A traffic network recovery method considering topology reconfiguration and passenger flow backtracking

Abstract

A traffic network recovery method considering topology reconstruction and passenger flow backtracking, comprising the following steps: S1, data preparation; S2, node state determination and parameter initialization; S3, selection and repair of nodes to be recovered; S4, topology reconstruction of recovered nodes; S5, passenger flow backtracking of recovered nodes; S6, calculation of network resilience index; S7, evolution termination determination. Through the method, the dynamic change process of the topology structure and the traffic passenger flow during the traffic network recovery can be finely modeled, and the network recovery effect can be quantitatively evaluated through multiple indexes, thereby laying a foundation for the traffic network resilience improvement and resource allocation optimization.

Description

Technical Field

[0001] This invention belongs to the field of virtual transportation system network basic database analysis, and relates to a transportation network recovery method that considers topology reconstruction and passenger flow tracing. Background Technology

[0002] With the rapid development of transportation infrastructure construction technology in my country, urban and regional transportation systems have formed complex and highly coupled transportation networks, serving the diverse travel needs of travelers at all times and in all modes of transportation. During the long-term operation of these networks, they are frequently affected by various unforeseen and uncertain factors such as extreme weather, geological disasters, traffic accidents, and human disturbances, leading to a decline or even failure of the operational capacity of some traffic nodes or routes, thereby disrupting network connectivity and reducing traffic efficiency. Therefore, when a transportation network is disturbed, the rapid restoration of its network topology and traffic operation functions is crucial for enhancing its resilience and safety.

[0003] The process of traffic network recovery includes not only the structural repair of failed nodes or lines, but also the dynamic adjustment of passenger flow after node repair. When a node fails, its passenger flow is transferred to neighboring nodes. When the node is repaired, the original network topology is re-established, the network structure is updated, and the transferred passenger flow returns to the node through dynamic backflow and redistribution to improve traffic efficiency. This process is mainly characterized by topology reconstruction and passenger flow tracking under traffic network recovery, and its recovery effect directly impacts the resilience and operational performance of the traffic network system.

[0004] Current traffic network recovery methods focus on representing the recovery process as nodes rejoining the network and evaluating changes in network performance. This process assumes the network structure remains unchanged during recovery, failing to reflect the dynamic process of network topology connectivity and road segment reconstruction after node repair. Furthermore, existing methods often neglect the traffic flow transferred during node failure and the passenger flow backtracking and redistribution behavior during node recovery, thus failing to describe the dynamic allocation process of traffic demand as the network recovers, leading to discrepancies between the network recovery effect and actual traffic operation. Based on this, this patent proposes a traffic network recovery method that considers topology reconstruction and passenger flow backtracking, providing a practical new solution for topology evolution and passenger flow updates under traffic network recovery. By constructing a network topology reconstruction mechanism oriented towards the node repair process and passenger flow backtracking and redistribution rules based on transferred traffic, refined modeling and optimization of the traffic network recovery process are achieved, thereby improving the recovery efficiency and system resilience of the traffic network after disturbance failure propagation, laying the foundation for further comprehensive traffic network resilience decision optimization. Summary of the Invention

[0005] To address the technical issues mentioned above, this invention proposes a traffic network recovery method considering topology reconstruction and passenger flow retrospection. The method includes sequential steps such as data preparation, node state determination and parameter initialization, selection and repair of nodes to be recovered, topology reconstruction of recovered nodes, passenger flow retrospection of recovered nodes, calculation of network resilience indicators, and determination of evolution termination. This method allows for refined modeling of the topology and dynamic changes in traffic flow during traffic network recovery, and quantitative evaluation of network recovery effectiveness using multiple indicators, thereby laying the foundation for improving traffic network resilience and optimizing resource allocation.

[0006] To achieve the above-mentioned technical objectives, the technical solution of the present invention is as follows:

[0007] A traffic network restoration method considering topology reconstruction and passenger flow retracing includes the following steps:

[0008] Step 1, Data Preparation: This step requires preparing data including the basic network and a list of failed nodes. Set of road segments associated with non-transferable failed nodes Transfer record set Backup node set Backup road segment collection This includes related information. The basic transportation network and various data obtained in Step 1 lay the foundation for topology reconstruction and passenger flow tracing in subsequent transportation network restoration.

[0009] The first step is to generate the basic transportation network. This step involves reading information such as the number of nodes and road segments in the transportation network, node attributes (including node number, node type, node coordinates, node status, and node passenger flow), the topological adjacency relationships between nodes, and road segment attributes (including road segment number, road segment start and end point, road segment length, road segment type, road segment level, road segment speed limit, number of lanes, road segment traffic flow, and road segment status) to generate the basic transportation network.

[0010] List of failed nodes This includes all nodes in the transportation network that have lost their traffic operation function, recording the node's ID, degree, betweenness centrality, and passenger flow information in the initial network state. Untransferred failed nodes refer to nodes that cannot transfer their passenger flow to neighboring nodes. When these nodes fail, their surrounding neighboring nodes are also in a failed state, preventing the transfer of their passenger flow. The set of associated road segments for untransferred failed nodes stores the connected road segments and their corresponding traffic flows. Transfer record set. It stores the passenger flow information transferred to adjacent nodes when each failed node fails, recording information such as the transferring node, receiving node, transferred passenger flow, transfer time, and receiving time.

[0011] Backup node set and backup road segment set This stores the basic attribute information of each node and road segment in the initial state of the network.

[0012] Step 2, Node State Determination and Parameter Initialization. Before starting network recovery, the evolution time is first initialized. =0, maximum evolution time Node bearing capacity coefficient Network repair resources (M), available repair resources Node unit repair speed Parameters such as these are then used. The set of failed nodes is then read to determine each node in the basic transportation network. The state of the node. If the node If it is in a normal state, then State value If node If it is a failed node, then State value At the same time, each node The load-bearing capacity was calculated as , For the moment of evolution Passenger flow at specific times.

[0013] After reading and determining the state of each node in the network, a network recovery strategy needs to be determined. There are four types: degree-based recovery strategy, betweenness centrality-based recovery strategy, node flow-based recovery strategy, and random recovery strategy. The first three strategies select nodes to be recovered based on their corresponding indicator values ​​(such as node degree and betweenness centrality) in the initial network state. The random recovery strategy randomly selects nodes for recovery.

[0014] Step 3: Selection and Repair of Nodes to be Restored. Based on the network recovery strategy and the amount of available repair resources, select nodes from the set of failed nodes. Select failed nodes for repair. Each selected node will be treated as a node to be recovered. And calculate its repair time. Then, each node to be recovered... and its repair time Newly added to the repair queue In the middle. For those already in the repair queue The nodes in the process are configured to have a repair time. Finally, iterate through the repair queue. If the node to be recovered If the repair time is 0, then Repair complete and add to recovery candidate set The specific implementation steps are as follows:

[0015] Step 31, determine the current number P of available repair resources. If Then from the set of failed nodes Based on the determined network recovery strategy, P failed nodes are selected for repair, and the value of each failed node is calculated according to the following formula. Repair time After completing the calculation, the nodes Add to repair queue In the middle. If If this is the case, it means that all repair resources have been used to repair the failed node, and proceed to step 32.

[0016]

[0017] Step 32, traverse the repair queue Each non-newly added node in the queue Update its repair time .

[0018] Step 33, for Each node Repair time Make a judgment. If 0, then node Repair complete and store the node in the recovery candidate set. Otherwise, continue with... The next node is then evaluated.

[0019] Step 4, Reconstruct the topology of the restored nodes. Based on the backup node set. Rebuild nodes in the network And generate its basic attribute information. Then, based on the backup road segment set... Traverse the search nodes In the current network Adjacent nodes The section of road between Regenerate adjacency relationships and construct road segments The specific implementation steps are as follows:

[0020] Step 41, traverse the candidate set for recovery Each node Processing is performed based on the backup node set. Reconstructing nodes in the network It generates basic attribute information, including node number, node spatial location, and node type.

[0021] Step 42, according to Middle node The adjacency relationships in the initial state, for the current time... Each of the adjacent nodes Perform a determination. If the adjacent node At the current evolutionary moment If it does not yet exist in the network, it indicates that the node has not yet recovered. At this point, Store in the set of adjacent nodes to be restored and record and The corresponding road sections to be processed If adjacent nodes If it exists on the network, it can be restored directly. and The adjacency relationship between them, and Rejoin The list of adjacent nodes.

[0022] Step 43, traverse the nodes Each neighbor node in the neighbor node list In the backup road segment set Search for the corresponding road segment The road segment reconstruction is completed. During the road segment construction process, its basic attribute information is generated simultaneously, including road segment number, road segment length, road segment start and end points, road segment type, road segment level, etc.

[0023] Step 44, determine the node Does it exist in the set of adjacent nodes to be restored? In the middle. If it exists, it means there are still nodes. The relevant road sections awaiting processing need to be restored. These road sections, in particular, refer to those at the nodes... Before recovery, its adjacent nodes It has been restored, but due to node... If a road segment is temporarily missing, preventing reconstruction from being completed, proceed to step 45; otherwise, proceed to step 46.

[0024] Step 45, Traverse middle Each road segment to be processed And then reconstruct it to generate its basic road segment attribute information. After completing the reconstruction... After all the road segments to be processed are reconstructed, From the set of adjacent nodes to be restored Delete it.

[0025] Step 46, for the recovered nodes The state value at the current moment Assign a range A random number is generated within the node to indicate that the node has returned to a normal state. Then, the node... Passenger flow The flow of the road segments connected to it is reinitialized to 0.

[0026] Step 5, passenger flow tracing at the restored node. When the node After completing the topology reconstruction, based on the transfer traffic library Set of road segments associated with non-transferable failed nodes right Perform passenger flow tracking and reload. The node passenger flow and Passenger flow will be redistributed across interconnected road sections. The specific implementation steps are as follows:

[0027] Step 51, traverse and restore the candidate set Each node in Process it.

[0028] Step 52: Traverse the set of road segments associated with the failed nodes that have not been moved. For each road segment, if that road segment One endpoint is The other endpoint If the traffic exists in the network at the current moment, then the traffic for the corresponding road segment will be loaded. Up, and simultaneously update the nodes using the following formula Passenger flow:

[0029]

[0030] Step 53, Traverse the transfer traffic database For any transfer record in the data, if the transfer node of that node is... And receiving node If the record exists in the network at the current moment, then store it in [the appropriate location]. Activation transfer record set In the middle; if the receiving node of the record is And the transfer node If the record exists in the current network, then write the record to... Activation receiving record set middle.

[0031] Step 54, for Activation transfer record set and activate the receiving record set Make a judgment.

[0032] ① At this point, both sets are empty, indicating that the nodes... There are no active transfer or receipt records, so there is no need to perform passenger flow tracing. Proceed to step 58.

[0033] ② At this point, the node... If only an active transfer record exists and no receiving record exists, proceed to step 55 and skip steps 56-57.

[0034] ③ At this point, the node... If an active receiving record exists, the transferred passenger flow received must first be calculated and returned, proceeding to step 55.

[0035] Step 55, Traverse the transfer record set Each record in the database. For Adjacent nodes ,if ,but Able to return transferred passenger flow Give Synchronously update neighboring nodes Passenger flow:

[0036]

[0037] if ,illustrate Not enough passenger flow to return to At this point, the transfer record will not be returned and will be deleted.

[0038] After processing each record in the transfer record set, the calculation is performed. Total recovered passenger flow can be obtained through passenger flow tracing. :

[0039]

[0040] Step 56, traverse the received record set For each record in the database, calculate It is necessary to repay the upstream neighboring contributing nodes. Total passenger flow :

[0041]

[0042] Step 57, Calculate the nodes Current total effective passenger flow .if This indicates the recovery node. Unable to repay all customers, the remaining customer traffic will be deleted. Each transfer record in the set; if , indicating nodes It can repay all returned customer traffic. Update nodes sequentially according to the following formula. Each upstream neighbor contributing node Passenger flow:

[0043]

[0044] Step 58, on the node After performing passenger flow retrospective analysis, it is necessary to update the actual passenger flow it carries and load it into the system. Traffic redistribution is achieved on each connected restored road segment. Nodes are updated according to the following formula: Passenger flow:

[0045]

[0046] Then, traverse the nodes. The passenger flow is redistributed across the various connected road sections according to the following formula:

[0047]

[0048] in, For nodes Current moment The set of adjacent nodes, For backup road segment sets The road section recorded Traffic value at the time of deletion.

[0049] Step 59, traverse the nodes Each adjacent node Update sequentially Traffic flow on each connected road segment. Due to and The section of road between The flow has already been updated in equation (8), so only the flow needs to be updated. The passenger flow can be redistributed to other road sections.

[0050] Traversing nodes The various connecting road sections ( (Except for) and redistribute passenger flow according to the following formula:

[0051]

[0052] in, For nodes Current moment The set of adjacent nodes, For backup road segment sets The road section recorded Traffic value at the time of deletion.

[0053] Specifically, the nodes in steps 55 and 56 mentioned above and nodes All are nodes The adjacent nodes, here only take The calculation process is illustrated using an example.

[0054] Step 510, Topology reconstruction and passenger flow tracking have been completed. From backup node set Failure Node Set Delete and Each connected road segment is from the backup road segment set Delete it.

[0055] Step 6: Calculate network resilience metrics. Based on the current evolution time... Based on the network topology and traffic operation status, calculate network resilience assessment indicators, including global network efficiency, network structure entropy, maximum network connectivity subgraph rate, total network passenger flow, number of network nodes, and number of network edges.

[0056] Step 7, Evolution Termination Determination. The termination of the traffic network recovery evolution is determined based on two conditions: ① Reaching the maximum evolution time; ② No failed nodes in the network. If either condition is met, the evolution ends; otherwise, it proceeds to the next evolution time. Then return to step 3.

[0057] Through steps 1 to 7 above, we can finally obtain the evolution results of the integrated transportation network and its resilience index after the failure nodes are restored.

[0058] This invention provides a traffic network restoration method that considers topology reconstruction and passenger flow retracing, which has the following advantages compared with existing technologies:

[0059] 1. This invention proposes a method for topology reconstruction of restored nodes. Based on the node set in the initial state of the traffic network, a list of adjacent nodes for restored nodes is regenerated, and the topological connections and corresponding road segments between restored nodes and their adjacent nodes are reconstructed. This method is logically clear and its steps are concise, enabling rapid identification and reconstruction of restored nodes and their connected road segments. It achieves a refined characterization of the network topology restoration process, laying the foundation for subsequent passenger flow tracing and resilience assessment after network recovery.

[0060] 2. This invention considers the transferred passenger flow generated during node failure and innovatively designs a method for passenger flow retrospection and redistribution at recovered nodes. Based on the transferred flow database and the status information of adjacent nodes of recovered nodes, it divides the data into an active receiving record set and an active transferring record set, and further calculates the total recovered passenger flow and the total returned passenger flow. On this basis, passenger flow retrospection updates are performed on recovered nodes and their adjacent nodes according to each transferring / receiving record, while passenger flow redistribution is carried out on the road segments connected to each node. This method has clear logic and steps, and can effectively describe the traffic passenger flow retrospection and dynamic redistribution process during node recovery, laying the foundation for resilience assessment after traffic network recovery.

[0061] 3. This invention proposes a traffic network restoration method that integrates network topology reconstruction and node passenger flow retrospection. Considering limitations in repair resources, unit repair speed, and network restoration strategies, a limited number of nodes to be restored are selected for repair. After the nodes are repaired, the restoration process is refined and the restoration effect is evaluated through steps such as node topology reconstruction, node passenger flow retrospection and traffic redistribution of connected road segments, and calculation of network resilience indicators. Compared with traditional restoration methods, the method proposed in this invention can characterize the dynamic evolution of network topology and traffic flow during the node restoration process, and is applicable to traffic networks of different sizes and types, demonstrating high engineering application value. Attached Figure Description

[0062] Figure 1 This is a flowchart of the method of the present invention;

[0063] Figure 2 This is a flowchart of the selection and repair process for nodes to be restored;

[0064] Figure 3 This is a flowchart of the restored node topology reconstruction process;

[0065] Figure 4 This is a diagram showing the adjacent nodes to be restored and the adjacent nodes that have been restored;

[0066] Figure 5 This is a flowchart showing the passenger flow tracing process at the restored nodes;

[0067] Figure 6 This is a diagram illustrating the division of transfer records;

[0068] Figure 7 This is a diagram illustrating the return of passenger flow at the node;

[0069] Figure 8 This is a diagram showing the node before and after recovery;

[0070] Figure 9 These are diagrams showing the results before and after the traffic network restoration in the example implementation.

[0071] Figure 10This is a diagram showing the global efficiency evolution of the integrated transportation network in the embodiment.

[0072] Figure 11 This is a diagram showing the evolution of the entropy of the integrated transportation network structure in the embodiment.

[0073] Figure 12 This is a diagram showing the evolution of the maximum connectivity subgraph rate of the integrated transportation network in the embodiment.

[0074] Figure 13 This is a diagram showing the evolution of passenger flow across the entire integrated transportation network in the example implementation.

[0075] Figure 14 This is a diagram showing the evolution of the number of nodes in the integrated transportation network in the embodiment.

[0076] Figure 15 This is a diagram showing the evolution of the number of edges in the integrated transportation network in the embodiment. Detailed Implementation

[0077] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0078] This invention designs a traffic network recovery method that considers topology reconstruction and passenger flow retracing. It can perform refined modeling of the network topology and dynamic evolution of traffic passenger flow during the traffic network recovery phase, and quantitatively evaluate the resilience trends during the recovery phase using multiple indicators, thereby laying the foundation for improving traffic network resilience and optimizing resource allocation. Figure 1 The diagram shows the overall flowchart of the traffic network restoration method considering topology reconstruction and passenger flow tracing. The steps are as follows:

[0079] Step 1, Data Preparation: This step requires preparing data including the basic network and a list of failed nodes. Set of road segments associated with non-transferable failed nodes Transfer record set Backup node set Backup road segment collection This includes related information. The basic transportation network and various data obtained in Step 1 lay the foundation for topology reconstruction and passenger flow tracing in subsequent transportation network restoration.

[0080] The first step is to generate the basic transportation network. This step involves reading information such as the number of nodes and road segments in the transportation network, node attributes (including node number, node type, node coordinates, node status, and node passenger flow), the topological adjacency relationships between nodes, and road segment attributes (including road segment number, road segment start and end point, road segment length, road segment type, road segment level, road segment speed limit, number of lanes, road segment traffic flow, and road segment status) to generate the basic transportation network.

[0081] List of failed nodes This includes all nodes in the transportation network that have lost their traffic operation function, recording the node's ID, degree, betweenness centrality, and passenger flow information in the initial network state. Untransferred failed nodes refer to nodes that cannot transfer their passenger flow to neighboring nodes. When these nodes fail, their surrounding neighboring nodes are also in a failed state, preventing the transfer of their passenger flow. The set of associated road segments for untransferred failed nodes stores the connected road segments and their corresponding traffic flows. Transfer record set. It stores the passenger flow information transferred to adjacent nodes when each failed node fails, recording information such as the transferring node, receiving node, transferred passenger flow, transfer time, and receiving time.

[0082] Backup node set and backup road segment set This stores the basic attribute information of each node and road segment in the initial state of the network.

[0083] Step 2, Node State Determination and Parameter Initialization. Before starting network recovery, the evolution time is first initialized. =0, maximum evolution time Node bearing capacity coefficient Network repair resources (M), available repair resources Node unit repair speed Parameters such as these are then used. The set of failed nodes is then read to determine each node in the basic transportation network. The state of the node. If the node If it is in a normal state, then State value If node If it is a failed node, then State value At the same time, each node The load-bearing capacity was calculated as , For the moment of evolution Passenger flow at specific times.

[0084] After reading and determining the state of each node in the network, a network recovery strategy needs to be determined. There are four types: Degree-Based Recovery (DRS), Betweenness Centrality-Based Recovery (BRS), Node Flow-Based Recovery (IRS), and Random Recovery (RRS). The first three strategies select nodes to be recovered based on their corresponding metric values ​​(such as degree and betweenness centrality) in the initial network state. The Random Recovery strategy randomly selects nodes for recovery.

[0085] Step 3: Selection and Repair of Nodes to be Restored. Based on the network recovery strategy and the amount of available repair resources, select nodes from the set of failed nodes. Select failed nodes for repair. Each selected node will be treated as a node to be recovered. And calculate its repair time. Then, each node to be recovered... and its repair time Newly added to the repair queue In the middle. For those already in the repair queue The nodes in the process are configured to have a repair time. Finally, iterate through the repair queue. If the node to be recovered If the repair time is 0, then Repair complete and add to recovery candidate set The specific implementation steps are as follows, such as... Figure 2 As shown:

[0086] Step 31, determine the current number P of available repair resources. If Then from the set of failed nodes Based on the determined network recovery strategy, P failed nodes are selected for repair, and the value of each failed node is calculated according to the following formula. Repair time After completing the calculation, the nodes Add to repair queue In the middle. If If this is the case, it means that all repair resources have been used to repair the failed node, and proceed to step 32.

[0087]

[0088] Step 32, traverse the repair queue Each non-newly added node in the queue Update its repair time .

[0089] Step 33, for Each node Repair time Make a judgment. If 0, then node Repair complete and store the node in the recovery candidate set. Otherwise, continue with... The next node is then evaluated.

[0090] Step 4, Reconstruct the topology of the restored nodes. Based on the backup node set. Rebuild nodes in the network And generate its basic attribute information. Then, based on the backup road segment set... Traverse the search nodes In the current network Adjacent nodes The section of road between Regenerate adjacency relationships and construct road segments The specific implementation steps are as follows, such as... Figure 3 As shown:

[0091] Step 41, traverse the candidate set for recovery Each node Processing is performed based on the backup node set. Reconstructing nodes in the network It generates basic attribute information, including node number, node spatial location, and node type.

[0092] Step 42, according to Middle node The adjacency relationships in the initial state, for the current time... Each of the adjacent nodes Make a judgment, such as Figure 4 As shown. If adjacent nodes At the current evolutionary moment If it does not yet exist in the network, it indicates that the node has not yet recovered. At this point, Store in the set of adjacent nodes to be restored and record and The corresponding road sections to be processed If adjacent nodes If it exists on the network, it can be restored directly. and The adjacency relationship between them, and Rejoin The list of adjacent nodes.

[0093] Step 43, traverse the nodes Each neighbor node in the neighbor node list In the backup road segment set Search for the corresponding road segment The road segment reconstruction is completed. During the road segment construction process, its basic attribute information is generated simultaneously, including road segment number, road segment length, road segment start and end points, road segment type, road segment level, etc.

[0094] Step 44, determine the node Does it exist in the set of adjacent nodes to be restored? In the middle. If it exists, it means there are still nodes. The relevant road sections awaiting processing need to be restored. These road sections, in particular, refer to those at the nodes... Before recovery, its adjacent nodes It has been restored, but due to node... If a road segment is temporarily missing, preventing reconstruction from being completed, proceed to step 45; otherwise, proceed to step 46.

[0095] Step 45, Traverse middle Each road segment to be processed And then reconstruct it to generate its basic road segment attribute information. After completing the reconstruction... After all the road segments to be processed are reconstructed, From the set of adjacent nodes to be restored Delete it.

[0096] Step 46, for the recovered nodes The state value at the current moment Assign a range A random number is generated within the node to indicate that the node has returned to a normal state. Then, the node... Passenger flow The flow of the road segments connected to it is reinitialized to 0.

[0097] Step 5, passenger flow tracing at the restored node. When the node After completing the topology reconstruction, based on the transfer traffic library Set of road segments associated with non-transferable failed nodes right Perform passenger flow tracking and reload. The node passenger flow and Passenger flow will be redistributed across interconnected road sections. The specific implementation steps are as follows: Figure 5 As shown:

[0098] Step 51, traverse and restore the candidate set Each node in Process it.

[0099] Step 52: Traverse the set of road segments associated with the failed nodes that have not been moved. For each road segment, if that road segment One endpoint is The other endpoint If the traffic exists in the network at the current moment, then the traffic for the corresponding road segment will be loaded. Up, and update the node simultaneously using the following formula Passenger flow:

[0100]

[0101] Step 53, Traverse the transfer traffic database For any transfer record in the data, if the transfer node of that node is... And receiving node If the record exists in the network at the current moment, then store it in [the appropriate location]. Activation transfer record set In the middle; if the receiving node of the record is And the transfer node If the record exists in the current network, then write the record to... Activation receiving record set In the middle. For example Figure 6 As shown.

[0102] Step 54, for Activation transfer record set and activate the receiving record set Make a judgment.

[0103] ① At this point, both sets are empty, indicating that the nodes... There are no active transfer or receipt records, so there is no need to perform passenger flow tracing. Proceed to step 58.

[0104] ② At this point, the node... If only an active transfer record exists and no receiving record exists, proceed to step 55 and skip steps 56-57.

[0105] ③ At this point, the node... If an active receiving record exists, the transferred passenger flow received must first be calculated and returned, proceeding to step 55.

[0106] Step 55, Traverse the transfer record set Each record in the database. For Adjacent nodes ,if ,but Able to return transferred passenger flow Give Update adjacent nodes synchronously according to the following formula. Passenger flow, such as Figure 7 Nodes in :

[0107]

[0108] if ,illustrate Not enough passenger flow to return to At this point, the transfer record will not be returned and will be deleted.

[0109] After processing each record in the transfer record set, the calculation is performed. Total recovered passenger flow can be obtained through passenger flow tracing. :

[0110]

[0111] Step 56, traverse the received record set For each record in the database, calculate It is necessary to repay the upstream neighboring contributing nodes. Total passenger flow :

[0112]

[0113] Step 57, Calculate the nodes Current total effective passenger flow .if This indicates the recovery node. Unable to repay all customers, the remaining customer traffic will be deleted. Each transfer record in the set; if , indicating nodes It can repay all returned customer traffic. Update nodes sequentially according to the following formula. Each upstream neighbor contributing node Passenger flow, such as Figure 7 Middle node :

[0114]

[0115] Step 58, on the node After performing passenger flow retrospective analysis, it is necessary to update the actual passenger flow it carries and load it into the system. Traffic redistribution is achieved on each connected restored road segment. Nodes are updated according to the following formula: Passenger flow:

[0116]

[0117] Then, traverse the nodes. The passenger flow is redistributed across the various connected road sections according to the following formula:

[0118]

[0119] in, For nodes Current moment The set of adjacent nodes, For backup road segment sets The road section recorded Traffic value at the time of deletion.

[0120] Step 59, traverse the nodes Each adjacent node Update sequentially Traffic flow on each connected road segment. Due to and The section of road between The flow has already been updated in equation (8), so only the flow needs to be updated. The passenger flow can be redistributed to other road sections.

[0121] Traversing nodes The various connecting road sections ( (Except for) and redistribute passenger flow according to the following formula:

[0122]

[0123] in, For nodes Current moment The set of adjacent nodes, For backup road segment sets The road section recorded Traffic value at the time of deletion.

[0124] Specifically, the nodes in steps 55 and 56 mentioned above and nodes All are nodes The adjacent nodes, here only take The calculation process is illustrated using an example.

[0125] Step 510, Topology reconstruction and passenger flow tracking have been completed. From backup node set Failure Node Set Restoring candidate sets Delete and Each connected road segment is from the backup road segment set Delete the node. Before and after recovery comparison Figure 8 As shown.

[0126] Step 6: Calculate network resilience metrics. Based on the current evolution time... Based on the network topology and traffic operation status, calculate network resilience assessment indicators, including global network efficiency, network structure entropy, maximum network connectivity subgraph rate, total network passenger flow, number of network nodes, and number of network edges.

[0127] Step 7, Evolution Termination Determination. The termination of the traffic network recovery evolution is determined based on two conditions: ① Reaching the maximum evolution time; ② No failed nodes in the network. If either condition is met, the evolution ends; otherwise, it proceeds to the next evolution time. Then return to step 3.

[0128] Preferably, in step 1 above, the basic network information that needs to be clarified includes the following six categories: Category 1: the number of nodes and road segments in the transportation network; Category 2: the node types in the network; Category 3: the node numbers and coordinates in the network. The network is located in a two-dimensional coordinate system, and the coordinates of each node in the network are represented by (x, y), representing their relative positions, where x represents the horizontal coordinate of the node and y represents the vertical coordinate of the node; Category 4: the passenger flow of each node in the network. The passenger flow of each node is the sum of the traffic flows of all the road segments connected to that node; Category 5: the connection relationships between nodes, including the node number, the number of other nodes connected to the current node, and the numbers of the other connected nodes; Category 6: the road segment attribute information in the network, including the road segment number, the road segment origin and destination numbers, the road segment length, the road segment type, the road segment grade, the road segment speed limit, the number of lanes, and the road segment traffic flow. The road segment type refers to the type of transportation to which the road segment belongs. The road segment grade refers to the technical or service level of the road segment, which is divided according to different types of road segments.

[0129] This method uses several parameters, including the maximum evolution time in step 2. Node bearing capacity coefficient Total repair resources (M), unit repair speed The above parameters can be set according to the scale of the transportation network, actual restoration needs, and constraints on the investment of repair resources.

[0130] To verify the effectiveness of the method of the present invention, a specific embodiment of the present invention is provided below.

[0131] The traffic network is generated based on the data preparation in step 1, and a list of failed nodes is prepared. Set of road segments associated with non-transferable failed nodes Transfer record set Backup node set Backup road segment collection The transportation network includes 4,257 nodes and 6,394 road segments; some node information is shown in Table 1 below, and some road segment information is shown in Table 2 below.

[0132] Table 1 Some Nodes

[0133]

[0134] Table 2 Some road sections

[0135]

[0136] After generating the traffic network, based on the set of failed nodes Determine the states of all nodes in the network to obtain the current network, and set different parameters: initialize the evolution time. =0、 500 0.3 50. 20000 network global efficiency, network structure entropy, maximum connected subgraph rate, total network traffic, number of network nodes, number of network edges

[0137] Then, the traffic network is restored through steps 3-7 until... At time 422, the evolution ended. The final restored traffic network and the results of various evaluation indicators are shown in Table 3-7 below. Figure 9-15 As shown.

[0138] Table 3. Global network efficiency results at some evolutionary points

[0139]

[0140] Table 4. Network structure entropy results at some evolutionary moments

[0141]

[0142] Table 5. Results of maximum connected subgraph rate at some evolutionary moments.

[0143]

[0144] Table 6. Total Passenger Flow Results at Partial Evolution Moments

[0145]

[0146] Table 7 Results of network node count and edge count at some evolutionary points

[0147]

[0148] The embodiments are merely illustrative of the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A method for restoring a transportation network considering topology reconstruction and passenger flow tracing, characterized in that, Includes the following steps: S1. Data preparation; This step requires the preparation of data including the basic network and a list of failed nodes. Set of road segments associated with non-transferable failed nodes Transfer record set Backup node set Backup road segment collection And obtain basic transportation network and various data, which will serve as the foundation for topology reconstruction and passenger flow tracking in the subsequent transportation network restoration; First, a basic network needs to be generated. This is done by reading the number of traffic network nodes and road segments, the attributes of nodes in the network, the topological adjacency relationships between nodes, and the attribute information of road segments in the network. The list of failed nodes It contains all nodes in the transportation network that have lost their traffic operation function, and records the number of each failed node, the degree value of the failed node in the initial state of the network, the betweenness centrality and the node's passenger flow information; A failed node that has not been transferred is a node that cannot transfer the passenger flow it carries to its adjacent nodes; The set of associated road segments for the non-transferable failed nodes stores the connected road segments of these nodes and the corresponding road segment traffic; the set of transfer records... It stores the passenger flow information transferred to adjacent nodes when each failed node fails, recording information including the transferring node, receiving node, transferred passenger flow, transfer time, and receiving time. The backup node set and backup road segment set This stores the basic attribute information of each node and road segment in the initial state of the network; S2. Node state determination and parameter initialization; Before starting network recovery, the evolution time is first initialized. =0, maximum evolution time Node bearing capacity coefficient Network repair resources (M), available repair resources Node unit repair speed ; Then, the set of failed nodes is read to determine each node in the basic transportation network. The state of the node; if the node If it is in a normal state, then State value If node If it is a failed node, then State value Meanwhile, each node The load-bearing capacity was calculated as , For the moment of evolution Passenger flow at specific times; After reading and determining the state of each node in the network, a network recovery strategy needs to be determined, which includes a degree-based recovery strategy, a betweenness-centrality-based recovery strategy, a node flow-based recovery strategy, and a random recovery strategy. Among them, the first three recovery strategies select the nodes to be recovered first based on the corresponding index values ​​of the failed nodes in the initial state of the network. S3. Selection and repair of nodes to be restored; Based on the network recovery strategy and the amount of available repair resources, from the set of failed nodes... Select failed nodes for repair; each selected node will be treated as a node to be recovered. And calculate its repair time. Then, each node to be recovered... and its repair time Newly added to the repair queue In the middle; for those already in the repair queue The nodes in the process are configured to have a repair time. Finally, iterate through the repair queue. If the node to be recovered If the repair time is 0, then Repair complete and add to recovery candidate set middle; S4. Node topology reconstruction has been restored; Based on the backup node set Rebuild nodes in the network And generate its basic attribute information; then based on the backup road segment set Traverse the search nodes In the current network Adjacent nodes The section of road between Regenerate adjacency relationships and construct road segments ; S5. Passenger flow tracking at the restored nodes has been completed. When node After completing the topology reconstruction, based on the transfer traffic library Set of road segments associated with non-transferable failed nodes right Perform passenger flow tracking and reload. The node passenger flow and Passenger flow will be redistributed across the connecting road sections; S6. Calculate network resilience metrics; Based on the current evolutionary time Based on the network topology and traffic operation status, calculate network resilience assessment indicators, including global network efficiency, network structure entropy, maximum network connectivity subgraph rate, total network passenger flow, number of network nodes, and number of network edges; S7. Determination of Evolution Termination; The termination of the traffic network recovery evolution is determined based on the following two conditions: Reaching the moment of maximum evolution; There are no failed nodes in the network; If any of the above conditions are met, the evolution ends; otherwise, it proceeds to the next evolutionary stage. Then return to step S3.

2. The traffic network restoration method considering topology reconstruction and passenger flow tracing according to claim 1, characterized in that, The specific process of step S3 is as follows: Step 31, determine the current number P of available repair resources; if Then from the set of failed nodes Based on the determined network recovery strategy, P failed nodes are selected for repair, and the value of each failed node is calculated according to the following formula. Repair time After completing the calculation, the nodes Add to repair queue In the middle; if If so, it means that all repair resources have been used to repair the failed node, and proceed to step 32; ； Step 32, traverse the repair queue Each non-newly added node in the queue Update its repair time ; Step 33, for Each node Repair time Make a judgment; if 0, then node Repair complete and store the node in the recovery candidate set. Otherwise, continue with... The next node is then evaluated.

3. The traffic network restoration method considering topology reconstruction and passenger flow tracing according to claim 3, characterized in that, The specific process of step S4 is as follows: Step 41, traverse the candidate set for recovery Each node Process it; Based on the backup node set Reconstructing nodes in the network It generates its basic attribute information, including node number, node spatial location and node type; Step 42, according to Middle node The adjacency relationships in the initial state, for the current time... Each of the adjacent nodes Perform a determination; if the adjacent node At the current evolutionary moment If it does not yet exist in the network, it indicates that the node has not yet recovered; at this time, Store in the set of adjacent nodes to be restored and record and The corresponding road sections to be processed If adjacent nodes If it exists on the network, it can be restored directly. and The adjacency relationship between them, and Rejoin The list of adjacent nodes; Step 43, traverse the nodes Each neighbor node in the neighbor node list In the backup road segment set Search for the corresponding road segment And complete the road reconstruction; During the construction of road segments, their basic attribute information is generated simultaneously, including road segment number, road segment length, road segment start and end points, road segment type, and road segment level; Step 44, determine the node Does it exist in the set of adjacent nodes to be restored? If it exists, it means there are still nodes. The relevant road sections awaiting processing need to be restored; whereby, the road sections awaiting processing refer to those at the nodes. Before recovery, its adjacent nodes It has been restored, but due to node... If a road segment is temporarily missing, preventing reconstruction from being completed, proceed to step 45; otherwise, proceed to step 46. Step 45, Traverse middle Each road segment to be processed And reconstruct it to generate its basic road segment attribute information; after completing the reconstruction... After all the road segments to be processed are reconstructed, From the set of adjacent nodes to be restored Delete; Step 46, for the recovered nodes The state value at the current moment Assign a range A random number is generated within the node to indicate that the node has returned to a normal state; then, the node... Passenger flow The flow of the road segments connected to it is reinitialized to 0.

4. The traffic network restoration method considering topology reconstruction and passenger flow tracing according to claim 3, characterized in that, The specific process of step S5 is as follows: Step 51, traverse and restore the candidate set Each node in Process it; Step 52: Traverse the set of road segments associated with the failed nodes that have not been moved. For each road segment, if that road segment One endpoint is The other endpoint If the traffic exists in the network at the current moment, then the traffic for the corresponding road segment will be loaded. Up, and update the node simultaneously using the following formula Passenger flow: ； Step 53, Traverse the transfer traffic database For any transfer record in the data, if the transfer node of that node is... And receiving node If the record exists in the network at the current moment, then store it in [the appropriate location]. Activation transfer record set In the middle; if the receiving node of the record is And the transfer node If the record exists in the current network, then write the record to... Activation receiving record set middle; Step 54, for Activation transfer record set and activate the receiving record set Make a judgment: 1) At this point, both sets are empty, indicating that the nodes... There are no active transfer or receipt records, so there is no need to perform passenger flow tracing. Proceed to step 58. 2) At this point, the node If only an active transfer record exists and no receiving record exists, proceed to step 55 and skip steps 56-57. 3) At this point, the node If there is an active receiving record, the transferred passenger flow received by it needs to be calculated and returned first, and then proceed to step 55. Step 55, Traverse the transfer record set Each record in; for Adjacent nodes ,if ,but Able to return transferred passenger flow Give Synchronously update neighboring nodes Passenger flow: ； if ,illustrate Not enough passenger flow to return to At this point, the transfer record will not be returned and will be deleted. After processing each record in the transfer record set, the calculation is performed. Total recovered passenger flow can be obtained through passenger flow tracing. : ； Step 56, traverse the received record set For each record in the database, calculate It is necessary to repay the upstream neighboring contributing nodes. Total passenger flow : ； Step 57, Calculate the nodes Current total effective passenger flow ;if This indicates the recovery node. Unable to repay all customers, the remaining customer traffic will be deleted. Each transfer record in the set; if , indicating nodes Able to repay all total customer traffic; update nodes sequentially according to the following formula. Each upstream neighbor contributing node Passenger flow: ； Step 58, on the node After performing passenger flow retrospective analysis, it is necessary to update the actual passenger flow it carries and load it into the system. Traffic redistribution is achieved on each connected restored road segment; nodes are updated according to the following formula. Passenger flow: ； Then, traverse the nodes. The passenger flow is redistributed across the various connected road sections according to the following formula: ； in, For nodes Current moment The set of adjacent nodes, For backup road segment sets The road section recorded Traffic value at the time of deletion; Step 59, traverse the nodes Each adjacent node Update sequentially Traffic flow in each connected road segment; due to and The section of road between The flow has already been updated in equation (8), so only the flow needs to be updated. The passenger flow can be redistributed on other road sections; Traversing nodes The Exclusion The passenger flow is redistributed to the various connecting road sections outside the main road network, according to the following formula: ； in, For nodes Current moment The set of adjacent nodes, For backup road segment sets The road section recorded Traffic value at the time of deletion; Step 510, Topology reconstruction and passenger flow tracking have been completed. From backup node set Failure Node Set Delete and Each connected road segment is from the backup road segment set Delete it.

5. The traffic network restoration method considering topology reconstruction and passenger flow tracing according to claim 4, characterized in that, The maximum evolution time in step S2 Node bearing capacity coefficient Total repair resources M Unit repair speed .

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