A three-dimensional path optimization method and system based on digital twinning technology

Abstract

The application discloses a three-dimensional path optimization method and system based on digital twin technology, relates to the technical field of path optimization, and comprises the following steps: collecting three-dimensional model data of a nuclear island plant, real-time dose data of a radiation monitoring system and permission data of an access control system; constructing a multi-layer three-dimensional road network topology model containing horizontal road networks and vertical road networks; constructing a weighted calculation mode, configuring the weight of each factor in the weighted calculation mode according to different constraint conditions, so as to calculate a target path meeting the constraint conditions; performing three-dimensional visualization on the model, rendering a planned path, and displaying a roaming position, a current cumulative radiation dose and a total amount of expected radiation dose in real time. The application integrates a three-dimensional path model in a nuclear power plant, real-time radiation dose and dynamic access permission data, adapts to the demand of different work paths, realizes path optimization under multiple constraint conditions, intuitively displays the path, improves work efficiency and improves the safety of radiation in work.

Description

Technical Field

[0001] This invention relates to the field of path optimization technology, and in particular to a three-dimensional path optimization method and system based on digital twin technology. Background Technology

[0002] During the operation and maintenance of nuclear power plants, the nuclear island area, as the core part, contains critical equipment such as the reactor, steam generator, pressure vessel, and main pumps. Its working environment is characterized by high radiation, complex structure, and restricted access. According to nuclear safety regulations, any personnel entering the nuclear island area must complete rigorous safety training, pass the assessment, and be properly protected before entering. Typically, personnel are not allowed to enter the nuclear island area during routine operation; it is only open during major or minor overhauls to ensure maintenance and inspection work can proceed.

[0003] However, due to the large and complex internal structure of the nuclear island, most of the workers are entering for the first time and often find it difficult to quickly locate the target equipment. This not only reduces work efficiency, but may also lead to excessive time spent in the radiation area due to unfamiliarity with the route, increasing the risk of radiation dose. In addition, the radiation field distribution within the nuclear island is uneven, and the radiation dose varies in different areas. There are strict limits on the annual radiation dose received by workers. Therefore, in actual operations, it is not only necessary to find a feasible path to the target equipment, but also to ensure that the path selection can minimize the cumulative radiation dose exposure.

[0004] Currently, existing path planning relies heavily on two-dimensional drawings or experience-based guidance, lacking intuitive and dynamic three-dimensional visualization path support. This makes it difficult to efficiently cope with complex spatial structures and changes in radiation data under different environments, resulting in low efficiency for operators in the process of optimizing work paths and an inability to scientifically quantify and assess the radiation safety of paths. Summary of the Invention

[0005] The purpose of this invention is to provide a three-dimensional path optimization method and system based on digital twin technology to solve the problems mentioned in the background.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a three-dimensional path optimization method based on digital twin technology, comprising the following steps:

[0007] Step S1: Collect 3D model data of the nuclear island plant, real-time dose data from the radiation monitoring system, and access control data from the access control system;

[0008] Step S2: Based on the 3D model data of the factory building, construct a multi-layer three-dimensional road network topology model that includes horizontal and vertical road networks;

[0009] Step S3: Receive the starting point and ending point information of the path planning through the human-computer interaction device. Based on the road network topology model, real-time dose data and permission data, construct a weighted calculation method that includes path length, radiation dose and access permission. Configure the weight of each factor in the weighted calculation method according to different constraints to calculate the target path that meets the constraints.

[0010] Step S4: Visualize the model in 3D, render the planned path, perform human-computer interaction and character roaming operation, and display the roaming position, current cumulative radiation dose, and expected total radiation dose in real time.

[0011] Preferably, in step S1, the three-dimensional model data includes the spatial coordinates and dimensional parameters of the floor structure, room layout, equipment installation location, stairs, elevators, and ladders. The three-dimensional model is constructed by laser scanning modeling combined with BIM technology. The three-dimensional model data of the nuclear island plant is collected by positioning sensors to collect plant equipment location data and feasible paths. The real-time dose data of the radiation monitoring system is collected by radiation monitoring sensors deployed in the nuclear island plant. The access control status of the access control system is controlled by the access control controller.

[0012] Preferably, in step S2, the steps for constructing the multi-layer three-dimensional road network topology model are as follows:

[0013] S21: Based on the three-dimensional data of the nuclear island plant, the point and line topology data of the horizontal and vertical road networks are generated to form a three-dimensional road network topology structure. The environmental radiation dose and access control data are stored in the multi-layer three-dimensional road network topology structure, and the data is processed.

[0014] S22: Construct feasible paths using points and lines as basic units, bind factory environment data to line segments and nodes of the road network topology in the form of point cloud, and establish real-time association between the factory environment and the model road network.

[0015] Preferably, in step S3, the starting point and ending point information of the path planning are input through the input device. After receiving the input information, the receiving end of the model performs different path optimization calculations and sets constraints. The constraints include one or more combinations of basic constraints that only consider path length, radiation constraints that consider radiation dose safety, access control constraints that disable specific access control, and physical constraints that limit path width and height.

[0016] Preferably, the weighted calculation method in step S3 is implemented through a multi-objective optimization function, which is:

[0017]

[0018] in, Let P be the total cost of the path, and P be the candidate path. These are the weighting coefficients for path length, radiation, and access control, respectively, which can be dynamically adjusted according to operational needs. When radiation is prioritized, Increase, when path length is prioritized. Increase The weight is the actual length of the line segment. The radiation dose weighting of the line segment, As a constraint weight for access control, when a person has the necessary permissions, When personnel do not have the necessary permissions, This indicates that the line segment is impassable.

[0019] Preferably, in step S3, when the constraint condition is a basic constraint considering only path length, the specific process of path calculation is as follows:

[0020] S311: Input the starting point S and the ending point T;

[0021] S312: Set the weight coefficients in the multi-objective optimization function , , ;

[0022] S313: Calculate the suggested paths and lengths from the starting point S to all nodes;

[0023] S314: Output the planned path and length from the starting point S to the ending point T.

[0024] Preferably, in step S3, when the constraint condition is a radiation constraint considering radiation dose safety, the specific process of path calculation is as follows:

[0025] S321: Input the starting point S and the ending point T;

[0026] S322: Set the weight coefficients in the multi-objective optimization function , , ;

[0027] S323: Calculate all reachable paths from the starting point S to the ending point T, where the path length is ≤ suggested path × 1.2;

[0028] S324: Calculate the cumulative radiation dose for each reachable path. ;

[0029] S325: Filter the path with safe cumulative radiation dose. If there are multiple paths with safe cumulative radiation dose, select the target path that meets the constraints and output it, and output the cumulative radiation dose at the same time.

[0030] Preferably, in step S3, when the constraint conditions are a combination of multiple constraints, the specific process of path calculation is as follows:

[0031] S331: Input the starting point S, the ending point T, and the combined constraints, which include disabling specific access control, radiation dose threshold, and path width and height limits;

[0032] S332: Perform preprocessing operations on the road network, mark the nodes corresponding to the disabled access control as impassable, and filter out nodes that exceed the safe range based on radiation dose thresholds;

[0033] S333: Dynamically adjust the weight coefficients of each item in the path multi-objective optimization function according to the current combined constraints;

[0034] S334: Calculate the comprehensive cost of each feasible path based on the adjusted multi-objective optimization function. ;

[0035] S335: Output the recommended solution that satisfies all constraints and meets the overall cost control requirements.

[0036] Preferably, in step S4, the radiation dose and cumulative radiation dose of the person's current location are displayed in real time through model visualization. When the cumulative dose approaches the threshold, an audible and visual warning is issued through a preset radiation dose warning device. At the same time, the radiation dose is represented by the depth of point cloud color, and the path line segments are marked with color according to the cumulative radiation dose, so as to intuitively display the risk area of ​​radiation exposure.

[0037] A three-dimensional path optimization system based on digital twin technology includes:

[0038] A data acquisition and management module, which is used to collect and manage factory data, radiation data, and access control data;

[0039] A road network topology modeling module, which is used to construct and maintain a multi-layer three-dimensional road network topology model;

[0040] A path optimization calculation engine, which is used to execute the path calculation steps and run the path optimization algorithm;

[0041] The 3D visualization and interaction module is used to realize the rendering of the planned path and the character roaming function. The character roaming function supports moving along the planned path from a first-person or third-person perspective, and dynamically displays the current radiation dose and the total cumulative radiation dose from the starting point in the roaming interface.

[0042] The technical effects and advantages of this invention are as follows:

[0043] (1) This invention integrates the three-dimensional model of the path in the nuclear power plant, real-time radiation dose and dynamic access control data, and through the proposed comprehensive weighted calculation method, dynamically adjusts the weights of path length, radiation dose and access control to adapt to the needs of different work paths, realizes path optimization under multiple constraints, and improves work efficiency and radiation safety during work by visualizing the path.

[0044] (2) This invention constructs a multi-layer three-dimensional road network topology model that combines spatial structure, radiation safety and access rights. It abstracts horizontal and vertical channels into a point-line topology, realizes the three-dimensional path connectivity expression across floors, and associates all horizontal and vertical line segments through node numbering to ensure the accessibility and path feasibility of any location. It provides a comprehensive data foundation for path planning, avoids the phenomenon of low work efficiency caused by unreasonable work paths, and is applicable to path planning under different spatial structures.

[0045] (3) This invention calculates and selects different paths under the constraints of single shortest path, minimum radiation and combined conditions of access control and size restriction, supports preprocessing filtering and dynamic weight adjustment, improves the practicality of path optimization, and displays the current position dose, cumulative dose and expected final dose in real time in the three-dimensional visualization interface, and intuitively identifies the radiation distribution through color gradient, and sets up a two-level early warning mechanism to enhance the radiation risk prevention and control capabilities of personnel.

[0046] (4) This invention supports human roaming and real-time positioning by applying different input forms and rendering the planned path in the three-dimensional model. It uses color depth to represent radiation level, making high-risk areas clear at a glance, improving the intuitiveness and ease of operation of maintenance work. It realizes the linkage between personnel positioning and access control through positioning terminal and access control. Before path calculation, it verifies permissions and excludes unpassable road sections, which not only ensures the security of area access, but also improves the accuracy of operation risk prediction and the reliability of path planning. Attached Figure Description

[0047] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0048] Figure 1 This is a schematic diagram of the method steps of the present invention;

[0049] Figure 2 This is a schematic diagram of the horizontal road network display of the present invention;

[0050] Figure 3 This is a room radiation point cloud display diagram of the present invention;

[0051] Figure 4 This is a character roaming display diagram of the present invention;

[0052] Figure 5 This is the planning path calculation framework of the present invention. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] This invention provides, for example Figures 1-5 The method for 3D path optimization based on digital twin technology, as shown, includes the following steps:

[0055] Step S1: Collect 3D model data of the nuclear island plant, real-time dose data from the radiation monitoring system, and access control data from the access control system;

[0056] The 3D model data includes the spatial coordinates and dimensional parameters of the floor structure, room layout, equipment installation locations, stairs, elevators, and ladders. The 3D model is constructed by laser scanning modeling combined with BIM technology. The 3D model data of the nuclear island plant is collected by positioning sensors to collect plant equipment location data and feasible paths. The real-time dose data of the radiation monitoring system is collected by radiation monitoring sensors deployed in the nuclear island plant, such as gamma-ray sensors and neutron sensors. The data collection timestamp, sensor number, and sensor location coordinates are collected synchronously. The access control system is controlled by the access control controller. The access control system is uniformly managed by the access control controller, and the specific location of personnel is obtained in real time with the help of Beidou / GPS wireless positioning terminals deployed on personnel, realizing the collaborative management of access control and dynamic location monitoring of personnel.

[0057] Step S2: Based on the 3D model data of the factory building, construct a multi-layer three-dimensional road network topology model that includes horizontal and vertical road networks;

[0058] The steps for constructing a multi-layered three-dimensional road network topology model are as follows:

[0059] S21: Based on the three-dimensional data of the nuclear island plant, the point and line topology data of the horizontal and vertical road networks are generated to form a three-dimensional road network topology structure. The data of the horizontal road network includes inspection routes and feasible passages. The construction of the horizontal road network is based on the floor division of the nuclear island plant, and the passages in each floor are abstracted into topological nodes and topological line segments. The construction of the vertical road network is based on the stairs, elevators and ladders connecting different floors, which are abstracted into special topological line segments and connected with the horizontal road network of each floor to form a complete three-dimensional road network topology structure.

[0060] The environmental radiation dose and access control data are stored in a multi-layered three-dimensional road network topology, and the data is processed. Temperature, humidity and air quality data of the factory are collected. The radiation dose data is updated every 30 minutes, and the access control data includes access control name, access control code, authorized personnel list and access time information.

[0061] S22: Feasible paths are constructed using points and lines as basic units. The 3D model data of the factory is based on points and lines. Points include inflection points, access control points, and passage endpoints, while lines represent feasible paths between two points. The factory environment data is bound to line segments and nodes of the road network topology in the form of a point cloud, establishing a real-time association between the factory environment and the model road network. Point attributes include number, type, coordinates (X / Y / Z), radiation dose, and associated access control code. The type includes, but is not limited to, inflection points, For access control and room entrances / exits, the radiation dose is based on the most recently bound sensor data. Line attributes include number, endpoint number, length, width, height, average radiation dose, and access restrictions. The average radiation dose is calculated by weighting the radiation dose of the nodes at both ends of the line segment with the line segment length. The vertical road network uses stairs, elevators, and ladders as vertical channels to connect horizontal road networks across different floors. The attributes of the lines corresponding to the vertical road network data include travel speed, with elevators having a higher travel speed than stairs, and stairs having a higher travel speed than ladders. The horizontal road network is constructed using buildings as the basic unit. Based on daily inspection routes and equipment distribution patterns, feasible channels are extracted from the 3D model of each floor. Feasible channels are defined by path inflection points, access control locations, room entrances / exits, and straight lines and curves between two points. Through the connection between the horizontal and vertical road networks, all horizontal and vertical segments are associated through node numbers, forming an integrated horizontal-vertical three-dimensional path structure. This ensures that any room and equipment point can achieve feasibility and accessibility through the connection of nodes and road segments.

[0062] Step S3: Receive the starting and ending point information of the route planning through a human-computer interaction device, which may include a touch screen, keyboard, voice input device, or mobile terminal APP, etc. Based on the road network topology model, real-time dose data, and access permission data, construct a comprehensive weighted calculation method that includes path length, radiation dose, and access permission. Configure the weights of each factor in the weighted calculation method according to different constraints to calculate the target path that meets the constraints, thereby achieving accurate calculation of the optimal path.

[0063] After submitting the start and end point information of the path planning via the input device, the model's receiving end will acquire and parse the input content and initiate the path optimization calculation process. Users can set different constraints according to their actual needs. These constraints include basic constraints that only consider path length, radiation constraints that consider radiation dose safety, access control constraints that disable specific access points, and physical constraints that require the path to meet minimum width and height limits. Combinations of these constraints are also possible.

[0064] The weighted calculation method is implemented through a multi-objective optimization function, which is:

[0065]

[0066] in, Let P be the total cost of the path, and e be the candidate path and the path segment. These are the weighting coefficients for path length, radiation, and access control, respectively, which can be dynamically adjusted according to operational needs. When radiation is prioritized, Increase, when path length is prioritized. Increase; The actual length weight of the line segment, in meters; The radiation dose weighting of the line segment, = Radiation dose × The unit is μSv, and the radiation dose weight represents the expected radiation dose for this line segment. Used to indicate the expected radiation dose through this line segment; As a constraint weight for access control, when a person has the necessary permissions, When personnel do not have the necessary permissions, This indicates that the line segment is impassable. At the same time, the multi-objective optimization function, i.e. the multi-condition constraint path optimization algorithm, also sets path physical constraints, including the minimum line segment width w_min and the minimum line segment height h_min, to ensure that the path meets the size requirements of the passing equipment / personnel. When constraining the path physical constraints, paths without the conditions can be filtered out.

[0067] When performing path optimization, the factory must ensure that the signal covers the entire road network segment to avoid data blind spots, and verify personnel permissions before path calculation to exclude impassable paths in advance and improve calculation efficiency.

[0068] When the constraint is a basic constraint that only considers path length, i.e., when the shortest path navigation needs to be selected, the specific process of path calculation is as follows:

[0069] S311: Input the starting point S and the ending point T;

[0070] S312: Set the weight coefficients in the multi-objective optimization function , , ;

[0071] S313: Calculate the suggested paths and lengths from the starting point S to all nodes. Here, the suggested path refers to the shortest path.

[0072] S314: Outputs the planned path and length from the starting point S to the ending point T, i.e. the shortest path and length.

[0073] When the constraint is a radiation constraint that considers radiation dose safety, i.e., when selecting the path with the minimum radiation dose for navigation, the specific process of path calculation is as follows:

[0074] S321: Input the starting point S and the ending point T;

[0075] S322: Set the weight coefficients in the multi-objective optimization function , , ;

[0076] S323: Calculate all reachable paths from the starting point S to the ending point T, where the path length is ≤ suggested path × 1.2, and the suggested path is the shortest path;

[0077] S324: Calculate the cumulative radiation dose for each reachable path. ;

[0078] The cumulative radiation dose is calculated by summing the rainy season exposure doses of all the topological segments it contains; the formula for calculating the expected exposure dose of a single topological segment is as follows:

[0079] ;

[0080] S325: Filter the path with safe cumulative radiation dose. The lower the radiation dose, the safer it is. If there are multiple paths with safe cumulative radiation dose, select the target path that meets the constraints and output it, that is, the shortest path, and output the cumulative radiation dose at the same time.

[0081] By planning the minimum radiation path, it is easier to reduce contact with high-risk areas, lower the radiation exposure dose of equipment personnel, and improve work efficiency.

[0082] When there are multiple constraints, i.e., when there are multiple access control restrictions, radiation dose limits, and path physical conditions, the specific steps for path calculation are as follows:

[0083] S331: Input the starting point S, the ending point T, and the combined constraints. The combined constraints include disabling specific access control, radiation dose thresholds, and path width and height limits.

[0084] S332: Perform preprocessing operations on the road network, mark the nodes corresponding to the disabled access control as impassable, remove path edges that do not meet the width and height constraints, and filter out nodes that exceed the safe range based on the radiation dose threshold;

[0085] S333: Based on the current combined constraints, dynamically adjust the weight coefficients of each item in the multi-objective optimization function of the path, such as the weight of factors like the number of access points, cumulative radiation dose, and path length;

[0086] S334: Calculate the comprehensive cost of each feasible path based on the adjusted multi-objective optimization function. When available paths are significantly reduced due to access control restrictions, Appropriately increase the weighting of access control-related factors and reassess the overall passage cost of the route. ;

[0087] S335: Output the recommended travel plan that satisfies all constraints and meets the overall cost control requirements, i.e., the optimal travel plan with the minimum overall path cost.

[0088] By coordinating the control of various constraints such as access control permissions, radiation safety, and physical access conditions, the probability of access control permission conflicts can be effectively reduced, and the actual passability of the path can be verified in advance, thereby improving the accuracy of operational risk prediction and the reliability of path planning.

[0089] Step S4: Visualize the model in 3D, render the planned path (i.e., the optimal path), perform human-computer interaction and character roaming operation, and display the roaming position, current cumulative radiation dose, and expected total radiation dose in real time.

[0090] The system visualizes and displays the radiation dose and cumulative radiation dose at a person's current location in real time, and also shows the roaming location of the staff based on their location. When the cumulative dose approaches the threshold, a preset radiation dose warning device issues an audible and visual warning. When the cumulative radiation dose reaches 80% of the threshold, a level one warning is triggered, enabling the warning device to provide audible and visual alerts. When the threshold is reached, a level two warning is triggered, prompting the personnel to pause, providing audible and visual alerts, and displaying a pop-up message. The system then recalculates and provides a recommended evacuation route with the minimum radiation dose. Simultaneously, the system uses the depth of point cloud color to represent radiation dose, and path segments are marked with colors according to the cumulative radiation dose, visually displaying the risk areas of radiation exposure. Radiation dose distribution can be represented by dark blue, blue, green, yellow, and red. Dose ≤0.1μSv / h is dark blue, 0.1-0.15μSv / h is blue, 0.5-1μSv / h is green, 1-5μSv / h is yellow, and >5μSv / h is red. The color depth indicates the level of radiation, making high-risk areas immediately apparent and improving the intuitiveness and ease of operation of maintenance tasks.

[0091] Visualized walkthroughs and dosage warnings facilitate early risk avoidance and improve the safety and efficiency of nuclear power plant operation and maintenance.

[0092] A three-dimensional path optimization system based on digital twin technology includes:

[0093] The data acquisition and management module is used to collect and manage plant data, radiation data, and access control data. Data acquisition utilizes radiation monitoring sensors, access controllers, and positioning devices to collect real-time radiation dose rate data, access control status data, and personnel / equipment location data within the nuclear island plant. The collected data is stored through a multi-source data fusion platform, including geometric data, road network data, environmental data, and access control data. Geometric data is the 3D model of the nuclear island plant, including floor structure, room layout, and stair and elevator locations. Road network data comprises point and line topology data for both horizontal and vertical road networks. Horizontal road network data corresponds to the topology of inspection routes and passageways within the nuclear island plant, while vertical road network data corresponds to the topology of stairs, elevators, and ladders within the nuclear island plant. Environmental data includes radiation dose rate data, temperature and humidity data, and air quality data, with radiation dose rate data updated every 30 minutes. Access control data includes access control names, access control codes, authorized personnel lists, and access time information.

[0094] The road network topology modeling module is used to construct and maintain multi-layered three-dimensional road network topology models. The model includes a 3D road network topology model and an environmental dynamic mapping model. The 3D road network topology model uses points and lines as basic units. Points include inflection points, access points, and passage endpoints, while lines represent feasible paths between two points. In the 3D road network topology model, point attributes include number, type, coordinates, radiation dose rate, and associated access control code. Types include inflection points, access points, and room entrances / exits. Line attributes include number, start point number, end point number, length, width, height, average radiation dose rate, and passage... Line restrictions are imposed, and the average radiation dose rate is calculated by weighting the radiation dose rates of the nodes at both ends of the line segment with the length of the line segment. The attributes of the line corresponding to the vertical road network data also include the passage speed. The environmental dynamic mapping model is used to bind environmental data to road network topology nodes and line segments in the form of point cloud, so as to realize the real-time association between environmental data and road network. By setting up Beidou / GPS terminals on personnel to realize personnel positioning, and linking access control according to personnel information, the system verifies permissions and excludes impassable road segments before path calculation, thus ensuring the security of area access and improving the effectiveness and reliability of path planning.

[0095] The path optimization calculation engine is used to execute path calculation steps and run path optimization algorithms. Based on the multi-condition constraint path optimization algorithm in the above method, the optimal path is calculated by inputting the starting point, ending point and constraint conditions.

[0096] The 3D visualization and interaction module is used to render the planned path and enable character roaming. The character roaming function supports movement along the planned path from a first-person or third-person perspective, and dynamically displays the current radiation dose and the total cumulative radiation dose from the starting point in the roaming interface. The 3D visualization and interaction module includes a path navigation unit, a visualization roaming unit, a radiation dose warning unit, and an access control unit, which are used to realize path navigation, virtual roaming, radiation warning, and access control verification functions.

[0097] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional path optimization method based on digital twin technology, characterized in that, Includes the following steps: Step S1: Collect 3D model data of the nuclear island plant, real-time dose data from the radiation monitoring system, and access control data from the access control system; Step S2: Based on the 3D model data of the factory building, construct a multi-layer three-dimensional road network topology model that includes horizontal and vertical road networks; Step S3: Receive the starting point and ending point information of the path planning through the human-computer interaction device. Based on the road network topology model, real-time dose data and permission data, construct a weighted calculation method that includes path length, radiation dose and access permission. Configure the weight of each factor in the weighted calculation method according to different constraints to calculate the target path that meets the constraints. Step S4: Visualize the model in 3D, render the planned path, perform human-computer interaction and character roaming operation, and display the roaming position, current cumulative radiation dose, and expected total radiation dose in real time.

2. The three-dimensional path optimization method based on digital twin technology according to claim 1, characterized in that: In step S1, the three-dimensional model data includes the spatial coordinates and dimensional parameters of the floor structure, room layout, equipment installation location, stairs, elevators, and ladders. The three-dimensional model is constructed by laser scanning modeling and combined with BIM technology. The three-dimensional model data of the nuclear island plant is collected by positioning sensors to collect plant equipment location data and feasible paths. The real-time dose data of the radiation monitoring system is collected by radiation monitoring sensors deployed in the nuclear island plant. The access control status of the access control system is controlled by the access control controller.

3. The three-dimensional path optimization method based on digital twin technology according to claim 1, characterized in that: In step S2, the steps for constructing the multi-layer three-dimensional road network topology model are as follows: S21: Based on the three-dimensional data of the nuclear island plant, the point and line topology data of the horizontal and vertical road networks are generated to form a three-dimensional road network topology structure. The environmental radiation dose and access control data are stored in the multi-layer three-dimensional road network topology structure, and the data is processed. S22: Construct feasible paths using points and lines as basic units, bind factory environment data to line segments and nodes of the road network topology in the form of point cloud, and establish real-time association between the factory environment and the model road network.

4. The three-dimensional path optimization method based on digital twin technology according to claim 1, characterized in that: In step S3, the starting point and ending point information of the path planning are input through the input device. After receiving the input information, the receiving end of the model performs different path optimization calculations and sets constraints. The constraints include one or more combinations of basic constraints that only consider path length, radiation constraints that consider radiation dose safety, access control constraints that disable specific access control, and physical constraints that limit path width and height.

5. The three-dimensional path optimization method based on digital twin technology according to claim 4, characterized in that: The weighted calculation method in step S3 is implemented through a multi-objective optimization function, which is: in, Let P be the total cost of the path, and P be the candidate path. These are the weighting coefficients for path length, radiation, and access control, respectively, which can be dynamically adjusted according to operational needs. When radiation is prioritized, Increase, when path length is prioritized. Increase The weight is the actual length of the line segment. The radiation dose weighting of the line segment, As a constraint weight for access control, when a person has the necessary permissions, When personnel do not have the necessary permissions, This indicates that the line segment is impassable.

6. The three-dimensional path optimization method based on digital twin technology according to claim 5, characterized in that: In step S3, when the constraint condition is a basic constraint that only considers path length, the specific process of path calculation is as follows: S311: Input the starting point S and the ending point T; S312: Set the weight coefficients in the multi-objective optimization function , , ; S313: Calculate the suggested paths and lengths from the starting point S to all nodes; S314: Output the planned path and length from the starting point S to the ending point T.

7. The three-dimensional path optimization method based on digital twin technology according to claim 5, characterized in that: In step S3, when the constraint condition is a radiation constraint considering radiation dose safety, the specific process of path calculation is as follows: S321: Input the starting point S and the ending point T; S322: Set the weight coefficients in the multi-objective optimization function , , ; S323: Calculate all reachable paths from the starting point S to the ending point T, where the path length is ≤ suggested path × 1.2; S324: Calculate the cumulative radiation dose for each reachable path. ; S325: Filter the path with safe cumulative radiation dose. If there are multiple paths with safe cumulative radiation dose, select the target path that meets the constraints and output it, and output the cumulative radiation dose at the same time.

8. The three-dimensional path optimization method based on digital twin technology according to claim 5, characterized in that: In step S3, when the constraints are a combination of multiple constraints, the specific process of path calculation is as follows: S331: Input the starting point S, the ending point T, and the combined constraints, which include disabling specific access control, radiation dose threshold, and path width and height limits; S332: Perform preprocessing operations on the road network, mark the nodes corresponding to the disabled access control as impassable, and filter out nodes that exceed the safe range based on radiation dose thresholds; S333: Dynamically adjust the weight coefficients of each item in the path multi-objective optimization function according to the current combined constraints; S334: Calculate the comprehensive cost of each feasible path based on the adjusted multi-objective optimization function. ; S335: Output the recommended solution that satisfies all constraints and meets the overall cost control requirements.

9. The three-dimensional path optimization method based on digital twin technology according to claim 1, characterized in that: In step S4, the radiation dose and cumulative radiation dose of the person's current location are displayed in real time through model visualization. When the cumulative dose approaches the threshold, an audible and visual warning is issued through a preset radiation dose warning device. At the same time, the radiation dose is represented by the color depth of the point cloud, and the path line segments are marked with colors according to the cumulative radiation dose, intuitively showing the risk area of ​​radiation exposure.

10. A three-dimensional path optimization system based on digital twin technology according to claim 1, characterized in that, include: A data acquisition and management module, which is used to collect and manage factory data, radiation data, and access control data; A road network topology modeling module, which is used to construct and maintain a multi-layer three-dimensional road network topology model; A path optimization calculation engine, which is used to execute the path calculation steps and run the path optimization algorithm; The 3D visualization and interaction module is used to realize the rendering of the planned path and the character roaming function. The character roaming function supports moving along the planned path from a first-person or third-person perspective, and dynamically displays the current radiation dose and the total cumulative radiation dose from the starting point in the roaming interface.

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