Main grid power transmission line path generation system based on geographic information system

Abstract

The invention discloses a main network power transmission line path generation system based on a geographic information system, which comprises a database processing module, the database processing module comprises a data import processor, a data preprocessor and a database, the database import processor is connected with the outside and imports external data into database content, and the database content is stored in the database processing module; the data preprocessor calls the data content of the database and performs primary processing according to the data category or attribute; and the path calculation module calls the data content from the database, and calculates and generates the shortest path under the cost constraint condition according to a set path generation algorithm. According to the method, dual cost calculation of unit attribute cost and moving cost is introduced, a power transmission line path planning model fusing static unit attributes and dynamic moving resistance is established, and on the premise of ensuring ecological compliance and engineering safety, inherent cost of quantified terrain and passage resistance between adjacent grid units are fused, so that the power transmission line path planning precision is improved. And the optimal calculation of the full-path comprehensive cost is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power, and more specifically, to a main network transmission line path generation system based on a geographic information system. Background Art

[0002] With the transformation of the global energy structure towards cleaner energy, as the core carrier for cross-regional power transmission, the planning complexity and accuracy requirements of high-voltage main network transmission lines have been significantly improved. The path planning method mainly based on manual on-site investigation and two-dimensional geographical drawing analysis has been gradually phased out by the times due to reasons such as large data scale and low processing efficiency. It has become very necessary to use computer technology to achieve the automatic generation of the main network transmission line path.

[0003] Although the shift to computer-aided automatic path generation technology has become an industry consensus, there are still serious design deviations in the existing algorithm frameworks. The automatic generation technology for the main network transmission line path usually simplifies path optimization to the solution of a single objective function. For example, simply pursuing the shortest straight-line distance or the lowest land compensation cost or the lowest movement cost, etc. Although this simplification can improve the calculation efficiency, it seriously deviates from the actual engineering requirements. For example, simply pursuing the shortest straight-line distance path without considering sudden changes in slope, resulting in additional slope support costs and significantly increasing the project cost. Another example is simply pursuing the lowest movement cost without considering the strengthening of ecological protection regulations, resulting in the need to change the path halfway through construction, etc. Or simply pursuing the lowest land compensation cost without considering the path distance and movement cost, resulting in an overly long main network transmission line path and increasing excessive additional construction costs, etc. Eventually, there are problems such as a gap between the automatically generated path and the actual construction, and the need for temporary improvement in actual construction. Summary of the Invention

[0004] In order to overcome the deficiency that the path optimization scheme of the existing path automatic generation technology is relatively single, the present invention provides a main network transmission line path generation system based on a geographic information system, introduces the dual-cost calculation of unit attribute cost and movement cost, establishes a transmission line path planning model that integrates static unit attributes and dynamic movement resistance, and on the premise of ensuring ecological compliance and engineering safety, integrates the inherent cost of the quantified terrain and the traffic resistance between adjacent grid cells to achieve the optimal calculation of the comprehensive cost of the entire path.

[0005] The technical solution of the present invention is as follows:

[0006] A main network transmission line path generation system based on a geographic information system, comprising

[0007] Database processing module, which includes a data import processor, a data pre-processor, and a database. The data import processor is connected to the outside and imports external data into the database. The data pre-processor retrieves the data content from the database and performs preliminary processing according to the data category or attribute.

[0008] Path calculation module, which retrieves data content from the database and calculates and generates the shortest path under cost constraint conditions according to the set path generation algorithm.

[0009] For the above-mentioned main network transmission line path generation system based on geographic information system, the data import processor imports the external data content into the database of the database processing module according to the data category and source, forming the database of the main network transmission line path generation system. The database of the main network transmission line path generation system includes a basic geographic information database, an environmental constraint database, and a dynamic database.

[0010] For the above-mentioned main network transmission line path generation system based on geographic information system, the data pre-processor pre-processes different types of data, converts the layers of different coordinate systems to the same projection to ensure spatial alignment, then performs grid processing on the set geographic area, divides each geographic area into multiple grid units according to the preset size, generates a grid unit attribute table, and combines the data in the database to label the values of different attribute fields of each grid unit.

[0011] Further, the division rule of the grid unit is defaulted to equal division.

[0012] Further, the determination method of the size of the grid unit includes the sampling correlation method and the curvature analysis method, and either one of them can be selected.

[0013] Sampling correlation method: If N elevation points are collected in the set geographic area, then the size n of the grid unit divided in the set geographic area is greater than N and less than 2N, and then dynamic adjustment is performed to make the size of the grid unit meet the grid unit equal division principle within the accuracy range. If there are multiple values, selection is made according to the terrain complexity.

[0014] Curvature analysis method: Select the representative contour lines in the set geographic area, analyze the curvature change of the representative contour lines, calculate the minimum curvature interval between the representative contour lines and the adjacent contour lines, or calculate the average value of all contour line intervals. Set the size n of the grid unit to be less than or equal to the minimum curvature interval between the representative contour lines and the adjacent contour lines, or the size n of the grid unit to be less than or equal to the average value of all contour line intervals, and then meet the grid unit equal division principle within the accuracy range. If there are multiple values, selection is made according to the terrain complexity.

[0015] The above-mentioned main network transmission line path generation system based on geographic information system, the data pre-processor calculates and quantifies the unit attribute cost of each grid cell, and the calculation formula is

[0016] c (i,j) = ω1·s ij + ω2·l ij + ω3·o ij ·∞,

[0017] where, c (i,j) is the unit attribute cost of the grid cell (i,j); i and j are the coordinates of the grid cell; ω1 is the terrain factor weight of the grid cell (i,j); s ij is the terrain complexity of the grid cell (i,j); ω2 is the geographic type weight of the grid cell (i,j); l ij is the geographic type cost of the grid cell (i,j); ω3 is the prohibited weight of the grid cell (i,j); o ij is the prohibited flag of the grid cell (i,j); ∞ represents an infinite cost value.

[0018] Furthermore, the value of the terrain complexity is determined by comprehensively considering three factors of the terrain slope, average altitude, and geology, and is calculated according to the respective subdivision weights of the slope, average altitude, and geology. The calculation formula is s ij = α·γ1 + β·γ2 + λ·γ3, where, s ij is the terrain complexity, α is the slope, the slope is the normalized value taken after being calculated by the digital elevation model, and the digital elevation model calculation formula of the slope is is the change rate of the elevation on the y-axis, α is the slope, is the change rate of the elevation on the x-axis; γ1 is the subdivision weight of the slope; β is the average altitude; γ2 is the subdivision weight of the average altitude; λ is the geological type, taking the normalized value after mapping; γ3 is the subdivision weight of the geological type.

[0019] Furthermore, the geographic type cost is mapped according to the actual economic cost, and the economic costs of each different geographic type are normalized, and the normalized value taken after mapping is used.

[0020] The above-mentioned main network transmission line path generation system based on geographic information system, the path generation algorithm adopts the Floyd algorithm, and the calculation process includes

[0021] Step S1. Establish a two-dimensional matrix - path matrix dist, and the matrix element is the cost from one grid cell to another grid cell;

[0022] Step S2. Initialize the path matrix dist, set the starting point of the path matrix dist as (i, j), the ending point as (k, l), record all the remaining grid cells within the set geographical area as intermediate nodes, take the straight-line path from the starting point (i, j) to the ending point (k, l) as the optimal path, and calculate the path cost of the current optimal path as the cost of the path matrix dist;

[0023] Step S3. Traverse all the intermediate nodes through a triple loop, determine the path matrix dist with the minimum cost, and generate the optimal path.

[0024] Furthermore, the function of the path cost is where C is the path cost, c (i,j) is the unit attribute cost, and c (i,j→k,l) is the movement cost.

[0025] Even further, the calculation formula for the unit attribute cost is

[0026] c (i,j) = ω1·s ij + ω2·l ij + ω3·o ij ·∞,

[0027] where c (i,j) is the unit attribute cost of the grid cell (i, j); i and j are the coordinates of the grid cell; ω1 is the terrain factor weight of the grid cell (i, j); s ij is the terrain complexity of the grid cell (i, j); ω2 is the geographical type weight of the grid cell (i, j); l ij is the geographical type cost of the grid cell (i, j); ω3 is the prohibition weight of the grid cell (i, j); o ij is the prohibition flag of the grid cell (i, j); ∞ represents an infinite cost value;

[0028] The calculation formula for the movement cost is

[0029]

[0030] where c (i,j→k,l) is the cost of moving from the grid cell (i, j) to the grid cell (k, l); ω4 is the slope weight; is the slope resistance; ω5 is the distance weight; is the movement distance; ω6 is the obstacle weight; is the obstacle crossing difficulty.

[0031] Furthermore, the triple loop includes an outer loop, a middle loop, and an inner loop. The outer loop is the traversal of the intermediate nodes, the middle loop is the loop for the starting point, and the inner loop is the loop for the midpoint;

[0032] During the triple - loop process, iterative optimization is achieved. The iterative optimization process is to add an intermediate node to the existing best path to form the current path, compare the cost of the current path with the cost of the best path. If the cost of the current path is lower than the cost of the best path, then the current path will replace the original best path to become the new best path, and then enter the next - level iterative calculation.

[0033] For the present invention according to the above - mentioned solution, its beneficial effects are as follows:

[0034] 1. By dividing the geographical area into evenly - divided or curvature - adaptive grid cells, the spatial alignment and unified management of multi - source data are realized. After automatic coordinate conversion and grid attribute table construction, discrete data such as terrain elevation, land type, and prohibited areas are uniformly mapped into a standardized grid, significantly improving the data fusion efficiency.

[0035] 2. The present invention adopts a two - layer cost calculation model of unit - attribute cost + movement cost, breaking through the limitations of traditional single economic cost or distance optimization. The unit - attribute cost is calculated comprehensively through terrain complexity (slope, altitude, geology), geographical type (compensation cost), and prohibited signs, accurately reflecting the construction fixed cost; the movement cost quantifies the dynamic resistance between adjacent grids (slope change, obstacle crossing), simulating the travel difficulty in actual construction. The integration of the two costs enables path planning to comprehensively balance economy, feasibility, and environmental impact. It can not only accurately evaluate the construction difficulty and cost of each grid cell but also dynamically adjust the path selection in path planning to avoid crossing high - cost areas.

[0036] 3. Numerical adjustment is convenient and efficient. The path costs of the present invention are all calculated through weights. Therefore, the weights can be adjusted separately according to actual needs or by setting a weight adjustment scheme without reconstructing the algorithm. The adjustment efficiency is greatly improved compared with code - level modification and is only completed in the data pre - processor of the database processing module, and direct replacement is also simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following - described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic diagram of the calculation process for path generation of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] A main grid transmission line path generation system based on a geographic information system comprises a database processing module, the database processing module comprises a data import processor, a data preprocessor and a database, the database import processor is connected to the outside to import external data into the database content, the data preprocessor retrieves the data content of the database and performs preliminary processing according to the data category or attribute; and a path calculation module, the path calculation module retrieves the data content from the database, calculates and generates the shortest path under cost constraints according to a set path generation algorithm.

[0041] The database of the main grid transmission line path generation system includes basic geographic information database, environmental constraint database, and dynamic database, as shown below.

[0042] Basic geographic information database, data content includes regional basic geographic information, such as terrain elevation (DEM), administrative divisions, land use types (such as residential areas, farmland, forests), water system distribution, transportation network, etc., usually from the public data of land and surveying and mapping departments or satellite remote sensing images. In the present invention, the geographic information in the basic geographic information database comes from GIS, i.e., geographic information system. Geographic Information System (Geographic Information System, referred to as GIS) is a specific spatial information system, which is a technical system for collecting, storing, managing, calculating, analyzing, displaying and describing the relevant geographic distribution data in the entire or part of the earth's surface, air and underground space under the support of computer hardware and software systems. GIS brings together advanced technologies such as geography, urban science, surveying and mapping remote sensing, management science, etc., and can comprehensively grasp the geographical distribution and spatial distribution of the earth's surface, so it can also be called a resource and environment information system or a geoscience information system. In the actual implementation process, third-party GIS data can be cited, or it can be established by itself.

[0043] Environmental constraint database, data content includes ecological red lines, nature reserves, cultural relics protection areas, electromagnetic radiation sensitive areas and other planning restrictions, mainly about the geographical location of these areas, mostly obtained from actual surveys or satellite remote sensing images to determine the precise area. Furthermore, these areas may be expanded or set a larger range of thresholds to avoid later changes and expansions of the area.

[0044] Dynamic database, the data content includes monitoring data of meteorology (wind speed, icing) and geological disasters (landslide, debris flow), which can be updated through the Internet of Things or drone inspection. Here, it includes real-time data and historical data. Regarding meteorology and geological disasters, if it does not affect the basic geographic information (such as terrain changes, etc.), the real-time data will not be regarded as a geographical restriction condition when generating a path. It is mainly used to restrict the selection of power-related data, etc., or to optimize the generated path. When generating a path, historical data is mainly used. For example, if the occurrence frequency of meteorological disasters and geological disasters in a certain geographical area is relatively high, different types of marks will be made on this geographical area according to the set program, forming different geographical type attributes, which will form a condition restriction for path generation.

[0045] The data import processor imports the external data content into the database in the database processing module according to the data category and source, forming the database of the main network transmission line path generation system. The data pre-processor pre-processes different types of data, such as coordinate unification and registration, converts the layers of different coordinate systems to the same projection to ensure spatial alignment. Then, the set geographical area is gridded, and each geographical area is divided into multiple grid cells according to the preset size, and a grid cell attribute table is generated. The grid cell attribute table contains attribute fields such as slope, land type, and prohibition mark, and different values are assigned to each attribute field according to the data in the database.

[0046] In this process, the data pre-processor simultaneously calculates and quantifies the unit attribute cost of each grid cell, and the calculation formula is

[0047] c (i,j) =ω1·s ij +ω2·l ij +ω3·o ij ·∞,

[0048] Among them, c (i,j) is the unit attribute cost of the grid cell (i,j), which is equivalent to the fixed overhead of passing through the grid cell (i,j);

[0049] i and j are the coordinates of the grid cell, which are the identifiers of the divided grid cells here, meaning that this grid cell is located in the i-th row and j-th column for the entire geographical area division;

[0050] ω1 is the terrain factor weight of the grid cell (i,j), indicating the weight of the terrain factor affecting the total construction cost of the grid cell;

[0051] s ij is the terrain complexity of the grid cell (i,j), indicating the terrain complexity or the construction difficulty directly caused by the terrain;

[0052] ω2 is the geographical type weight of the grid cell (i,j), representing the weight of the economic cost corresponding to the land use or surface cover type in the total construction cost of the grid cell;

[0053] l ij is the geographical type cost of the grid cell (i,j), that is, the economic cost corresponding to the geographical type defined according to the land use, usually the market price or compensation standard or the payment cost other than the non-engineering cost, such as farmland compensation, residential compensation, etc.;

[0054] ω3 is the prohibition weight of the grid cell (i,j), usually set to 1;

[0055] o ij is the prohibition identifier of the grid cell (i,j), a binary variable, 0 for non-prohibited areas, 1 for prohibited areas, used to mark the grid cells that are prohibited from passing through, such as rivers, ecological protection areas, military areas, mining areas, densely populated areas, etc.;

[0056] ∞ represents an infinite cost value. When o ij is 1, the cost of the grid cell (i,j) obtained by calculation is infinite, thus avoiding selecting to pass through this grid cell.

[0057] Among them, the terrain factor weight represents the influence ratio of the terrain factor on the total construction cost of the grid cell. Usually, it directly affects the construction through the terrain complexity; the geographical type weight represents the influence ratio of the economic cost caused by using the geographical area on the total construction cost of the grid cell. Such economic costs are usually compensation or payment costs other than non-engineering costs, such as farmland compensation, residential compensation, etc. These weight values are basically obtained from the experience of construction personnel or engineering designers, and can also be obtained by computer analyzing past data, such as expert experience or regression analysis. On the other hand, it can also be oriented according to the purpose. For example, if the ecological protection level of this construction is relatively high, then relatively speaking, the terrain factor weight will be lower and the geographical type weight will be higher. Or, if the area passed by this construction is a densely populated area, then the geographical type weight will be higher and the terrain factor weight will be lower, and so on.

[0058] Terrain complexity represents the construction difficulty of the grid cell with the terrain as the influencing factor. Specifically, factors such as the slope, average altitude, and geology of the terrain can be comprehensively considered, and then calculated according to the respective subdivision weights of the slope, average altitude, and geology, that is, s ij =α·γ1 + β·γ2 + λ·γ3, where s ij is the terrain complexity, α is the slope, γ1 is the subdivision weight of the slope, β is the average altitude, taking the normalized value, γ2 is the subdivision weight of the average altitude, λ is the geological type, taking the normalized value, γ3 is the subdivision weight of the geological type. Among them, the slope is calculated through the digital elevation model, and the calculation formula is is the rate of change of elevation on the y-axis, and α is the slope. is the rate of change of elevation on the x-axis. After calculating the slope, mapping processing is performed to normalize it. In a specific embodiment, the slope obtained by calculating through a digital elevation model for a certain grid cell is 25%, and the normalized value after mapping is 8. Then, based on expert experience or historical data regression analysis, considering the combination of slope, average elevation, and geology, the weight value of the slope is 0.6; the average elevation is mapped according to the actual value, and the value is normalized. In a specific embodiment, the average elevation of a certain grid cell is 500 meters. After mapping processing, the normalized value of the mapping is 3. Considering the combination of slope, average elevation, and geology, the weight value of the average elevation is 0.1; similarly for geology, mapping processing is performed according to the geological situation to normalize the value. For example, the normalized value for the geological type of soil is set to 1. Considering the combination of slope, average elevation, and geology, the weight value of the geological type of soil is 0.1, the normalized value for the geological type of weathered rock is 5, and considering the combination of slope, average elevation, and geology, the weight value of the geological type of soil is 0.3, the normalized value for the geological type of hard bedrock is 10, and considering the combination of slope, average elevation, and geology, the weight value of the geological type of soil is 0.6, and so on.

[0059] The geographical type cost needs to be mapped according to the actual economic cost, and the economic costs of different geographical types are normalized and mapped to the same range. In a specific embodiment, the geographical type attribute is wasteland, and its actual cost is 0.1 ten thousand yuan per mu. After normalization processing and mapping, the geographical type cost value of the grid cell with the geographical type attribute of wasteland is 1; the geographical type attribute is forest land, and its actual cost is 2.0 ten thousand yuan per mu. After normalization processing and mapping, the geographical type cost value of the grid cell with the geographical type attribute of forest land is 3; the geographical type attribute is cultivated land, and its actual cost is 5.0 ten thousand yuan per mu. After normalization processing and mapping, the geographical type cost value of the grid cell with the geographical type attribute of cultivated land is 5; the geographical type attribute is construction land, and its actual cost is 15.0 ten thousand yuan per mu. After normalization processing and mapping, the geographical type cost value of the grid cell with the geographical type attribute of construction land is 8.

[0060] Grid cells are defaulted to be evenly divided, that is, the areas of all grid cells are the same. If dynamic division rules are adopted according to the terrain, in principle, the more complex the terrain, the smaller the divided grid cells. Considering the dynamic division rules, it is necessary to further consider issues such as the complexity of the adjacency relationship of grid cells and whether the area of the divided geographical region meets the smaller division rules. Therefore, for simplicity, the grid cells are defaulted to be evenly divided. The methods for determining the size of grid cells include sampling correlation method and curvature analysis method. In the sampling correlation method, if N elevation points are collected in the set geographical region (i.e., the region where the path is intended to be generated), then the size n of the grid cells divided in the set geographical region is greater than N and less than 2N, and then dynamic adjustment is carried out to make it meet the principle of even division of grid cells within the accuracy range (i.e., the decimal accuracy of the area of the specified grid cells). If there are multiple values, selection is made according to the terrain complexity. In the curvature analysis method, representative contour lines within the set geographical region are selected, the curvature changes of the representative contour lines are analyzed, the minimum curvature interval between the representative contour lines and adjacent contour lines is calculated, or the average value of all contour line intervals is calculated. The size n of the grid cells is set to be less than or equal to the minimum curvature interval between the representative contour lines and adjacent contour lines or the size n of the grid cells is less than or equal to the average value of all contour line intervals, and then it meets the principle of even division of grid cells within the accuracy range (i.e., the decimal accuracy of the area of the specified grid cells). If there are multiple values, selection is made according to the terrain complexity.

[0061] When calculating and generating the path of the main grid transmission line, based on the total cost of generating the path of the main grid transmission line, that is, calculating the path cost. The function of the path cost is where C is the path cost, c (i,j) is the unit attribute cost, c (i,j→k,l) is the movement cost. When calculating the path cost, only the grid cells that need to be constructed (such as the grid cells where power towers and substations need to be constructed. According to the preset intervals, such as the intervals between power towers vary according to different voltages and different voltage levels have different interval ranges. When calculating the path cost, according to the length of the current path, the number of power towers is determined by rounding up, and then the grid cells for construction are arranged according to the unit attributes of the grid cells. If necessary, the interval is reduced and the number of power towers is increased) include the unit attribute cost, while the grid cells simply passed through (such as the aerial area crossed by the wire) only consider the movement cost.

[0062] The movement cost is used to quantify the resistance to moving from the current grid cell to the adjacent cell, and its core is to reflect the dynamic influence of factors such as terrain and obstacles on the movement operation. The calculation formula of the movement cost is

[0063]

[0064] where c (i,j→k,l)is the cost of moving from grid cell (i, j) to grid cell (k, l);

[0065] ω4 is the slope weight, representing the influence intensity of the slope of the grid cell on the movement cost;

[0066] is the slope resistance, manifested as the slope change from grid cell (i, j) to grid cell (k, l);

[0067] ω5 is the distance weight, representing the influence intensity of the distance from grid cell (i, j) to grid cell (k, l) on the movement cost;

[0068] is the movement distance, that is, the actual physical distance from grid cell (i, j) to grid cell (k, l);

[0069] ω6 is the obstacle weight, representing the influence intensity of the obstacles in the grid cell on the movement cost;

[0070] is the obstacle crossing difficulty, manifested as the engineering difficulty of crossing the obstacles from grid cell (i, j) to grid cell (k, l).

[0071] Among them, the slope weight, distance weight, and obstacle weight are all obtained based on expert experience or regression analysis of historical data. The historical data can include past project energy consumption data and past project time-consuming data, so as to determine the values of each weight.

[0072] The calculation formula for the slope resistance is where is the slope change from grid cell (i, j) to grid cell (k, l), that is, the slope difference from grid cell (i, j) to grid cell (k, l), α (k,l) is the slope of grid cell (k, l), α (i,j) is the slope of grid cell (i, j), and m is the horizontal distance from grid cell (i, j) to grid cell (k, l) (the horizontal component of the path crossing two grid cells).

[0073] The movement distance, the actual physical distance from grid cell (i, j) to grid cell (k, l), which needs to be determined by judging the positional relationship between grid cell (i, j) and grid cell (k, l), that is, it is necessary to determine whether the movement path from grid cell (i, j) to grid cell (k, l) is horizontal / vertical movement or diagonal movement. The movement distance in the former case is directly equal to the side length of the grid cell, and the movement distance in the latter case is the grid cell ×

[0074] Obstacle crossing difficulty, one of the grid cell property assignments. The normalized value obtained by determining the original value of the obstacle crossing difficulty of the grid cell, through mapping and normalization processing, and substituting it into the movement cost formula is this normalized value. This obstacle crossing difficulty depends on the geographical type of the grid cell property. According to multiple rounds of expert assignments or historical data regression analysis, the mapping assignments for each geographical type are obtained. If the geographical type of a certain grid cell is a shallow ditch, the obstacle crossing difficulty value mapped according to the main network transmission line path generation system is 1. If the geographical type of a certain grid cell is a dense forest, the obstacle crossing difficulty value mapped according to the main network transmission line path generation system is 3. If the geographical type of a certain grid cell is a fence, the obstacle crossing difficulty value mapped according to the main network transmission line path generation system is 2. If the geographical type of a certain grid cell is a river, the obstacle crossing difficulty value mapped according to the main network transmission line path generation system is ∞.

[0075] The main network transmission line path generation algorithm uses the Floyd algorithm, such as Figure 1As shown. Let the starting point of the main grid transmission line path be the grid cell (i, j), and the ending point be the grid cell (k, l). All other grid cells within the set geographical area are intermediate nodes. A two-dimensional matrix - path matrix dist is established, and the matrix element is the cost from one grid cell to another, that is, the path cost C. Initialize the path matrix dist, set the starting point of the path matrix dist as (i, j), the ending point as (k, l), and record all other grid cells within the set geographical area as intermediate nodes. Then, the shortest path determined by the initialized path matrix dist is the straight-line path from the starting point (i, j) to the ending point (k, l), and the path cost is calculated as the cost of the path matrix dist. Then, all intermediate nodes are traversed through a triple loop, including the outer loop, the middle loop, and the inner loop. The outer loop is for traversing the intermediate nodes, the middle loop is for looping through the starting points, and the inner loop is for looping through the midpoints. And iterative optimization is achieved during the triple loop. That is, add an intermediate node to the existing best path (i.e., the path with the lowest cost) to form the current path, compare the cost of the current path with the cost of the best path. If the cost of the current path is lower than the cost of the best path, then replace the original best path with the current path to become the new best path. Thus, all intermediate nodes are traversed. In a specific embodiment, if the current best path is (i, j) → (k, l), add the intermediate node (h1, s1) to form the current path (i, j) → (h1, s1) → (k, l). If the path cost of the current path is less than the path cost of the best path, then the best path iteratively becomes (i, j) → (h1, s1) → (k, l). Continue the next iterative optimization. Add the intermediate node (h2, s2) to the best path (i, j) → (h1, s1) → (k, l) to form the current path (i, j) → (h1, s1) → (h2, s2) → (k, l). Compare the path costs of the current path (i, j) → (h1, s1) → (h2, s2) → (k, l) and the best path (i, j) → (h1, s1) → (k, l). If the path cost of the current path (i, j) → (h1, s1) → (h2, s2) → (k, l) is higher than the path cost of the best path (i, j) → (h1, s1) → (k, l), then the best path remains the best path (i, j) → (h1, s1) → (k, l). If the path cost of the current path (i, j) → (h1, s1) → (h2, s2) → (k, l) is lower than the path cost of the best path (i, j) → (h1, s1) → (k, l), then the best path will iteratively optimize to the current path (i, j) → (h1, s1) → (h2, s2) → (k, l). Thus, the best path obtained after traversing all intermediate nodes is the main grid transmission line path generated by the main grid transmission line path generation system.

[0076] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A main network transmission line path generation system based on a geographic information system, characterized in that, including a database processing module, which includes a data import processor, a data pre-processor and a database. The data import processor is connected to the outside and imports external data into the database. The data pre-processor retrieves the data content in the database and performs preliminary processing according to the data category or attribute; a path calculation module, which retrieves the data content from the database and calculates and generates the shortest path under the cost constraint condition according to the set path generation algorithm.

2. The main network transmission line path generation system based on a geographic information system according to claim 1, wherein The data pre-processor pre-processes different types of data, converts the layers in different coordinate systems to the same projection to ensure spatial alignment, then performs grid processing on the set geographical area, divides each geographical area into multiple grid units according to the preset size, generates a grid unit attribute table, and marks the values of different attribute fields of each grid unit in combination with the data in the database.

3. The main network transmission line path generation system based on a geographic information system according to claim 2, wherein, The method for determining the size of the grid unit includes the sampling correlation method and the curvature analysis method, and either one of them can be selected; Sampling correlation method: If N elevation points are collected in the set geographical area, then the size n of the grid unit divided in the set geographical area is greater than N and less than 2N, and then dynamic adjustment is performed to make the size of the grid unit meet the grid unit equal division principle within the accuracy range. If there are multiple values, selection is made according to the terrain complexity; Curvature analysis method: Select the representative contour line in the set geographical area, analyze the curvature change of the representative contour line, calculate the minimum curvature interval between the representative contour line and the adjacent contour line, or calculate the average value of all contour line intervals. Set the size n of the grid unit to be less than or equal to the minimum curvature interval between the representative contour line and the adjacent contour line, or the size n of the grid unit is less than or equal to the average value of all contour line intervals, and then meet the grid unit equal division principle within the accuracy range. If there are multiple values, selection is made according to the terrain complexity.

4. A main network transmission line path generation system based on a geographic information system according to claim 1, wherein The data pre-processor calculates and quantifies the unit attribute cost of each grid unit, and the calculation formula is c (i,j) = ω1·s ij + ω2·l ij + ω3·o ij · ∞, Among them, c (i,j) is the cell attribute cost of the grid cell (i, j); i and j are the coordinates of the grid cell; ω1 is the terrain factor weight of the grid cell (i, j); s ij is the terrain complexity of the grid cell (i, j); ω2 is the geographical type weight of the grid cell (i, j); l ij is the geographical type cost of the grid cell (i, j); ω3 is the prohibition weight of the grid cell (i, j); o ij is the prohibition flag of the grid cell (i, j); ∞ represents an infinite cost value.

5. The main network transmission line path generation system based on a geographic information system according to claim 4, wherein The numerical determination of terrain complexity comprehensively considers three factors: the slope of the terrain, the average elevation, and the geology. It is calculated according to the respective sub - weights of the slope, average elevation, and geology. The calculation formula is s ij = α·γ1 + β·γ2 + λ·γ3, where s ij is the terrain complexity, α is the slope, and the slope is the normalized value after mapping calculated from the digital elevation model. The calculation formula of the digital elevation model for the slope is is the change rate of elevation on the y - axis, α is the slope, is the change rate of elevation on the x - axis; γ1 is the sub - weight of the slope; β is the average elevation; γ2 is the sub - weight of the average elevation; λ is the geological type, taking the normalized value after mapping; γ3 is the sub - weight of the geological type.

6. The main network transmission line path generation system based on a geographic information system according to claim 4, wherein The geographical type cost is mapped according to the actual economic cost, and the economic costs of different geographical types are normalized, and the normalized value after mapping is taken.

7. A main network transmission line path generation system based on a geographic information system according to claim 1, characterized in that The path generation algorithm adopts the Floyd algorithm, and the calculation process includes Step S1. Establish a two-dimensional matrix - path matrix dist, and the matrix element is the cost from one grid unit to another grid unit; Step S2. Initialize the path matrix dist, set the starting point of the path matrix dist as (i,j), the ending point as (k,l), record all the remaining grid units within the set geographical area as intermediate nodes, take the straight-line path from the starting point (i,j) to the ending point (k,l) as the optimal path, and calculate the path cost of the current optimal path as the cost of the path matrix dist; Step S3. Traverse all intermediate nodes through a triple loop, determine the path matrix dist with the minimum cost, and generate the optimal path.

8. A main network transmission line path generation system based on a geographic information system according to claim 7, characterized in that The function of the path cost is C = ∑c (i,j) + ∑c (i,j→k,l) , where C is the path cost, c (i,j) is the unit attribute cost, and c (i,j→k,l) is the movement cost.

9. The main network transmission line path generation system based on a geographic information system according to claim 8, characterized in that, The calculation formula of the unit attribute cost is c (i,j) = ω1·s ij + ω2·l ij + ω3·o ij · ∞, Among them, c (i,j) is the unit attribute cost of the grid cell (i, j); i and j are the coordinates of the grid cell; ω1 is the terrain factor weight of the grid cell (i, j); s ij is the terrain complexity of the grid cell (i, j); ω2 is the geographical type weight of the grid cell (i, j); l ij is the geographical type cost of the grid cell (i, j); ω3 is the prohibition weight of the grid cell (i, j); o ij is the prohibition flag of the grid cell (i, j); ∞ represents an infinite cost value; The calculation formula of the movement cost is where c (i,j→k,l) is the cost of moving from grid cell (i, j) to grid cell (k, l); ω4 is the slope weight; is the slope resistance; ω5 is the distance weight; is the moving distance; ω6 is the obstacle weight; is the obstacle crossing difficulty.

10. The main network transmission line path generation system based on a geographic information system according to claim 1, characterized in that The triple loop includes an outer loop, a middle loop and an inner loop. The outer loop is the traversal of the intermediate nodes, the middle loop is the loop of the starting point, and the inner loop is the loop of the midpoint; During the triple loop, iterative optimization is achieved. The iterative optimization process is to add an intermediate node to the existing best path to form the current path, compare the cost of the current path with the cost of the best path. If the cost of the current path is lower than the cost of the best path, then the current path will replace the original best path to become the new best path, and then enter the next level of iterative calculation.

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