[0052] Figure 4 It is a binary raster map containing the distribution of obstacles in that specific region.

[0053] Figure 5 This is a risk gradient decay map for that specific region.

[0054] Figure 6 It is a normalized accessibility map of that specific area.

[0055] Figure 7 It is a accessibility map of that specific area. Detailed Implementation

[0056] The technical solutions of the embodiments of this application will be further described clearly and completely below with reference to the accompanying drawings. It should be noted that the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of this invention, and these all fall within the protection scope of this invention.

[0058] The embodiments of this application will be described in further detail below with reference to the accompanying drawings:

[0059] This application provides a method for obtaining a seabed mining area accessibility map, the method comprising the following steps:

[0060] Step 1: Acoustic sensing equipment is used to acquire seabed topographic elevation data, and the acquired seabed topographic elevation data is preprocessed.

[0061] The acoustic sensing device in this application can be a high-precision measuring device for acquiring seabed topographic data underwater. In order to improve the measurement accuracy, this application uses multibeam forward-looking sonar to acquire high-precision seabed topographic elevation data. Multibeam forward-looking sonar has high measurement accuracy and a wide measurement range, which can improve the accuracy of topographic elevation data acquisition.

[0062] After collecting seabed topographic elevation data using multibeam forward-looking sonar, a series of data preprocessing steps are required to ensure data quality and accuracy. Step one of this application further includes the following data preprocessing steps: acquiring the seabed topographic elevation data collected by the multibeam forward-looking sonar; cleaning the seabed topographic elevation data to eliminate outlier data points; calibrating the cleaned data; and interpolating and smoothing the calibrated data to obtain the processed topographic elevation data.

[0063] Raw seabed topography data acquired by acoustic sensing devices often includes anomalous data points influenced by equipment and environmental factors, impacting overall data accuracy. Data preprocessing necessitates reviewing and cleaning the raw data to remove anomalous points caused by equipment malfunctions, operational errors, or environmental interference. Seabed topography data needs to be correlated with geographical location information; therefore, the acquisition time must be synchronized with the navigation equipment's time. Furthermore, to ensure accurate correlation between topography and geographical location data, precise angle and distance calibration of the sonar system is required. Since the speed of sound varies in areas with significant changes in water temperature, salinity, or depth, local sound velocity profile data must be acquired and applied to correct for sound wave propagation speed in water. Additionally, beam angle correction is used to reduce distance measurement errors caused by beam angle. To improve data continuity and overall quality, calibrated data undergoes interpolation and smoothing to fill in missing data and reduce measurement noise. This comprehensive application of data preprocessing ensures the reliability and accuracy of the acquired seabed topography data in subsequent analysis and applications.

[0064] refer to Figure 1 In this study, digital elevation model data of a certain mining area with cobalt-rich crust in the Pacific Ocean was obtained using acoustic sensing equipment, and topographic elevation data of a specific area were selected for subsequent processing.

[0065] Step 2: Based on the processed topographic elevation data, calculate the topographic slope, topographic relief, topographic roughness, and topographic step change values ​​of the seabed mining area to establish a topographic information map of the seabed mining area.

[0066] In the embodiments of this application, terrain features are calculated based on processed terrain elevation data. Specifically, terrain slope information, terrain relief information, terrain roughness information, and terrain step change values ​​are calculated for the seabed mining area, thus constructing a terrain information map of the seabed mining area. Each grid cell in the terrain information map of the seabed mining area includes the terrain slope information, terrain relief information, terrain roughness information, and terrain step change value for that grid cell.

[0067] Since topographic slope information, topographic relief information, topographic roughness information, and topographic step change values ​​reflect the changing trends of the seabed topography, this application uses a window of a preset size to calculate the topographic elevation data of the seabed mining area when using preprocessed seabed topographic elevation data. To fully reflect the changing trends of the center point and surrounding topography, an n*n window is preferred. Furthermore, to improve the calculation efficiency of the topographic information map, further reference is made... Figure 2In a preferred embodiment of this application, a 3x3 grid window is selected. Topographic elevation data within an 8-neighbor window are used to calculate the topographic slope, topographic relief, topographic roughness, and topographic step change values ​​of the seabed mining area, thus creating a topographic information map of the seabed mining area. Using a 3x3 grid window and topographic elevation data within an 8-neighbor window to obtain the topographic information map of the seabed mining area allows for the acquisition of the topographic change trend between the window's center point and the surrounding 8 neighboring grids. Compared to windows of other sizes, this significantly improves computational efficiency while ensuring that the calculated topographic information accurately represents the actual topographic features of the center point. The specific calculation methods for each topographic feature in the topographic information map are as follows:

[0068] Slope reflects the degree of inclination of a local terrain surface and is a fundamental element for feature analysis and visualization of seabed topography. It is also a crucial terrain factor restricting the passage of tracked mining vehicles (DSMV). Mining area slopes specifically manifest as topographic undulations, gaps, troughs, or ridges. Slope terrain exhibits stability issues due to geological activity, sedimentation, or erosion, posing challenges to ore extraction and safety. Therefore, the seabed topographic information map in this application includes topographic slope information. By acquiring this slope information, a topographic information map is constructed, thereby obtaining a seabed navigability map, providing crucial information for determining the optimal strategies and technical means for mining area development. In calculating seabed topographic slope information based on elevation data, this application employs the third-order inverse distance squared difference method. Let the elevation value of the center point of the window be z(i,j). The topographic slope information is calculated based on the elevation data of each grid within the 8-neighborhood of the center point.

[0069]

[0070]

[0071]

[0072] θ ascepct =arctan(slope) x / slope y );

[0073] Among them, slope x Let slope be the rate of change of slope in the x-direction. y Let θ be the rate of change of slope in the y-direction, d be the raster resolution, and θ be the slope. slope For slope, θ ascepct The slope aspect is defined, with true north as 0° and clockwise as the positive direction, where 0° ≤ θ. ascepct ≤360°.

[0074] Topographic relief is a key indicator describing changes in topography at small scales, such as seabed elevation, slope, and curvature. It is the result of multiple factors, including geological and geomorphological processes, and provides a quantitative understanding of topographic complexity and variability. Topographic relief poses a significant challenge to tracked mining vehicles (DSMVs). Extracting topographic relief from DEM data can visually reflect the undulating characteristics of the terrain. In this application, topographic relief is calculated using the Topographic Relief Index (TRI).

[0075] TRI(i,j)=sqrt(∑((z(i+m,j+n)-z(i,j)) 2 )

[0076] Where TRI(i,j) is the topographic relief index of the cell in the i-th row and j-th column of the topographic elevation data, z(i,j) represents the elevation of the center point of the window, z(i+m,j+n) is the elevation of the 8-neighborhood of the center point, the set of values ​​for m and n is {-1, 0, 1}, and ∑ represents the summation of all 8-neighborhood grids.

[0077] The roughness of seabed topography is an important factor reflecting the unevenness of the Earth's surface, and can be represented by a statistical measure of the degree of elevation variation between a unit grid and its neighborhood. In this application, the topographic roughness information is calculated as the ratio of the standard deviation of the elevation data of the window's center point and its eight neighboring grids to the average elevation within the window:

[0078]

[0079] Among them, z i The elevation values ​​of each grid cell within the 8-neighborhood window of the central grid are given by z. avg This represents the average elevation of each grid cell within the window.

[0080] A step change in terrain refers to a rapid change in elevation over a relatively short distance, typically marked on a map as a cliff, precipice, plateau edge, or ridge. These terrain features pose significant safety hazards to mining vehicles and are geologically associated with fault zones, erosion boundaries, or tectonic activity. In this application, the step change in terrain is calculated as the difference between the highest and lowest elevation points within a given window.

[0081] h = z max -z min

[0082] Among them, z max z is the maximum elevation value within the window. min This is the minimum elevation value within the window.

[0083] Step 3: Process the topographic information map of the seabed mining area based on the geometric passability of the deep-sea mining vehicle to obtain the risk gradient attenuation map of the seabed mining area. The risk gradient attenuation map represents the potential collision risk level of each area in the seabed mining area.

[0084] After obtaining the seabed mining area topographic information map based on terrain elevation data, it is necessary to evaluate the geometric passability of the mining vehicle in order to ensure its safe passage. In this application, the maximum terrain undulation, maximum terrain slope, maximum terrain roughness, and maximum terrain step difference of the mining vehicle are selected for evaluation. Specifically, the maximum terrain undulation, maximum terrain slope, maximum terrain roughness, and maximum terrain step difference that the deep-sea mining vehicle can pass through are obtained; the obtained seabed mining area topographic information map is binarized according to the maximum terrain undulation, maximum terrain slope, maximum terrain roughness, and maximum terrain step difference that the deep-sea mining vehicle can pass through, resulting in a grid map composed of (0, 1), where 1 represents the obstacle area and 0 represents the passable area. In the binarization process, if the terrain undulation, slope, roughness, and step difference in the seabed mining area exceed the maximum traversable terrain undulation, slope, roughness, and step difference for the deep-sea mining vehicle, the deep-sea mining vehicle cannot safely pass through the corresponding grid area. Forcing its way through would compromise the vehicle's safety. Furthermore, since any one of these terrain parameters exceeds the maximum traversable value for the deep-sea mining vehicle, it cannot pass safely. Therefore, grids in the seabed mining area where the terrain undulation, slope, roughness, and step difference are all less than the maximum traversable terrain undulation, slope, roughness, and step difference for the deep-sea mining vehicle are assigned a value of 0, representing traversable areas. Other grids are assigned a value of 1, representing obstacle areas, thus obtaining a grid map composed of (0, 1).

[0085] Furthermore, to provide a more visually intuitive and accurate safe driving strategy for deep-sea mining vehicles, this application establishes a risk buffer zone centered on obstacles. The edge grid cells marked as obstacle areas are extended outwards by S meters to create a buffer zone surrounding the obstacles. Then, a risk assessment function R(c) is used to evaluate the risk cost of all extended grid cells, forming a risk buffer zone with gradually decreasing gradient values. Specifically, a risk gradient decay map between the deep-sea mining vehicle and obstacles is formed based on the distance between each grid cell and the obstacle area, as shown in the following formula:

[0086]

[0087] Where R(c) represents the risk level, different values ​​represent different risk levels, the higher the value, the closer to the obstacle, the higher the risk level, and vice versa, d is the actual distance of the current grid from the edge of the obstacle, S1, S2, S3 are the critical values ​​of the risk gradient level, where S1≤S2≤S3.

[0088] Step four: Process the seabed mining area topographic information map based on the geometric passability of the deep-sea mining vehicle to obtain a normalized passability map of the seabed mining area.

[0089] In the study of deep-sea terrain accessibility, the embodiments of this application assess the ease of movement of deep-sea mining vehicles in each grid based on the extracted terrain information. To further improve the driving safety of deep-sea mining vehicles, this application processes the seabed mining area terrain information map according to the geometric passability of the deep-sea mining vehicle to obtain a normalized accessibility map of the seabed mining area.

[0090] Based on the mechanical characteristics and geometric constraints of the deep-sea mining vehicle, this application obtains the maximum terrain undulation θ that the deep-sea mining vehicle can traverse, according to the vehicle's geometric passability. max Maximum terrain slope R max Maximum terrain roughness Tri max and the maximum terrain step difference h max ;

[0091] Based on the maximum terrain relief θ that deep-sea mining vehicles can traverse max Maximum terrain slope R max Maximum terrain roughness Tri max and the maximum terrain step difference h max Normalize the topographic relief θ, topographic slope R, topographic roughness Tri, and topographic step difference h of each grid in the topographic information map of the seabed mining area.

[0092] The normalized accessibility T of the seafloor mining area is calculated based on the normalized topographic relief, topographic slope, topographic roughness, and topographic step difference:

[0093]

[0094] Where α1, α2, α3, α4 are non-negative numbers, and satisfy α1 + α2 + α3 + α4 = 1, θ n R n Tri n h n These are the normalized topographic relief, topographic slope, topographic roughness, and topographic step difference, respectively.

[0095] A normalized accessibility map of the seabed mining area is constructed based on the value of the normalized accessibility T. The lower the T value, the higher the accessibility level of the grid, and the higher the safety of deep-sea mining vehicles passing through the area.

[0096] Step 5: Construct a traversable map of the seabed mining area based on the risk gradient decay map and the normalized traversability map.

[0097] In this application, step five, constructing a navigable map of the seabed mining area based on a risk gradient decay map and a normalized navigability map, includes: fusing the risk gradient decay map and the normalized navigability map to obtain a seabed mining area navigability map. Through this seabed mining area navigability map, when a mining vehicle travels to the edge of an obstacle for operation, the risk level of the obstacle is visualized, and the overall navigability level of the map is also visible. This improves the safety of the mining vehicle, lays the foundation for the initial path planning of the mining vehicle, and enhances the passage efficiency of deep-sea mining vehicles.

[0098] By combining a risk gradient decay map and a normalized accessibility map, a accessibility map with risk gradient decay is constructed. This map is used to provide mining vehicles with accurate navigation and travel strategies, taking into account the risk level of obstacles and the accessibility level of the entire mining area.

[0099] This application uses acoustic sensing equipment to accurately collect seabed topographic elevation data, and calculates the topographic features of the seabed mining area based on the acquired seabed topographic elevation data to obtain a topographic information map of the seabed mining area. The topographic information map of the seabed mining area is then processed in conjunction with the geometric passability of the mining vehicle to obtain a risk gradient attenuation map and a normalized accessibility map of the seabed mining area. The risk gradient attenuation map and the normalized accessibility map are then fused to obtain a visualized seabed mining area accessibility map. This seabed mining area accessibility map helps the mining vehicle visualize the risk level of obstacles when operating at the edge of obstacles, and displays the accessibility level of the entire map in real time. This provides strong support for the safe driving and path planning of the mining vehicle, greatly improving the passage and operation efficiency of the mining vehicle.

[0100] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, component splitting or combination, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for obtaining a seabed mining area accessibility map, characterized in that, Includes the following steps: Step 1: Acoustic sensing equipment is used to acquire seabed topographic elevation data, and the acquired seabed topographic elevation data is preprocessed. Step two involves calculating the topographic slope, topographic relief, topographic roughness, and topographic step change values ​​of the seabed mining area based on the processed topographic elevation data, and establishing a topographic information map of the seabed mining area. This step includes: establishing a 3x3 window and using the topographic elevation data within an 8-neighbor window to calculate the topographic slope, topographic relief, topographic roughness, and topographic step change values ​​of the seabed mining area, and establishing a topographic information map of the seabed mining area. This step two involves extracting the topographic slope, topographic relief, topographic roughness, and topographic step change values ​​of the seabed mining area based on the processed topographic elevation data, and establishing a topographic information map of the seabed mining area. The terrain slope is calculated using the third-order inverse distance squared difference method, specifically including: setting the elevation of the center point of the window as... Calculate the terrain slope based on the elevation data of each grid cell within the 8-neighborhood of the center point: ， ， ； ； in, This represents the component of the slope along the x-axis. This represents the component of the slope along the y-axis. For grid resolution, For slope, The slope aspect is defined, with true north as 0° and clockwise as the positive direction. ; Step 3: Process the seabed mining area topographic information map based on the geometric passability of the deep-sea mining vehicle to obtain a risk gradient attenuation map of the seabed mining area. This risk gradient attenuation map characterizes the potential collision risk level of each region within the seabed mining area. The process of processing the seabed mining area topographic information map based on the geometric passability of the deep-sea mining vehicle in Step 3 to obtain the risk gradient attenuation map includes: Obtain the maximum terrain undulation, maximum terrain slope, maximum terrain roughness, and maximum terrain step difference that the deep-sea mining vehicle can traverse; The obtained seabed mining area topographic information map is binarized based on the maximum terrain undulation, maximum terrain slope, maximum terrain roughness, and maximum terrain step difference that the deep-sea mining vehicle can pass through, resulting in a grid map composed of (0, 1), where 1 represents the obstacle area and 0 represents the passable area. A risk gradient attenuation map of the deep-sea mining vehicle and obstacles is generated based on the distance between each grid and the obstacle area. The specific formula is as follows: ， in This indicates the risk level; different values ​​represent different risk levels. A higher value indicates a closer proximity to the obstacle and a higher risk level, while a lower value indicates a lower risk level. 'd' represents the actual distance of the current grid cell from the obstacle's edge. This represents the critical value for the risk gradient level, where ; Step four involves processing the seabed mining area topographic map based on the geometric passability of the deep-sea mining vehicle to obtain a normalized accessibility map of the seabed mining area. This step four, processing the seabed mining area topographic map based on the geometric passability of the deep-sea mining vehicle to obtain the normalized accessibility map of the seabed mining area, includes: Obtain the maximum terrain relief that the deep-sea mining vehicle can traverse. Maximum terrain slope Maximum terrain roughness and maximum terrain step difference ; Based on the maximum terrain undulation that deep-sea mining vehicles can traverse. Maximum terrain slope Maximum terrain roughness and maximum terrain step difference Topographic relief of each grid cell in the seabed mining area topographic information map Topographic slope Topographic roughness and terrain step difference Perform normalization calculations; The normalized accessibility T of the seafloor mining area is calculated based on the normalized topographic relief, topographic slope, topographic roughness, and topographic step difference: ， in, It is a non-negative number and satisfies , These are the normalized topographic relief, topographic slope, topographic roughness, and topographic step difference, respectively. A normalized accessibility map of the seabed mining area is constructed based on the normalized accessibility value T. The lower the T value, the higher the accessibility level of the grid, and the higher the safety for deep-sea mining vehicles to pass through the area. Step 5: Construct a traversable map of the seabed mining area based on the risk gradient decay map and the normalized traversability map.

2. The method for obtaining a seabed mining area accessibility map according to claim 1, characterized in that, Step one specifically includes: Acquire seabed topographic elevation data collected by multibeam forward-looking sonar, and perform data cleaning on the seabed topographic elevation data to eliminate outlier data points; The cleaned data is calibrated, and the calibrated data is then interpolated and smoothed to obtain the processed terrain elevation data.

3. The method for obtaining a seabed mining area accessibility map according to claim 1, characterized in that, Step two, based on the processed topographic elevation data, extracts topographic slope information, topographic relief information, topographic roughness information, and topographic step change values ​​of the seabed mining area to establish a topographic information map of the seabed mining area, including: The terrain relief is calculated using the Terrain Relief Index (TRI): ， in, It is the topographic relief index of the cell in the i-th row and j-th column of the topographic elevation data. Indicates the elevation of the center point of the window. The elevation of the 8-neighborhood of the center point. and The set of values ​​is Σ represents the summation over all 8-neighbor raster cells.

4. The method for obtaining a seabed mining area accessibility map according to claim 1, characterized in that, Step two, based on the processed topographic elevation data, extracts topographic slope information, topographic relief information, topographic roughness information, and topographic step change values ​​of the seabed mining area to establish a topographic information map of the seabed mining area, including: The terrain roughness information is calculated by the ratio of the standard deviation of the elevation data of the center point of the window and the 8 neighboring grids to the average elevation within the window: ， in, The elevation values ​​of each grid cell within the 8-neighborhood window of the central grid. This represents the average elevation of each grid cell within the window.

5. The method for obtaining a seabed mining area accessibility map according to claim 1, characterized in that, Step two, based on the processed topographic elevation data, extracts topographic slope information, topographic relief information, topographic roughness information, and topographic step change values ​​of the seabed mining area to establish a topographic information map of the seabed mining area, including: The step change in terrain is calculated as the difference between the maximum and minimum elevation points within the window: ， in, This represents the maximum elevation value within the window. This is the minimum elevation value within the window.

6. The method for obtaining a seabed mining area accessibility map according to claim 1, characterized in that, Step five involves constructing a traversable map of the seabed mining area based on the risk gradient decay map and the normalized traversability map, including: fusing the risk gradient decay map and the normalized traversability map to obtain a traversable map of the seabed mining area.

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