Drainage pipeline inside and outside integrated mapping method and related device

Abstract

The application relates to the field of pipeline detection and specifically discloses a drainage pipeline field and office integrated mapping method and a related device, which comprises the following steps: collecting field data of drainage pipelines in a to-be-detected area to obtain pipe point positioning data and pipeline connection relationship data, encoding the data into standardized pipeline data after pre-checking; obtaining a design base map and performing coordinate registration and superposition on the standardized pipeline data; performing topological checking on the data after registration and superposition; performing automatic mapping on the data passing the checking to generate a pipeline result map. The application integrates field collection, data standardized encoding, coordinate registration, topological checking and automatic mapping in a unified data flow, reduces manual transcription and format conversion links, reduces the error rate of the pipeline result map, and improves the mapping efficiency of the drainage pipeline detection project.

Description

Technical Field

[0001] This application relates to the field of pipeline inspection, and in particular to a method and apparatus for integrated indoor and outdoor mapping of drainage pipelines. Background Technology

[0002] Drainage pipeline inspection is a fundamental task in urban pipe network operation and maintenance. Its core output is a pipeline map reflecting the spatial location, connection relationships, and attribute information of the pipelines. The generation of pipeline maps typically involves two stages: field data collection and indoor drawing. In the field stage, inspection personnel go to the site and manually observe and record data such as the location, direction, diameter, and material of the pipelines. In the indoor stage, drafters manually draw pipeline diagrams and annotate attribute information in computer-aided design software based on the data collected in the field.

[0003] In the aforementioned workflow, data transfer between field and office work relies on hand-drawn sketches and paper record sheets. Field personnel need to manually record the coordinates of each pipe point, the connection relationships of each pipeline segment, and attribute information such as pipe diameter and material on-site. After recording, the sketches and record sheets are handed over to office personnel for secondary data entry. Due to the inherent errors in the hand-drawn sketches and the inconsistent recording habits and accuracy levels of different inspection personnel, office personnel are prone to problems such as pipe point coordinate offsets, incorrect well numbering, and omissions in pipeline connection relationships when transcribing the sketch data into digital drawings. When the pipeline scale in the inspection area is large, these errors accumulate during the office drawing process, causing the error rate of the pipeline output drawings to increase with the increase of the inspection mileage.

[0004] Furthermore, there is a lack of a unified data format and coordinate benchmark between the data collected in the field and the indoor drawing software. The data format output by the field acquisition equipment is often inconsistent with the input format of the indoor mapping system, requiring multiple format conversions before it can be imported into the mapping system. Each format conversion may introduce field mapping errors or information loss, such as pipeline attribute fields being truncated during the conversion process or pipe point coordinates being offset when converted between different coordinate systems. When the original construction design drawings exist for the area to be inspected, the coordinate alignment between the field measured data and the design base map also relies on manual registration. The offset rate of manual registration is relatively high, affecting the spatial accuracy of the pipeline output map.

[0005] After the internal mapping is completed, the quality verification of pipeline drawings is mainly done through manual visual inspection. Because pipeline inspection projects involve various pipeline types and complex topological relationships, manual inspection is insufficient to cover all verification dimensions, such as pipeline connectivity, consistency of drainage flow direction and elevation, and the rationality of sudden changes in pipe diameter. This can easily lead to overlooking logical errors. If errors are discovered later, field personnel need to return to the site for supplementary measurements. After the supplementary measurement data is returned, the internal staff must manually modify the drawings again, creating an inefficient cycle of repeated rework. Summary of the Invention

[0006] In order to integrate field data collection and indoor mapping in a unified data flow, reduce manual transcription and format conversion steps, and reduce the error rate of pipeline maps through automatic verification, this application provides an integrated indoor and outdoor mapping method and related apparatus for drainage pipelines.

[0007] Firstly, this application provides a method for integrated indoor and outdoor mapping of drainage pipelines, which adopts the following technical solution: A method for integrated indoor and outdoor mapping of drainage pipelines includes the following steps: S1. Conduct field data collection on the drainage pipelines in the area to be inspected, collect pipe points to obtain pipe point location data and pipeline connection relationship data, perform pre-verification on the pipe point location data and the pipeline connection relationship data, and encode the pre-verified pipe point location data and pipeline connection relationship data into standardized pipeline data; S2. Obtain the design base map of the area to be detected, and perform coordinate registration and overlay of the design base map with the standardized pipeline data; S3. Perform topology verification on the registered and superimposed standardized pipeline data; S4. Perform automatic mapping on standardized pipeline data that has passed topology verification to generate pipeline result maps.

[0008] By adopting the above technical solution, the pipeline location data and pipeline connection relationship data collected in the field are pre-verified during the collection stage. After passing the verification, they are encoded into standardized pipeline data, so that subsequent coordinate registration, topology verification, and automatic mapping all use the same standardized data as input, eliminating multiple format conversion steps in the process of transferring field data to the office system. After the design base map and standardized pipeline data are registered and overlaid in a unified coordinate system, the topology verification is performed on the registered data. The data that passes the verification directly drives the automatic mapping to generate the pipeline result map, forming a coherent data flow from field collection to result map output. This reduces the intervention of manual transcription and manual drawing, and helps to reduce coordinate offsets and connection relationship omissions introduced by manual operation in the pipeline result map.

[0009] Optionally, S1 includes the following sub-steps: S11. Collect pipe points sequentially along the pipeline path, record the pipeline connection relationship between adjacent pipe points, and calculate the change in pipeline direction angle between adjacent pipe points in real time during the collection process; S12. In response to the pipeline direction angle change exceeding a preset direction angle threshold, the acquisition mode is switched from sparse acquisition mode to dense acquisition mode; in response to the pipeline direction angle change falling back below the preset direction angle threshold, the acquisition mode is switched back to sparse acquisition mode. S13. The drainage pipeline is located by a combination of satellite positioning and inertial navigation, and the fusion positioning result is corrected by combining the known well point coordinates; S14. Based on the number of visible satellites and the accuracy attenuation factor during the positioning process, assign a positioning quality level label to the positioning results of each pipeline point, and write the positioning quality level label into the standardized pipeline data; S15. Perform a pre-verification on the pipe point location data and the pipeline connection relationship data, the pre-verification including pipeline connectivity check and pipe point coordinate rationality check; S16. Encode the pre-verified pipe point location data and the pipeline connection relationship data into the standardized pipeline data.

[0010] By adopting the above technical solution, the system automatically switches between sparse and dense acquisition modes based on the pipeline orientation angle changes during the acquisition phase. This allows straight pipeline sections to be covered with fewer acquisition points, while curved pipeline sections are reconstructed with more acquisition points, improving the accuracy of curved section orientation reconstruction while controlling the overall acquisition workload. Satellite positioning and inertial navigation fusion positioning, combined with known wellpoint coordinate correction, ensures usable pipeline coordinates can still be obtained in areas where satellite signals are blocked. Positioning quality level labels are assigned to each pipeline point and written into standardized pipeline data, enabling subsequent verification and mapping processes to identify the positioning reliability of each pipeline point and providing a basis for differentiated processing. Pre-verification intercepts anomalies related to pipeline connectivity and coordinate rationality before data encoding into a standardized format, preventing erroneous data from entering the subsequent registration and mapping processes.

[0011] Optionally, when locating each pipe point in S13, the number of visible satellites and the accuracy attenuation factor are monitored in real time; in response to the number of visible satellites falling below a first preset threshold or the accuracy attenuation factor exceeding a second preset threshold, the system switches from the fixed solution mode for satellite positioning to the fusion mode of floating-point solution for satellite positioning and inertial navigation-assisted calculation; in response to the number of visible satellites recovering to above the first preset threshold and the accuracy attenuation factor falling back below the second preset threshold, the system switches back to the fixed solution mode for satellite positioning.

[0012] By adopting the above technical solution, the positioning mode is switched in real time according to the number of visible satellites and the accuracy attenuation factor. This enables the automatic activation of inertial navigation-assisted calculation in environments with weak satellite signals, such as densely built-up areas or areas with tree shade. After the signal is restored, it automatically switches back to the fixed solution mode with higher accuracy. This avoids the continuous use of fixed solution positioning with insufficient accuracy in signal-blocked areas or remaining in the fusion mode with low accuracy after the signal is restored. This allows each monitoring point to obtain the best positioning accuracy achievable under the current conditions in different environments.

[0013] Optionally, step S2 includes the following sub-steps: S21. Convert the design base map to the same target coordinate system as the standardized pipeline data; S22. Select control well points with known coordinates from the standardized pipeline data as registration anchor points, and perform coordinate registration transformation on the transformed design base map using the registration anchor points, so that the design base map and the standardized pipeline data are superimposed in the target coordinate system; S23. Calculate the deviation between the design position of each pipeline segment in the design base map and the measured position in the standardized pipeline data after registration and superposition; S24. Map the attribute information of each pipeline segment in the design base map to the corresponding pipeline segment in the standardized pipeline data, and assign an inheritance confidence level based on the deviation value of the mapped attribute information.

[0014] By adopting the above technical solution, the control well points measured in the field are used as registration anchor points to perform coordinate transformation on the design base map, aligning the design base map and the measured data in the same coordinate system. This utilizes existing well point coordinate data from the field data acquisition process as anchor points, eliminating the need for additional control points. After registration, the deviation between the design position and the measured position of each pipeline segment is calculated, and this deviation is used as the confidence weight when mapping design attributes to measured pipeline segments. This allows pipeline segments with smaller deviations to directly inherit design attributes, while those with larger deviations are marked as having low confidence to prompt subsequent confirmation. This frees field personnel from the task of manually entering all pipeline attributes, allowing them to focus only on pipeline segments with low confidence.

[0015] Optionally, the topology verification performed on the registered and superimposed standardized pipeline data in step S3 includes performing three levels of verification sequentially: The mandatory verification level is used to verify pipeline connectivity, pipe point repeatability, and the rationality of coordinate range. Standardized pipeline data that fails to pass the verification is blocked. The logical verification level is used to verify the consistency between drainage flow direction and elevation, as well as the rationality of sudden changes in pipe diameter. Standardized pipeline data that fails to pass is marked as a warning. The statistical verification level is used to identify outliers in pipeline segment length and burial depth deviation based on the statistical distribution characteristics of the standardized pipeline data of the current project. Standardized pipeline data that fails to pass the verification are recorded. Among them, a whitelist of abnormal operating conditions is pre-configured and categorized in a structured manner according to pipeline type, area type, and anomaly type. In each level of verification, standardized pipeline data that matches the whitelist of abnormal operating conditions skips the corresponding level of verification.

[0016] By adopting the above technical solution, topology verification is divided into three levels: mandatory, logical, and statistical, and executed sequentially. Differentiated responses—interception, warning, and logging—are used for anomalies of varying severity. This ensures that errors requiring correction are prevented before mapping, potentially reasonable anomalies are alerted to human intervention, and statistical deviations are recorded for later analysis. This avoids the problem of either overly strict verification thresholds leading to too many false alarms or overly lenient thresholds leading to missed errors. The structured whitelist of abnormal operating conditions is categorized by pipeline type, area type, and anomaly type. This ensures that known reasonable non-standard operating conditions are automatically skipped in the corresponding level of verification, avoiding false alarms for known situations such as abandoned branch pipes and temporary blockages, while not affecting the normal detection of other types of anomalies.

[0017] Optionally, step S4 includes the following sub-steps: S41. For each pipeline segment in the standardized pipeline data that has passed the topology verification, the pipeline direction is fitted according to the spatial relationship between adjacent pipe points. Linear interpolation is used for straight pipeline segments in each pipeline segment, and spline fitting is used for curved pipeline segments in each pipeline segment. S42. Based on the well points among the pipe points determined by the pipe point positioning data, identify the pipeline topology type according to the number of pipelines connected to the well point and the difference in orientation angle between the pipelines connected to the well point, and call the corresponding mapping template to perform mapping according to the pipeline topology type; S43. In response to the pipeline topology type identification confidence level being lower than a preset confidence threshold, the corresponding pipeline area is marked as an area to be manually confirmed.

[0018] By employing the above technical solutions, linear interpolation and spline fitting are used to reconstruct the routing of straight and curved pipe segments, respectively, ensuring that the routing lines in the pipeline diagram match the actual spatial relationship of the pipelines. At each well point, the pipeline topology type is automatically identified based on the number of connecting pipelines and differences in orientation angles, and the corresponding mapping template is called. This allows different topological structures such as standard intersections, Y-bifurcations, and ends to be expressed with corresponding graphic symbols, eliminating the need for manual selection of drawing methods. When the confidence level of topology identification is below a threshold, the area is marked as requiring manual confirmation rather than being forcibly mapped automatically. This avoids erroneous topological representations when the identification results are unreliable, limiting the applicability of automatic mapping to areas with sufficient confidence.

[0019] Optionally, the following steps may also be included: S5. In response to the existence of standardized pipeline data that failed the topology verification in S3, an automatic supplementary testing task list is generated based on the type of failure and the location information of the corresponding problematic pipeline segment. The supplementary testing task list includes the problem type code, the start and end well point numbers of the problematic pipeline segment, and the coordinate boundaries of the suggested supplementary testing range. S6. Push the supplementary test task list to the field data acquisition terminal and receive the supplementary test data returned after the supplementary test is performed according to the supplementary test task list; S7. Perform local incremental verification on the supplementary measurement data and the associated pipeline segments of the problematic pipeline segment corresponding to the supplementary measurement data. Perform local re-mapping on the standardized pipeline data that passes the local incremental verification. Then, stitch the local mapping results with the existing pipeline result map.

[0020] By adopting the above technical solution, problems discovered during topology verification are automatically converted into a structured supplementary measurement task list containing the problem type, location, and scope, and pushed to the field end. Field personnel can directly navigate to the problem location and perform supplementary measurements based on the coordinates and scope in the task list without reading the verification report. After the supplementary measurement data is returned, only local incremental verification and local re-mapping are performed on the supplementary pipe section and its related pipe sections, rather than re-performing full verification and full mapping on all pipeline data. This limits the workload of re-verification and mapping caused by supplementary measurements to the affected local area. The local mapping results are stitched together with the existing results to form an updated complete pipeline result map. This ensures that the entire process from problem discovery to map correction is automatically closed within a unified data flow, eliminating the need for manual location of the problem pipe section and manual merging of correction results in the office system.

[0021] Secondly, the computer device provided in this application adopts the following technical solution: A computer device comprising: One or more processors; Memory; One or more computer programs, wherein the one or more computer programs are stored in the memory and configured to be executed by the one or more processors, the one or more computer programs being configured to: Perform the steps described above for the integrated indoor and outdoor mapping method for drainage pipelines.

[0022] Thirdly, this application provides a computer-readable storage medium that adopts the following technical solution: A computer-readable storage medium storing a computer program that can be loaded by a processor and executed by the above-described integrated indoor and outdoor mapping method for drainage pipelines.

[0023] The storage medium stores at least one instruction, at least one program, a code set, or an instruction set, wherein the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the following: The steps of the above-described method for integrating indoor and outdoor mapping of drainage pipelines are as follows.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. By integrating field data collection, pre-verification, standardized coding, coordinate registration, topology verification, and automatic mapping into a unified data flow, multiple format conversions and manual transcription steps are eliminated during the transfer of field data to the office system, reducing the risk of coordinate offsets and omissions in pipeline connection relationships caused by manual operation; 2. By automatically switching between sparse and dense acquisition modes based on the change in pipeline direction angle, and in conjunction with satellite positioning and inertial navigation fusion positioning and the end-to-end transmission of positioning quality level labels, the subsequent verification and mapping stages can be differentiated according to the positioning reliability of each pipeline point, so as to obtain the best positioning accuracy achievable under the current conditions under different environmental conditions. 3. By dividing topology verification into three levels—mandatory, logical, and statistical—and executing them sequentially, along with a structured whitelist of abnormal operating conditions, three differentiated responses—interception, warning, and logging—are adopted for anomalies of different severity. At the same time, known and reasonable non-standard operating conditions are automatically skipped from the corresponding level of verification, avoiding the problem of too many false alarms or missed errors under a single verification threshold. Furthermore, after a problem is found during verification, a structured supplementary test task is automatically generated and pushed to the field end. After the supplementary test data is returned, only local incremental verification and local re-mapping are performed. The entire process from problem discovery to correction and mapping is automatically closed in a unified data flow. Attached Figure Description

[0025] Figure 1 A flowchart illustrating the integrated mapping method for drainage pipelines (both internal and external) in one embodiment of this application is shown.

[0026] Figure 2 A sub-flowchart of the field data acquisition step S1 in one embodiment of this application is shown.

[0027] Figure 3 A flowchart illustrating the logical judgment process for switching positioning modes in one embodiment of this application is shown.

[0028] Figure 4 A sub-flowchart of the coordinate registration and attribute inheritance step S2 in one embodiment of this application is shown.

[0029] Figure 5 A flowchart illustrating a three-level topology verification in one embodiment of this application is shown.

[0030] Figure 6 A sub-flowchart of the automatic mapping step S4 is shown in one embodiment of this application.

[0031] Figure 7 A flowchart illustrating steps S5-S7 of the supplementary closed-loop test in one embodiment of this application is shown.

[0032] Figure 8 A schematic diagram of a computer device according to an embodiment of this application is shown. Detailed Implementation

[0033] The present application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the application and are not intended to limit the scope of the application.

[0034] This application provides an integrated method for generating drainage pipeline maps, combining field and office data. The method pre-verifies and standardizes pipe location data and pipeline connection relationship data collected in the field, then overlays them with the design base map using coordinate registration. Topology verification is used to intercept connection errors, thereby automatically generating the pipeline map.

[0035] Pipeline inspection involves two types of points: well points and non-well points. Well points are structures located at pipeline nodes, such as inspection wells, storm drains, and intercepting wells. Non-well points are characteristic locations along the pipeline path where no well structures are present, such as elbows, tees, and reducers. Pipeline connection data records whether pipeline segments connect between points and the type of pipeline connecting those segments. Standardized pipeline data refers to a structured dataset formed by uniformly encoding information such as pipe point coordinates, pipeline connection relationships, pipeline attributes, and location quality level labels.

[0036] Taking a municipal drainage network inspection project as an example, the area to be inspected is a residential community with a total pipeline length of approximately 3.5 kilometers, including both rainwater and sewage pipelines, totaling about 120 pipe points, of which about 80 are manhole points and about 40 are non-manhole points. The following section uses this project as a scenario to explain each step in detail.

[0037] First, field data collection is required for the drainage pipelines in the area to be inspected in order to obtain the original pipeline data needed for subsequent coordinate registration and automatic mapping.

[0038] like Figure 1 As shown, S1 involves field data collection of drainage pipelines in the area to be inspected, obtaining pipeline location data and pipeline connection relationship data, performing pre-verification on the pipeline location data and pipeline connection relationship data, and encoding the pre-verified pipeline location data and pipeline connection relationship data into standardized pipeline data.

[0039] During field data collection, field personnel, carrying positioning equipment and data acquisition terminals, walked along the pipeline path, manhole by manhole. At each manhole, the field personnel opened the manhole cover to observe the pipeline connection direction, diameter, and material, while simultaneously collecting the spatial coordinates of that manhole using the positioning equipment. Along the pipeline path between adjacent manholes, if there were non-manhole pipe points such as elbows or reducers, the field personnel also collected coordinates at those locations and recorded the connection relationships. The coordinate data of each pipe point constitutes the pipe point positioning data, and the connection records between each pipe point constitute the pipeline connection relationship data.

[0040] Taking the aforementioned residential community project as an example, field personnel started from the first rainwater well W1 at the community entrance, followed the rainwater pipeline path, passing through W2 and W3 sequentially until the terminal well, and then performed the same data collection process along the sewage pipeline path. After the data collection was completed, the pipeline location data contained the spatial coordinates of 120 pipeline points, and the pipeline connection relationship data contained the connection records between each adjacent pipeline point and the corresponding pipeline type label.

[0041] Before being encoded into standardized pipeline data, the collected pipe point location data and pipeline connection relationship data undergo pre-verification to intercept obvious acquisition errors. After successful pre-verification, the pipe point location data and pipeline connection relationship data are encoded into standardized pipeline data for subsequent S2 coordinate registration and overlay. Details of each sub-step in S1 are elaborated below.

[0042] Specifically, such as Figure 2 As shown, S1 includes sub-steps S11-S16.

[0043] S11. Collect pipe points sequentially along the pipeline path, record the pipeline connection relationship between adjacent pipe points, and calculate the change in pipeline direction angle between adjacent pipe points in real time during the collection process.

[0044] During the process of collecting data from pipe points sequentially along the pipeline route, field personnel simultaneously record the pipeline connection relationships between each pipe point and its adjacent points. These connection relationships include the starting pipe point number, the ending pipe point number, and the corresponding pipeline type. For example, after reaching well point W3, the field personnel record a rainwater pipeline connection between W2 and W3, and another rainwater pipeline connection between W3 and W4. The connection relationships recorded at each pipe point are then summarized to form the pipeline connection relationship data.

[0045] The change in pipeline orientation angle refers to the difference in azimuth angle between two adjacent pipeline segments. For example, if the azimuth angle of pipeline segment W1→W2 is 45° and the azimuth angle of pipeline segment W2→W3 is 47°, then the change in pipeline orientation angle at W2 is 2°. This change reflects the degree of change in the pipeline's direction at that point; a larger change indicates a more pronounced bend in the pipeline at that location.

[0046] S12. In response to the pipeline orientation angle change exceeding a preset orientation angle threshold, switch the acquisition mode from sparse acquisition mode to dense acquisition mode. In response to the pipeline orientation angle change falling back below the preset orientation angle threshold, switch the acquisition mode back to sparse acquisition mode.

[0047] In sparse acquisition mode, field personnel trigger acquisition at fixed intervals, such as acquiring a pipe point every 50 meters. In dense acquisition mode, the acquisition interval is shortened, such as acquiring a pipe point every 5 meters. The switching between the two modes is driven by the change in pipeline azimuth angle. Taking the aforementioned residential community project as an example, the preset azimuth angle threshold is set to 15°. Field personnel start from W1 and acquire data along the rainwater pipeline. W1→W2→W3 is a straight segment. The azimuth angle change at W2 is 2°, and at W3 it is 3°, both below 15°, so the sparse acquisition mode is maintained during the acquisition process. When traveling to the W3→W4 segment, the pipeline turns at W4, and the azimuth angle change at W4 is 35°, exceeding 15°, so the acquisition mode automatically switches to dense acquisition mode. After W4, the pipeline resumes a straight direction, and the azimuth angle change at W5 drops back to 5°, so the acquisition mode switches back to sparse acquisition mode. Through the above switching mechanism, straight pipe sections are covered with fewer sampling points, while curved pipe sections are restored to their original direction with more sampling points.

[0048] In addition to the adaptive acquisition density control based on the change in direction angle mentioned above, the "sequential acquisition of pipe points along the pipeline path" in S11 can also adopt a fixed acquisition mode with equal spacing. That is, the acquisition is carried out point by point with a uniform acquisition interval throughout the entire process, without distinguishing between sparse and dense modes. The operation process of the equal spacing mode is simpler and is suitable for detection areas where the pipeline direction changes little and is mainly straight segments. Both of the above acquisition modes belong to the implementation methods of "field data acquisition of drainage pipelines" in S1.

[0049] S13. The positioning of each pipe point of the drainage pipeline is carried out by a combination of satellite positioning and inertial navigation, and the fusion positioning results are corrected by combining the known well point coordinates.

[0050] Satellite positioning utilizes BeiDou RTK (Real-Time Kinematic) technology, providing centimeter-level accuracy in pipe point coordinates under favorable satellite signal conditions. Inertial navigation uses the inertial measurement unit (IMU) built into the data acquisition terminal to sense changes in the device's acceleration and angular velocity, calculating the device's position. Fusing the positioning results from both methods allows for continued positioning continuity even when satellite signals are obstructed. Known wellpoint coordinates refer to wellpoints whose coordinates were determined using high-precision measurement methods before the project commenced. During field data acquisition, when passing these known wellpoints, the fused positioning results are compared with the known coordinates, the deviation is calculated, and corrections are applied to the positioning results of subsequent pipe points.

[0051] Besides the fusion of satellite positioning and inertial navigation, the "positioning of each pipe point" in S13 can also employ other positioning methods such as total station measurement or network RTK. Total station measurement obtains pipe point coordinates through photoelectric ranging and angle observation, suitable for scenarios with long-term satellite signal obstruction and requiring higher accuracy. Network RTK obtains differential correction values ​​by connecting to regional CORS stations, without relying on self-built base stations. The above methods also fall under the implementation methods of "positioning each pipe point of the drainage pipeline" in S1.

[0052] In the fieldwork environment of drainage pipeline inspection, inspectors often need to locate pipe points in locations with unstable satellite signal conditions, such as densely built-up areas, entrances to underground pipe corridors, and areas shaded by trees. When satellite signals are sufficient, the fixed solution mode of satellite positioning can provide positioning results with centimeter-level accuracy; when satellite signals are blocked, the positioning accuracy of the fixed solution mode decreases or even fails to achieve effective positioning. However, if a lower-accuracy fusion mode is consistently used in areas with signal blockage, remaining in that mode after the signal is restored will cause unnecessary accuracy loss. Therefore, in some embodiments, such as Figure 3 As shown, during the positioning of each pipe point in S13, the number of visible satellites and the accuracy attenuation factor (PDOP) are monitored in real time. In response to the number of visible satellites falling below a first preset threshold or the accuracy attenuation factor exceeding a second preset threshold, the system switches from fixed-solution satellite positioning mode to a fusion mode combining floating-point satellite positioning solution and inertial navigation-aided calculation. In response to the number of visible satellites recovering to above the first preset threshold and the accuracy attenuation factor falling back below the second preset threshold, the system switches back to fixed-solution satellite positioning mode.

[0053] Taking the aforementioned residential community project as an example, the first preset threshold is set to 5 satellites, and the second preset threshold is set to 4.0. When data is collected at point W3, the number of visible satellites is 8, and the PDOP value is 1.5, both meeting the threshold conditions, and the RTK fixed solution mode is used. Upon reaching point W4, located in a passageway between two high-rise residential buildings, the number of visible satellites drops to 3, and the PDOP value rises to 6.2. With the number of visible satellites below 5 and the PDOP value exceeding 4.0, the system automatically switches to a fusion mode combining floating-point solution and inertial navigation-assisted calculation. After leaving the obstructed area, at point W5, the number of visible satellites recovers to 7, and the PDOP value drops to 2.1, both returning to within the threshold range, and the system switches back to the fixed solution mode.

[0054] S14. Based on the number of visible satellites and the accuracy attenuation factor during the positioning process, assign positioning quality level labels to the positioning results of each pipeline point, and write the positioning quality level labels into the standardized pipeline data.

[0055] Positioning quality level labels are divided into three levels: Level A corresponds to positioning results obtained in RTK fixed solution mode, indicating positioning accuracy at the centimeter level; Level B corresponds to positioning results obtained in floating-point solution and inertial navigation fusion mode, indicating positioning accuracy at the decimeter to meter level; Level C corresponds to positioning results obtained in pure inertial navigation extrapolation mode, indicating lower positioning accuracy and used only as a reference value. Continuing the example above, W3 uses RTK fixed solution positioning and is assigned a Level A label. W4 uses floating-point solution and inertial navigation fusion mode positioning and is assigned a Level B label. W5 reverts to RTK fixed solution and is assigned a Level A label. The positioning quality level label for each pipeline point is written as a dynamic metadata field into the standardized pipeline data for subsequent topology verification and attribute inheritance processes to differentiate based on positioning reliability.

[0056] S15. Perform pre-verification on pipe point location data and pipeline connection relationship data. Pre-verification includes pipeline connectivity check and pipe point coordinate rationality check.

[0057] Pipeline connectivity checks verify that each pipe point is connected to at least one adjacent pipe point. If a pipe point has no connection record in the pipeline connection data, it is considered an isolated pipe point, indicating a data omission or entry error. Pipeline coordinate rationality checks verify two aspects: whether the coordinates of each pipe point fall within the geographical area to be monitored, and whether the distance between adjacent pipe points is within a reasonable range. For example, the geographical range of this residential area is 121.45°E to 121.46°E and 29.95°N to 29.96°N; pipe point coordinates outside this range are considered abnormal. The reasonable distance range between adjacent pipe points is set to 0.5 meters to 200 meters. A distance less than 0.5 meters may indicate duplicate data collection, and a distance greater than 200 meters may indicate missed intermediate pipe points.

[0058] During field data acquisition, after collecting and locating all pipe points for a section of pipeline, field personnel need to move to the next well point to continue collecting data. In the traditional model, pre-verification and data encoding are performed centrally after all pipeline data collection is completed, resulting in a waiting interval between field and office work. In some embodiments, after collecting data for a section of pipeline, the data is automatically pre-verified and standardized using the time spent moving to the next well point. The encoded standardized pipeline data is then uploaded to the data processing server, ensuring that the data processing server has received the pre-verified standardized pipeline data by the time field data collection ends. For example, after field personnel complete the collection of rainwater pipeline sections W1 to W10, during the movement from W10 to W11, the data acquisition terminal automatically performs pipeline connectivity checks and pipe point coordinate rationality checks on the data for sections W1 to W10. After passing the checks, the data is encoded into standardized pipeline data and uploaded.

[0059] S16. Encode the pre-verified pipe point location data and pipeline connection relationship data into standardized pipeline data.

[0060] Standardized pipeline data employs a unified field structure. Each pipeline point record includes fields such as pipeline point number, pipeline point type, spatial coordinates, location quality level label, and pipeline type. Each pipeline segment record includes fields such as starting pipeline point number, ending pipeline point number, pipeline type, pipe diameter, material, and installation method. The encoding process fills in the raw data output from the field data acquisition terminal line by line according to the above field structure, generating standardized pipeline data with a unified format. This data can be directly read for subsequent S2 coordinate registration and overlay without requiring additional format conversion.

[0061] After completing the field data collection and encoding the data into standardized pipeline data, it is necessary to coordinate and overlay the standardized pipeline data with the design base map of the area to be inspected. The design base map refers to the pipeline design drawings formed when the area to be inspected was completed during construction. It is usually a CAD format file, which contains attribute information such as the pipe diameter, material, and burial method of each pipeline segment. If the attribute information in the design base map can be automatically mapped to the measured pipeline segments, the workload of field personnel manually entering attributes one by one can be reduced. However, the coordinate system of the design base map may be different from the coordinate system of the measured data, and the design map reflects the pipeline position at the time of completion, which may deviate from the pipeline position after many years of actual operation. Therefore, it is necessary to first register and overlay the design base map and the standardized pipeline data in a unified coordinate system.

[0062] like Figure 4 As shown, S2 is to obtain the design base map of the area to be inspected, and then perform coordinate registration and overlay between the design base map and the standardized pipeline data.

[0063] Specifically, S2 includes sub-steps S21-S24.

[0064] S21. Convert the design base map to the same target coordinate system as the standardized pipeline data.

[0065] The target coordinate system refers to the spatial reference datum used uniformly by the project, such as the CGCS2000 national geodetic coordinate system or a local coordinate system defined by the project. The design base map may use a construction coordinate system or an older local coordinate system upon completion, which may be inconsistent with the coordinate system output by the field data acquisition equipment. S21 uses coordinate transformation to unify the coordinates of all pipe points and pipeline segments on the design base map to the target coordinate system, providing a consistent coordinate datum for subsequent registration and overlay.

[0066] S22. Select control well points with known coordinates from the standardized pipeline data as registration anchor points, and perform coordinate registration transformation on the transformed design base map using the registration anchor points, so that the design base map and the standardized pipeline data are superimposed in the target coordinate system.

[0067] Control well points refer to well points whose coordinates have been determined using high-precision measurement methods before the project starts. These well points are also collected during the field data acquisition process, and therefore have corresponding records in both the standardized pipeline data and the design base map. Taking the aforementioned residential community project as an example, three control well points, W1, W40, and W80, distributed at different locations in the detection area, are selected as registration anchor points. The coordinates of W1 in the design base map are (3318450.2, 520125.8), and the measured coordinates of W1 in the standardized pipeline data are (3318450.5, 520126.1). Based on the coordinate pairs of the three anchor points in the design base map and the standardized pipeline data, affine transformation parameters are calculated, and an affine transformation is performed on all coordinates in the design base map. After the transformation, the design base map and the standardized pipeline data are superimposed in the target coordinate system.

[0068] Besides affine transformation, the coordinate registration transformation in S22 can also employ thin-plate spline transformation. Affine transformation is suitable for scenarios where the overall design base map is primarily subject to translation and rotational deviations, with globally uniform transformation parameters. Thin-plate spline transformation is suitable for scenarios where the design base map exhibits localized nonlinear deformations, such as when the coordinate deviation directions and magnitudes differ across different regions of the design map; in this case, thin-plate spline transformation can apply different transformation amounts to each region. Both transformation methods are implementations of the "coordinate registration transformation" in S2.

[0069] S23. Calculate the deviation between the design position of each pipeline segment on the design base map and the measured position in the standardized pipeline data after registration and superposition.

[0070] After registration and overlay, the design base map and standardized pipeline data are in the same coordinate system, allowing for comparison of the spatial differences between the design and measured positions for each pipeline segment. The deviation is calculated as follows: the average of the distances between the design and measured coordinates of the starting point and the ending point of the pipeline segment is taken as the deviation value for that segment. Continuing with the example above, for pipeline segment W5-W6, the distance between the design and measured coordinates of the starting point W5 is 0.25 meters, and the distance between the design and measured coordinates of the ending point W6 is 0.35 meters. The deviation value for pipeline segment W5-W6 is (0.25 + 0.35) / 2 = 0.3 meters. For pipeline segment W22-W23, the deviation distance of the starting point W22 is 2.5 meters, and the deviation distance of the ending point W23 is 3.1 meters. The deviation value for pipeline segment W22-W23 is (2.5 + 3.1) / 2 = 2.8 meters.

[0071] S24. Map the attribute information of each pipeline segment in the design base map to the corresponding pipeline segment in the standardized pipeline data, and assign the inheritance confidence level according to the deviation value of the mapped attribute information.

[0072] The inheritance confidence level is divided into three levels based on the deviation value: a deviation value of less than 1.0 meter is "directly accepted", indicating that the design location and the measured location are basically consistent, and the design attributes can be directly inherited to the measured pipeline segment; a deviation value between 1.0 meter and 3.0 meter is "to be confirmed", indicating that there is a certain difference between the design location and the measured location, and the inherited attributes need to be confirmed by field personnel in subsequent review; a deviation value of more than 3.0 meter is "invalid", indicating that the difference between the design location and the measured location is too large, the design attributes are not inherited, and the attributes of the corresponding pipeline segment need to be re-entered by field personnel.

[0073] Continuing with the above example, the deviation value of pipeline segment W5-W6 is 0.3 meters, which is less than 1.0 meter. Therefore, its inherited confidence level is "directly accepted." The attribute information recorded in the design base drawing, such as the pipe diameter (DN300), material (PVC), and burial method (direct burial), is directly mapped to the corresponding fields of pipeline segment W5-W6 in the standardized pipeline data. The deviation value of pipeline segment W22-W23 is 2.8 meters, falling between 1.0 and 3.0 meters. Its inherited confidence level is "pending confirmation." Although the attribute information of W22-W23 in the design base drawing is mapped to the standardized pipeline data, a "pending confirmation" mark is added to the attribute record, prompting field personnel to verify the pipe diameter and material of this pipeline segment on-site during subsequent review.

[0074] Through the processes described in S21-S24, the attribute information in the design base map is mapped to standardized pipeline data segment by segment, and different confidence levels are assigned to the mapping results based on the deviation values. Field personnel only need to focus on the pipeline segments with the "Pending Confirmation" level for on-site verification, while pipeline segments with the "Directly Acceptable" level do not need to be verified one by one, and pipeline segments with the "Invalid" level need to have their attributes re-entered.

[0075] After the coordinate registration and overlay of the design base map and standardized pipeline data are completed, the standardized pipeline data already contains pipe point coordinates, pipeline connection relationships, and attribute information inherited from the design base map. Registration and overlay solves the problems of coordinate alignment and attribute mapping, but the standardized pipeline data may still contain logical-level issues such as incorrect pipeline connection relationships and inconsistencies between drainage flow direction and elevation. These problems are not exposed at the coordinate level and need to be identified through specialized topology logic verification.

[0076] like Figure 5 As shown, S3 performs topology verification on the registered and superimposed standardized pipeline data. The input to S3 is the registered and superimposed standardized pipeline data output from S2, and the output is the dataset after topology verification. The verification result status of each pipeline segment is marked as "passed", "blocked", "warning", or "recorded". The data that passes verification is used for automatic mapping in S4, while the data that fails verification triggers the supplementary measurement closed-loop process of S5-S7.

[0077] In pipeline data quality verification, different types of data errors have varying degrees of impact on the mapping results. Missing pipeline connectivity or pipe point coordinates outside a reasonable range constitute structural errors; if not intercepted, these will result in broken lines or missing points in the mapping. Inconsistencies between drainage flow direction and elevation, or sudden changes in pipe diameter, are logical anomalies, potentially reflecting actual operating conditions or data entry errors; they require manual attention but not necessarily interception. Statistical anomalies in pipeline segment length or burial depth are deviation anomalies, generally not affecting mapping but helpful in identifying systematic deviations. If a uniform verification threshold and response method are applied to all types of anomalies, either the threshold is too strict, leading to false alarms for reasonable non-standard operating conditions, or too lenient, causing structural errors to be missed. Therefore, in some embodiments, S3 performs topology verification on the registered and overlaid standardized pipeline data, including sequentially performing three levels of verification.

[0078] The first level is the mandatory verification level, which verifies pipeline connectivity, pipe point repeatability, and coordinate range rationality. Standardized pipeline data that fails the verification is intercepted. Pipeline connectivity verification overlaps with the pre-verification in S15, but their execution timing and verification targets differ: S15's pre-verification is performed on the raw data of a single pipeline segment during the field acquisition phase, while the mandatory verification level is performed on the standardized pipeline data of the entire project after registration and overlay. This can identify connectivity issues across pipeline segments, such as the lack of connection between two independently acquired pipeline segments at their junction points. Pipe point repeatability verification checks if the coordinate distance between two pipe points is less than a preset minimum spacing threshold. For example, if the distance between two pipe points is less than 0.3 meters, it may indicate that the same pipe point has been repeatedly acquired. Coordinate range rationality verification is consistent with the checks in S15, and is performed again after registration and overlay to verify whether the registration transformation has introduced coordinate out-of-bounds errors.

[0079] Upon undertaking the aforementioned residential community project, after the mandatory verification was executed, it was discovered that pipe point W18 only had coordinate records in the standardized pipeline data, but no pipeline segment records were associated with W18, meaning W18 was an isolated pipe point and was therefore blocked.

[0080] The second level is the logical verification level, which verifies the consistency of drainage flow direction and elevation, as well as the rationality of sudden changes in pipe diameter. Standardized pipeline data that fails to pass is marked as a warning. The rule for verifying the consistency of drainage flow direction and elevation is: the drainage direction of the drainage pipeline should be from the pipe point with higher elevation to the pipe point with lower elevation. If the drainage direction of a certain pipeline segment is marked as flowing from the lower elevation end to the higher elevation end, it is marked as abnormal. The rule for verifying the rationality of sudden changes in pipe diameter is: the difference in pipe diameter between two adjacent pipeline segments on the same continuous pipeline should not exceed two standard specification grades. For example, changing directly from DN300 to DN800 is considered an abnormal change.

[0081] Continuing with the example above, the logic verification level found that the drainage direction of pipeline segment W30-W31 was marked as flowing from W30 to W31, but the bottom elevation of W30 was 2.1 meters and the bottom elevation of W31 was 2.5 meters. The drainage direction was inconsistent with the elevation direction, and a warning was marked.

[0082] The third level is the statistical verification level. Based on the statistical distribution characteristics of the standardized pipeline data for the current project, it identifies outliers in pipeline segment length and burial depth deviations, and records any standardized pipeline data that fails the verification. Unlike the first two levels, statistical verification does not rely on fixed rule thresholds for judgment; instead, it identifies outliers based on the statistical distribution of the project's own data. For example, it calculates the mean and standard deviation of the lengths of all pipeline segments in the entire project, and marks pipeline segments exceeding the mean plus twice the standard deviation as length outliers.

[0083] Continuing with the example above, this project involves approximately 110 pipeline segments across 120 pipe points. The average segment length is 32 meters, with a standard deviation of 18 meters. The average plus twice the standard deviation equals 68 meters. Segment W55-W56 is 85 meters long, exceeding 68 meters, and is recorded. This record is neither intercepted nor warned; it is simply retained as deviation information for project management personnel to reference in subsequent analysis.

[0084] During the execution of the three-level verification process, a pre-configured whitelist of abnormal operating conditions is used, categorized by pipeline type, area type, and anomaly type. In each level of verification, standardized pipeline data matching the whitelist skips the corresponding level's verification. For example, one rule in the whitelist is: Pipeline type "Rainwater," Area type "Old Renovation Area," Anomaly type "Diameter Sudden Change." This indicates that in rainwater pipelines within an old renovation area, a diameter sudden change is a known and reasonable operating condition because the pipelines in this area have undergone expansions and renovations over different periods, and inconsistencies in the diameter of adjacent pipe sections are normal. When the logical verification level detects a diameter sudden change in a rainwater pipeline within an old renovation area, it matches this whitelist entry, skips the diameter sudden change verification, and does not mark it as a warning. Another rule in the whitelist is: Pipeline type "Sewage," Area type "New Residential Area," Anomaly type "Abandoned Branch Pipe." This indicates that abandoned branch pipes in the sewage pipelines of a new residential area will not be blocked due to connectivity issues in the mandatory verification level.

[0085] Because the positioning accuracy of different pipe points during field data acquisition may vary due to satellite signal obstruction or multipath effects, in some embodiments, the verification threshold for the corresponding pipeline segment is dynamically adjusted based on the positioning quality level label of each pipe point during topology verification. The positioning quality level label reflects the reliability of the coordinate data of each pipe point. For pipeline segments with low-level labels, the uncertainty of their coordinate data is higher. If the same verification threshold is used as for high-level pipeline segments, logical verification anomalies caused by coordinate deviations may be ignored.

[0086] For example, the positioning quality grade labels for both endpoints W4 and W5 of pipeline segment W4-W5 are both Grade B. In the logical verification, the elevation difference threshold for consistency between drainage flow direction and elevation is tightened from the default 0.5 meters to 0.3 meters. That is, when the drainage direction is inconsistent with the elevation direction and the elevation difference is within 0.3 meters, a warning is issued. The positioning quality grade labels for both endpoints W6 and W7 of pipeline segment W6-W7 are both Grade A, and the elevation difference threshold remains at the default 0.5 meters. Through this linkage mechanism, pipeline segments with low-precision positioning are subject to stricter scrutiny during verification, reducing the possibility of overlooking logical anomalies caused by coordinate deviations.

[0087] After topology verification, the standardized pipeline data that passes verification possesses accurate coordinates, complete connectivity relationships, and mapped attribute information, and can be used to automatically generate pipeline result maps. Standardized pipeline data contains discrete pipe point coordinates and pipeline segment connection records, while pipeline result maps need to represent the spatial orientation of the pipeline using continuous linear graphics and the pipeline topology structure at each well point using corresponding graphic symbols. Therefore, it is necessary to restore discrete pipe points to continuous linear shapes through orientation fitting and determine the type of graphic symbol at each well point through topology identification.

[0088] like Figure 6 As shown, S4 is used to automatically generate a pipeline result map from the standardized pipeline data that has passed the topology verification.

[0089] Specifically, S4 includes sub-steps S41-S43.

[0090] S41. For each pipeline segment in the standardized pipeline data that has passed the topology verification, the pipeline direction is fitted according to the spatial relationship between adjacent pipe points. Linear interpolation is used for straight pipe segments in each pipeline segment, and spline fitting is used for curved pipe segments in each pipeline segment.

[0091] The purpose of pipeline alignment fitting is to restore discrete pipe point coordinates to a continuous pipeline shape. Straight pipe segments exhibit minimal alignment changes; the alignment can be reconstructed by connecting adjacent pipe points with straight line segments, achieved using linear interpolation. Curved pipe segments, however, show significant alignment changes at bends. Using linear interpolation in such cases would result in distorted, polygonal alignment. Spline fitting, on the other hand, can generate smooth curves passing through each pipe point.

[0092] The determination of whether a pipeline segment is straight or curved is based on the change in pipeline direction angle at both ends of the segment. It's important to note that the straight / curved segment determination threshold here differs from the preset direction angle threshold used for switching acquisition modes in S12. The preset direction angle threshold controls the switching of acquisition density during the field acquisition phase, while the straight / curved segment determination threshold is used to select the alignment fitting method during the office mapping phase. Their values ​​can be set independently; for example, the preset direction angle threshold can be set to 15°, and the straight / curved segment determination threshold to 10°. The straight / curved segment determination threshold is lower than the preset direction angle threshold because the smoothness requirement for the alignment shape in the mapping phase is higher than the sensitivity requirement for switching acquisition density in the acquisition phase.

[0093] For the aforementioned residential project, the directional angle changes at the two endpoints W2 and W3 of pipeline segment W2-W3 are 2° and 3° respectively, both below the preset straightness / curvature threshold of 10°, thus classifying it as a straight pipeline segment and using linear interpolation. The directional angle change at the terminal endpoint W4 of pipeline segment W3-W4 is 35°, exceeding 10°, thus classifying it as a curved pipeline segment, and using cubic spline fitting to generate a smooth curve segment passing through W3 and W4.

[0094] Besides linear interpolation and spline fitting, the "pipeline routing fitting" in S41 can also use Bézier curve fitting. Bézier curves adjust the curve shape using control points and are suitable for scenarios where local adjustments to the routing shape are needed near pipeline intersections. This method also falls under the implementation of the "pipeline routing fitting" in S4.

[0095] S42. Based on the well points among the pipe points determined by the pipe point positioning data, identify the pipeline topology type according to the number of pipelines connected to the well point and the difference in orientation angle between the pipelines connected to the well point, and call the corresponding mapping template to perform mapping according to the pipeline topology type.

[0096] Pipeline topology type refers to the connection structure of pipelines at a wellpoint. Based on the combination of the number of pipelines connected to the wellpoint and the difference in their azimuth angles, pipeline topology types are categorized as follows: Standard straight connection: Two pipelines pass through a wellpoint in a straight line, with two pipelines connected and their azimuth angles differing by approximately 180°; T-junction: Three pipelines converge at a wellpoint, with three pipelines connected and their azimuth angles relatively evenly distributed; Y-branch: Two pipelines branch off from a wellpoint at a small angle, with three pipelines connected, and the azimuth angle difference between two of the pipelines is significantly smaller than the difference with the third pipeline; Multi-pipe intersection: Four or more pipelines converge at a wellpoint; End point: A wellpoint connected by only one pipeline, typically located at the start or end of the pipeline. Mapping templates refer to predefined CAD graphic symbols, with different graphic symbols corresponding to each topology type.

[0097] Continuing with the previous example, well point W10 connects two pipelines with orientation angles of 85° and 263°, respectively. The difference in orientation angles is 178°, close to 180°, indicating a standard straight connection with a confidence level of 0.95. Using the standard straight connection template, it is drawn in the result graph as a straight line passing through the well point symbol. Well point W25 connects three pipelines with orientation angles of 10°, 130°, and 250°, respectively. The differences between adjacent orientation angles are 120°, 120°, and 120°, evenly distributed, indicating a T-junction with a confidence level of 0.82. Using the T-junction template, it is drawn in the result graph as a three-way intersection symbol.

[0098] S43. In response to the pipeline topology type identification confidence level being lower than the preset confidence threshold, the corresponding pipeline area is marked as an area to be manually confirmed.

[0099] The confidence level is calculated based on a comprehensive score of the uniformity of the directional angle difference distribution and the matching degree between the number of pipelines and the known template. When the directional angle difference distribution closely matches the theoretical distribution of a certain known topology type, the confidence level is high; when the directional angle difference distribution lies between two topology types and cannot be clearly classified, the confidence level is low.

[0100] Continuing with the example above, well point W38 connects three pipelines with orientation angles of 0°, 15°, and 185°. The two pipelines with orientation angles of 0° and 15° differ by only 15°, nearly parallel, similar to a Y-shaped bifurcation pattern. However, the difference between orientation angles of 15° and 185° is 170°, resembling the pattern of two pipelines crossing each other in a standard straight connection. The topology at W38 is between a Y-shaped bifurcation and a standard straight connection with a branch pipe, with an identification confidence level of 0.55, lower than the preset confidence threshold of 0.7. Therefore, W38 and its adjacent pipeline segments are marked as areas requiring manual confirmation. In the pipeline output map, these areas are marked with dashed lines and question marks to visually distinguish them from automatically generated areas, prompting staff to manually determine and draw these areas when reviewing the output map.

[0101] In scenarios such as pipeline maintenance where repeated inspections of the same pipeline area are required, re-executing the complete mapping process for all pipeline data after each inspection would result in unnecessary duplication of work. For example, in the aforementioned residential community, a complete map of 3.5 kilometers of pipeline was generated after the initial inspection. However, during a follow-up inspection six months later, the actual changed pipeline section might only be 200 meters. In some embodiments, the mapping system maintains a baseline pipeline map, which is the pipeline map generated during the initial inspection. After each new round of field inspections, the measured standardized pipeline data is compared twice with the baseline pipeline map: coordinate deviation comparison checks whether the coordinates of each pipe point have shifted beyond the deviation threshold, and attribute difference comparison checks whether the pipe diameter, material, and other attributes of each pipeline segment have changed. Only pipeline segments with coordinate deviations exceeding the threshold or attribute changes are identified as changed pipeline segments. These changed pipeline segments are then partially re-mapped, and the corresponding area in the baseline pipeline map is updated. Unchanged pipeline segments retain their original shape in the baseline pipeline map.

[0102] After topology verification is completed, if there are pipeline data that failed the verification, field personnel need to return to the site to conduct supplementary testing on the problematic pipeline sections. Traditionally, office staff manually read the verification report, summarize the problem types line by line, and manually record the location information of the problem points, then inform the field personnel by phone or document. This process relies on the office staff's understanding and relaying of the verification results, which can easily lead to unclear problem descriptions or inaccurate point locations. In some embodiments, such as... Figure 7 As shown, in response to the existence of standardized pipeline data that failed the topology verification in S3, a supplementary test task list is automatically generated based on the type of failure and the location information of the corresponding problematic pipeline segment.

[0103] Specifically, S5 includes sub-steps S51-S53.

[0104] S51. Extract all failed verification records from the topology verification results. Each record contains the verification level, verification item name, and identification of the failed pipeline segment.

[0105] After topology verification is completed, the verification result status of each pipeline segment has been marked as "Pass", "Blocked", "Warning", or "Record". S51 traverses all verification results and extracts records with the status of "Blocked", "Warning", and "Record". Continuing with the aforementioned residential community project, the verification results of S3 contain two failed records: the first comes from the mandatory verification level, verifying pipeline connectivity, and the failed pipeline segment is identified as W18 (isolated pipe point); the second comes from the logical verification level, verifying drainage flow direction and elevation consistency, and the failed pipeline segments are identified as W30-W31.

[0106] S52. For each failed verification record, assign a problem type code according to the verification level and verification item name, and obtain the start and end well point numbers of the corresponding pipeline segment according to the identifier of the failed pipeline segment.

[0107] Problem type coding uses a format of the first letter of the verification level followed by a serial number. "F" represents mandatory verification level, "L" represents logical verification level, and "S" represents statistical verification level. The serial number increases sequentially within each verification level according to the verification items. For example, "F-001" represents the first type of problem at the mandatory verification level, i.e., missing pipeline connectivity; "F-002" represents the second type of problem at the mandatory verification level, i.e., duplicate pipe points; "L-001" represents the first type of problem at the logical verification level, i.e., inconsistent drainage flow direction and elevation; and "L-002" represents the second type of problem at the logical verification level, i.e., sudden changes in pipe diameter. This coding rule allows field personnel to identify the nature of the problem based on the code without reading the original verification report.

[0108] Continuing with the example above, the first record has a mandatory verification level, a verification item of pipeline connectivity, and is assigned the code "F-001". W18 is an isolated pipe point, so its adjacent upstream and downstream well point numbers W17 and W19 are obtained, with the start and end well point numbers being W17-W19. The second record has a logical verification level, a verification item of drainage flow direction and elevation consistency, and is assigned the code "L-001", with the start and end well point numbers being W30-W31.

[0109] S53. Based on the start and end well point numbers and the coordinates of each well point, calculate the coordinate boundary of the suggested supplementary measurement range, combine the problem type code, start and end well point numbers and coordinate boundary into a supplementary measurement task record, and summarize all supplementary measurement task records into a supplementary measurement task list.

[0110] The recommended calculation rule for the supplementary survey range is as follows: using the starting and ending well points of the problematic pipeline segment as the benchmark, extend upwards and downstream by one well spacing, and take the rectangular outer envelope covered by the extended pipeline segment as the coordinate boundary. The reason for extending upwards and downstream is that adjacent pipeline segments of the problematic pipeline segment may be related to the problem; for example, the connection relationship of isolated pipeline points may be that the connection with upstream or downstream well points has been missed.

[0111] Continuing with the example above, the first record starts and ends at well points W17-W19, extending upstream by one well spacing to W16 and downstream to W20, resulting in an extended range from W16 to W20. The rectangular outer envelope is calculated based on the coordinates of W16 and W20. For example, the coordinates of W16 are (3318480.5, 520180.3), and the coordinates of W20 are (3318510.2, 520220.7), with the coordinate boundaries being 3318480.5 to 3318510.2 east-west and 520180.3 to 520220.7 north-south. The second record starts and ends at well points W30-W31, extending upstream to W29 and downstream to W32, with the rectangular outer envelope calculated similarly. The two supplementary survey records are summarized into a supplementary survey task list.

[0112] Specifically, S6 includes sub-steps S61-S63.

[0113] S61. The supplementary test task list is pushed to the field data acquisition terminal through the communication module. After receiving the supplementary test task list, the field data acquisition terminal displays each supplementary test task in a list form on the acquisition interface. Each task is marked with the problem type code and the suggested supplementary test scope.

[0114] Following the example above, after the field personnel's data acquisition terminal receives the supplementary measurement task list, two tasks are displayed on the acquisition interface: the first task is marked "F-001W17-W19 connectivity missing", and the second task is marked "L-001W30-W31 elevation direction abnormality".

[0115] S62. After the field personnel select a supplementary measurement task, the field data acquisition terminal marks the supplementary measurement range on the map interface according to the coordinate boundary of the task, and navigates to the starting well point within the suggested supplementary measurement range.

[0116] Continuing with the example above, the field personnel select the first task, "F-001W17-W19". The terminal marks the supplementary measurement range from W16 to W20 with a highlighted rectangle on the map interface and initiates navigation to guide the field personnel to W16. When multiple tasks in the supplementary measurement task list involve adjacent or overlapping supplementary measurement ranges, the field data acquisition terminal automatically merges the overlapping ranges into a continuous supplementary measurement range, avoiding repeated walking between adjacent areas by the field personnel.

[0117] S63. Field personnel shall re-collect pipeline location data and pipeline connection relationship data within the supplementary measurement area according to the procedures of S11-S16. After the data collection is completed, the supplementary measurement data shall be transmitted back to the data processing server through the communication module.

[0118] Following the example above, after the field personnel arrived at W16, they re-collected the location and connection data of five pipe points (W16, W17, W18, W19, and W20) according to the S11-S16 process. During the data collection, it was discovered that W18 was actually connected to both W17 and W19 by pipelines, but the connection relationship of W18 was missing in the original data collection due to an oversight. After the supplementary data was pre-verified by S15, it was encoded into standardized pipeline data by S16 and transmitted back to the data processing server via the communication module. The format of the supplementary data is consistent with the standardized pipeline data format output by S16, and the data processing server can read it directly without additional format conversion.

[0119] After receiving the supplementary measurement data, the data processing server needs to re-perform verification and mapping of the supplementary measurement pipe section and its surrounding related pipe sections. Unlike S3 and S4, which perform global verification and full mapping on all project data, S7 only performs incremental verification and local mapping on the local area affected by the supplementary measurement, avoiding repeated verification and mapping operations on unaffected pipe sections.

[0120] Specifically, S7 includes sub-steps S71-S74.

[0121] S71. After receiving the supplementary measurement data, determine the scope of the local incremental verification. The verification scope includes the supplementary pipeline segment itself and at least one pipeline segment upstream and downstream of the starting and ending well points of the supplementary pipeline segment.

[0122] The reason for extending the verification scope to the upstream and downstream adjacent pipe segments of the supplementary test segment is that the starting and ending well points of the supplementary test segment are also the endpoints of adjacent pipe segments. The coordinates and connection relationships of these well points in the supplementary test data may differ from the original data of the adjacent pipe segments. Verifying only the supplementary test segment itself cannot detect such cross-segment connection problems; therefore, it is necessary to include adjacent pipe segments in the verification scope.

[0123] For the aforementioned residential community project, the supplementary measurement data for the first task, "F-001W17-W19," covered five pipe points from W16 to W20. The supplementary pipeline segments were W17-W18 and W18-W19. W17 is connected to the upstream pipeline segment W16-W17, and W19 is connected to the downstream pipeline segment W19-W20. Therefore, the scope of the local incremental verification was determined to be four pipeline segments: W16-W17, W17-W18, W18-W19, and W19-W20.

[0124] S72. Perform the same topology verification process as S3 on the pipeline data within the verification scope. The verification items and verification rules are consistent with the global verification.

[0125] The verification process executed in S72 is exactly the same as in S3, namely, performing three levels of verification in sequence: mandatory verification level, logical verification level, and statistical verification level. The verification rules and threshold settings are consistent with the global verification. If the linkage mechanism between the verification threshold and the location quality level label is enabled in the current embodiment, it also applies to the local verification in S72. The only difference is the scope of the verification data: S3 performs verification on approximately 110 pipeline segments across the entire project, while S72 performs verification only on the four pipeline segments identified above.

[0126] Continuing with the example above, S72 performs a three-level verification on four pipeline segments: W16-W17, W17-W18, W18-W19, and W19-W20. The mandatory verification level checks the connectivity of W18. The supplementary data shows that W18 has connection records with both W17 and W19, meaning W18 is no longer an isolated pipe point; the mandatory verification level passes. The logical verification level checks the consistency of the drainage flow direction and elevation of the four pipeline segments. The bottom elevations of W16, W17, W18, W19, and W20 are 3.2 meters, 2.8 meters, 2.5 meters, 2.1 meters, and 1.8 meters respectively. The drainage direction is from the higher elevation end to the lower elevation end in all four segments; the logical verification level passes. The statistical verification level checks whether the lengths of the four pipeline segments exceed the abnormal range of the overall project's statistical distribution. The lengths of the four pipeline segments are 28 meters, 25 meters, 30 meters, and 32 meters respectively, all within the normal range; the statistical verification level passes.

[0127] S73. For pipeline data that has passed the local incremental verification, perform local re-mapping according to the process of S41-S43 to generate a local pipeline result map covering the verification range.

[0128] The mapping process executed by S73 is exactly the same as that of S41-S43, namely, performing direction fitting on each pipeline segment, identifying the topology type at each well point, and calling the corresponding mapping template. Continuing with the example above, S73 performs direction fitting on four pipeline segments: W16-W17, W17-W18, W18-W19, and W19-W20. The changes in the pipe point orientation angles of these four pipeline segments are all below the straightness / curvature determination threshold, and linear interpolation is used for all of them. Topology types were identified at well points W17, W18, and W19: W17 connects two pipelines, W16-W17 and W17-W18, with a direction angle difference of 176°, identified as a standard direct connection; W18 connects two pipelines, W17-W18 and W18-W19, with a direction angle difference of 172°, identified as a standard direct connection; W19 connects two pipelines, W18-W19 and W19-W20, with a direction angle difference of 179°, identified as a standard direct connection. The topology identification confidence scores for all three well points were higher than 0.7. A standard direct connection template was used to generate a local pipeline map covering the area from W16 to W20.

[0129] S74. Erase the area corresponding to the verification range in the existing pipeline result map, replace it with the local pipeline result map, and generate an updated complete pipeline result map.

[0130] S74 erases the graphics in areas W16 to W20 of the existing pipeline result map generated by S4, including the original pipeline lines, well point symbols, and attribute labels within that area. After erasing, the local pipeline result map generated by S73 is inserted into this area, and its boundaries are aligned and stitched with the graphics upstream of W16 and downstream of W20 in the existing pipeline result map to generate an updated complete pipeline result map. During the stitching process, the pipeline lines in the local result map automatically connect with the pipeline lines in the existing result map at the boundaries, without creating breakpoints or overlaps.

[0131] Following the example above, in the updated pipeline results diagram, W18 is no longer an isolated point, but is presented as a well point symbol drawn with a standard direct connection template. The two pipeline segments W17-W18 and W18-W19 are connected by continuous lines, seamlessly splicing with the upstream of W16 and the downstream of W20 in the original results diagram.

[0132] If there are still failed verification records in the local incremental verification, the verification result of S72 will trigger S5 to generate a new supplementary verification task list, repeating the S5-S7 process. For example, after the supplementary verification, the connectivity problem of W18 has been corrected, but a new inconsistency appears between the drainage flow direction and elevation of the W19-W20 section in the supplementary verification data. S72 marks this anomaly as a warning, and S5 generates a new round of supplementary verification tasks based on this warning. To avoid infinite loops, a maximum number of supplementary verification rounds is set, for example, 3 rounds by default. When there are still failed verification records after 3 rounds of supplementary verification, the remaining failed records are transferred to manual intervention and manually corrected by the office staff in the pipeline result diagram.

[0133] The updated pipeline map after S74 stitching is the final deliverable of this inspection project. If there are new inspection tasks for the same area in the future, this map can be used as the baseline pipeline map in the above incremental update mapping mode.

[0134] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0135] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 8As shown, the computer device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage medium. The database contains data related to the integrated mapping method for drainage pipelines (both internal and external). The network interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements an integrated mapping method for drainage pipelines (both internal and external).

[0136] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the integrated indoor and outdoor mapping method for drainage pipelines described in the above embodiment.

[0137] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the integrated indoor and outdoor mapping method for drainage pipelines described in the above embodiment.

[0138] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments of this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0139] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0140] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A sewer pipeline field-maintenance integrated mapping method, characterized by, Includes the following steps: S1. Conduct field data collection on the drainage pipelines in the area to be inspected, collect pipe points to obtain pipe point location data and pipeline connection relationship data, perform pre-verification on the pipe point location data and the pipeline connection relationship data, and encode the pre-verified pipe point location data and pipeline connection relationship data into standardized pipeline data; S2. Obtain the design base map of the area to be detected, and perform coordinate registration and overlay of the design base map with the standardized pipeline data; S3. Perform topology verification on the registered and superimposed standardized pipeline data; S4. Perform automatic mapping on standardized pipeline data that has passed topology verification to generate pipeline result maps; The topology verification performed on the registered and superimposed standardized pipeline data in step S3 includes performing three levels of verification sequentially: The mandatory verification level is used to verify pipeline connectivity, pipe point repeatability, and the rationality of coordinate range. Standardized pipeline data that fails to pass the verification is blocked. The logical verification level is used to verify the consistency between drainage flow direction and elevation, as well as the rationality of sudden changes in pipe diameter. Standardized pipeline data that fails to pass is marked as a warning. The statistical verification level is used to identify outliers in pipeline segment length and burial depth deviation based on the statistical distribution characteristics of the standardized pipeline data of the current project. Standardized pipeline data that fails to pass the verification are recorded. Among them, a whitelist of abnormal operating conditions is pre-configured and categorized in a structured manner according to pipeline type, area type, and anomaly type. In each level of verification, standardized pipeline data that matches the whitelist of abnormal operating conditions skips the corresponding level of verification.

2. The sewer pipeline design method according to claim 1, wherein S1 includes the following sub-steps: S11. Collect pipe points sequentially along the pipeline path, record the pipeline connection relationship between adjacent pipe points, and calculate the change in pipeline direction angle between adjacent pipe points in real time during the collection process; S12. In response to the pipeline direction angle change exceeding a preset direction angle threshold, the acquisition mode is switched from sparse acquisition mode to dense acquisition mode; in response to the pipeline direction angle change falling back below the preset direction angle threshold, the acquisition mode is switched back to sparse acquisition mode. S13. The drainage pipeline is located by a combination of satellite positioning and inertial navigation, and the fusion positioning result is corrected by combining the known well point coordinates; S14. Based on the number of visible satellites and the accuracy attenuation factor during the positioning process, assign a positioning quality level label to the positioning results of each pipeline point, and write the positioning quality level label into the standardized pipeline data; S15. Perform a pre-verification on the pipe point location data and the pipeline connection relationship data, the pre-verification including pipeline connectivity check and pipe point coordinate rationality check; S16. Encode the pre-verified pipe point location data and the pipeline connection relationship data into the standardized pipeline data.

3. The sewer pipeline design method according to claim 2, wherein When locating each pipe point in S13, the number of visible satellites and the accuracy attenuation factor are monitored in real time. In response to the number of visible satellites falling below a first preset threshold or the accuracy attenuation factor exceeding a second preset threshold, the system switches from the fixed solution mode for satellite positioning to the fusion mode of floating-point solution for satellite positioning and inertial navigation-assisted calculation. In response to the number of visible satellites recovering to above the first preset threshold and the accuracy attenuation factor falling back below the second preset threshold, the system switches back to the fixed solution mode for satellite positioning.

4. The integrated indoor and outdoor mapping method for drainage pipelines according to claim 1, characterized in that, S2 includes the following sub-steps: S21. Convert the design base map to the same target coordinate system as the standardized pipeline data; S22. Select control well points with known coordinates from the standardized pipeline data as registration anchor points, and perform coordinate registration transformation on the transformed design base map using the registration anchor points, so that the design base map and the standardized pipeline data are superimposed in the target coordinate system; S23. Calculate the deviation between the design position of each pipeline segment in the design base map and the measured position in the standardized pipeline data after registration and superposition; S24. Map the attribute information of each pipeline segment in the design base map to the corresponding pipeline segment in the standardized pipeline data, and assign an inheritance confidence level based on the deviation value of the mapped attribute information.

5. The integrated indoor and outdoor mapping method for drainage pipelines according to claim 1, characterized in that, S4 includes the following sub-steps: S41. For each pipeline segment in the standardized pipeline data that has passed the topology verification, the pipeline direction is fitted according to the spatial relationship between adjacent pipe points. Linear interpolation is used for straight pipeline segments in each pipeline segment, and spline fitting is used for curved pipeline segments in each pipeline segment. S42. Based on the well points among the pipe points determined by the pipe point positioning data, identify the pipeline topology type according to the number of pipelines connected to the well point and the difference in orientation angle between the pipelines connected to the well point, and call the corresponding mapping template to perform mapping according to the pipeline topology type; S43. In response to the pipeline topology type identification confidence level being lower than a preset confidence threshold, the corresponding pipeline area is marked as an area to be manually confirmed.

6. The integrated indoor and outdoor mapping method for drainage pipelines according to claim 1, characterized in that, It also includes the following steps: S5. In response to the existence of standardized pipeline data that failed the topology verification in S3, an automatic supplementary testing task list is generated based on the type of failure and the location information of the corresponding problematic pipeline segment. The supplementary testing task list includes the problem type code, the start and end well point numbers of the problematic pipeline segment, and the coordinate boundaries of the suggested supplementary testing range. S6. Push the supplementary test task list to the field data acquisition terminal and receive the supplementary test data returned after the supplementary test is performed according to the supplementary test task list; S7. Perform local incremental verification on the supplementary measurement data and the associated pipeline segments of the problematic pipeline segment corresponding to the supplementary measurement data. Perform local re-mapping on the standardized pipeline data that passes the local incremental verification. Then, stitch the local mapping results with the existing pipeline result map.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the integrated internal and external mapping method for drainage pipelines as described in any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the integrated mapping method for drainage pipelines as described in any one of claims 1 to 6.

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