A method for updating urban living circle accessible range based on spatial monitoring results

Abstract

This invention discloses a method for updating the reachability of urban living circles based on spatial monitoring results, specifically relating to the fields of spatial monitoring and urban spatial computing. The method includes acquiring current monitoring results, previous monitoring results, pedestrian road networks, community entrances and exits, and service points. In edge computing nodes, each access-related element is compared according to its location correspondence. Newly added elements are recorded as new elements, and missing elements are recorded as invalid elements, generating a status change table. The status change table and pedestrian road network are read, and the access connections corresponding to the newly added elements are connected to the pedestrian road network. By comparing the current and previous monitoring results item by item, and performing localized recalculation and result write-back after generating the status change table in the edge computing nodes, locally closed areas can be promptly removed, and locally restored areas can be promptly added, thus ensuring that the dynamic reachability corresponds to the actual affected areas.

Description

Technical Field

[0001] This invention relates to the field of spatial monitoring and urban spatial computing technology, and more specifically, to a method for updating the reachability of urban living circles based on spatial monitoring results. Background Technology

[0002] In the process of delineating the 15-minute living circle in the city, most existing technologies revolve around the analysis of the walkability between the residence and public service facilities. The common approach is to collect information on the basic road network, road connectivity, community population distribution and facility location, and then calculate the range on the platform according to the preset travel time to obtain the corresponding living circle boundary. Taking an urban area where open blocks, underground passages, school routes, and construction fences frequently alternate as an example, the system needs to continuously receive updates from spatial monitoring data on boundary opening and closing, passage start and stop, and changes in local slow-moving conditions. On the other hand, it also needs to rely on edge computing nodes to promptly adjust the affected area at the street or community scale, rather than repeatedly calculating the entire urban area after each local change. Under these application conditions, existing methods often exhibit the following phenomena: The local boundaries have been closed, but the relevant areas within the resulting range are still preserved; Some passages have been reopened, but areas that should have been reinstated cannot be replenished in a timely manner; Or, if only a few areas experience changes in traffic conditions, the system may still trigger a large-scale recalculation, causing the updated results to not correspond to the actual affected areas. The reason for the above situation is that the existing generation logic usually regards the living circle range as the result of a static road network formed at one time, and it cannot combine spatial monitoring results to perform local recalculation and result writing on the edge side for local traffic status changes. The technical problem this application aims to solve is: how to combine spatial monitoring results and rely on edge computing to perform localized updates on the dynamic reachability of the 15-minute urban living circle caused by changes in local traffic conditions, so that the output results are consistent with the actual affected areas. Summary of the Invention

[0003] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a method for updating the reachability of urban living circles based on spatial monitoring results. By comparing traffic-related elements in spatial monitoring results from adjacent time periods, a status change table is generated and the pedestrian road network is updated accordingly. Then, local recalculation and result writing are performed on community entrances, road sections, plots, and service points affected by local traffic status changes, thereby solving the problem mentioned in the background art that the dynamic reachability of the 15-minute urban living circle under local traffic status changes cannot keep correspondence with the actual affected area.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for updating the reachability of urban living circles based on spatial monitoring results, comprising: S1. Obtain the current monitoring results, the previous monitoring results, the pedestrian road network, community entrances and exits and life service points. In the edge computing node, compare the relevant elements of passage one by one according to the location correspondence. Record the newly added elements as new elements and the missing elements as invalid elements, and generate a status change table. S2. Read the status change table and pedestrian network, add the access connection corresponding to the newly added element to the pedestrian network, delete the access connection corresponding to the failed element from the pedestrian network, and disconnect or detour the blocked road section to generate an updated road network. S3. Read the updated road network and community entrances and exits. Starting from each community entrance and exit, accumulate the travel time segment by segment along the updated road network. When the accumulated time does not exceed 15 minutes, retain the currently reached road segment, plot and service point, and generate the initial reachable range of the community. S4. Read the status change table, update the road network and the initial reachability of the community. Starting from each status change location, trace the continuous connected parts along the updated road network. Only re-perform the 15-minute cumulative calculation for the traced community entrances and exits, road segments, plots and life service points to generate the local update range. S5. Read the initial reachability range and partial update range of the community, delete the original results corresponding to the partial update range, and write the partial update range into the range result of the corresponding community to generate the dynamic reachability range of the city's 15-minute living circle.

[0005] In a preferred embodiment, S1 includes: S1-1. Read the current monitoring results, the previous monitoring results, the pedestrian network, community entrances and exits, and living service points. The current monitoring results and the previous monitoring results are both sets of spatial monitoring thematic elements for the corresponding time period. Both the current monitoring results and the previous monitoring results include spatial elements corresponding to boundary openings, public passages, underground passages, street crossings, fence closures, and slow-moving obstacles. The pedestrian network includes road segments, intersections, and plot boundaries. The community entrances and exits are the locations where each community connects to the pedestrian network. The living service points are the locations of each living service facility. Extract the element type, location coordinates, boundary range, and connection endpoints of the spatial elements to generate the current element table and the previous element table. The set of spatial monitoring thematic elements represents the summary results of various spatial monitoring objects and their spatial location, range, and status information at the target time.

[0006] In a preferred embodiment, S1 further includes: S1-2. Read the current feature table, the previous feature table, and the pedestrian network. Pair them one by one according to the same feature type, overlapping location coordinates, overlapping boundary ranges, and connecting endpoints falling into the same road segment, the same intersection, or the same plot boundary. Record the unpaired features in the current feature table as new features and the unpaired features in the previous feature table as invalid features, and generate a change feature table. S1-3. Read the change element table, and write the element type, location coordinates, boundary range, connection endpoints, corresponding road network location and change direction of each newly added element and each failed element into the corresponding record to generate a status change table.

[0007] In a preferred embodiment, S2 includes: S2-1. Read the status change table and pedestrian network. Using the connection endpoints and corresponding network locations of each new and failed element as the positioning reference, divide the road segments crossed by the boundary range in the pedestrian network into sub-segments at the intersection of the lines and the surface. Determine the dividing points of the nearest sub-segments on both sides of each new element as access endpoints. Determine the sub-segments within the coverage area of ​​each failed element as deleted sub-segments. Determine the dividing points of the nearest sub-segments on both sides of each blocked element as detour endpoints. Generate the access table, deletion table, and detour table. S2-2. Read the access table, deletion table, detour table and pedestrian network. First, delete the corresponding deletion sub-segment in the deletion table. Then, connect the access endpoint in the access table directly to the corresponding sub-segments on both sides to form a new connection. Search for continuous sub-segment chains outside the boundary range of the blocking element for each group of detour endpoints in the detour table. Select the target detour chain in the following order: first, accumulate the number of blocking crossings and take the zero value result; then, accumulate the link length and take the minimum value result; then, accumulate the number of turns and take the minimum value result. Write the target detour chain into the pedestrian network. S2-3. Read the pedestrian road network after access, deletion and detour writing. For each newly added connection and each target detour chain, check whether the first and last endpoints fall into the original corresponding sub-segment splitting point. Check whether adjacent sub-segments are continuously connected in such a way that the end point of the previous sub-segment and the start point of the next sub-segment coincide. Delete isolated connected subgraphs that do not contain community entrances or service points, and generate an updated road network.

[0008] In a preferred embodiment, S3 includes: S3-1. Read the updated road network, community entrances and exits, and service points. Divide the updated road network into directed sub-segments according to intersections, plot boundary intersections, community entrance / exit projection points, and service point projection points. Record the start number, end number, sub-segment travel time, start waiting time, boundary number, and direction number of each directed sub-segment. Establish a transfer table based on the relationship that the end number of the previous directed sub-segment is the same as the start number of the next directed sub-segment. Then, calculate the direction difference, boundary change times, and time increment for each subsequent directed sub-segment and sort them in ascending order to generate an ordered transfer table.

[0009] In a preferred embodiment, S3 further includes: S3-2. Read the ordered transfer table and the starting directed sub-segments corresponding to each community entrance / exit. Perform forward recursion for each community entrance / exit. Record the cumulative time of the starting directed sub-segment as the sum of the sub-segment travel time and the starting point waiting time, the cumulative number of boundary changes as the starting boundary change count, and the cumulative number of turns as zero. Then expand the subsequent directed sub-segments according to the ordered transfer table, and accumulate the time increment, the number of boundary changes, and the number of turns respectively. For multiple records that reach the same endpoint number, filter out the first record in the order of cumulative time from low to high, cumulative number of boundary changes from few to many, and cumulative number of turns from few to many, and write it into the preceding directed sub-segment number. Stop expansion when the cumulative time of the first record to be expanded exceeds 15 minutes, and generate a forward reachable table. S3-3. Read the forward reachability table, plot boundaries, and service points. For each retained record in the forward reachability table, backtrack according to the preceding directed sub-segment number to form a access chain. Delete discontinuous access chains between adjacent sub-segments and backtracking access chains that cross the same boundary but do not reach the community entrance or service point in the middle. Then merge the directed sub-segments covered by the remaining access chains into reachable segments. Record the plots that intersect with reachable segments and whose corresponding access chains have not been deleted as reachable plots. Record the service points whose projection points fall into reachable segments or reachable plots as reachable service points. Generate the initial reachability range of the community.

[0010] In a preferred embodiment, S4 includes: S4-1. Read the status change table, update the road network and the initial reachability of the community. Divide the updated road network into directed sub-segments according to the status change location, intersection, plot boundary intersection, community entrance / exit projection point, and service point projection point. Construct the sub-segment transfer time matrix, the sub-segment to plot projection matrix, and the sub-segment to service point projection matrix. Construct the initial arrival vector for the directed sub-segment corresponding to the status change location. Use the least addition recursion to calculate the forward cumulative time along the travel direction and the backward cumulative time along the reverse connection direction. In each round of recursion, add the previous round's cumulative time to the current transfer time and write it to the corresponding endpoint. Then, retain the record with the first cumulative time for the same endpoint. Stop the recursion when all newly written records have a cumulative time exceeding 15 minutes. Generate the forward time table and the backward time table.

[0011] In a preferred embodiment, S4 further includes: S4-2. Read the forward timetable, backward timetable, sub-segment to plot projection matrix, sub-segment to service point projection matrix and initial reachability of the community. Take the intersection of directed sub-segments with forward cumulative time not exceeding 15 minutes and backward cumulative time not exceeding 15 minutes to obtain the affected sub-segment set. Next, the affected sub-segment sets are projected onto the plots and service points respectively to obtain the affected plot set and the affected service point set. The affected community entrances and exits are screened out according to the connectivity between the affected sub-segment sets and the projected points of the community entrances and exits. Local recalculation is performed starting from the directed sub-segments corresponding to each affected community entrance and exit. The cumulative time, cumulative boundary change count, and cumulative turning count are calculated for the states that reach the same endpoint number. The first state is screened out in the order of cumulative time from low to high, cumulative boundary change count from few to many, and cumulative turning count from few to many, and the predecessor number is written. When the cumulative time of the first state to be expanded exceeds 15 minutes, the expansion stops and a local recalculation table is generated.

[0012] In a preferred embodiment, S4 further includes: S4-3. Read the local recalculation table and the initial reachability of the community. For each state in the local recalculation table, backtrack in reverse according to the predecessor number to form an updated access chain. Map the directed sub-segments covered by the updated access chain to updated sub-segments. Map the plots that have boundary intersections with the updated sub-segments to updated plots. Map the service points whose projection points fall into the updated sub-segments or updated plots to updated service points. Then, calculate the intersection and difference between the updated sub-segments, updated plots, and updated service points and the initial reachability of the community, respectively, to obtain the retention result, the addition result, and the removal result. Delete isolated connected components that cannot simultaneously connect the community entrance / exit and the service points to generate the local updated range.

[0013] In a preferred embodiment, S5 includes: S5-1. Read the initial reachable range and partial update range of the community. Extract the original road segments, original plots, and original service points in the initial reachable range of the community, as well as the updated road segments, updated plots, and updated service points in the partial update range, according to the community number. Pair the original road segments with the updated road segments according to the same road segment number or overlapping spatial range. Pair the original plots with the updated plots according to the same plot number or overlapping boundary range. Pair the original service points with the updated service points according to overlapping point coordinates. Record the original results that are successfully paired and exist in the partial update range as results to be replaced. Record the paired results that only exist in the initial reachable range of the community as results to be deleted. Record the results that only exist in the partial update range as results to be written. Generate a result processing table. S5-2. Read the result processing table, delete each result to be replaced and the original road segment, original land parcel and original service point corresponding to each result to be deleted, then write each updated road segment, each updated land parcel and each updated service point into the scope result of the corresponding community, and collect the written road segment, land parcel and service point according to the community number to generate the dynamic reachability range of the city's 15-minute living circle.

[0014] The technical effects and advantages of this invention are as follows: By comparing the current monitoring results with the previous monitoring results item by item, and after generating a status change table at the edge computing node, local recalculation and result writing are performed to enable local closed areas to exit in a timely manner and local recovery areas to be added in a timely manner, so that the dynamic reachable range corresponds to the actual affected area. By connecting newly added elements to the pedestrian network, deleting the corresponding connections of invalid elements, and disconnecting or replacing obstructed road sections, the road network status can be adjusted synchronously with the opening and closing of boundaries, the opening and closing of passages, and changes in pedestrian obstacles, thereby relatively improving the traffic basis for subsequent range calculations. By dividing the updated road network into directed sub-segments and filtering the traffic chains according to cumulative time, number of boundary changes and number of turns, the interference introduced by turnaround paths and boundary round-trip paths can be suppressed under the 15-minute constraint, so that the initial accessibility of the community is relatively close to the actual slow-moving accessibility relationship. By using forward and backward timelines to identify affected sub-road segments, and performing local recalculation only on connected community entrances and exits, and then writing back the results by intersection and difference with the original results, we can reduce the participation of irrelevant areas in the update, thereby relatively reducing the spread of results caused by large-scale duplicate calculations. Attached Figure Description

[0015] Figure 1 This is a flowchart of the method steps of the present invention. Detailed Implementation

[0016] 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.

[0017] Refer to the instruction manual appendix Figure 1 The present invention provides a method for updating the reachability of urban living circles based on spatial monitoring results, comprising: S1. Obtain the current monitoring results, the previous monitoring results, the pedestrian road network, community entrances and exits and life service points. In the edge computing node, compare the relevant elements of passage one by one according to the location correspondence. Record the newly added elements as new elements and the missing elements as invalid elements, and generate a status change table. In this embodiment, S1 is used to convert the spatial monitoring results of two adjacent time periods into a status change table that can be directly called upon for subsequent road network updates. During processing, the current monitoring results, the previous monitoring results, the pedestrian road network, community entrances and exits, and service points are first placed under the same spatial reference. Then, spatial elements corresponding to boundary openings, public passages, underpasses, pedestrian crossings, fence closures, and pedestrian barriers are extracted from the monitoring results, and the element type, location coordinates, boundary range, and connectivity endpoints are determined for each spatial element. Subsequently, the current element table is paired with the previous element table item by item to identify newly added and invalidated traffic-related elements in the current time period relative to the previous time period. Finally, the changes in the newly added and invalidated elements are written into the status change table so that subsequent steps can update the pedestrian road network according to the changed location and direction. The spatial monitoring thematic element set represents the summary results of various spatial monitoring objects and their spatial location, range, and status information in the target time period. This implementation process includes the following steps: In S1-1, the current monitoring results, the previous monitoring results, the pedestrian network, community entrances and exits, and service points are read first. The current and previous monitoring results are sets of spatial monitoring thematic elements for the corresponding time period. The pedestrian network includes road segments, intersections, and plot boundaries. Community entrances and exits are the locations where each community connects to the pedestrian network, and service points are the locations of various service facilities. Subsequently, boundary openings, public passages, underpasses, pedestrian crossings, fence closures, and pedestrian barriers from the current and previous monitoring results are extracted as spatial elements and categorized into point, line, and area types. Pedestrian crossings are treated as point elements, recording their coordinates, and adjacent road segments connected to these points are included. Points are used as connection endpoints; boundary openings, public passages, and underground passages are used as linear elements, recording the coordinates of the beginning and end of the line segment and its range, with the beginning and end endpoints used as connection endpoints; fences and pedestrian barriers are used as area elements, recording their boundary range, with the intersection of this boundary with the boundary of adjacent road segments or plots as connection endpoints; then, the element type, location coordinates, boundary range, and connection endpoints of each spatial element are written into the current element table and the previous element table, respectively; if a public passage is represented as a connecting line passing through a commercial street, then the beginning and end endpoints of the passage and the coverage area of ​​the line segment are written into the element record; if a pedestrian barrier is represented as a construction area occupying the road, then the boundary of the area and its intersection with the surrounding road segments are written into the element record; In S1-2, the current feature table, the previous feature table, and the pedestrian network are read. For each feature record in the current feature table, the corresponding record in the previous feature table is searched sequentially. During the search, it is first determined whether the feature types of the two records are the same, and then whether the location coordinates correspond to the same spatial location. Specifically, point features are judged based on whether the point falls in the same intersection or the same access point; linear features are judged based on the correspondence between the start and end endpoints and the intersection relationship of the line segments; and area features are judged based on the boundary intersection relationship and the coverage relationship. After the feature type and location relationship are satisfied, it is then determined whether there is an overlapping part in the boundary range of the two records. Finally, it is determined whether the connected endpoints of the two records are projected onto the pedestrian network. After the road network is completed, it is determined whether the current record falls within the same road segment, intersection, or boundary of the same plot. If all four conditions are met, the current record and the previous record are recorded as a paired record, and the search for the current record is stopped. If the current record has not found a paired record after traversing the previous element table, the current record is recorded as a new element. If the records in the previous element table have not been paired after all comparisons are completed, the previous record is recorded as an invalid element. After all records are processed, a change element table is obtained. Taking the addition of an opening in a school wall as an example, if there is a boundary opening line in the current time, and there is no corresponding boundary opening at the same location in the previous time, then this element is recorded as a new element after the pairing is completed. Here, taking the closure of an underground passage as an example, if the underground passage existed in the previous time period, but no longer exists at the corresponding location in the current time period, then this element is recorded as a failed element. In S1-3, the change element table is read, and change fields are written for each new element record and each invalid element record. The element type directly uses the corresponding field in the change element table; the location coordinates directly use the point coordinates, line segment start and end coordinates, or the center position of the area boundary; the boundary range directly uses the line segment range or area boundary range; the connecting endpoints directly use the endpoints or intersections extracted from the element in S1-1; the corresponding road network location is obtained by projecting the connecting endpoints or boundary ranges onto the road segments, intersections, or plot boundaries in the pedestrian road network to obtain the corresponding object number; the change direction is recorded as either a new or invalid element. When an element record corresponds to multiple road network objects, each object number is recorded separately, and the correspondence between the element and each object number is retained in the same change record. After all change elements are written, a status change table is generated. Thus, each record in the status change table corresponds to an actual change location, a specific object, and a definite change direction, allowing subsequent steps to perform connection access, connection deletion, road segment disconnection, or detour replacement. Through the above process, the monitoring changes from the two time periods can be organized into a status change table that can be directly used for road network reconstruction. This allows subsequent steps to directly read the structured records that already contain object locations, scope of action, and direction of change, instead of directly dealing with the original monitoring layer. At the same time, point, line, and area features have already completed field splitting and road network positioning before entering the status change table, so the access location, deletion location, and blocking location can be directly determined when updating the road network. In practical applications: If an open neighborhood adds two boundary openings in the current time, an underpass changes from closed to open, and a commercial street is closed off and obstructed by construction, the system first extracts the corresponding spatial elements from the current and previous monitoring results, and then writes them into the current element table and the previous element table respectively. Then, it matches them item by item according to element type, location coordinates, boundary range, and connection endpoints, identifying the two boundary openings and the underpass as new elements, and the original pedestrian passage cut off by the construction fence as a failed element. Finally, it writes the type, location, range, endpoints, corresponding road network location, and direction of change of these elements into the status change table for subsequent steps to call.

[0018] S2. Read the status change table and pedestrian network, add the access connection corresponding to the newly added element to the pedestrian network, delete the access connection corresponding to the failed element from the pedestrian network, and disconnect or detour the blocked road section to generate an updated road network. In this embodiment, S2 is used to partially reconstruct the pedestrian network based on the state change table, so that the traffic relationship in the previous time period can be connected, deleted, disconnected and replaced according to the changes in boundary openings, public passages, underground passages, street crossings, fence closures and slow-moving obstacles in the current time period. During processing, the road segments to be segmented are first determined based on the corresponding positions of newly added, invalid, and blocking elements in the pedestrian network, and the segmented sub-segments, access endpoints, deleted sub-segments, and detour endpoints are recorded respectively. Then, the deleted sub-segments corresponding to invalid elements are first removed from the pedestrian network, and the access endpoints corresponding to newly added elements are connected to adjacent sub-segments. For blocked road segments corresponding to blocking elements, alternative passage chains are re-searched. Finally, the location and continuity of each newly added connection and target detour chain are verified, and isolated connected subgraphs that do not participate in the connection between community entrances / exits and service points are removed, resulting in the updated road network used for subsequent reachability calculations. This implementation process includes the following steps: In S2-1, the status change table and pedestrian road network are read. First, the relevant road segments, intersections and plot boundaries are extracted according to the corresponding road network locations in the status change table. Then, the cutting position is determined based on the intersection relationship between the boundary range of the newly added elements, failed elements and blocking elements and the road segments. For each road segment crossed by the boundary range, the intersection point between the center line of the road segment and the boundary range is first obtained. Then, the road segments are cut in sequence according to the order of the intersection points on the line to obtain multiple sub-road segments that are connected end to end. For each sub-road segment, the original road segment number, cutting sequence number, starting coordinates and ending coordinates are recorded. For newly added elements, first identify their connecting endpoints, then project these endpoints onto the centerline of adjacent road segments. The dividing point of the sub-road segment where the projection point is located is used as a candidate access point. If multiple candidate dividing points exist on both sides of the same connecting endpoint, the dividing point reached first along the travel direction by the connecting endpoint is selected, and the corresponding dividing points on both sides are recorded as access endpoints. For failed elements, delete sub-segments are filtered out segment by segment according to the sub-road segments covered by their boundary range. If the same failed element covers multiple consecutive sub-road segments, these consecutive sub-road segments are combined as the same deletion unit. For blocking elements, first determine the blocked road segments covered by their boundary range, then... Extract the nearest dividing points to the blocking boundary at the beginning and end of the blocking range, and record these two dividing points as detour endpoints. Based on this, write the new elements and their access endpoints into the access list, write the failed elements and their deleted sub-segments into the deletion list, and write the blocking elements and their detour endpoints and blocked road segments into the detour list. If a new boundary opening is added to an open block, the dividing points of the pedestrian road segments connected to both sides of the boundary opening are used as access endpoints. If a construction fence crosses a pedestrian passage, the continuous sub-segments covered by the fence are used as blocked road segments, and the nearest dividing points before and after the fence are used as detour endpoints. In S2-2, the to-be-accessed table, to-be-deleted table, to-be-detoured table, and pedestrian network are read. First, according to the deletion sub-segment number in the to-be-deleted table, the corresponding sub-segments are deleted one by one from the pedestrian network, and the connectivity relationships with the deleted sub-segment as the predecessor or successor are deleted simultaneously. Then, according to each set of access endpoints in the to-be-accessed table, the endpoints of the sub-segments on both sides corresponding to the new element are directly connected to form a new connection, and the start number, end number, and the number of the new element to which the new connection belongs are recorded. After that, a detour chain search is performed on each set of detour endpoints in the to-be-detoured table. During the search, the sub-segment where the detour endpoint is located is used as the start and end point. Continuous sub-segment chains are enumerated outside the boundary range of the blocking element, and three types of quantities are calculated for each candidate chain in sequence: the first type is the blocking... The first category is the number of crossings, which is the number of times the centerline of each sub-segment in the candidate chain intersects with the boundary range of the blocking element; the second category is the link length, which is the cumulative length of each sub-segment in the candidate chain; the third category is the number of turns, which is the number of times the direction number of two adjacent sub-segments changes. When screening candidate chains, first retain candidate chains with zero blocking crossings. If there are no candidate chains with zero blocking crossings, it is determined that there are no usable detour chains for that group of detour endpoints. Among the candidate chains with zero blocking crossings, select the candidate chain with the first-highest link length. If the link lengths are the same, select the candidate chain with the first-highest number of turns. The screened candidate chains are determined as the target detour chains, and each sub-segment in the target detour chain and its connectivity are written back to the pedestrian network. Here, taking the construction site of a commercial street that cuts off the original slow lane as an example, the system first deletes the sub-segment covered by the construction site, and then searches for a chain of sub-segments that are continuously connected along the perimeter of the street, with the starting and ending points of the detours on both sides of the construction site as the starting and ending points. Candidate chains that still pass through the construction site are first eliminated, and then the shortest chain in total length is selected from the remaining candidate chains. If there are two shortest chains, the chain with fewer turns is selected as the target detour chain. In S2-3, the pedestrian network after access, deletion, and detour writing is read. For each newly added connection, its starting and ending endpoints are checked to ensure they fall within the original sub-segment's dividing point. Specifically, the start and end point numbers of the new connection are checked to ensure they match the corresponding access endpoint numbers in the access table. If they do not match, the new connection is deleted. For each target detour chain, the connection relationship between adjacent sub-segments is checked segment by segment. This involves checking if the end point coordinates of the previous sub-segment match the start point coordinates of the next sub-segment, or if they reference the same dividing point number. If any condition is not met, subsequent sub-segments are deleted from that point until a continuous pedestrian chain is formed. After the verification of new connections and target detour chains is completed, the verified pedestrian network is used. Construct connected components and determine whether each connected component contains at least one community entrance / exit or at least one service point. If a connected component contains neither, delete all road segments, intersections, and related connections in that connected component, retaining only the connected components containing community entrances / exits or service points, and generate an updated road network. If a newly added connection is successfully written but its tail endpoint does not correspond to the originally planned access split point, the newly added connection is not retained. If there are two sub-road segments in a target detour chain whose coordinates are not connected, the part after the non-connected position is not written into the updated road network. If a construction remnant forms a branch road that is disconnected from all community entrances / exits and service points, the isolated connected subgraph corresponding to the branch road is deleted. Through the above process, the changes in the status change table can be accurately implemented at the sub-segment level of the pedestrian network, so that newly added passage connections, invalid passage connections, and blocked alternative passage chains correspond to clear dividing points, sub-segments, and connectivity relationships, respectively. Simultaneously, through continuous processing of deletion, access, detours, and connectivity verification, the system avoids retaining invalid paths, writing discontinuous detour chains, or leaving invalid isolated branches in the network, thus providing a directly callable updated network for subsequent 15-minute cumulative calculations. In practical applications: if a new boundary opening is added on the east side of a community, an underpass is reopened on the south side, and a section of pedestrian walkway on the west side is cut off by construction barriers, the system first uses the status change table to re-encode the relevant road segments according to their intersection locations. The system divides the road into sub-segments, then writes the connecting endpoints corresponding to the opening on the east side of the boundary and the underground passage on the south side into the list to be connected, writes the sub-segments covered by the fence into the list to be deleted, and writes the dividing points on both sides of the fence into the list to be bypassed. Subsequently, the system first deletes the sub-segments covered by the fence, then writes the newly added connections formed by the boundary opening and the underground passage into the pedestrian road network, and searches for continuous sub-segment chains that do not cross the fence area starting from the bypass endpoints on both sides of the fence. The system selects the target bypass chain with the shortest link length and the fewest turning times and writes it back into the road network. Finally, the system verifies the access position and continuous connection relationship of each newly added connection and bypass chain, and deletes isolated connected subgraphs that do not contain community entrances and exits and life service points to obtain the updated road network for the current time.

[0019] S3. Read the updated road network and community entrances and exits. Starting from each community entrance and exit, accumulate the travel time segment by segment along the updated road network. When the accumulated time does not exceed 15 minutes, retain the currently reached road segment, plot and service point, and generate the initial reachable range of the community. In this implementation, S3 is used to determine, based on the updated road network, the road segments, plots, and service points that can be continuously reached within 15 minutes from each community entrance / exit, thus forming the initial reachable range of the community. During processing, the updated road network is first divided into directed sub-segments according to intersections, plot boundaries, community entrance / exit projection points, and service point projection points. Each directed sub-segment is assigned a travel time, waiting time, boundary number, and direction number. A transfer table is then established based on the connection between the beginning and end of the directed sub-segments. Subsequently, starting from the initial directed sub-segment corresponding to each community entrance / exit, subsequent directed sub-segments are gradually expanded according to cumulative time, number of boundary changes, and number of turns, stopping expansion when the cumulative time exceeds 15 minutes. Finally, each retained record is traced back to form a travel chain, discontinuous and zigzag travel chains are eliminated, and the remaining travel chains are converted into reachable road segments, reachable plots, and reachable service points to obtain the initial reachable range of the community. This implementation process includes the following steps: In S3-1, the updated road network, community entrances and exits, and service points are read and updated. First, the community entrances and exits and service points are projected onto the nearest road segments in the updated road network that correspond to their connectivity, thus obtaining the community entrance and exit projection points and the service point projection points. Then, using intersections, plot boundary intersections, community entrance and exit projection points, and service point projection points as dividing points, each road segment in the updated road network is divided into multiple directional sub-segments that are connected end to end according to their position along the line. For each directional sub-segment, the starting point number, ending point number, sub-segment travel time, starting point waiting time, boundary number, and direction number are recorded. The sub-segment travel time is obtained by dividing the sub-segment length by the corresponding walking speed. The starting point waiting time is the waiting value corresponding to whether the starting point of the directional sub-segment is located at a pedestrian crossing, underpass entrance, public passage entrance, or boundary opening. Positions that do not involve waiting are recorded as zero. The boundary number is the number of the plot boundary or boundary crossing of the directional sub-segment. The direction number is the direction from the starting point to the ending point of the directional sub-segment. Then, a transfer table is established based on the relationship that the endpoint number of the preceding directed sub-segment is the same as the starting number of the following directed sub-segment. For each subsequent directed sub-segment corresponding to the preceding directed sub-segment, the direction difference, the number of boundary changes, and the time increment are calculated. The direction difference is the angle difference between the preceding and following direction numbers, the number of boundary changes is the count value that the preceding and following boundary numbers are different, and the time increment is the sum of the passage time of the subsequent directed sub-segment and the waiting time at the starting point. The transfer table is then sorted from front to back according to the direction difference, the number of boundary changes, and the time increment to generate an ordered transfer table. If a community entrance is projected onto a pedestrian segment outside the east gate of the community, the projection point divides the segment into two directed sub-segments. If a service point is located in front of a convenience store on a street corner, the projection point of the service point further divides the adjacent pedestrian segment, so that it can be directly determined whether the service point falls into the reachable passage chain. In S3-2, the ordered transfer table and the starting directed sub-segments corresponding to each community entrance / exit are read. For each community entrance / exit, a record table to be expanded and a forward reachable table are established. First, the starting directed sub-segments are written into the record table to be expanded. The cumulative time of this starting directed sub-segment is recorded as the sum of the sub-segment travel time and the starting point waiting time. The number of starting boundary changes is recorded as the count value where the boundary number of the community entrance / exit is different from the boundary number of the starting directed sub-segment; if they are the same, it is recorded as zero. The cumulative number of turns is also recorded as zero. Subsequently, the subsequent directed sub-segments are expanded sequentially according to the record with the first-ranked cumulative time in the record table to be expanded. For each subsequent directed sub-segment, the new cumulative time, cumulative boundary change count, and cumulative turn count are calculated. The new cumulative time is equal to the sum of the cumulative time of the previous record and the time increment of the subsequent directed sub-segment. The new cumulative boundary change count is equal to the cumulative boundary change count of the previous record and the number of changes between the previous and subsequent boundary numbers. The sum of the counts is equal to the sum of the counts of the previous record's cumulative turning counts and the counts that are different from the previous and subsequent direction numbers. For multiple records reaching the same destination number, the first record is selected in the order of cumulative time from low to high, cumulative boundary change count from few to many, and cumulative turning count from few to many. The preceding directed sub-segment number of the first record is written into the forward reachability table and the record table to be expanded. If a destination number already has a record, and the new record is ranked higher in the above sorting, the new record replaces the original record. When the cumulative time of the first record in the record table to be expanded exceeds 15 minutes, the expansion of the community entrance / exit is stopped, and the corresponding forward reachability table is generated. If a community entrance / exit can reach the same intersection via two paths, one path has a shorter cumulative time, and the other path has the same time but more boundary changes, then only the record corresponding to the first path is retained. If the cumulative time and boundary change count of the two paths are the same, then the ranking continues by the number of turning counts. In S3-3, the forward reachability table, land parcel boundaries, and service points are read. For each retained record in the forward reachability table, each record is backtracked in reverse order according to its preceding directed sub-segment number until the initial directed sub-segment is reached, forming the corresponding access chain. For each access chain, continuity is first checked by comparing the endpoint number of an adjacent directed sub-segment with the starting point number of the next directed sub-segment. If any point is discontinuous, the access chain is deleted. Next, the existence of round trips across the same boundary is checked according to the boundary number and crossing direction. If an access chain crosses the same boundary twice in opposite directions, and the directed sub-segment between these two crossings does not cover the community entrance / exit projection point or the service point projection point, the access chain is recorded as a foldback access chain and deleted. For undeleted access chains, continuous and directional directed sub-segments are merged into reachable segments. Plots that intersect with reachable segments or are traversed by reachable segments and whose corresponding access chains have not been deleted are recorded as reachable plots. Service points whose projection points fall on reachable segments or reachable plots are recorded as reachable service points. Reachable segments, reachable plots, and reachable service points are aggregated according to community number to generate the initial reachable range of the community. If an access chain crosses the street boundary and then crosses back to the same boundary in the opposite direction without reaching any service points in between, the access chain is deleted and no longer used as a basis for reachability. If an access chain covers the segment where the vegetable market is located, the corresponding service point of the vegetable market is recorded as a reachable service point. Through the above process, the continuous traffic relationships in the updated road network can be transformed into the initial reachable range of the community directly corresponding to the community entrances and exits. This allows subsequent local recalculations to no longer be re-expanded from the entire road network, but to directly identify the affected parts based on the existing reachable results. At the same time, by jointly filtering the time increment of sub-road segments, the number of boundary changes, and the number of turns, unnecessary turnaround paths and boundary round-trip paths can be suppressed, making the retained traffic chains more consistent with the actual slow-speed accessibility relationships. In practical applications: If the east and south gates of a community connect to different pedestrian routes, there is an underpass on the north side of the community, a farmers' market on the west side, and a community health service point on the south side, the system first projects the east and south gates, the underpass entrance, the farmers' market location, and the community health service point location onto the updated road network. Then, it uses these projected points, intersections, and plot boundaries to jointly divide the updated road network, generating directed sub-segments and an ordered transfer table. Subsequently, it performs forward recursion on the starting directed sub-segments corresponding to the east and south gates. For destinations reachable within 15 minutes, the first record is retained step by step, and the preceding directed sub-segment numbers are written into the forward reachability table. Finally, the retained records are backtracked one by one to form a access chain, discontinuous access chains and back-and-forth access chains are deleted, the road segments covered by the remaining access chains are recorded as reachable road segments, the blocks that intersect with these reachable road segments are recorded as reachable blocks, and the vegetable markets and community health service points that fall into reachable road segments or reachable blocks are recorded as reachable service points, thus obtaining the initial reachability range of the community in the current time.

[0020] S4. Read the status change table, update the road network and the initial reachability of the community. Starting from each status change location, trace the continuous connected parts along the updated road network. Only re-perform the 15-minute cumulative calculation for the traced community entrances and exits, road segments, plots and life service points to generate the local update range. In this embodiment, S4 is used to determine the local area that is truly affected by the change after the state change has been applied to the updated road network, and only the community entrances, road sections, plots and service points within the local area are recalculated for 15 minutes to avoid repeated calculation of the initial reachability of the entire community when the local traffic status changes. In the process, starting from the location of the state change, the accumulated time is recursively calculated along the travel direction and the reverse connection direction in the updated road network to obtain the impact extension results of the state change towards service points and the impact backtracking results towards community entrances and exits. Then, the affected sub-segment set is delineated using both types of results. Subsequently, community entrances and exits that have connectivity with the affected sub-segment set are screened out, and the local accessibility results are recalculated starting from these community entrances and exits. Finally, the local recalculated results are intersected and the initial community accessibility range is calculated to obtain the retained results, the added results, and the removed results, and the local update range is formed accordingly. This implementation process includes the following steps: In S4-1, the status change table is read, the road network and the initial reachable range of the community are updated, and the updated road network is further divided according to the status change location, intersection, plot boundary intersection, community entrance and exit projection point and life service point projection point to obtain directed sub-road segments with the same caliber as S3. The status change location is taken from the connecting endpoints or boundary intersections of the road network locations corresponding to each newly added element and each failed element in the status change table. The community entrance / exit projection point and the service point projection point are taken from the corresponding access points of the community entrance / exit and the service point in the updated road network, respectively. Then, the starting point number, ending point number, and transfer time are recorded for each directed sub-segment, and a sub-segment transfer time matrix is ​​constructed accordingly. In this matrix, the rows represent the preceding directed sub-segments, and the columns represent the following directed sub-segments. If the ending point number of the preceding directed sub-segment is the same as the starting point number of the following directed sub-segment, the corresponding matrix cell is written with the sum of the passage time and the starting point waiting time of the following directed sub-segment; otherwise, the matrix cell is recorded as an unreachable item. Then, a sub-segment to plot projection matrix is ​​constructed based on the intersection relationship between the directed sub-segment and the plot boundary, and a sub-segment to service point projection matrix is ​​constructed based on whether the service point projection point falls into the directed sub-segment. Next, an initial arrival vector is constructed based on the directed sub-segments corresponding to each state change location. Zero values ​​are written to the directed sub-segments corresponding to the state change locations in the initial arrival vector, and unreachable items are written to the remaining directed sub-segments. Based on this, a minimum addition recursion is performed along the travel direction and along the reverse connection direction. The forward cumulative time along the travel direction represents the cumulative time required to propagate from the state change location towards the service point to each directed sub-segment, while the backward cumulative time along the reverse connection direction represents the cumulative time required to backtrack from the state change location towards the community entrance / exit to each directed sub-segment. During each round of recursion, the cumulative time of the reachable directed sub-segments from the previous round is added to the current transfer time, and the result is written to the corresponding endpoint number. If multiple candidate values ​​exist for the same endpoint number, they are sorted from lowest to highest cumulative time, and the first record and its predecessor number are retained. The endpoint record written for the first time in this round and the endpoint record that replaces the original first record in this round are both recorded as newly written records. When the cumulative time of all newly written records exceeds 15 minutes, the recursion stops, and a forward timetable and a backward timetable are generated respectively. If a certain state change location corresponds to a new opening in the school wall, the directed sub-segment corresponding to the aforementioned new opening is used as the starting point for forward and backward recursion. If a certain state change location corresponds to a construction fence cutting off the passage, the directed sub-segment corresponding to the intersection of the aforementioned fence boundary and the blocked road segment is used as the starting point for recursion. In S4-2, the forward timetable, backward timetable, sub-segment to land parcel projection matrix, sub-segment to service point projection matrix, and initial reachability range of the community are read. First, the set of directed sub-segments with a forward cumulative time not exceeding 15 minutes is extracted from the forward timetable, and then the set of directed sub-segments with a backward cumulative time not exceeding 15 minutes is extracted from the backward timetable. The intersection of the two is calculated to obtain the set of affected sub-segments. Among them, only the directed sub-segments that can be reached within 15 minutes by both forward propagation and backward backtracking are considered as the part whose state change can actually affect the accessibility between the community entrance / exit and the service point. Subsequently, the set of affected sub-segments is multiplied by the sub-segment to land parcel projection matrix and the sub-segment to service point projection matrix, respectively, to obtain the set of affected land parcels and the set of affected service points. The affected community entrances / exits are then screened out by whether the community entrance / exit projection point falls into the set of affected sub-segments or whether it can be connected to the set of affected sub-segments through a continuous chain of directed sub-segments. Subsequently, a local recalculation is performed starting from the directional sub-segments corresponding to the entrances and exits of each affected community. The expansion scope of the local recalculation is consistent with S3, that is, the cumulative time, cumulative number of boundary changes, and cumulative number of turns are calculated for each expanded state. Among them, the cumulative time is the sum of the cumulative time of the previous state and the time increment of the subsequent directional sub-segment; the cumulative number of boundary changes is the sum of the counts of the differences between the previous boundary number and the subsequent boundary number; and the cumulative number of turns is the sum of the counts of the differences between the previous direction number and the subsequent direction number. For multiple states that reach the same endpoint number, the cumulative time is ranked from low to high, and the cumulative number of boundary changes is ranked accordingly. The first state is selected in ascending order of the number of turns and the number of cumulative turns is selected in ascending order, and its predecessor number is written. If a new state is ranked before an existing state in the above sorting, the new state replaces the existing state. When the cumulative time of the first state to be expanded exceeds 15 minutes, the expansion of the corresponding community entrance is stopped, and a local recalculation table is generated. If an underground passage is reopened, reconnecting a previously inaccessible street, the affected community entrances connected to it on both sides of the underground passage will be screened into the local recalculation. If a fence only affects a section of pedestrian walkway on the west side of the commercial street, community entrances not connected to that section of pedestrian walkway will not be included in the local recalculation. In S4-3, the local recalculation table and the initial reachable range of the community are read. Each state in the local recalculation table is backtracked in reverse order according to the predecessor number until the starting directed sub-segment of the corresponding affected community entrance is reached, forming an updated access chain. Subsequently, the directed sub-segments covered by the updated access chain are merged into updated segments according to the continuous relationship between the beginning and end. Plots that have boundary intersections with the updated segments or are entered into the boundary range of the updated segments are mapped as updated plots. The life service points whose projection points fall into the updated segments or updated plots are mapped as updated service points. The intersection and difference of the updated road segment and the original road segment in the initial reachable range of the community are calculated separately. The intersection and difference of the updated land parcel and the original land parcel in the initial reachable range of the community are calculated separately. The intersection and difference of the updated service point and the original living service point in the initial reachable range of the community are calculated separately. The intersection part is recorded as the retained result, the difference part that only exists in the updated result is recorded as the added result, and the difference part that only exists in the initial reachable range of the community is recorded as the removed result. Based on this, a local subgraph is constructed using updated road segments. Connectivity component partitioning is performed on the local subgraph, and each connected component is checked to see if a continuous path exists corresponding to both the community entrance / exit projection point and the service point projection point. For isolated connected components that cannot simultaneously connect the community entrance / exit and the service point, their corresponding updated road segments, updated plots, and updated service points are deleted, while the remaining parts are retained to generate a local update range. If a state change only shortens an existing path but does not change the accessibility of its corresponding service point, the result is recorded as a retained result. If a newly added boundary opening allows a previously unincluded market to re-enter the 15-minute range, the market is recorded as an added result. If a construction fence makes an existing community health service point unreachable, the service point is recorded as a removed result. Through the above process, the impact of state changes can be limited to the affected area jointly determined by forward propagation and backward backtracking. Then, the cumulative calculation for 15 minutes is re-executed only at the community entrances and exits corresponding to this part, thereby avoiding duplicate calculations for the entire community. At the same time, the local recalculation results do not directly replace the original results. Instead, they first go through updating the access chain backtracking, mapping road segments and plots, dividing intersections and differences, and deleting isolated connected components before finally forming the local update range. Therefore, it is possible to distinguish which results to retain, which results to add, and which results to remove. In practical applications: If the underground passage on the north side of a community is reopened to traffic at the current time, and a pedestrian passage on the south side of the commercial street is blocked by construction barriers, the system first constructs an initial arrival vector based on the directed sub-segments corresponding to the underground passage location and the barrier location, and obtains the forward timetable and the backward timetable respectively. Then, it takes the intersection of the directed sub-segments that can be reached within 15 minutes from the two to determine the set of affected sub-segments actually affected by the underground passage on the north side and the barrier on the south side. Subsequently, it projects the set of affected sub-segments onto the plot and the living service point, filters out the community entrances and exits that are truly affected, and only re-performs the 15-minute cumulative calculation for these community entrances and exits to obtain a local recalculation table. Finally, the status in the local recalculation table is traced back line by line to form an updated access chain. The newly accessible vegetable market on the north side after the underground passage is restored is recorded as the added result, the convenience service point on the south side that is no longer accessible after being cut off by the fence is recorded as the removed result, and the original road sections and plots that are still accessible are recorded as the retained result. After deleting isolated connected components, the local update range is formed.

[0021] S5. Read the initial reachability and partial update range of the community, delete the original results corresponding to the partial update range, and write the partial update range into the range result of the corresponding community to generate the dynamic reachability of the city's 15-minute living circle. In this implementation, S5 is used to write back the local update range to the range result of the corresponding community, so that the updated road segments, updated plots, and updated service points obtained from the local recalculation replace the corresponding affected parts in the original result, while retaining the unaffected parts, and finally obtaining the dynamic reachability range of the city's 15-minute living circle. During processing, firstly, the original road segments, original plots, and original service points in the initial reachability range of the community, as well as the updated road segments, updated plots, and updated service points in the local update range, are extracted according to the community number. Then, road segments, plots, and service points are matched one-to-one according to object type, and the matching results are divided into results to be replaced, results to be deleted, and results to be written. Subsequently, the corresponding original results are deleted, and the updated results are written to the range result of the corresponding community. Finally, the road segments, plots, and service points of each community after the write-back are aggregated according to the community number to form the dynamic reachability range of the city's 15-minute living circle. This implementation process includes the following steps: In S5-1, the initial reachable range and partial update range of the community are read. First, the original road segments, original land parcels, and original service points in the initial reachable range are extracted according to the community number, as well as the updated road segments, updated land parcels, and updated service points in the partial update range. Pairing sets are then established for each road segment, land parcel, and service point according to object type. For original and updated road segments, it is first determined whether the road segment numbers are the same. If they are the same, they are directly paired; otherwise, it is further determined whether the spatial ranges overlap. Spatial range overlap means that the centerlines of the two road segments overlap or that the start and end points of one road segment both fall within the range of another road segment. If an updated road segment corresponds to multiple original road segments, then the updated road segment is selected. The original road segment with the longest overlap is uniquely paired. For existing and renovated land parcels, first determine if the parcel numbers are the same. If they are the same, they are directly paired. If they are different, continue to determine if the boundary ranges overlap. Overlapping boundary ranges mean that the boundaries of two parcels intersect or the area enclosed by the boundary of one parcel falls into the area enclosed by the boundary of another parcel. If a renovated land parcel corresponds to multiple existing land parcels, the original land parcel with the longest overlap is uniquely paired. For existing and renovated service points, pairing is based on whether the point coordinates overlap. If the coordinates of two points are the same, they are recorded as the same service point. If there are multiple candidate points, the existing service point with coordinates that are exactly the same as the renovated service point is uniquely paired. After pairing is completed, the original road segments, original plots, and original service points that have been paired and whose corresponding update results exist within the local update range are recorded as results to be replaced. The original results that are located within the local update range but do not appear in the updated road segments, updated plots, and updated service points are recorded as results to be deleted. The updated road segments, updated plots, and updated service points that only exist within the local update range are recorded as results to be written. The community number, object type, original object number, updated object number, and processing category are written into the result processing table. If the updated road segment in a local update range has a different number than the original road segment, but their center lines overlap, then the original road segment and the updated road segment are paired. If an updated plot is split from an original plot, then the original plot with the first overlapping boundary of the updated plot is taken as the pairing object. If a newly added service point does not have a corresponding location in the initial reachable range of the community, then the newly added service point is directly recorded as a result to be written. In S5-2, the result processing table is read, and the results to be replaced, deleted, and written for each community are processed according to the community number. For the results to be replaced, the original objects corresponding to them are deleted from the original road segment set, original land parcel set, and original service point set of the corresponding community according to the object type. For the results to be deleted, the corresponding original road segment, original land parcel, and original service point are deleted according to the object type. For the results to be written, the corresponding updated road segment, updated land parcel, and updated service point are written into the scope result of the corresponding community. For the original road segment, original land parcel, and original service point that are not included in the result processing table, they are kept unchanged in the scope result of the corresponding community. After all deletion and writing operations are completed, the road segments, land parcels, and service points in the scope result of each community are aggregated according to the community number to obtain the city-level result set. The scope result of each community is composed of the retained original results and the written updated results. After the scope results of each community are merged, the dynamic reachability range of the city's 15-minute living circle is generated. For example, if a new road section and a new community service point are added after the underground passage on the north side of a community is reopened, then the new road section and the new community service point will be included in the results for that community. If a pedestrian walkway and its corresponding community service point are no longer retained after the fence on the south side of a community is closed, then the original road section and the original community service point will be deleted. If a group of original plots on the east side of a community remain accessible during the partial update and are not included in the results processing table, then the group of original plots will continue to be included in the results for that community. Through the above process, the local update range can be accurately written back to the range result of the corresponding community, so that the affected part is replaced according to the local recalculation result, and the unaffected part is retained, thereby avoiding the regeneration of the entire city's reachability range due to local changes; at the same time, the three types of objects, road segments, plots, and life service points, are matched, deleted, and written respectively, which can ensure that different object types are not mixed, and the connection between the local update range and the initial reachability range of the community can also be maintained within the same object level; In practical applications: If a new detour route is formed due to the adjustment of the construction site fence on the west side of a community, and an original accessible section of road is replaced, and the detour route is reconnected to a farmers' market, while another original convenience service point is no longer accessible due to the construction site fence, the system first extracts the original road sections, original plots of land, and original service points of the community by community number, as well as the updated road sections, updated plots of land, and updated service points in the local update range. Then, it completes the matching by road section number or spatial range, plot number or boundary range, and point coordinates respectively. The original replaced road section is recorded as the result to be replaced, the original convenience service point that no longer appears is recorded as the result to be deleted, and the newly added detour route and the farmers' market that are re-included in the range are recorded as the result to be written. Subsequently, the corresponding original results are deleted, the new results are written into the results of the community range, and the remaining original plots of land and service points that have not entered the result processing table are retained. Finally, the results are aggregated with other community results to generate the dynamic accessible range of the city's 15-minute living circle at the current time.

[0022] Working principle: This scheme first reads the current monitoring results and the previous monitoring results, comparing each of the following: boundary openings, public passages, underpasses, pedestrian crossings, fence closures, and pedestrian obstacles. It identifies which traffic elements are newly added and which are no longer valid, generating a status change table accordingly. Then, according to the status change table, the pedestrian network is segmented, connected, deleted, and replaced with alternative routes to obtain an updated network reflecting the current traffic status. Next, starting from each community entrance / exit, the travel time is accumulated segment by segment in the updated network to obtain the initial accessible range of the community. Based on this, the affected parts are tracked starting from the status change location, and only the affected community entrances / exits, road segments, plots, and service points are recalculated with a 15-minute cumulative calculation to form a locally updated range. Finally, the locally updated range is written back into the original results, retaining the unaffected parts and replacing the affected parts to obtain the dynamic accessible range of the city's 15-minute living circle. The entire process has a clear sequential relationship: first, changes are identified; then the road network is updated; then the initial results are calculated; then, local recalculations are performed; finally, the range update is completed. For example, in an old urban area, a new entrance is opened in the wall of a school, an underpass is reopened, and a section of a commercial street is blocked by construction barriers, cutting off the original pedestrian route. The system will first identify these changes from the monitoring results, then connect the newly opened entrance and underpass to the pedestrian network, disconnect the road section affected by the barriers, and find available detour routes for the disconnected road section. Then, starting from the entrances and exits of surrounding communities, it will recalculate the road sections, blocks, and service points that residents can actually walk to within fifteen minutes. For the parts affected by these changes, the system will only recalculate locally, rather than recalculating the entire urban area. In this way, the vegetable market that was previously inaccessible due to the barriers will be removed from the scope, and the convenience stores or community service points that are now accessible again after the barriers will be added to the scope, ultimately obtaining a living circle result consistent with the current actual traffic conditions.

[0023] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for updating the reachability of urban living circles based on spatial monitoring results, characterized in that, include: S1. Obtain the current monitoring results, the previous monitoring results, the pedestrian road network, community entrances and exits and life service points. In the edge computing node, compare the relevant elements of passage one by one according to the location correspondence. Record the newly added elements as new elements and the missing elements as invalid elements, and generate a status change table. S2. Read the status change table and pedestrian network, add the access connection corresponding to the newly added element to the pedestrian network, delete the access connection corresponding to the failed element from the pedestrian network, and disconnect or detour the blocked road section to generate an updated road network. S3. Read the updated road network and community entrances and exits. Starting from each community entrance and exit, accumulate the travel time segment by segment along the updated road network. When the accumulated time does not exceed 15 minutes, retain the currently reached road segment, plot and service point, and generate the initial reachable range of the community. S4. Read the status change table, update the road network and the initial reachability of the community. Starting from each status change location, trace the continuous connected parts along the updated road network. Only re-perform the 15-minute cumulative calculation for the traced community entrances and exits, road segments, plots and life service points to generate the local update range. S5. Read the initial reachability range and partial update range of the community, delete the original results corresponding to the partial update range, and write the partial update range into the range result of the corresponding community to generate the dynamic reachability range of the city's 15-minute living circle.

2. The method for updating the reachability of urban living circles based on spatial monitoring results according to claim 1, characterized in that: S1 includes: S1-1. Read the current monitoring results, the previous monitoring results, the pedestrian network, community entrances and exits, and living service points. The current monitoring results and the previous monitoring results are both sets of spatial monitoring thematic elements for the corresponding time period. Both the current monitoring results and the previous monitoring results include spatial elements corresponding to boundary openings, public passages, underground passages, street crossings, fence closures, and slow-moving obstacles. The pedestrian network includes road segments, intersections, and plot boundaries. The community entrances and exits are the locations where each community connects to the pedestrian network. The living service points are the locations of each living service facility. Extract the element type, location coordinates, boundary range, and connection endpoints of the spatial elements to generate the current element table and the previous element table. The set of spatial monitoring thematic elements represents the summary results of various spatial monitoring objects and their spatial location, range, and status information at the target time.

3. The method for updating the reachability of urban living circles based on spatial monitoring results according to claim 2, characterized in that: S1 further includes: S1-2. Read the current feature table, the previous feature table, and the pedestrian network. Pair them one by one according to the same feature type, overlapping location coordinates, overlapping boundary ranges, and connecting endpoints falling into the same road segment, the same intersection, or the same plot boundary. Record the unpaired features in the current feature table as new features and the unpaired features in the previous feature table as invalid features, and generate a change feature table. S1-3. Read the change element table, and write the element type, location coordinates, boundary range, connection endpoints, corresponding road network location and change direction of each newly added element and each failed element into the corresponding record to generate a status change table.

4. The method for updating the reachability of urban living circles based on spatial monitoring results according to claim 3, characterized in that: S2 includes: S2-1. Read the status change table and pedestrian network. Using the connection endpoints and corresponding network locations of each new and failed element as the positioning reference, divide the road segments crossed by the boundary range in the pedestrian network into sub-segments at the intersection of the lines and the surface. Determine the dividing points of the nearest sub-segments on both sides of each new element as access endpoints. Determine the sub-segments within the coverage area of ​​each failed element as deleted sub-segments. Determine the dividing points of the nearest sub-segments on both sides of each blocked element as detour endpoints. Generate the access table, deletion table, and detour table. S2-2. Read the access table, deletion table, detour table and pedestrian network. First, delete the corresponding deletion sub-segment in the deletion table. Then, connect the access endpoint in the access table directly to the corresponding sub-segments on both sides to form a new connection. Search for continuous sub-segment chains outside the boundary range of the blocking element for each group of detour endpoints in the detour table. Select the target detour chain in the following order: first, accumulate the number of blocking crossings and take the zero value result; then, accumulate the link length and take the minimum value result; then, accumulate the number of turns and take the minimum value result. Write the target detour chain into the pedestrian network. S2-3. Read the pedestrian road network after access, deletion and detour writing. For each newly added connection and each target detour chain, check whether the first and last endpoints fall into the original corresponding sub-segment splitting point. Check whether adjacent sub-segments are continuously connected in such a way that the end point of the previous sub-segment and the start point of the next sub-segment coincide. Delete isolated connected subgraphs that do not contain community entrances or service points, and generate an updated road network.

5. The method for updating the reachability of urban living circles based on spatial monitoring results according to claim 4, characterized in that: S3 includes: S3-1. Read the updated road network, community entrances and exits, and service points. Divide the updated road network into directed sub-segments according to intersections, plot boundary intersections, community entrance / exit projection points, and service point projection points. Record the start number, end number, sub-segment travel time, start waiting time, boundary number, and direction number of each directed sub-segment. Establish a transfer table based on the relationship that the end number of the previous directed sub-segment is the same as the start number of the next directed sub-segment. Then, calculate the direction difference, boundary change times, and time increment for each subsequent directed sub-segment and sort them in ascending order to generate an ordered transfer table.

6. The method for updating the reachability of urban living circles based on spatial monitoring results according to claim 5, characterized in that: S3 further includes: S3-2. Read the ordered transfer table and the starting directed sub-segments corresponding to each community entrance / exit. Perform forward recursion for each community entrance / exit. Record the cumulative time of the starting directed sub-segment as the sum of the sub-segment travel time and the starting point waiting time, the cumulative number of boundary changes as the starting boundary change count, and the cumulative number of turns as zero. Then expand the subsequent directed sub-segments according to the ordered transfer table, and accumulate the time increment, the number of boundary changes, and the number of turns respectively. For multiple records that reach the same endpoint number, filter out the first record in the order of cumulative time from low to high, cumulative number of boundary changes from few to many, and cumulative number of turns from few to many, and write it into the preceding directed sub-segment number. Stop expansion when the cumulative time of the first record to be expanded exceeds 15 minutes, and generate a forward reachable table. S3-3. Read the forward reachability table, plot boundaries, and service points. For each retained record in the forward reachability table, backtrack according to the preceding directed sub-segment number to form a access chain. Delete discontinuous access chains between adjacent sub-segments and backtracking access chains that cross the same boundary but do not reach the community entrance or service point in the middle. Then merge the directed sub-segments covered by the remaining access chains into reachable segments. Record the plots that intersect with reachable segments and whose corresponding access chains have not been deleted as reachable plots. Record the service points whose projection points fall into reachable segments or reachable plots as reachable service points. Generate the initial reachability range of the community.

7. The method for updating the reachability of urban living circles based on spatial monitoring results according to claim 6, characterized in that: S4 includes: S4-1. Read the status change table, update the road network and the initial reachability of the community. Divide the updated road network into directed sub-segments according to the status change location, intersection, plot boundary intersection, community entrance / exit projection point, and service point projection point. Construct the sub-segment transfer time matrix, the sub-segment to plot projection matrix, and the sub-segment to service point projection matrix. Construct the initial arrival vector for the directed sub-segment corresponding to the status change location. Use the least addition recursion to calculate the forward cumulative time along the travel direction and the backward cumulative time along the reverse connection direction. In each round of recursion, add the previous round's cumulative time to the current transfer time and write it to the corresponding endpoint. Then, retain the record with the first cumulative time for the same endpoint. Stop the recursion when all newly written records have a cumulative time exceeding 15 minutes. Generate the forward time table and the backward time table.

8. The method for updating the reachability of urban living circles based on spatial monitoring results according to claim 7, characterized in that: S4 further includes: S4-2. Read the forward timetable, backward timetable, sub-segment to plot projection matrix, sub-segment to service point projection matrix and initial reachability of the community. Take the intersection of directed sub-segments with forward cumulative time not exceeding 15 minutes and backward cumulative time not exceeding 15 minutes to obtain the affected sub-segment set. Next, the affected sub-segment sets are projected onto the plots and service points respectively to obtain the affected plot set and the affected service point set. The affected community entrances and exits are screened out according to the connectivity between the affected sub-segment sets and the projected points of the community entrances and exits. Local recalculation is performed starting from the directed sub-segments corresponding to each affected community entrance and exit. The cumulative time, cumulative boundary change count, and cumulative turning count are calculated for the states that reach the same endpoint number. The first state is screened out in the order of cumulative time from low to high, cumulative boundary change count from few to many, and cumulative turning count from few to many, and the predecessor number is written. When the cumulative time of the first state to be expanded exceeds 15 minutes, the expansion stops and a local recalculation table is generated.

9. A method for updating the reachability of urban living circles based on spatial monitoring results according to claim 8, characterized in that: S4 further includes: S4-3. Read the local recalculation table and the initial reachability of the community. For each state in the local recalculation table, backtrack in reverse according to the predecessor number to form an updated access chain. Map the directed sub-segments covered by the updated access chain to updated sub-segments. Map the plots that have boundary intersections with the updated sub-segments to updated plots. Map the service points whose projection points fall into the updated sub-segments or updated plots to updated service points. Then, calculate the intersection and difference between the updated sub-segments, updated plots, and updated service points and the initial reachability of the community, respectively, to obtain the retention result, the addition result, and the removal result. Delete isolated connected components that cannot simultaneously connect the community entrance / exit and the service points to generate the local updated range.

10. A method for updating the reachability of urban living circles based on spatial monitoring results according to claim 9, characterized in that: S5 includes: S5-1. Read the initial reachable range and partial update range of the community. Extract the original road segments, original plots, and original service points in the initial reachable range of the community, as well as the updated road segments, updated plots, and updated service points in the partial update range, according to the community number. Pair the original road segments with the updated road segments according to the same road segment number or overlapping spatial range. Pair the original plots with the updated plots according to the same plot number or overlapping boundary range. Pair the original service points with the updated service points according to overlapping point coordinates. Record the original results that are successfully paired and exist in the partial update range as results to be replaced. Record the paired results that only exist in the initial reachable range of the community as results to be deleted. Record the results that only exist in the partial update range as results to be written. Generate a result processing table. S5-2. Read the result processing table, delete each result to be replaced and the original road segment, original land parcel and original service point corresponding to each result to be deleted, then write each updated road segment, each updated land parcel and each updated service point into the scope result of the corresponding community, and collect the written road segment, land parcel and service point according to the community number to generate the dynamic reachability range of the city's 15-minute living circle.

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