Low-altitude double-air-route cooperative generation method and system based on space-time aging mark

Abstract

The application discloses a low-altitude double-air-route cooperative generation method and system based on a space-time label, relates to the technical field of space cooperative scheduling, acquires operation area, inspection points, space restrictions and emergency task information, labels the passing risk, occupation period and releasable state of a space unit, and constructs a space-time occupation graph; generates an inspection reference air route based on the graph and performs slice labeling, calculates an emergency takeover adaptation value in combination with long-term occupation, avoidance cost and recovery entry, forms an inspection air route set, selects an adaptive space window in response to an emergency task, generates an emergency temporary air route in combination with an emergency target position, an aircraft state and obstacle avoidance requirements, resolves time conflicts of double air routes, converts conflict air segments into inspection avoidance slices or suspended slices, and connects uncompleted inspection air segments in accordance with recovery entries after the release of emergency occupation, generates a low-altitude double-air-route cooperative execution scheme, and realizes emergency priority response and continuous inspection execution.

Description

Technical Field

[0001] This invention relates to the field of airspace collaborative scheduling technology, specifically to a method and system for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking. Background Technology

[0002] As low-altitude inspection and emergency response missions are increasingly conducted in parallel within the same operational airspace, different missions place higher demands on airspace resource occupation time, traffic priority, and route continuity. Existing low-altitude route planning typically generates single-mission routes based on fixed airspace restrictions and flight distances, lacking a unified time-sensitive marker for airspace unit occupation periods, traffic risks, and release status. This makes it difficult to accurately distinguish between long-term controlled occupation, inspection plan occupation, and airspace resources available for temporary takeover by emergency missions. When an emergency mission is triggered temporarily, it often requires a large-scale re-search of routes, making it difficult to balance emergency response speed, airspace safety constraints, and the execution costs of the original inspection mission.

[0003] Meanwhile, existing multi-task route coordination methods typically employ overall detours, delayed execution, or direct termination of the original route, lacking conflict identification and local adjustment mechanisms based on route slices. When emergency routes and inspection routes conflict in terms of time and space occupation, it is difficult to choose an avoidance or suspension method based on the availability of surrounding airspace. There is also a lack of a recovery entry point and timing calibration mechanism after emergency occupation is released, which can easily lead to duplicate planning of inspection segments, mission interruptions, or timing mismatches in subsequent segments.

[0004] Therefore, there is an urgent need for a method and system for the collaborative generation of low-altitude dual routes based on airspace time-based marking, which can perform spatiotemporal integrated description of airspace resources, pre-identify inspection route slices suitable for emergency takeover, and achieve dynamic coordination between inspection routes and emergency temporary routes through conflict segment avoidance, suspension and release follow-up mechanisms. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a method and system for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking.

[0006] The technical solution to achieve the purpose of this invention is as follows:

[0007] On the one hand, the low-altitude dual-line collaborative generation method based on airspace timeliness marking includes the following steps:

[0008] Acquire information on work areas, inspection points, airspace restrictions, and emergency tasks; mark airspace units with passage risks, occupation periods, and release status; and construct an airspace time-bound occupation map.

[0009] Based on the airspace occupancy map, a patrol baseline route is generated, and the patrol baseline route is sliced ​​and marked. The emergency takeover adaptation value is calculated by combining long-term occupancy, avoidance cost and restoration entry, and a patrol route set is formed.

[0010] In response to emergency mission information, airspace windows are selected based on emergency takeover compatibility values, release time slices, and emergency target locations, and emergency temporary flight paths are generated in combination with aircraft status and obstacle avoidance requirements.

[0011] The system performs time-sensitive conflict resolution on the inspection route set and emergency temporary routes, converting conflicting routes into inspection avoidance slices or suspended slices. After the emergency occupation is released, the system continues the unfinished inspection segments based on the restored entry point, generating a low-altitude dual-route collaborative execution plan.

[0012] Further calculations of the emergency takeover suitability value include:

[0013] The route slice boundary is determined based on the release status jump or occupation attribute category switch of adjacent airspace units, and the inspection benchmark route is divided into avoidable slices and non-avoidable slices.

[0014] For avoidable slices, the long-term control occupancy status of the slice and adjacent airspace units is statistically analyzed. The spatial offset increment, flight time increment, and passage risk increment of the avoidance path relative to the original slice are calculated to determine the passage risk, release status, and long-term control occupancy status of the restored entry point.

[0015] The emergency takeover adaptation value is obtained by weighting the scores of the long-term occupation dimension, the avoidance cost dimension, and the recovery entry dimension.

[0016] Further, the resolution of time-related conflicts includes:

[0017] The pre-occupancy markers and emergency mandatory occupancy markers of the inspection plan are detected on an airspace unit and time slice by the inspection baseline route and emergency temporary route, and continuous spatiotemporal conflict points are aggregated to form conflict segments.

[0018] Based on the passage risk and release status of the airspace units surrounding the conflict segment, the avoidance conditions are determined. If the avoidance conditions are met, the avoidance path is replanned in the airspace surrounding the conflict segment, and the conflict segment is converted into an inspection avoidance slice. If the avoidance conditions are not met, it is converted into a suspended slice.

[0019] After the emergency forced occupation is terminated, the airspace unit at the end of the conflict segment is used as the entry point to continue the unfinished inspection segment, and the time slice sequence of the subsequent segment is adjusted according to the avoidance time or hanging time.

[0020] Furthermore, the construction of the airspace occupancy time map includes:

[0021] Airspace units are divided according to the horizontal geographical boundaries and vertical height control range of the work area, and the spatial location and time slice of the airspace units are recorded.

[0022] Analyze airspace restrictions, inspection points and emergency mission information, map control attributes to corresponding airspace units, map inspection points to units that must be inspected, and mark airspace units covered by emergency target areas as high-probability emergency occupation units.

[0023] For each airspace unit, calculate the passage risk, discretely mark the occupied time period, and assign a release status based on the passage risk and the occupant;

[0024] Using airspace units as graph nodes, directed edges are established to satisfy spatial adjacency relationships that meet the differences in traffic risk and obstacle constraints. An airspace time occupancy graph is constructed based on traffic risk and spatiotemporal cost of edge connection.

[0025] Furthermore, the generation of the inspection baseline route includes:

[0026] The search starts from the airspace unit corresponding to the takeoff position, ends at the airspace unit corresponding to the landing position, and passes through the necessary inspection nodes.

[0027] The passage risk label value of the airspace unit and the weight of the directed connection are incorporated into the comprehensive evaluation cost value, and the cost value is estimated heuristically based on the three-dimensional Manhattan distance and the average basic risk.

[0028] The order of segmented nodes is determined according to the spatial proximity of the units that must be inspected, and segmented path search is performed under the condition of excluding the time slice occupied by long-term control.

[0029] The backtracking path yields the inspection baseline route, which consists of a continuous airspace unit sequence, a time slice sequence, and an inspection point passage sequence.

[0030] Further, slice markers include:

[0031] Traverse the airspace unit occupancy sequence of the inspection baseline route along the time axis, and determine the slice boundary at the point where the release status of adjacent airspace units changes or the occupancy attribute category switches.

[0032] The spatially continuous and time-sensitive flight segments are divided into flight route slices, and the spatiotemporal identification codes of the starting airspace unit, the spatiotemporal identification codes of the ending airspace unit, the slice start time slice number, the slice end time slice number, the total number of airspace units, and the average passage risk value are recorded.

[0033] Based on the release status of the time slice covered by the route slice, the route slice is marked as an avoidable slice or an unavoidable slice.

[0034] Furthermore, the formation of the inspection route set includes:

[0035] Using the inspection baseline route as the initial model, the order of the necessary inspection units is exchanged, and the vertical height layer of a single continuous avoidable slice is adjusted to generate alternative inspection routes.

[0036] Exclude alternative inspection routes that do not fully cover the units that must be inspected, have long-term control time slots, or do not meet the flight distance requirements.

[0037] For the remaining alternative inspection routes, slice marking and emergency takeover adaptation value calculation are performed, and the routes are screened based on average traffic risk and emergency takeover adaptation value of avoidable slices.

[0038] The selected alternative inspection routes and the baseline inspection route are stored to form an inspection route set.

[0039] Furthermore, the generation of emergency temporary flight routes includes:

[0040] The core occupied segment is the airspace interval corresponding to the optimal takeover airspace window, the starting point of the route is the airspace unit corresponding to the emergency take-off position, the mandatory transit node is the airspace unit corresponding to the emergency target position, and the ending point of the route is the airspace unit corresponding to the standby position.

[0041] Based on the airspace unit passage risk and the spatiotemporal cost of directed connections, a path search is performed, limiting the time slice of the core occupied segment to the releaseable time slice interval of the optimal takeover airspace window, and limiting the non-core segment to exclude long-term control occupation.

[0042] Based on obstacles, changes in altitude during a single time slice, remaining flight time, and cruise speed, the path is verified, and an emergency temporary route is generated.

[0043] Furthermore, the generation of a low-altitude dual-route coordinated execution plan includes:

[0044] Integrate emergency temporary routes with the adjusted inspection baseline routes, and record inspection avoidance slices, suspended slices, continuation segments, airspace unit sequences, time slice occupancy sequences, segment status markers, and occupancy priorities;

[0045] Verify the occupancy priority of the same airspace unit in the same time slot, and verify the coverage of the adjusted inspection baseline route to the units that must be inspected and the duration of operation stay.

[0046] If the verification passes, a low-altitude dual-route collaborative execution plan is generated; if the verification fails, the conflict segment is returned for classification and handling, and the avoidance path is adjusted or the optimal takeover airspace window is changed.

[0047] Secondly, the low-altitude dual-route collaborative generation system based on airspace timeliness marking includes an airspace construction module, an inspection slice module, an emergency generation module, and a conflict continuation inspection module:

[0048] The airspace construction module acquires information on work areas, inspection points, airspace restrictions, and emergency tasks, marks airspace units with passage risks, occupation periods, and release status, and constructs an airspace time-bound occupation map.

[0049] The inspection slicing module generates inspection baseline routes based on the airspace time-occupancy map, slices and marks the inspection baseline routes, and calculates the emergency takeover adaptation value by combining long-term occupation, avoidance cost and recovery entry, forming an inspection route set;

[0050] The emergency generation module responds to emergency mission information, filters airspace windows based on emergency takeover adaptation values, releasable time slices and emergency target locations, and generates emergency temporary flight paths in combination with aircraft status and obstacle avoidance requirements.

[0051] The conflict continuation patrol module performs time-sensitive conflict resolution on the patrol route set and emergency temporary routes, converts conflicting segments into patrol avoidance slices or suspended slices, and continues the incomplete patrol segments based on the recovery entry after the emergency occupation is released, generating a low-altitude dual-route collaborative execution plan.

[0052] Compared with the prior art, the advantages of this invention are as follows:

[0053] 1. By marking the passage risk, occupancy period, and release status of airspace units at the time slice level, an airspace time-based occupancy map is constructed. The inspection baseline route is divided into route slices with continuous time-based attributes. Furthermore, emergency takeover suitability values ​​are calculated by combining long-term occupancy, avoidance costs, and recovery entry points. This allows for the pre-quantification of temporary transfer capabilities for different inspection segments before an emergency mission is triggered, forming a set of inspection routes with multiple takeover airspace windows. This avoids indiscriminate replanning of the entire airspace after an emergency mission arrives, improving the targeting of emergency airspace resource selection and the efficiency of route generation.

[0054] 2. Conflict resolution is performed on an airspace unit-by-airspace and time-slice basis for both inspection routes and emergency temporary routes. Based on the release conditions of the surrounding airspace, the conflicting segments are converted into inspection avoidance slices or suspended slices, respectively. After emergency occupation is released, the incomplete inspection segments are continued with a preset recovery entry point, and the time-slice sequence of subsequent segments is calibrated based on the avoidance or suspension duration. This ensures priority access to airspace resources for emergency tasks while maintaining the spatial continuity and execution integrity of inspection tasks, reducing the additional scheduling overhead caused by overall route reconstruction and restarting of inspection tasks. Attached Figure Description

[0055] Figure 1 This is a flowchart of the low-altitude dual-flight collaborative generation method based on airspace timeliness marking in this invention;

[0056] Figure 2 This is a schematic diagram of the three-dimensional structure and attribute markings of the spatial domain time-occupancy map in this invention;

[0057] Figure 3 This is a schematic diagram of the slice division and emergency takeover adaptation of the inspection baseline route in this invention.

[0058] Figure 4 This is a schematic diagram illustrating the handling of time-related conflicts between the inspection baseline route and the emergency temporary route, as well as the resumption of inspections in this invention. Detailed Implementation

[0059] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0060] Example 1

[0061] This invention discloses a method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking, comprising the following steps:

[0062] S1: Obtain information on work areas, inspection points, airspace restrictions, and emergency tasks; mark airspace units with passage risks, occupation periods, and release status; and construct an airspace time-based occupation map.

[0063] S2: Generate inspection baseline routes based on the airspace occupancy map, slice and mark the inspection baseline routes, and calculate the emergency takeover adaptation value based on long-term occupancy, avoidance costs and restoration entry points to form an inspection route set.

[0064] S3: Respond to emergency mission information, centrally select airspace windows that meet the emergency takeover adaptation value from the inspection routes, and generate short-term priority emergency temporary routes based on the location of emergency targets, aircraft status and obstacle avoidance requirements.

[0065] S4: Perform time-sensitive conflict resolution on the inspection route set and emergency temporary route, convert conflicting segments into inspection avoidance slices or suspended slices, and after emergency occupation is released, continue the incomplete inspection segments based on the restored entrance to generate a low-altitude dual-route collaborative execution plan.

[0066] refer to Figure 1 , Figure 1 This is a flowchart of a low-altitude dual-route collaborative generation method based on airspace timeliness marking.

[0067] Figure 1 The overall process of the low-altitude dual-route collaborative generation method based on airspace timeliness marking is shown, including the construction of airspace timeliness occupancy map, the formation of inspection route set, the generation of emergency temporary routes, and the dual-route timeliness conflict resolution and recovery and continuation process, which is used to demonstrate the overall technical process from airspace resource modeling to the generation of dual-route collaborative execution scheme.

[0068] It should be noted that, Figure 1This is for illustrative purposes only, intended to help understand the process structure and data organization, and does not represent the precise working state in actual operation.

[0069] In step S1, information on the work area, inspection points, airspace restrictions, and emergency tasks is obtained. Airspace units are marked with passage risks, occupancy periods, and release status to construct an airspace time-bound occupancy map, including:

[0070] S101: Three-dimensional meshing of the work area and standardized definition of spatial units.

[0071] Based on the horizontal geographical boundaries and vertical height control range of the operational area, a three-dimensional meshing rule with equal resolution is used to generate full-area airspace units. The horizontal meshing granularity is set to 50 meters × 50 meters, and the vertical meshing granularity is set to 20 meters per layer. This granularity parameter matches the minimum safe separation constraint for low-altitude aircraft. The 50-meter horizontal granularity provides sufficient safety redundancy, and the 20-meter vertical layering conforms to the general layering system for low-altitude airspace height control.

[0072] The number of horizontal grid cells is determined by dividing the longitudinal span of the work area by 50 meters and the latitudinal span by 50 meters, and then rounding up. The number of vertical layers is determined by dividing the difference between the upper and lower height limits of the work area by 20 meters and then rounding up. All spatial units are continuous and non-overlapping, completely covering the horizontal boundaries and vertical height range of the work area.

[0073] Each airspace unit is assigned a unique spatiotemporal identification code, with the encoding format being "horizontal grid X-coordinate - horizontal grid Y-coordinate - vertical height layer number - reference time slice number". The reference time slice granularity is set to 1 second, which covers the millisecond-level response cycle of the low-altitude aircraft flight control system, meeting the accuracy requirements of time-sensitive scheduling. The latitude, longitude, and altitude values ​​of the eight vertices, effective passage volume, and geometric center coordinates of each airspace unit are recorded synchronously. The effective passage volume refers to the remaining three-dimensional space volume within a single airspace unit, after deducting the space occupied by static obstacles such as buildings and towers, which allows for the safe passage of low-altitude aircraft. It is calculated based on the total geometric volume of the airspace unit, combined with the proportion of the horizontal projected area of ​​obstacles within the unit and the proportion of the vertical height of obstacles within this layer. The total geometric volume is determined by multiplying the horizontal and vertical partitioning granularities. This parameter provides the spatial dimension basis for subsequent passage risk marking and path feasibility verification. After completing the above attribute recording, the standardized modeling of the airspace unit is complete.

[0074] S102: Structured analysis and cell attribute mapping of multi-source spatial information.

[0075] The acquired airspace restriction information is structured and analyzed to extract the vector spatial range and effective time periods of no-fly, restricted-fly, and controlled airspace. A polygonal spatial intersection algorithm is used to map control attributes to airspace units. First, the two-dimensional vector boundary of airspace restrictions is vertically stretched along the controlled altitude range to generate a three-dimensional closed control volume. Axis-aligned bounding boxes are used for rapid pre-screening to eliminate airspace units with no possibility of intersection. Then, the separating axis theorem is used to perform precise intersection volume calculations on candidate units. Units whose intersection volume accounts for more than 80% of the total volume of airspace units are fully assigned the corresponding control attributes; units with an intersection volume between 20% and 80% are assigned a downgraded control attribute; and units with an intersection volume below 20% are not assigned any control attributes. The 80% threshold corresponds to the boundary for determining whether a unit's main body is subject to control constraints, effectively avoiding misjudgment of control attributes for boundary units.

[0076] Spatial mapping is performed on the inspection point information, and the Euclidean distance from the inspection point to the geometric center of each airspace unit is calculated. The airspace unit with the smallest distance is selected as the unit to which the inspection point belongs, and this unit is marked as a mandatory inspection unit. At the same time, the operation dwell time of the inspection point is recorded. The operation dwell time is set to 30 seconds by default, matching the nominal time range of single-point focusing and data acquisition of conventional photoelectric inspection equipment, and serving as a general benchmark parameter for low-altitude inspection scenarios.

[0077] Emergency mission information is pre-analyzed to extract potential take-off and landing points, target areas, and estimated execution periods. A buffer zone analysis method is employed to generate a spatial buffer zone with a radius of 200 meters and the geometric center of the emergency target area as its center. Airspace units within the buffer zone are marked as high-probability emergency occupancy units. The 200-meter buffer zone radius is suitable for the maneuvering needs of low-altitude aircraft during emergency turns and altitude adjustments, reserving ample space for emergency flight avoidance.

[0078] S103: Quantitative calculation and assignment of multi-dimensional timeliness markers for spatial units.

[0079] For each airspace unit, three core attributes are calculated and assigned sequentially: passage risk marker, occupied time period marker, and release status marker. All attributes are bound to the corresponding time slice dimension to achieve spatiotemporal integrated marking of airspace units.

[0080] The airspace risk labeling uses a tiered quantification method, calculated by summing a static inherent risk value with a dynamic risk coefficient and then rounding it down. The static inherent risk value corresponds one-to-one with the risk level, with the value equal to the corresponding level number, ranging from 0 to 5. Higher values ​​indicate stronger airspace restrictions and higher flight safety risks. First, the static inherent risk value is calculated: no-fly zones are assigned a level of 5; restricted zones with permanent altitude restrictions are assigned a level of 4, while those with only time-limited flight restrictions are assigned a level of 3; high-frequency control zones in controlled airspace are assigned a level of 2, and low-frequency control zones are assigned a level of 1; unrestricted airspace is assigned a level of 0. Next, the dynamic risk coefficient is calculated: based on the proportion of the projected area of ​​obstacles within the zone, the risk coefficient increases by 0.5 for every 10% increase in the proportion; based on meteorological conditions, the risk coefficient increases by 1 when visibility is below 1 km and by 0.5 when wind speed exceeds 12 m / s. The final airspace risk label value is the sum of the static inherent risk value and the dynamic risk coefficient, rounded down, with a maximum value of 5. The five-level risk classification system matches the civil aviation low-altitude flight risk management standards and can directly correspond to different levels of flight permit conditions.

[0081] The occupancy period marking adopts a time-slice discretization method, using 1 second as the base time slice granularity, and setting the entire scheduling cycle to 24 hours to divide continuous time slices. Each time slice is marked with occupancy attributes, categorized into four types: long-term control occupancy, pre-occupancy for inspection plans, potential emergency occupancy, and idle availability. The start and end times of each occupancy status are recorded simultaneously, with time precision uniformly at the second level. This time granularity can accurately capture timing conflicts in low-altitude flights, ensuring the accuracy of timeliness calculations for dual-line coordination.

[0082] When marking a space as releaseable, a preset passage risk level threshold of level 2 is used. This threshold corresponds to the risk level of low-frequency controlled airspace. Airspace units at or below this level have sufficient safety margins, and their release can still meet low-altitude flight safety constraints for temporary use by emergency missions. Simultaneously, it avoids safety hazards caused by scheduling changes in high-risk airspace, aligning with the safety-first airspace scheduling principle. For time slots with a passage risk level of 2 or less and where the occupant is an inspection plan, the space is marked as releaseable, with a corresponding release response delay of 5 seconds. This 5-second release response delay covers the end-to-end delay between low-altitude aircraft route replanning and ground command issuance, reserving sufficient safety redundancy for command execution. For time slots where the occupant is subject to long-term control or emergency mandatory occupancy, the space is directly marked as non-releaseable.

[0083] S104: Topology construction and consistency verification of airspace time-occupancy map.

[0084] All airspace units that have completed three types of attribute marking are used as graph nodes, and for each airspace unit, six spatially adjacent units including four horizontal neighbors and upper and lower vertical neighbors are selected as adjacent units. When the difference in passage risk levels between adjacent units is less than or equal to level 2, and no permanent obstacle runs through between the two units, a directed connected edge is established between the two units, so as to construct a directed weighted graph with spatio-temporal attributes, that is, the time-effective airspace occupancy graph.

[0085] Wherein, the weight of the graph node is directly determined by the passage risk marking value of the unit; the weight of the connected edge is calculated by weighting the horizontal distance factor, the height difference factor and the time effectiveness matching factor, and the weight proportions of the three types of factors are 0.6, 0.2 and 0.2 respectively. The horizontal distance factor is the ratio of the horizontal distance between the centers of adjacent units to the reference granularity of 50 meters, the height difference factor is the ratio of the absolute value of the height difference of adjacent units to the reference granularity of 20 meters, and the time effectiveness matching factor is the ratio of the time difference of the first same-state time slice of adjacent units to the reference time slice granularity. This weight distribution fits the characteristics of energy consumption and time consumption of low-altitude flight. Horizontal displacement is the main source of flight cost, so it is given the highest weight, and time effectiveness matching is used to ensure the continuity of route timing.

[0086] After the topology construction is completed, the spatio-temporal consistency check of the whole graph is performed, and the check items include three categories: the first category is the continuity check of occupancy period connection. If the timing deviation of the same attribute time slice of adjacent units is less than or equal to 1 second, it is determined as qualified, otherwise the time slice boundary is corrected; the second category is the spatial gradient check of passage risk. If the difference in passage risk levels of adjacent units is greater than level 2, it is determined as abnormal, and the mapping accuracy of control boundaries is re-checked; the third category is the logical check of releasable state. If a unit with non-releasable attribute has a releasable mark, it will be corrected directly. Re-perform attribute mapping and marking calculation for units that fail the check until the whole graph passes the check, and finally generate the time-effective airspace occupancy graph.

[0087] Reference Figure 2 , Figure 2 is a schematic diagram of the three-dimensional structure and attribute marking of the time-effective airspace occupancy graph.

[0088] Figure 2 shows the three-dimensional airspace structure based on airspace unit division, the spatial adjacency relationship between airspace units, and the attribute marking process such as passage risk, occupancy period and releasable state bound to time slices, which is used to reflect the unified description mode of the time-effective airspace occupancy graph for spatial position and time state.

[0089] It should be noted that, Figure 2 is only a schematic diagram of principle, which is used to help understand the process structure and data organization mode, and does not represent the accurate working state of actual operation.

[0090] In step S2, a baseline inspection route is generated based on the airspace occupancy map. This baseline route is then sliced ​​and marked. Emergency takeover adaptation values ​​are calculated based on long-term occupancy, avoidance costs, and recovery entry points, forming a set of inspection routes, including:

[0091] S201: Generation of inspection baseline routes based on spatiotemporal weighted cost model.

[0092] Using the airspace occupancy timeliness map as the spatiotemporal path search carrier, and taking the airspace unit corresponding to the takeoff position as the search starting point, the airspace unit corresponding to the landing position as the search ending point, and all mandatory inspection units as transit nodes, the A* algorithm with timeliness constraints is used to solve for the optimal path. This algorithm improves upon the standard A* heuristic search framework in three dimensions: cost model, heuristic function, and constraint embedding. It incorporates the passage risk of airspace units and the spatiotemporal cost of adjacent edges into a unified comprehensive cost system; constructs an admissible heuristic function using three-dimensional Manhattan distance combined with average basic risk; and embeds timeliness compliance and mandatory transit node constraints during the search process, ultimately generating the optimal inspection baseline route that satisfies multiple constraints. The algorithm uses the comprehensive evaluation cost value as the priority basis for node expansion. The comprehensive cost function consists of two parts: the cumulative actual cost and the heuristically estimated cost, calculated as follows:

[0093] ,

[0094] in, The comprehensive evaluation value of the current airspace unit, The cumulative actual cost from the starting point to the current airspace unit. The heuristic estimation value from the current spatial unit to the endpoint.

[0095] Cumulative actual cost The calculation method is as follows:

[0096] ,

[0097] in, For the first The passage risk marker value of each transit airspace unit. For the first The and the first Weights of directed edges between spatial units; This is the node cost weight, with a value of 0.4; The edge cost weight is set to 0.6. This weighting balances flight safety risks and time-space navigation costs, aligns with the scheduling principle of prioritizing safety over efficiency in low-altitude inspection operations, and is consistent with the weighting logic of the airspace occupancy map.

[0098] Heuristic estimation of cost The algorithm employs a 3D Manhattan distance combined with minimum passage risk calculation, maintaining dimensional consistency with the cumulative actual cost and satisfying admissibility constraints to ensure convergence to the global optimum. The 3D grid coordinates of the current spatial cell are defined as follows: The three-dimensional grid coordinates of the endpoint spatial unit are ,in, The horizontal grid coordinate number. This refers to the vertical height layer number. The calculation formula is:

[0099] ,

[0100] in, The spatial distance baseline cost term is calculated based on the three-dimensional Manhattan distance, using the sum of ideal edge costs corresponding to the minimum grid step size. The calculation formula is:

[0101] ,

[0102] in, The total number of Manhattan grid steps in the horizontal direction represents the theoretical minimum number of horizontal movement units from the starting point to the ending point; The difference in height between vertical layers represents the theoretical minimum number of layers that need to be moved vertically. The baseline edge weight for horizontally adjacent units is set to 0.6. This value follows the edge weight calculation rules of the spatial time occupancy map, corresponding to the ideal adjacency state of horizontal positive adjacency, height difference of 0, and perfect time matching: at this time, the horizontal distance factor is 1, the height difference factor is 0, and the time matching factor is 0. The minimum horizontal edge weight of 0.6 is obtained by calculating the weight ratio of the three factors of 0.6, 0.2, and 0.2. The baseline edge weight for vertically adjacent units is set to 0.2. Similarly, for the ideal adjacency state of vertical positive adjacency, horizontal distance of 0, and perfect temporal matching, the height difference factor is 1, the horizontal distance factor is 0, and the temporal matching factor is 0, resulting in a minimum vertical edge weight of 0.2. This item uses the ideal adjacency cost with no temporal deviation and no additional risk as a benchmark to calculate the theoretical minimum edge cost from the current unit to the endpoint, ensuring that the distance estimate is always no higher than the edge cost of the actual path.

[0103] To calculate the average traffic risk cost, we first statistically analyze the traffic risk marker values ​​of all non-no-fly airspace units within the operational area and then calculate their arithmetic mean, which is denoted as the average basic risk. The total step size of the 3D Manhattan grid represents the estimated total number of path elements. Multiplying the two yields the theoretical minimum total node risk cost, calculated as follows:

[0104] ,

[0105] in, The risk statistics of all accessible airspace units are obtained, which allows the heuristic function to simultaneously incorporate both distance and risk-based look-ahead constraints. At the same time, this term adopts the average risk reduction of the entire domain, and the heuristic estimated cost is always no higher than the actual node cost of any real feasible path, which meets the admissibility requirement of the A* algorithm. This ensures that the algorithm eventually converges to the global optimum, and at the same time, it allows the heuristic function to simultaneously incorporate both distance and risk-based look-ahead constraints, guiding the search path to favor low-risk airspace corridors in advance.

[0106] The specific process of the algorithm to solve for the optimal path is as follows: First, add the starting airspace unit corresponding to the takeoff position to the open list, initialize its cumulative actual cost to 0, and the comprehensive evaluation cost value to the corresponding heuristic estimated cost; then, iteratively select the airspace unit with the smallest comprehensive evaluation cost value from the open list as the current expansion node, and traverse its horizontal four-neighbor and vertical up-down neighbor, a total of six neighboring units that meet the edge connection conditions; for each neighboring unit, calculate the cumulative actual cost corresponding to reaching the unit through the current expansion node. If the cost value is lower than the cumulative actual cost already recorded by the neighboring unit, update its cost and parent node information and add it to the open list; after completing the neighborhood traversal, move the current expansion node to the closed list.

[0107] Two types of rigid constraints are enforced during the route search process: First, timeliness compliance constraints, excluding long-term control occupancy status for all airspace units along the route extension to ensure static control compliance of the route; second, mandatory route constraints, using a segmented optimization method, with all mandatory inspection units as segment nodes, and the route search is performed segment by segment after sorting by spatial proximity; the spatial proximity is calculated based on the Euclidean distance between the geometric centers of the corresponding airspace units of each mandatory inspection unit, the smaller the distance between two points, the higher the spatial proximity. When sorting, the starting airspace unit is used as the initial reference node, and the nearest unpassed mandatory inspection units to the current reference node are selected in sequence to determine the order of passing each segment node; the dwell time at each mandatory inspection unit matches the calibrated operation dwell time to ensure that the route fully covers all inspection points.

[0108] When the search extends to the endpoint airspace unit corresponding to the landing position, and all inspection-passing units have been included in the path sequence, the search is terminated and the parent node link is traced back to generate an inspection baseline route consisting of a continuous airspace unit sequence, a corresponding time slice sequence, and an inspection point path sequence. Under the premise of satisfying all constraints, this route achieves the optimization goal of full point coverage and the lowest overall cost.

[0109] S202: Spatiotemporal consistency slicing and attribute labeling of the inspection baseline route.

[0110] The airspace unit occupancy sequence of the inspection baseline route is sliced ​​along the time axis, and the slice boundaries are determined using spatiotemporal attribute continuity rules: Each airspace unit's corresponding time slice is traversed sequentially along the route time sequence. When the release status of an adjacent unit changes or the occupancy attribute category switches, the current airspace unit is used as the slice boundary node, dividing the internally continuous time-sensitive segments into an independent route slice. Time-sensitive attributes refer to the dynamic airspace attributes bound to the time slice dimension, including occupancy attribute category and release status. Their classification and determination rules are completely consistent with the labeling system used in the airspace time-sensitive occupancy map construction phase. Each route slice is a spatially continuous subset of the smallest flight segments with consistent time-sensitive attributes, serving as the smallest scheduling unit for emergency takeover.

[0111] Each route slice is labeled with all attribute fields, including the slice's unique ID, the starting airspace unit's spatiotemporal identification code, the ending airspace unit's spatiotemporal identification code, the slice's starting time slice number, the slice's ending time slice number, the total number of airspace units included, and the average passage risk value within the slice. A avoidable attribute determination is performed synchronously: if all time slices covered by the slice are in a releaseable state, the slice is marked as an avoidable slice; if any time slice within the slice is in a non-releaseable state, it is marked as an unavoidable slice.

[0112] S203: Quantitative calculation of emergency takeover adaptation value for multi-dimensional coupling.

[0113] For all avoidable slices, an emergency takeover suitability value is calculated based on three dimensions: long-term occupancy, avoidance cost, and recovery entry point. The suitability value ranges from 0 to 100, with higher scores indicating that the corresponding spatial window of the slice is more suitable for emergency task takeover. Emergency Takeover Suitability Value The calculation formula is:

[0114] ,

[0115] in, , , The weighting coefficients for the three dimensions are 0.3, 0.4, and 0.3, respectively. This weighting allocation takes the avoidance cost as the core evaluation dimension, which directly determines the route deviation and flight cost increase caused by emergency takeover. Long-term occupation and recovery entry point correspond to basic airspace constraints and subsequent connection capabilities, respectively. The two have a similar degree of influence and are in line with the priority logic of "takeoverable, low disturbance, and easy recovery" in emergency dispatch. For long-term occupied dimension scores, To avoid scoring in the cost dimension, To restore the entry dimension score, the three scores are all in the range of [0, 100].

[0116] Long-term occupation dimension score Used to assess the control constraint strength of a slice and its surrounding airspace, this method calculates the proportion of time slices occupied by long-term control within all airspace units of the slice itself and its six corresponding neighboring airspace units, relative to the total number of time slices in the entire scheduling cycle. The calculation formula is:

[0117] ,

[0118] For every 5% increase in the proportion of long-term controlled routes, 5 points are deducted from the score, with a maximum score of 100 points achieved when the proportion is zero. Including the assessment of neighboring units can ensure lateral maneuvering margins for emergency routes and improve the feasibility of takeover.

[0119] Avoidance cost dimension score The incremental flight cost used to assess slice avoidance is comprehensively considered in conjunction with the incremental spatial offset. Flight duration increment Increased traffic risks The three types of indicators are calculated using the following formulas:

[0120] ,

[0121] in, The distance reference step size is set to 50 meters. This is the deduction value corresponding to the single-step distance increment, with a value of 2. The time reference step is set to 10 seconds. This is the deduction value corresponding to the single-step time increment, with a value of 2. The deduction value corresponding to a single-level risk increment is set to 10. The matching relationship between each baseline step size and the deduction value is adapted to the cost sensitivity of low-altitude inspection flights. The deduction weights for distance and delay increments are balanced, and the penalty weight for increased risk level is higher, which aligns with the airspace scheduling principle of prioritizing safety; spatial offset increment The constraint path search is used to find the shortest avoidance path within the airspace occupancy map that avoids all airspace units of the original slice and satisfies the releaseable state constraint. The flight duration increment is calculated as the difference between the total distance of the avoidance path and the nominal total distance of the original slice. Based on the nominal cruise speed conversion, the nominal cruise speed of the low-altitude aircraft is set to a fixed value of 15 m / s. This value matches the conventional operational cruise speed range of multi-rotor low-altitude inspection aircraft, ensuring that the time conversion accuracy is consistent with the actual engineering situation. The estimated flight time of the avoidance path is obtained by dividing the total distance of the avoidance path by the preset nominal cruise speed, and the difference between this and the original slice's nominal flight time is calculated. Increased traffic risk By calculating the average risk difference, the arithmetic mean of the passage risk markers of the avoidance path and the original slice's airspace unit are obtained respectively, and the difference between the two is the passage risk increment.

[0122] Restore entry dimension score This method is used to assess the continuity of patrol routes after emergency occupancy is released. The segmented termination airspace unit is used as the recovery entry node, and three constraints are considered: a passage risk level of 2 or lower, the corresponding time slice being in a releaseable state, and no long-term control occupancy obstructing the subsequent connecting segment. 100 points are awarded if all three constraints are met; 60 points are awarded if the first two are met and only low-level control obstruction exists subsequently; and 0 points are awarded if either of the first two is not met.

[0123] The emergency takeover adaptation value for unavoidable slices is directly assigned to 0, and they are not included in the emergency takeover candidate window range.

[0124] S204: Construction of inspection route set by two-dimensional perturbation iteration.

[0125] Using the baseline inspection route as the initial model, a two-dimensional perturbation mechanism is employed to generate candidate inspection routes in batches. The first dimension is the perturbation of the inspection point traversal order, which uses a random pairwise swapping method to adjust the passing order of two mandatory inspection units. The second dimension is the segment altitude layer offset perturbation, which selects a single continuous avoidable slice and shifts it up or down by one vertical altitude layer. All candidate routes generated by the perturbation must meet mandatory constraints: complete coverage of all mandatory inspection units, no long-term control occupation in any time slice of the segment, and the total flight distance does not exceed 120% of the baseline inspection route.

[0126] For each candidate route that meets the mandatory constraints, the spatiotemporal consistency slice division and emergency takeover adaptation value calculation are performed sequentially, and the entry screening is performed: the average traffic risk level of the entire route is less than or equal to level 2, and the minimum emergency takeover adaptation value of all avoidable slices within the route is greater than or equal to 40 points.

[0127] The disturbance generation and screening process is iteratively executed until the number of valid candidate routes reaches a preset value of 20, or the cumulative number of iterations reaches 200, at which point generation terminates. The 20-route limit covers different combinations of spatial paths and takeover windows, ensuring sufficient differentiated alternatives for emergency dispatch while avoiding excessive storage and screening costs due to an overly large route set, thus adapting to the conventional alternative capacity requirements of low-altitude inspection and dispatch. The 200-iteration limit avoids invalid loops in scenarios with strong airspace constraints and sparse feasible solutions, controlling the overall computational time of route generation and ensuring the algorithm's real-time performance and engineering usability. All selected candidate routes and the inspection baseline route are stored together in the inspection route set, simultaneously storing the airspace unit time sequence, time slice mapping relationship, slice attribute set, and adaptation value dataset for each route, forming a multi-option route set that can support rapid dispatching of emergency tasks.

[0128] In step S3, in response to emergency mission information, airspace windows that meet the emergency takeover adaptation value are selected from the inspection route pool. Based on the emergency target location, aircraft status, and obstacle avoidance requirements, short-term priority emergency temporary routes are generated, including:

[0129] S301: Emergency mission parameter analysis and preliminary screening of candidate airspace windows.

[0130] The system receives and structures emergency mission information, extracting four core parameters: emergency takeoff position, emergency target position, estimated mission execution duration, and latest response start time. The estimated mission execution duration is the nominal operating time defined for the emergency mission, and the latest response start time is the latest permitted takeoff time, both expressed in seconds. The estimated mission execution duration and latest response start time are mapped to the time axis of the entire scheduling cycle at a reference time slice granularity, yielding the corresponding number of estimated mission execution time slices and the sequence number of the latest response start time slice. The mapping rule is consistent with the time slice division rule for airspace unit occupancy period marking. Simultaneously, real-time status parameters of the patrol aircraft are acquired, including the spatiotemporal identification code of the current airspace unit, remaining endurance, and current vertical altitude layer.

[0131] The process iterates through all avoidable slices of the entire inspection route set, performing a triple-constraint initial screening to select eligible route slices as candidate airspace windows. The first constraint is an adaptation value constraint: the emergency takeover adaptation value corresponding to the slice is greater than or equal to a preset adaptation threshold of 60. This threshold corresponds to a medium-to-high adaptation level for emergency takeover, ensuring a sufficient number of candidate windows while maintaining controllable avoidance costs, balancing response speed and scheduling feasibility. The second constraint is a time-coverage constraint: the releaseable time slice interval of the slice completely covers the estimated number of time slices required for task execution, and the slice's start time slice number is earlier than the latest response start time slice number. The total releaseable duration of the window is calculated by multiplying the difference between the slice's end time slice number and start time slice number by the base time slice granularity, representing the longest continuous duration that the window can be occupied by emergency tasks. The third constraint is spatial matching: the horizontal distance from the geometric center of the airspace unit set corresponding to the slice to the emergency target location is less than or equal to a preset spatial matching threshold of 800 meters. This threshold covers the normal operating radius of short-range maneuvers for low-altitude aircraft, which can control the total deviation of the emergency flight path within an acceptable range and avoid excessively prolonging the response time. Flight path slices that simultaneously meet all three constraints are included in the candidate window set.

[0132] S302: Multi-dimensional window comprehensive adaptation calculation and optimal window selection.

[0133] For each spatial window within the candidate window set, the comprehensive adaptability score is calculated using four dimensions: basic takeover adaptability, spatial proximity, temporal matching, and duration margin. The final comprehensive adaptability score is obtained by weighting and summing the four dimensions according to their respective weights, with basic takeover adaptability accounting for 0.4, spatial proximity for 0.3, temporal matching for 0.2, and duration margin for 0.1. This weighting distribution emphasizes the core position of basic emergency takeover adaptability capabilities while also considering spatial and temporal matching, aligning with the scheduling logic of prioritizing takeover capability in emergency missions before optimizing response efficiency. The scores for each of the four dimensions range from 0 to 100.

[0134] The basic dimension of takeover adaptation directly uses the emergency takeover adaptation value of the corresponding flight path slice as the score, reflecting the slice's basic emergency takeover capability. Spatial proximity score is calculated based on the horizontal distance between the window and the emergency target. The geometric center of the window is obtained by taking the arithmetic mean of the geometric center coordinates of all airspace units contained in the slice. A perfect score is achieved with zero distance between the window and the emergency target; 5 points are deducted for every 50-meter increase in distance, with a minimum score of 0. The distance benchmark step size is consistent with the horizontal subdivision granularity of the airspace units, and the deduction value matches the weight of spatial distance on response timeliness, achieving a linear adaptation between distance increment and score decay. Time matching score is calculated based on the difference between the window start time and the response time limit. The latest response start time slice number is obtained by mapping the latest response start time of the emergency task through time slices. A perfect score is achieved with the window start time and the latest response time completely coinciding; 5 points are deducted for every 10-second increase in start delay, with a minimum score of 0. The time baseline step corresponds to a 10-second scheduling granularity, matching the scheduling precision of second-level time slices. The deduction value is adapted to the sensitivity of emergency response to start-up delays. The duration margin score is calculated based on the redundancy of the available window duration, which is the difference between the total release duration of the window and the estimated execution time of the emergency task. A zero-margin state is used as the zero-score baseline, and every 10-second increase in duration redundancy corresponds to an increase of 5 points, with a maximum score of 100 points. The margin baseline step corresponds to a 10-second duration redundancy, and the scoring gradient matches the uncertainty and fault tolerance requirements of task execution, distinguishing the duration buffer capacity of different windows.

[0135] Candidate windows are sorted from highest to lowest based on their overall adaptability. The airspace window with the highest ranking is selected as the optimal takeover airspace window, and its associated inspection route is used as the inspection benchmark route to provide an airspace resource benchmark for the generation of emergency temporary routes.

[0136] S303: Time-priority emergency temporary route planning and constraint verification.

[0137] The path search is performed using the airspace interval corresponding to the optimal takeover airspace window as the core occupied segment, the airspace unit corresponding to the emergency take-off position as the starting point of the route, the airspace unit corresponding to the emergency target position as the mandatory transit node, and the airspace unit corresponding to the standby position after the emergency mission ends as the ending point of the route. The time-priority A* algorithm is used to perform the path search.

[0138] The overall cost of path search follows the architecture of weighted node cost and edge cost, with adjustments to the weighting ratio to address the short-time priority of emergency tasks: node cost accounts for 0.2, and edge cost accounts for 0.8. This weighting ratio weakens the static impact of unit risk and strengthens the dynamic weight of path timeliness, aligning with the scheduling principle of emergency tasks prioritizing reaching the target in the shortest possible time. The heuristic cost estimation uses the three-dimensional Manhattan distance, consistent with the inspection baseline route, combined with the average basic passage risk conversion rule, ensuring the algorithm's adoptability and convergence.

[0139] Three types of constraints are enforced during the path search process: First, safety constraints: the passage risk level of all airspace units traversed by the flight segment is less than or equal to level 3. Level 3 and below risk levels correspond to time-limited or low-level controlled airspace, providing passage space in emergency priority scenarios and maximizing path selection flexibility within the safety boundary; and there are no permanent obstacles penetrating between units, meeting obstacle avoidance requirements. Second, time constraints: the time slice interval of the core occupied segment falls entirely within the releaseable time slice range of the optimal takeover airspace window, and the time slices traversed by non-core segments are excluded from long-term controlled occupation. Third, aircraft performance constraints: altitude changes within a single time slice do not exceed one vertical altitude layer to avoid flight instability and sharp increases in energy consumption caused by large maneuvers; the total flight time of the route is less than or equal to the remaining endurance of the aircraft, and the cruise speed does not exceed the nominal cruise speed.

[0140] After the search is completed, an emergency temporary route is generated, consisting of a continuous airspace unit sequence, a corresponding time slice sequence, and a route node sequence. This route satisfies multiple constraints, including short-term priority occupation, safety compliance, and performance adaptation.

[0141] S304: Emergency temporary route validity attribute marking and occupation priority locking.

[0142] All airspace units and corresponding time slots traversed by the generated emergency temporary flight routes are uniformly marked as being in an emergency mandatory occupation status. This status belongs to the high-priority category of occupation time slot marking, with an occupation priority higher than pre-occupancy in the inspection plan and potential emergency occupation, ensuring priority access to airspace resources for emergency missions. Simultaneously, each occupied unit is marked with an occupation start time slot number, an occupation end time slot number, and an estimated release time. The estimated release time is consistent with the estimated end time of the emergency mission, which is obtained by adding the estimated execution duration of the mission to the start time of the emergency mission.

[0143] The optimal takeover airspace window is marked as pending avoidance in the inspection baseline route, and the airspace resource scheduling authority corresponding to this window is locked, prohibiting other non-emergency tasks from occupying it. After completing the timeliness attribute marking, an emergency temporary route with fixed spatiotemporal range and priority attributes is formed, providing a benchmark for subsequent dual-route timeliness conflict resolution and collaborative execution.

[0144] refer to Figure 3 , Figure 3 A schematic diagram illustrating the segmentation of the inspection baseline route and its adaptation for emergency takeover.

[0145] Figure 3 The process of dividing the inspection baseline route into route slices according to the continuity of time attributes, and the process of determining the emergency takeover adaptation value and screening candidate airspace windows by combining long-term occupation, avoidance costs and recovery entry points, are used to demonstrate the implementation of the inspection route's ability to partially transfer and take over in an emergency.

[0146] It should be noted that, Figure 3 This is for illustrative purposes only, intended to help understand the process structure and data organization, and does not represent the precise working state in actual operation.

[0147] In step S4, timeliness conflict resolution is performed on the inspection route set and emergency temporary routes, converting conflicting segments into inspection avoidance slices or suspended slices. After the emergency occupation is released, the incomplete inspection segments are continued based on the recovery entry point, generating a low-altitude dual-route collaborative execution plan, including:

[0148] S401: Detection and location of conflict segments in time and space occupancy of dual routes.

[0149] Based on the spatiotemporal marking system of the airspace occupancy map, a unit-by-unit, time-slice-by-time conflict detection is performed on the inspection baseline route and the emergency temporary route. All airspace units and corresponding occupancy time slices covered by the emergency temporary route are traversed in ascending order along the time axis. Each airspace unit is examined to determine whether, under the same time slice number, both the inspection plan pre-occupancy mark of the inspection baseline route and the emergency mandatory occupancy mark of the emergency temporary route exist simultaneously. The spatiotemporal location where both types of occupancy marks coexist is identified as a spatiotemporal conflict point.

[0150] Continuous spatiotemporal conflict points are aggregated into independent conflict segments. For each conflict segment, the spatiotemporal identification code of the starting airspace unit, the spatiotemporal identification code of the ending airspace unit, the conflict start time slice number, the conflict end time slice number, and the total number of conflict airspace units included are recorded. The conflict coverage level is simultaneously determined: if the number of conflict time slices accounts for more than 80% of the total number of time slices in the corresponding inspection segment, it is considered a complete conflict; if it is less than 80%, it is considered a partial conflict. This provides a basis for subsequent classification and handling. The 80% threshold is consistent with the judgment boundary mapped to airspace control attributes, ensuring a uniform scale for conflict classification.

[0151] S402: Conflict segment classification and handling and slice status transition.

[0152] For each conflict segment, the principle of prioritizing avoidance and suspending if avoidance is not possible is followed by classified handling, which is converted into inspection avoidance segments or suspended segments respectively. The entire handling process maintains the spatial continuity and temporal correlation between the preceding and following segments of the inspection route.

[0153] For conflict segments with avoidance conditions, they are converted into inspection avoidance slices. The judgment rule is: within the horizontal four-neighborhood and vertical up-down-down-neighborhood of all airspace units within the conflict segment, the proportion of airspace units with a passage risk level of less than or equal to level 2 and marked as releaseable is not less than 60%. This threshold corresponds to the resource condition that the surrounding airspace has at least two alternative detour paths, which can avoid secondary risks and secondary conflicts during the avoidance process. Local path replanning is used to solve for the shortest avoidance path. The replanning process takes the starting airspace unit of the conflict segment as the path start point and the ending airspace unit of the conflict segment as the path end point. Spatially, it is limited to all airspace units within the two-layer neighborhood of the conflict segment, that is, expanding outward two layers of grid along the horizontal four-neighborhood and vertical up-down-down-neighborhood directions to form a closed set of locally replanned airspace, thereby narrowing the search range and improving the efficiency of avoidance path generation. The path search adopts the A* algorithm consistent with the inspection baseline route. The cost calculation follows the architecture of weighted node cost and edge cost. The node cost is the passage risk marker value of the airspace unit passed through, and the edge cost adopts the edge weight of the corresponding adjacent unit in the airspace time occupancy graph. The weight ratio is consistent with the inspection baseline route. The generated avoidance path is smoothly connected to the airspace units before and after the conflict segment at the beginning and end, and the updated path, duration increment and corresponding time slice sequence of the avoidance slice are marked simultaneously.

[0154] For conflict segments where avoidance is not feasible, they are converted into suspended segments. The criteria for determination are: the proportion of surrounding releaseable airspace units is less than 60%, or the average traffic risk level of alternative avoidance paths exceeds level 3. The inspection task corresponding to the conflict segment is temporarily suspended, and the suspension start time segment number and the expected recovery time segment number are marked. The expected recovery time segment number is consistent with the end time segment number of the emergency mandatory occupation. During the suspension period, the airspace resources corresponding to this segment are fully allocated to emergency temporary routes for priority use.

[0155] S403: Route continuation and timing calibration after emergency occupation release.

[0156] The release node is the time slice number corresponding to the expected release time marked by the emergency temporary flight route, and the spatial connection point is the pre-set recovery entrance of the termination airspace unit of the conflict segment. The continuation operation of the unfinished flight segment is carried out to ensure the integrity and continuity of the inspection task.

[0157] For inspection avoidance slices, at the end of the avoidance path, i.e., the recovery entry point, the unexecuted segment after the conflict segment in the original inspection route is directly connected; based on the duration increment generated by the avoidance slice, the time slice sequence number of all subsequent unexecuted segments is shifted backward by the corresponding duration to complete global timing calibration, and the calibration granularity is consistent with the granularity of the reference time slice.

[0158] For suspended segments, at the release node, the suspended inspection segment is restarted from the recovery entry point and continues to be executed according to the original segment's airspace unit sequence and flight parameters; based on the total suspended duration, the time slice sequence numbers of all subsequent unexecuted segments are shifted backward by the corresponding suspended duration to complete the time sequence extension.

[0159] After timing calibration is completed, the legality of the follow-up segment is verified. The passage risk level, release status and single time slice altitude change constraints of the follow-up path are checked to ensure that the follow-up segment meets all airspace control requirements and aircraft performance constraints, and to avoid new conflicts during the follow-up phase.

[0160] S404: Generation and consistency verification of low-altitude dual-route collaborative execution scheme.

[0161] The system integrates the full-time execution sequence of emergency temporary routes and the adjusted execution sequence of inspection baseline routes, including three types of flight segments: inspection avoidance segments, suspended segments, and continuation segments, as well as airspace occupancy priority rules, to generate a structured low-altitude dual-route collaborative execution plan. The core content of the plan includes: the airspace unit sequence for each of the two routes, the corresponding time slice occupancy sequence, segment status markers, occupancy priorities, the determination method for emergency occupancy release nodes, the execution of inspection segment continuation and timing calibration, and the path readjustment process when verification fails. The segment status markers include three categories: normal, avoidance, and suspended, corresponding to the status attributes of non-conflicting segments, inspection avoidance segments, and suspended segments.

[0162] The entire scheme is subjected to a spatiotemporal consistency check, which includes two types of checks: The first type is the priority check, which ensures that there is no double occupation of the same airspace unit in the same time slice within the entire scheduling cycle, and that high-priority tasks always occupy airspace resources first; The second type is the inspection integrity check, which ensures that the adjusted inspection route fully covers all the units that must be inspected, and that the operation dwell time at each point meets the task requirements.

[0163] After all verification items pass, the final low-altitude dual-route collaborative execution plan is output as the basis for scheduling and execution of low-altitude dual-aircraft collaborative operations. If there are any verification items that fail, the process returns to the conflict resolution stage to readjust the avoidance path or change the candidate takeover airspace window until the plan meets all constraints.

[0164] refer to Figure 4 , Figure 4This diagram illustrates the handling of time-related conflicts between the baseline inspection route and the emergency temporary route, as well as the resumption of inspections.

[0165] Figure 4 The diagram illustrates the spatiotemporal conflict detection, conflict segment classification and handling, inspection avoidance slice or suspended slice conversion, and the resumption of the entry point after emergency occupation release during the airspace occupation process between the inspection baseline route and the emergency temporary route. This is used to demonstrate the generation mechanism of the dual-route collaborative execution plan.

[0166] It should be noted that, Figure 4 This is for illustrative purposes only, intended to help understand the process structure and data organization, and does not represent the precise working state in actual operation.

[0167] This embodiment constructs an airspace time-based occupancy map with passage risks, occupancy periods, and release status. It then segments and marks inspection routes and calculates emergency takeover adaptation values, selecting suitable airspace windows to generate emergency temporary routes. Furthermore, based on time-based conflict resolution, it avoids or suspends conflicting flight segments and continues unfinished inspection segments after emergency occupancy is released, based on the recovery entry point. This achieves coordinated allocation and continuous execution of airspace resources for inspection and emergency tasks.

[0168] Example 2

[0169] This invention discloses a low-altitude dual-flight collaborative generation system based on airspace timeliness marking, including an airspace construction module, an inspection slice module, an emergency generation module, and a conflict continuation inspection module:

[0170] The airspace construction module acquires information on the work area, inspection points, airspace restrictions, and emergency tasks, marks the passage risks, occupancy periods, and release status of airspace units, and constructs an airspace time-based occupancy map.

[0171] The inspection slicing module generates inspection baseline routes based on the airspace time-based occupancy map, slices and marks the inspection baseline routes, and calculates emergency takeover adaptation values ​​based on long-term occupancy, avoidance costs, and recovery entry points to form an inspection route set.

[0172] The emergency generation module responds to emergency mission information, selects airspace windows that meet the emergency takeover adaptation value from the inspection routes, and generates short-term priority emergency temporary routes based on the location of the emergency target, the status of the aircraft, and obstacle avoidance requirements.

[0173] The conflict continuation patrol module performs time-sensitive conflict resolution on the patrol route set and emergency temporary routes, converts conflicting segments into patrol avoidance slices or suspended slices, and continues the incomplete patrol segments based on the recovery entry after emergency occupation is released, generating a low-altitude dual-route collaborative execution plan.

[0174] The specific functional implementation of each module is described in the relevant content of the low-altitude dual-line collaborative generation method based on airspace timeliness marking in Embodiment 1, and will not be repeated here.

[0175] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking, characterized in that, Includes the following steps: Acquire information on work areas, inspection points, airspace restrictions, and emergency tasks; mark airspace units with passage risks, occupation periods, and release status; and construct an airspace time-bound occupation map. Based on the airspace occupancy map, a patrol baseline route is generated, and the patrol baseline route is sliced ​​and marked. The emergency takeover adaptation value is calculated by combining long-term occupancy, avoidance cost and restoration entry, and a patrol route set is formed. In response to emergency mission information, airspace windows are selected based on emergency takeover compatibility values, release time slices, and emergency target locations, and emergency temporary flight paths are generated in combination with aircraft status and obstacle avoidance requirements. The system performs time-sensitive conflict resolution on the inspection route set and emergency temporary routes, converting conflicting routes into inspection avoidance slices or suspended slices. After the emergency occupation is released, the system continues the unfinished inspection segments based on the restored entry point, generating a low-altitude dual-route collaborative execution plan.

2. The method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking as described in claim 1, characterized in that, The calculation of emergency takeover suitability values ​​includes: The route slice boundary is determined based on the release status jump or occupation attribute category switch of adjacent airspace units, and the inspection benchmark route is divided into avoidable slices and non-avoidable slices. For avoidable slices, the long-term control occupancy status of the slice and adjacent airspace units is statistically analyzed. The spatial offset increment, flight time increment, and passage risk increment of the avoidance path relative to the original slice are calculated to determine the passage risk, release status, and long-term control occupancy status of the restored entry point. The emergency takeover adaptation value is obtained by weighting the scores of the long-term occupation dimension, the avoidance cost dimension, and the recovery entry dimension.

3. The method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking as described in claim 1, characterized in that, Time-related conflict resolution includes: The pre-occupancy markers and emergency mandatory occupancy markers of the inspection plan are detected on an airspace unit and time slice by the inspection baseline route and emergency temporary route, and continuous spatiotemporal conflict points are aggregated to form conflict segments. Based on the passage risk and release status of the airspace units surrounding the conflict segment, the avoidance conditions are determined. If the avoidance conditions are met, the avoidance path is replanned in the airspace surrounding the conflict segment, and the conflict segment is converted into an inspection avoidance slice. If the avoidance conditions are not met, it is converted into a suspended slice. After the emergency forced occupation is terminated, the airspace unit at the end of the conflict segment is used as the entry point to continue the unfinished inspection segment, and the time slice sequence of the subsequent segment is adjusted according to the avoidance time or hanging time.

4. The method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking as described in claim 1, characterized in that, The construction of the airspace occupancy time map includes: Airspace units are divided according to the horizontal geographical boundaries and vertical height control range of the work area, and the spatial location and time slice of the airspace units are recorded. Analyze airspace restrictions, inspection points and emergency mission information, map control attributes to corresponding airspace units, map inspection points to units that must be inspected, and mark airspace units covered by emergency target areas as high-probability emergency occupation units. For each airspace unit, calculate the passage risk, discretely mark the occupied time period, and assign a release status based on the passage risk and the occupant; Using airspace units as graph nodes, directed edges are established to satisfy spatial adjacency relationships that meet the differences in traffic risk and obstacle constraints. An airspace time occupancy graph is constructed based on traffic risk and spatiotemporal cost of edge connection.

5. The method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking as described in claim 1, characterized in that, The generation of the inspection baseline route includes: The search starts from the airspace unit corresponding to the takeoff position, ends at the airspace unit corresponding to the landing position, and passes through the necessary inspection nodes. The passage risk label value of the airspace unit and the weight of the directed connection are incorporated into the comprehensive evaluation cost value, and the cost value is estimated heuristically based on the three-dimensional Manhattan distance and the average basic risk. The order of segmented nodes is determined according to the spatial proximity of the units that must be inspected, and segmented path search is performed under the condition of excluding the time slice occupied by long-term control. The backtracking path yields the inspection baseline route, which consists of a continuous airspace unit sequence, a time slice sequence, and an inspection point passage sequence.

6. The method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking as described in claim 5, characterized in that, Slice markers, including: Traverse the airspace unit occupancy sequence of the inspection baseline route along the time axis, and determine the slice boundary at the point where the release status of adjacent airspace units changes or the occupancy attribute category switches. The spatially continuous and time-sensitive flight segments are divided into flight route slices, and the spatiotemporal identification codes of the starting airspace unit, the spatiotemporal identification codes of the ending airspace unit, the slice start time slice number, the slice end time slice number, the total number of airspace units, and the average passage risk value are recorded. Based on the release status of the time slice covered by the route slice, the route slice is marked as an avoidable slice or an unavoidable slice.

7. The method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking as described in claim 1, characterized in that, The formation of inspection route sets includes: Using the inspection baseline route as the initial model, the order of the necessary inspection units is exchanged, and the vertical height layer of a single continuous avoidable slice is adjusted to generate alternative inspection routes. Exclude alternative inspection routes that do not fully cover the units that must be inspected, have long-term control time slots, or do not meet the flight distance requirements. For the remaining alternative inspection routes, slice marking and emergency takeover adaptation value calculation are performed, and the routes are screened based on average traffic risk and emergency takeover adaptation value of avoidable slices. The selected alternative inspection routes and the baseline inspection route are stored to form an inspection route set.

8. The method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking as described in claim 1, characterized in that, The generation of emergency temporary flight routes includes: The core occupied segment is the airspace interval corresponding to the optimal takeover airspace window, the starting point of the route is the airspace unit corresponding to the emergency take-off position, the mandatory transit node is the airspace unit corresponding to the emergency target position, and the ending point of the route is the airspace unit corresponding to the standby position. Based on the airspace unit passage risk and the spatiotemporal cost of directed connections, a path search is performed, limiting the time slice of the core occupied segment to the releaseable time slice interval of the optimal takeover airspace window, and limiting the non-core segment to exclude long-term control occupation. Based on obstacles, changes in altitude during a single time slice, remaining flight time, and cruise speed, the path is verified, and an emergency temporary route is generated.

9. The method for collaborative generation of low-altitude dual flight routes based on airspace timeliness marking as described in claim 1, characterized in that, The generation of a low-altitude dual-route coordinated execution plan includes: Integrate emergency temporary routes with the adjusted inspection baseline routes, and record inspection avoidance slices, suspended slices, continuation segments, airspace unit sequences, time slice occupancy sequences, segment status markers, and occupancy priorities; Verify the occupancy priority of the same airspace unit in the same time slot, and verify the coverage of the adjusted inspection baseline route to the units that must be inspected and the duration of operation stay. If the verification passes, a low-altitude dual-route collaborative execution plan is generated; if the verification fails, the conflict segment is returned for classification and handling, and the avoidance path is adjusted or the optimal takeover airspace window is changed.

10. A low-altitude dual-flight collaborative generation system based on airspace timeliness marking, used to implement the low-altitude dual-flight collaborative generation method based on airspace timeliness marking as described in any one of claims 1-9, characterized in that, include: The airspace construction module acquires information on work areas, inspection points, airspace restrictions, and emergency tasks, marks airspace units with passage risks, occupation periods, and release status, and constructs an airspace time-bound occupation map. The inspection slicing module generates inspection baseline routes based on the airspace time-occupancy map, slices and marks the inspection baseline routes, and calculates emergency takeover adaptation values ​​by combining long-term occupation, avoidance costs and recovery entry points to form an inspection route set. The emergency generation module responds to emergency mission information, filters airspace windows based on emergency takeover adaptation values, releasable time slices and emergency target locations, and generates emergency temporary flight paths in combination with aircraft status and obstacle avoidance requirements. The conflict continuation patrol module performs time-sensitive conflict resolution on the patrol route set and emergency temporary routes, converts conflicting segments into patrol avoidance slices or suspended slices, and continues the incomplete patrol segments based on the recovery entry after the emergency occupation is released, generating a low-altitude dual-route collaborative execution plan.

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