Construction path optimization model, modeling method, recording medium and system

Abstract

The invention belongs to the technical field of geographic space information, and particularly relates to a construction path optimization modeling method, engineering constraint conditions are verified in real time in a Dijkstra search process, a spline curve is introduced to smooth a grid path, a refined cost model is constructed, and flexible factors such as environmental influence, safety risk and driving comfort are considered, so that the construction path optimization modeling method has the advantages that the construction efficiency is improved, and the construction cost is reduced. And generation of multiple feasible schemes and comprehensive comparison and selection of technical economy are supported. According to the method, through collaborative optimization of technical feasibility and economic rationality, it is ensured that the path generation scheme has engineering applicability and cost controllability, and the working efficiency is remarkably improved. The method is not only suitable for construction road design in mountainous areas with complex terrains, but also suitable for road planning in areas with flat terrains, and has good universality and expansibility. The invention further provides a non-transient readable recording medium storing the program of the method and a system comprising the medium, the program can be called through a processing circuit to execute the method, and meanwhile, a modularly-built construction path optimization model is provided for practice.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of geographic spatial information, and discloses a construction path optimization model and a modeling method, system and recording medium storing a program capable of executing the method. BACKGROUND

[0002] In large engineering projects such as power transmission lines, the design and construction of construction roads are of great importance. It not only directly affects the construction progress and efficiency, but also relates to the engineering cost, environmental protection and construction safety.

[0003] Due to cost and environmental protection reasons, only one road is usually built to the tower site in the construction of power transmission line construction roads. In flat terrain areas, the main consideration for road construction is economic cost. In mountainous areas, due to topographic constraints, factors such as cost, vehicle driving requirements, safety and comfort need to be considered.

[0004] Construction roads will make full use of existing construction roads, and the existing road will usually be used as the starting point for building a construction road to the tower site. If the existing road can be used but the width is insufficient, the existing road will be widened under the condition that the condition allows. If there is no existing road, a new construction road needs to be built.

[0005] Traditional construction road design mainly relies on design personnel to manually select lines and plot based on three-dimensional map software combined with engineering experience. It has certain applicability in projects with simple terrain conditions and fewer constraint factors, but under the current background of increasing mechanization of power transmission line construction and increasingly complex corridor topography and geographical environment, its limitations are increasingly prominent, especially in mountainous areas where the terrain is complex and the construction road path design is very difficult.

[0006] In recent years, with the development of geographic information systems (GIS), digital elevation models (DEM) and artificial intelligence technology, some research attempts to introduce path planning algorithms into road selection. However, there are the following technical problems in actual application: (1) Existing methods focus on limited natural geographical factors such as slope and ground cover, and engineering constraint modeling is insufficient.

[0007] Existing methods do not comprehensively consider various economic costs of engineering constraints and construction roads, such as not effectively incorporating minimum turning radius, continuous climbing length, longitudinal slope continuity and other engineering constraints, and not considering construction road recovery costs. There is no mention of flexible evaluation such as driving safety and comfort, resulting in a road scheme that is theoretically feasible, such as the shortest road path, the smallest turning radius, the largest longitudinal slope, and poor driving safety and comfort. In fact, it is not applicable and can only be used as a reference for construction road schemes, and there is still a significant difference between the actual road scheme.

[0008] (2) Static cost models generally adopt a two-stage strategy of “first synthesizing the static comprehensive cost surface and then searching for the path”, which cannot dynamically verify local constraints during the search process.

[0009] (3) The lack of a selection mechanism for generating multiple feasible solutions and supporting quantitative technical and economic indicators makes it difficult to support scientific decision-making.

[0010] (4) Usually it is necessary to specify the start and end points of the construction road, but in reality, the tower location is known as the end point of the road and the existing road network. The start point is not determined because the selection of the start point is also part of the road route design.

[0011] Therefore, there is an urgent need for an intelligent construction road path design method and system that can integrate multi-dimensional constraints, support dynamic feasibility verification, and have the ability to compare multiple technical and economic options, so as to improve the scientific nature, automation level and implementation reliability of construction road design for power transmission line projects.

[0012] Shi Han et al.'s "Intelligent Road Planning Based on GIS Cost Path" considered factors such as land use, slope, aspect, elevation, and undulation in their research. Xia Qinxue's "Research on Intelligent Route Selection Algorithm and Scheme Comparison Method for Hydropower Station Access Roads" considered factors such as undulation, terrain slope, land features, and distance. It further narrowed down the range of selectable nodes through angle and slope constraints, thereby improving algorithm efficiency and the local engineering rationality of the initial path selection. However, this approach is highly likely to conflict with the turning radius requirements of engineering vehicles. Furthermore, it employs the analytic hierarchy process (AHP) combined with Dijkstra's "static cost synthesis" paradigm, and the resulting road is a grid-based polyline path, which cannot guarantee that the entire path meets engineering requirements. Summary of the Invention

[0013] To address the above problems, this invention provides a construction path optimization modeling method. It embeds Yen's algorithm into Dijkstra's algorithm and incorporates engineering constraints and a comprehensive cost evaluation mechanism to form a model framework. The design within this framework includes the following steps: S1. Set up grid nodes for the passage area including the starting point to the end point, connect each node, and embed geographic three-dimensional coordinates, geology, construction costs and travel direction angle information into each node to form a status grid diagram; S2. Replace the spatial distance weight in Dijkstra's algorithm with a cost function that is a weighted sum of the total engineering economic cost and the flexibility evaluation index, wherein the flexibility evaluation index includes environmental impact, safety risk, and driving comfort; select the straight-line path with the lowest cost that includes all nodes through it using Dijkstra's algorithm, with the line segments between adjacent nodes serving as state transition edges; generate spline curves based on the straight-line path as candidate paths; wherein the cost function is obtained by multiplying the cost function per unit length of each road segment by the length of that road segment and then summing them up. S3. Embed Yen's algorithm, define a state transition edge in the currently generated straight line segment path as a forbidden segment, rerun the above method, generate the next alternative path on the state mesh diagram, until the number of alternative paths meets the preset requirement; S4. Map the multiple alternative paths generated in S3 from the grid space to the digital elevation model, perform engineering constraint verification, calculate the cost function under the digital elevation model for each alternative path that passes the verification, and select the alternative path with the lowest cost as the final path.

[0014] Preferably, the unit cost function is designed as follows: ; C T The total economic cost per unit length of the project; I F , representing the flexibility evaluation index per unit length; Fc, the comprehensive cost function per unit length; C ref The benchmark economic cost per unit length; I ref The benchmark flexibility evaluation index per unit length; w1 and w2 are the corresponding weights, satisfying w1+w2=1, and both are greater than or equal to 0.

[0015] Preferably, the total economic cost per unit length of the project is C. T =C E +C C +C I +C Y +C Q ; In the formula, C E Cost per unit length of earthwork; C C The cost of road construction per unit length is calculated based on the unit price corresponding to the road width and road type. C I The indirect and external costs per unit length are calculated based on the road width and the unit price data of indirect and external costs. For road widening, only the cost of the widened part is considered. C Y The equivalent transportation cost per unit length; C Q Additional costs per unit length.

[0016] Preferred flexibility evaluation index per unit length ; In the formula, w F1 w F2 w F3 For the corresponding weights, satisfying wF1 +w F2 +w F3 =1, and all are greater than or equal to 0; I E , representing the environmental impact index per unit length; I S , representing the safety risk index per unit length; I C , which represents the driving comfort index per unit length; Preferably, the engineering constraints include the maximum longitudinal slope, minimum turning radius, continuous uphill length, and the longitudinal slope continuity must meet the set requirements; The turning radius is determined by fitting the circumcircle of three consecutive path nodes onto the horizontal projection plane, and using the radius of the circumcircle as the turning radius at that point. The dynamic verification mechanism for path search is defined as follows: when Dijkstra's algorithm performs reverse search, engineering constraint verification is triggered in real time; it is determined whether each state transition edge meets the requirements of maximum longitudinal slope, minimum turning radius, continuous uphill length, and longitudinal slope continuity; if the verification fails, the cost of the state transition edge is considered to be a maximum value that far exceeds the engineering cost, thus being equivalent to an impassable road segment.

[0017] Preferably, the starting point is a starting point on the map or any point in a preset starting area.

[0018] The present invention also provides a non-transient readable recording medium for storing one or more programs containing multiple instructions, which, when executed, cause the processor to execute the above-described construction path optimization modeling method.

[0019] Based on this, the present invention also provides a construction path optimization modeling system, including a processing circuit and a memory electrically coupled thereto, the memory being configured to store at least one program, the program containing multiple instructions, the processing circuit running the program, and being able to execute the above-described construction path optimization modeling method.

[0020] Based on the same inventive principle, the present invention also provides a construction path optimization model, comprising the following interconnected modules: The data input module is used to input user-configured road design parameters, including engineering constraints, earthwork calculation parameters, plant unit price library, road type and construction unit price, transportation cost parameters, weight coefficients and benchmark values ​​required for flexibility evaluation, benchmark economic cost per unit length, benchmark flexibility evaluation index per unit length, and benchmark length; as well as to set the design scope; and in a 3D scene loaded with digital elevation model and orthophoto, to automatically plot features manually or through intelligent feature recognition, set land occupation fees; plot and set soil and rock types; plot mandatory avoidance areas, set the areas to be avoided and the starting and ending points of the plotting; set the step size for generating grid nodes; and set the width of the proposed road. The calculation module is used to customize the cost calculation mechanism of Dijkstra's algorithm. It replaces the spatial distance weight with a cost function that is a weighted sum of the total engineering economic cost and the flexibility evaluation index. It selects the straight line path with the lowest cost, which includes multiple passing nodes, and generates spline curves based on the straight line path as candidate paths. The cost function is the unit length cost function composed of the total engineering economic cost and the flexibility evaluation index of each road segment, multiplied by the length of the road segment and then summed. The Yen's algorithm is embedded. It defines one line segment in the generated straight line path as a prohibited segment in turn, and calculates new candidate paths in the same way until the number of candidate paths meets the preset requirements. The verification module is used to re-verify the candidate routes under engineering constraints, retrieve the relevant indicators of each segment of the candidate routes that have passed the verification, conduct a special evaluation, and output the route optimization result. If the optimization result is not satisfactory, the grid is refined in the area formed by the start and end points of the problematic road segment and their adjacent nodes, new nodes are inserted, and the above steps are repeated until a satisfactory route optimization result is output. The data output module is used to output alternative routes and relevant indicators for each road segment under its jurisdiction, as well as coordinates, land cover types, vegetation types, and cost grid data required for algorithm analysis.

[0021] Compared to existing technologies, the construction path optimization model, modeling method, recording medium, and system provided by this invention verifies engineering constraints such as slope, turning radius, continuous uphill length, and longitudinal slope continuity in real time during the Dijkstra search process. It also introduces spline curves to smooth the grid path, achieving the conversion from algorithm results to engineering drawings. Simultaneously, it constructs a refined cost model covering the entire lifecycle, including earthwork, road construction, land occupation, crop damage, temporary land restoration, transportation costs, and other additional expenses. Furthermore, it considers flexible factors such as environmental impact, safety risks, and driving comfort, supporting the generation of multiple feasible solutions and comprehensive techno-economic comparison. Specifically, it produces the following beneficial effects: (1) Achieve fully automated design and significantly improve work efficiency. By integrating geographic information processing, intelligent path search and automatic engineering quantity calculation functions, this invention can automatically complete the entire process from raw data input to feasible path output, effectively replacing the traditional manual plotting and repeated verification operation mode, significantly reducing the workload of designers and improving the overall efficiency of path planning and design.

[0022] (2) Supports comprehensive optimization of multi-dimensional constraints. This invention integrates engineering technical feasibility constraints (such as longitudinal slope, turning radius, continuous uphill length, and longitudinal slope continuity), mandatory avoidance areas (such as ecological protection red lines, adverse geological bodies, and important structures), land occupation and construction costs, transportation and operation costs, and flexible compliance requirements (such as environmental impact and safety impact) into a quantitative evaluation system to achieve synergistic optimization of technical feasibility and economic rationality, and ensure that the generated route plan has both engineering applicability and cost controllability.

[0023] (3) Provide scientific and data-driven decision support capabilities. Under the premise of meeting various rigid constraints, the system can generate multiple technically feasible and economically optimal candidate path schemes, and perform quantitative verification and comparison based on the refined cost and engineering quantity calculation results, output key indicator comparison data of each scheme, provide objective and comprehensive technical basis for engineering decision-making, and effectively reduce scheme deviations caused by subjective experience differences and algorithm simplification.

[0024] (4) It has good versatility and scalability. This invention is not only applicable to the design of construction access roads in mountainous areas with complex terrain, but also to road planning in flat areas (the constraints can be simplified). After parameter adjustment, it can also be extended to the route optimization scenarios of various linear projects such as power transmission lines, highways, railways, and oil and gas pipelines. It has wide engineering applicability and promotion application value.

[0025] (5) By using path smoothing and curve fitting algorithms to post-process the initial optimized path, the "sawtooth" path phenomenon caused by discrete grid search is effectively eliminated, and a smooth route with continuous linearity that meets the requirements of vehicle driving characteristics and construction technology is generated. This realizes the key transformation from theoretical optimal solution to actual feasible engineering solution and improves the engineering usability of path results. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the operation process of the construction path optimization model in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without innovative effort are within the scope of protection of the present invention.

[0028] See the instruction manual appendix Figure 1 The following is a detailed implementation of the construction path optimization modeling method: S1) Parameter Settings Set relevant parameters for road design, including engineering and technical constraints, earthwork calculation parameters, plant unit price library, road type and construction unit price, transportation cost parameters, weight coefficients and benchmark values ​​for flexibility evaluation, benchmark economic cost per unit length, benchmark flexibility evaluation index per unit length, benchmark length, and width of the proposed road. The engineering constraints refer to the basic technical requirements that ensure the feasibility of the proposed solution; failure to meet these requirements renders the solution infeasible. These constraints include maximum longitudinal slope, minimum turning radius, continuous uphill length, and longitudinal slope continuity. When the road path is represented by a sequence of nodes, the specific constraints are as follows: (1) Longitudinal slope constraint: The ratio of the elevation difference to the horizontal distance between adjacent road nodes is defined as the longitudinal slope, i.e. If the calculated longitudinal slope exceeds the maximum allowable longitudinal slope preset by the system (for example, for a construction access road in a mountainous area, when the maximum allowable angle is 20°, the corresponding longitudinal slope is 0.364), then the route plan is deemed infeasible.

[0029] (2) Turning radius constraint: The circumcircle of three consecutive adjacent path nodes is fitted, and the radius of the circumcircle is used as the actual turning radius of the turning point. If the radius is less than the minimum allowable turning radius set by the system (for example, for heavy engineering vehicle transportation scenarios, the minimum turning radius is set to 12 meters), the path segment is determined to be impassable.

[0030] (3) Consecutive uphill length constraint: The continuous uphill length refers to the cumulative length of a continuous uphill section with a gradient not less than the set lower limit gradient (e.g., 0.03). When the cumulative length exceeds the maximum continuous uphill length specified by the system (e.g., for diesel-powered transport vehicles, the maximum continuous uphill length is 300 meters), the route plan is deemed to not meet the operational safety requirements and is prohibited.

[0031] (4) Longitudinal slope continuity constraint: This is used to assess the smoothness of slope changes between adjacent slope segments, preventing sudden changes from an uphill slope to a sharp downhill slope, and avoiding safety risks caused by obstructed visibility or delayed operation by the driver. The specific verification method is to calculate the algebraic difference of the longitudinal slopes of adjacent slope segments. Its absolute value must not exceed a preset threshold (e.g.) To ensure safe driving in both directions, the route must be checked in both the forward and reverse directions. If the algebraic difference of the longitudinal slope at a certain slope change point in either direction exceeds the limit, then the slope change point is determined to not meet the longitudinal slope continuity requirement.

[0032] (5) Road earthwork calculation parameters: used to accurately estimate the amount of excavation and filling work during the construction of the road, including the following specific parameters: calculation step length (e.g., 5 meters), allowable vertical excavation height on the uphill side of the road (e.g., 2.0 meters), slope ratio of the excavation side on the uphill side (e.g., height: horizontal = 1:0.33), whether filling is allowed on the downhill side (can be set to "yes" or "no"), the terrain slope threshold for allowable filling (e.g., filling is allowed only when the natural terrain slope is not greater than 0.1), allowable filling height on the downhill side of the road (e.g., 1.5 meters), slope ratio of the filling side on the downhill side (height: horizontal = 1:0.33).

[0033] (6) Compensation parameters for seedlings: Establish a database of compensation unit prices for seedlings containing multiple plant types to estimate the compensation cost for vegetation along the route. The database fields include plant name (such as fir, camellia, rice, citrus), plant type (divided into economic crops, economic forests, general tree species, and general crops), growth stage (divided into juvenile stage, growth stage, and peak production stage), and corresponding compensation unit prices for different stages (for example, the compensation unit price for camellia in the peak production stage is 120 yuan / plant, and for general tree species in the growth stage it is 30 yuan / plant).

[0034] (7) Road structure type parameters: The available road types include gravel road, steel plate temporary road, roadbed shaping and compaction road, paddy field special roadbed, etc. Different types correspond to different benchmark construction costs and traffic capacity.

[0035] (8) Transportation cost parameters: used to evaluate the operating costs after the route is put into use, including the expected total number of transportation trips (e.g., 30 trips) and the unit mileage cost per trip (e.g., 20.0 yuan / vehicle·km). Combined with the total route length, the full-cycle transportation cost can be calculated.

[0036] S2) Data loading and plotting processing In a 3D scene loaded with a digital elevation model (DEM) and orthophotos, features are plotted automatically or manually and supplemented by feature recognition, and land occupation-related fees are set; soil and rock types are plotted and set; mandatory avoidance areas are plotted, or avoidance is set in already plotted areas; additional fees are preset for specific areas.

[0037] (1) Ground features include existing roads, ecologically sensitive areas (such as drinking water source protection areas and core areas of nature reserves), forest distribution areas, residential buildings, power lines and communication lines, rivers and water systems, and artificial ditches, which are key ground objects that need to be identified and avoided in route planning.

[0038] (2) Land-related costs include temporary land use compensation, timber felling and seedling compensation, and costs for land reclamation or ecological restoration after the project is completed. Among them, seedling compensation is calculated by automatically matching the preset seedling compensation unit price database with the plant species and specifications involved in the route traversing the area (divided into juvenile, adult, and peak production stages).

[0039] (3) Other additional costs refer to the costs of additional engineering measures incurred due to the route passing through specific terrain or feature areas. For example, when the route needs to cross ditches or small waterways, the cost of laying reinforced concrete culverts should be included, with the standard being a Φ1.0 m circular culvert, the unit price being approximately RMB 800 / meter, and the length calculated as 2 meters beyond the width of the ditch; when crossing areas with weak foundations, the cost of foundation reinforcement treatment needs to be added, with a reference standard of RMB 80 / square meter.

[0040] (4) The mandatory avoidance area is the geographical area that the route plan must avoid, including but not limited to: the ecological protection red line area, the basic farmland protection area, the landslide body, the collapse area, the debris flow prone area and other adverse geological areas, as well as the safety control range of important structures such as high-voltage substations and oil and gas pipelines. If the route plan has a spatial conflict with the above-mentioned areas, it will be directly determined as infeasible.

[0041] (5) For existing roads but areas with insufficient width, the cost of road construction should be considered based on the cost of widening the road. If it is necessary to widen the road by 1.5m, the cost should be considered based on the cost of building a 1.5m road.

[0042] S3) Design Scope Setting Set the start and end points of the construction road, or set an existing road as the start point and set the end point; select a rectangular area that can surround the start and end points as the design calculation range.

[0043] S4) Data Gridding and Attribute Attachment Within the design calculation range, a regular grid of points is generated at equal intervals in the X and Y directions; grid points falling within the avoidance area are marked, and the cost is set to a maximum value far exceeding the engineering cost, retaining all feasible points; through spatial interpolation and overlay analysis, the attribute information of all geographic elements in step S1 is attached to each feasible grid point, forming a gridded basic database with multidimensional attribute data.

[0044] The attribute information of the geographic element includes spatial coordinates (X, Y, Z), land cover type (such as houses, woodland, rivers, power lines, ecologically sensitive areas, etc.), soil and rock type (such as sandy soil, clay, gravelly soil, rock, etc.), topographic slope in eight adjacent directions (for example, the slope value in each direction is calculated using a 5m × 5m grid), vegetation type (such as coniferous forest, broad-leaved forest, shrubland, crops, etc.), and various economic attribute parameters related to the geographic unit.

[0045] The various economic attribute parameters include: temporary land occupation compensation fees (reference standard is 18,000 yuan / mu), forest felling and seedling compensation fees (automatically matched from the preset seedling compensation unit price database according to plant species, specifications and growth stage, such as 120 yuan / tree for peak-growing camellia and 30 yuan / tree for general-growing tree species), land reclamation or ecological restoration fees (reference standard for farmland reclamation is 25,000 yuan / mu, and for forest ecological restoration is 30,000 yuan / mu), and other additional engineering measures fees (such as the cost of 1.0 m reinforced concrete pipe for ditch crossing is listed at 800 yuan / meter, and soft soil treatment is listed at 80 yuan / square meter).

[0046] Based on the basic mesh diagram, its nodes are expanded to state nodes (x,y,z,θ) containing spatial coordinates (x,y,z) and travel direction angle θ, thus constructing a state mesh diagram; The orientation angle θ of the state grid diagram is the direction of travel on the horizontal projection plane. Each state transition edge (U, V) represents the transition from state node U to state node V and stores its geometric information (such as the road segment length d(U,V) and the direction change Δθ).

[0047] By using the orientation angle θ and the standard grid step size, the previous point Prev(U) of state node U can be calculated. Prev(U), U, and V support the calculation of turning angle and turning radius, and also support the calculation of dynamic verification and comprehensive cost (a function of length, turning angle, turning radius, etc.).

[0048] To support the operation and evaluation of path optimization algorithms, the system further outputs the following two types of basic parameters for the algorithms to use: (1) Cost database parameters: include unit construction price per unit length for different road structure types, such as 120 yuan / meter for gravel road, 280 yuan / meter for steel plate temporary road, 90 yuan / meter for roadbed shaping and compaction road, and 450 yuan / meter for paddy field special roadbed section; and also include excavation and filling unit prices for different rock and soil types, such as 18 yuan / cubic meter for ordinary earthwork excavation and 65 yuan / cubic meter for rock excavation.

[0049] (2) Setting parameters: including technical constraint parameters for road engineering design (such as maximum longitudinal slope 0.364, minimum turning radius 12 meters, maximum continuous uphill length 300 meters, longitudinal slope algebraic difference limit 2.5%), refined calculation parameters for road earthwork volume (such as calculation step length 5 meters, maximum excavation height on the uphill side 2.0 meters, excavation slope ratio 1:0.33, allowable filling height on the downhill side 1.5 meters, filling slope ratio 1:0.33), transportation cost parameters (estimated total number of transportation trips, such as 30 trips; single unit length transportation cost, such as 20 yuan / vehicle·km), weight coefficients and benchmark values ​​required for flexibility evaluation (such as environmental impact weight 0.4, safety risk impact weight 0.4, driving comfort weight 0.2)), and benchmark economic cost per unit length (reference value 150 yuan / meter), used for normalized cost comparison, benchmark flexibility evaluation index per unit length (reference value 3), and benchmark length (reference value 400 meters).

[0050] The aforementioned attribute information and parameter set constitute the multi-dimensional input data system of the intelligent path optimization system, supporting multi-objective collaborative optimization analysis of technology, economy, and environment in a three-dimensional terrain environment.

[0051] S5) Coordinate Alignment Align the user-inputted start and end coordinates to the nearest grid point in the digital elevation model to ensure that the path search is performed in a discrete grid space.

[0052] S6) Improved synthesis cost function Based on Dijkstra's algorithm, its cost calculation mechanism is modified to define a cost function that can take into account engineering and technical constraints, avoidance requirements, and comprehensively evaluate the total economic cost and flexibility of the project. This function replaces the simple spatial distance weight to find the shortest path that satisfies the constraints.

[0053] (1) Project economic cost The aforementioned engineering economic cost refers to the comprehensive cost target that needs to be minimized throughout the entire life cycle, which mainly includes direct construction costs, indirect and external costs, transportation costs, and other additional expenses.

[0054] The direct construction costs mentioned above include earthwork, road construction, and other expenses.

[0055] The indirect and external costs mentioned include temporary land occupation fees, compensation for logging and seedlings, and costs for recultivation or ecological restoration.

[0056] The total economic cost function per unit length of the project is defined as follows: Total economic cost per unit length of the project C T =C E +C C +C I +C Y+C Q ; In the formula, C E Cost per unit length of earthwork; C C The cost of road construction per unit length is calculated based on the unit price corresponding to the road width and road type. C I The indirect and external costs per unit length are calculated based on the road width and the unit price data of indirect and external costs. For road widening, only the cost of the widened part is considered. C Y The equivalent transportation cost per unit length; C Q Additional costs per unit length.

[0057] Since accurate earthwork volume depends on three-dimensional cross-sectional analysis after the road route is determined, a nonlinear approximate model based on the ground slope along the route is used here to estimate the earthwork volume per unit length, as shown in the following formula: i1, the slope of the road cross-section terrain; i2, square root slope; W, road width; V E Earthwork volume per unit length P E Earthwork volume unit price; W S The slope width refers to the width of the excavated slope, which is used to calculate the area occupied by the slope due to the excavation process. K E The unit price coefficient for earthwork is categorized by geological conditions into soft soil, ordinary soil, firm soil, gravelly firm soil, soft rock, moderately firm rock, firm rock, and extra firm rock. The unit price coefficients are shown in the table below.

[0058] Table 1 Relative unit price coefficients for various types of soil The equivalent transportation cost per unit length is calculated using the following formula: a. The slope influence conversion factor can be taken as 0.1 to 2.0; b. The slope affects the conversion index, which can be taken as 1.0 to 3.0; i. Road longitudinal slope; c. The turning radius affects the conversion factor, which can be taken as 0.1 to 2.0; d. The turning radius affects the conversion index, which can be taken as 1.0 to 3.0; R, the road turning radius; i0 is the reference slope. If it is 0.06, no correction is made if it is less than the reference slope. R0 is the baseline turning radius. If it is 20m, no correction is made if it is larger than the baseline turning radius. n, the estimated number of transport trips; P Y Transportation cost per unit length.

[0059] (2) Flexibility evaluation The aforementioned flexible evaluation includes assessments of environmental impact, safety risks, and driving comfort.

[0060] Flexibility evaluation index per unit length ; In the formula, w F1 w F2 w F3 For the corresponding weights, satisfying w F1 +w F2 +w F3 =1, and all are greater than or equal to 0; I E , representing the environmental impact index per unit length; I S , representing the safety risk index per unit length; I C , which represents the driving comfort index per unit length.

[0061] The Environmental Impact Index is calculated by weighting and summing the volume of excavated earth and rock, the area of ​​ecologically sensitive land such as forest land, grassland, shrubland, and cultivated land occupied, and their baseline values, combined with the corresponding sensitivity coefficients. The formula is as follows: In the formula, w E1 w E2 w E3 w E4 This corresponds to the sensitivity coefficient; A forest The area of ​​forest land occupied per unit length; A grass The area of ​​grassland and shrubs occupied per unit length; A farm The area of ​​cultivated land occupied per unit length; V ref_T The earthwork volume per unit length is taken as the earthwork volume, for example, the average earthwork volume per unit length of road is 1.5m. A ref_forestThe area of ​​forest land occupied per unit length is taken as a reference, such as taking 20% ​​of the area of ​​the road per unit length; A ref_grass The area occupied by grassland and shrubs is taken as a reference for the unit length, such as taking 20% ​​of the area of ​​the road per unit length; A ref_farm The unit length is based on the area of ​​cultivated land occupied, such as taking 20% ​​of the area of ​​the road per unit length; Safety risk assessment is based on key linear elements such as road longitudinal slope, downhill side slope gradient, and turning radius. A safety risk index is calculated through weighted fusion to quantify the potential driving safety risks of road sections. The formula is as follows: In the formula, w S1 w S2 w S3 For the corresponding weights, satisfying w S1 +w S2 +w S3 =1, and all are greater than or equal to 0.

[0062] i0 is the baseline slope, such as 0.06; R0 is the baseline turning radius, such as 20m; α1, β1, γ1 are exponents, which can be taken as 1.5 to 2.0; i represents the road slope; i down , is the slope of the downhill side of the road; R is the road turning radius; Driving comfort is assessed by considering parameters such as steepness, undulation, and winding terrain. The driving comfort index is calculated using the following formula: In the formula, w C1 w C2 w C3 For the corresponding weights, satisfying w C1 +w C2 +w C3 =1, and all are greater than or equal to 0.

[0063] △i0 is the baseline slope difference, such as 0.02; △i represents the slope difference; α2 is an exponent, which can be taken as 1.5 to 2.5. The ramp load increases non-linearly (higher value is taken for heavy load). β2 is an exponential value, which can be taken as 1.0 to 1.5. Small changes in slope have little effect, while large abrupt changes are more sensitive. γ2 is an exponent, which can be taken as 1.2 to 1.8. The sharper the turn, the faster the discomfort increases. (3) Comprehensive cost function per unit length Unit length comprehensive cost function Fc, the comprehensive cost function per unit length; C ref The benchmark economic cost per unit length can be determined based on previous projects, such as taking 1000 yuan / m; I ref The benchmark flexibility evaluation index per unit length; w1 and w2 are the corresponding weights.

[0064] Overall road cost assessment function L 基准 The baseline road length; n, the number of road segments; Li, the length of the segmented road; By taking into account engineering constraints, avoidance requirements, and an improved comprehensive cost function, the algorithm will automatically prioritize areas with lower comprehensive costs under the premise of engineering and technical constraints, generating an approximate optimal solution path that meets the actual engineering requirements.

[0065] S7) Multi-path generation Based on the improved Dijkstra algorithm in S6, the Yen's algorithm, a path diversity mechanism, is introduced. Alternatively, after finding an optimal path, some key nodes on that path are temporarily disabled sequentially, and the search is repeated to generate the top N economically reasonable paths (N is an integer greater than 1) that meet the constraints, providing a data foundation for scheme comparison and verification.

[0066] Furthermore, the algorithm of this invention supports path optimization in two path start point setting modes: 1) Set the starting point and ending point of the road. The ending point is usually the location of the target project, such as the location of a power transmission line tower or a substation. The algorithm finds the road path.

[0067] 2) Define a starting region, such as an existing road network, and a definite destination. The algorithm does not need to start from a fixed point, but can start from any point within the starting region, autonomously explore, and find a satisfactory solution to the destination.

[0068] In practice, the specified endpoint is used as the starting point of the search, and the algorithm is run in reverse. When the reverse search first encounters any node in the starting area, the path from that node to the endpoint can be considered as a path scheme.

[0069] S8) Spline curve optimization road For each generated path scheme, it is an initial polyline path formed by connecting a series of grid center points. This is used as the control point of the spline curve, and algorithms such as B-spline or cubic spline interpolation are used to generate a smooth and continuous road centerline.

[0070] S9) Scheme Detailed Quantitative Calculation, Verification, and Comparison Review For each optimized spline curve, a precise quantitative calculation and verification is then performed using a digital elevation model to support the selection of alternative solutions.

[0071] (1) Earthwork Calculation. Based on DEM data, for each unit road length a, for example 0.5m, the cross-section method is used. According to the requirements of slope and embankment rules, the excavation and embankment heights of the points on the cross-section are calculated at equal intervals b, for example 0.2m. By accumulating each unit, the earthwork volume of each road scheme is calculated as 0.5m × 0.2m. Areas that are significantly higher than the excavation or embankment limit height are marked to facilitate viewing the excavation situation in combination with the three-dimensional scene and to support scheme comparison.

[0072] (2) Total cost calculation. Using the final actual route, refine the calculation step length c. For example, if the grid is 5m, the step length can be adjusted to 1m. Perform economic cost calculation according to steps and content in S6).

[0073] (3) Environmental impact assessment, safety risk assessment, driving comfort are calculated according to the contents of S6), and the road route after spline curve optimization, with a detailed calculation step.

[0074] (4) Verification of engineering and technical constraints. For each scheme, the key indicators such as maximum longitudinal slope, minimum turning radius, continuous uphill length, and longitudinal slope continuity are calculated based on the road route optimized by spline curves and compared with the set rules for verification.

[0075] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computers or available storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0076] This invention is described with reference to flowchart illustrations and / or block diagrams of systems, methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0077] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0078] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0079] The above methods and steps are compiled into a program and stored on a hard disk or other non-transitory storage medium, which constitutes the technical solution of "a non-transitory readable recording medium" of the present invention; and the storage medium is electrically connected to a computer processor, and the construction path optimization modeling process can be controlled through data processing, which constitutes the technical solution of "a construction path optimization modeling method" of the present invention.

[0080] Another embodiment of a construction path optimization model is provided, including the following modules that are interconnected (these modules are further subdivisions of the functional modules in the invention description): (1) Parameter setting module, which is used for users to configure road design related parameters, including engineering technical constraints, road earthwork calculation parameters, plant unit price library, road type and construction unit price, transportation cost parameters, weight coefficients and benchmark values ​​required for flexibility evaluation, benchmark economic cost per unit length, benchmark flexibility evaluation index per unit length, benchmark length, proposed road width, etc.; and to set the design scope.

[0081] (2) Three-dimensional terrain loading and plotting module, used to automatically plot ground features in a three-dimensional scene with loaded digital elevation model (DEM) and orthophoto, by manual or intelligent ground feature recognition, and set land occupation related fees; plot and set soil and rock types; plot mandatory avoidance areas, or set avoidance areas in already plotted areas; preset other additional fees for specific areas.

[0082] (3) Data output module, used to output coordinates, land cover type, vegetation type and cost grid data required for algorithm analysis; and output parameter setting data.

[0083] (4) Path planning module, used to perform the multi-path search steps, including coordinate alignment, Dijkstra's algorithm based on the mechanism of increasing engineering technical constraints and modification costs, Yen's algorithm which introduces the path diversity mechanism, or temporarily disabling some key nodes on the path after finding an optimal path, and outputting a polyline path with multiple options. (5) Curve fitting module, which receives the polyline path output by the path planning module, generates a smooth plane curve using algorithms such as B-spline or cubic spline interpolation, and superimposes it with the high-precision digital elevation model, re-evaluates the elevation of the curve nodes, and outputs the three-dimensional road path coordinates with accurate elevation information. (6) Scheme comparison module, used to comprehensively evaluate each path scheme, including the calculation of engineering and technical constraints, the results of engineering and technical constraints and avoidance verification, and the composition of economic costs. It also supports environmental impact assessment, safety risk assessment and driving comfort evaluation, and provides list comparison function. (7) Result output module, used to generate visual paths in the three-dimensional scene, supports interactive fine-tuning and local manual optimization of road path nodes; supports outputting a list of road schemes and associating them with road schemes in the three-dimensional scene, supports users to easily switch schemes, and highlights the currently selected scheme in the three-dimensional scene.

[0084] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, 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 modeling optimal construction paths, characterized in that, By embedding Yen's algorithm into Dijkstra's algorithm, introducing engineering constraints and a comprehensive cost evaluation mechanism, a model framework is formed. The following process is then incorporated within this framework to complete the modeling: S1. Set up grid nodes for the passage area including the starting point to the end point, connect each node, and embed geographic three-dimensional coordinates, geology, construction costs and travel direction angle information into each node to form a status grid diagram; S2. Replace the spatial distance weight in Dijkstra's algorithm with a cost function that is a weighted sum of the total engineering economic cost and the flexibility evaluation index, wherein the flexibility evaluation index includes environmental impact, safety risk, and driving comfort; select the straight-line path with the lowest cost that includes all nodes through it using Dijkstra's algorithm, with the line segments between adjacent nodes serving as state transition edges; generate spline curves based on the straight-line path as candidate paths; wherein the cost function is obtained by multiplying the cost function per unit length of each road segment by the length of that road segment and then summing them up. S3. Embed Yen's algorithm, define a state transition edge in the currently generated straight line segment path as a forbidden segment, rerun the above method, generate the next alternative path on the state mesh diagram, until the number of alternative paths meets the preset requirement; S4. Map the multiple alternative paths generated in S3 from the grid space to the digital elevation model, perform engineering constraint verification, calculate the cost function under the digital elevation model for each alternative path that passes the verification, and select the alternative path with the lowest cost as the final path.

2. The construction path optimization modeling method according to claim 1, characterized in that, The unit cost function is designed as follows: ; C T The total economic cost per unit length of the project; I F , representing the flexibility evaluation index per unit length; Fc, the comprehensive cost function per unit length; C ref The benchmark economic cost per unit length; I ref The benchmark flexibility evaluation index per unit length; w1 and w2 are the corresponding weights, satisfying w1+w2=1, and both are greater than or equal to 0.

3. The construction path optimization modeling method according to claim 2, characterized in that, Total economic cost per unit length of the project C T =C E +C C +C I +C Y +C Q ; In the formula, C E Cost per unit length of earthwork; C C The cost of road construction per unit length is calculated based on the unit price corresponding to the road width and road type. C I The indirect and external costs per unit length are calculated based on the road width and the unit price data of indirect and external costs. For road widening, only the cost of the widened part is considered. C Y The equivalent transportation cost per unit length; C Q Additional costs per unit length.

4. The construction path optimization modeling method according to claim 3, characterized in that, Flexibility evaluation index per unit length ; In the formula, w F1 w F2 w F3 For the corresponding weights, satisfying w F1 +w F2 +w F3 =1, and all are greater than or equal to 0; I E , representing the environmental impact index per unit length; I S , representing the safety risk index per unit length; I C , which represents the driving comfort index per unit length.

5. The construction path optimization modeling method according to claim 4, characterized in that, The engineering constraints include the maximum longitudinal slope, minimum turning radius, continuous uphill length, and the requirement that the longitudinal slope continuity must meet the specified requirements. The turning radius is determined by fitting the circumcircle of three consecutive path nodes onto the horizontal projection plane, and using the radius of the circumcircle as the turning radius at that point. The dynamic verification mechanism for path search is defined as follows: when Dijkstra's algorithm performs reverse search, engineering constraint verification is triggered in real time; it is determined whether each state transition edge meets the requirements of maximum longitudinal slope, minimum turning radius, continuous uphill length, and longitudinal slope continuity; if the verification fails, the cost of the state transition edge is considered to be a maximum value that far exceeds the engineering cost, thus being equivalent to an impassable road segment.

6. The construction path optimization modeling method according to claim 5, characterized in that, The starting point can be a starting point on the map or any point in a preset starting area.

7. A non-transitory readable recording medium for storing one or more programs containing multiple instructions, characterized in that, When the instruction is executed, it will cause the processor to perform a construction path optimization modeling method according to any one of claims 1-6.

8. A construction path optimization modeling system, characterized in that, The method includes a processing circuit and a memory electrically coupled thereto, the memory being configured to store at least one program containing a plurality of instructions, the processing circuit running the program being able to execute a construction path optimization modeling method according to any one of claims 1-6.

9. A construction path optimization model, characterized in that... Includes the following modules that are interconnected: The data input module is used to input user-configured road design parameters, including engineering constraints, earthwork calculation parameters, plant unit price library, road type and construction unit price, transportation cost parameters, weight coefficients and benchmark values ​​required for flexibility evaluation, benchmark economic cost per unit length, benchmark flexibility evaluation index per unit length, and benchmark length; as well as to set the design scope; and in a 3D scene loaded with digital elevation model and orthophoto, to automatically plot features using manual or intelligent feature recognition methods, set land occupation fees; plot and set soil and rock types; plot mandatory avoidance areas, and set the areas to be avoided and the starting and ending points of the plotting; Set the step size for generating mesh nodes; set the width of the road to be constructed; The calculation module is used to customize the cost calculation mechanism of Dijkstra's algorithm. It replaces the spatial distance weight with a cost function that is a weighted sum of the total engineering economic cost and the flexibility evaluation index. It selects the straight line path with the lowest cost, which includes multiple passing nodes, and generates spline curves based on the straight line path as candidate paths. The cost function is the unit length cost function composed of the total engineering economic cost and the flexibility evaluation index of each road segment, multiplied by the length of the road segment and then summed. The Yen's algorithm is embedded. It defines one line segment in the generated straight line path as a prohibited segment in turn, and calculates new candidate paths in the same way until the number of candidate paths meets the preset requirements. The verification module is used to re-verify the candidate routes under engineering constraints, retrieve the relevant indicators of each segment of the candidate routes that have passed the verification, conduct a special evaluation, and output the route optimization result. If the optimization result is not satisfactory, the grid is refined in the area formed by the start and end points of the problematic road segment and their adjacent nodes, new nodes are inserted, and the above steps are repeated until a satisfactory route optimization result is output. The data output module is used to output alternative routes and relevant indicators for each road segment under its jurisdiction, as well as coordinates, land cover types, vegetation types, and cost grid data required for algorithm analysis.

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