A method and system for detecting underground damage based on ground-penetrating radar

Abstract

This application proposes a ground-penetrating radar (GPR)-based method and system for detecting underground damage. The detection method filters the primary echo data of the GPR by querying a pre-set map database or obtaining corresponding known obstacle information from external sources. When no known obstacle information is available, obstacle features are inferred from the current environment or obtained from external input, resulting in a primary detection result. This method effectively utilizes known obstacle information and features to filter GPR data, eliminating potential misjudgments. Furthermore, it improves overall detection accuracy and reliability by performing local secondary detection. The GPR-based underground damage detection system, by applying this detection method, effectively utilizes existing geographic information, significantly improving the accuracy and precision of interpreting underground damage results.

Description

Technical Field

[0001] This invention relates to the field of underground detection, specifically to an underground damage detection method and system based on ground-penetrating radar. Background Technology

[0002] In the process of inspecting the underground structures of existing roads, ground-penetrating radar (GPR) is often used. This involves emitting high-frequency electromagnetic pulses into the ground and using the reflected signals to obtain underground information about the surveyed area, including the size and distribution of cavities, cracks, and other underground damage. Some existing road infrastructure may already have underground structures such as electrical wires and water pipes. These known structures are not considered damage, but they will still appear in the GPR detection results as changes in image waveforms.

[0003] Existing radar data often still relies on professional personnel for interpretation, which is time-consuming and inefficient. When professionals are unfamiliar with the distribution of these pipelines in the target area, the presentation of these known structures on radar images may mislead them, reducing the efficiency of underground damage detection. Furthermore, ground-penetrating radar has low resolution, and its detection accuracy cannot meet the needs for detecting minute damage. Summary of the Invention

[0004] In view of this, this application proposes a ground-penetrating radar-based method and system for detecting underground damage, the specific scheme of which is as follows:

[0005] Firstly, a ground-penetrating radar-based method for detecting underground damage is proposed, the method comprising:

[0006] The target detection area is determined, and the transmission frequency band of the ground-penetrating radar module is determined based on the depth range and environmental feature data of the target detection area.

[0007] The ground-penetrating radar module is triggered by the encoder, causing the ground-penetrating radar module to detect the target detection area at a preset speed and obtain one echo data.

[0008] Based on the coordinates of the target detection area, known obstacle information corresponding to the target detection area is obtained from a preset map library or from external sources;

[0009] The echo data is filtered based on the known obstacle information to obtain a detection result. When there is no known obstacle information, the obstacle features are inferred based on the environmental features or obtained from external input. The echo data is then filtered based on the inferred obstacle features to obtain the detection result.

[0010] Based on the first detection result, mark the points to be verified in the target detection area, and perform a second detection on the points to be verified using an ultrasonic module to obtain the second detection result.

[0011] The results of the first and second tests are combined to obtain an underground damage detection report.

[0012] In some specific embodiments, filtering the echo data based on the known obstacle information to obtain a detection result includes:

[0013] Based on the first echo data, the predicted underground damage location data is obtained;

[0014] The known obstacle information includes at least one known obstacle, and each known obstacle corresponds to an obstacle medium type, obstacle coordinates, and obstacle depth; each known obstacle corresponds to different obstacle waveform data features;

[0015] Predicted underground damage points that overlap with the known obstacle's coordinates and depth are selected; the current waveform data corresponding to the predicted underground damage points is compared with the obstacle waveform data features corresponding to the obstacle to obtain a matching score;

[0016] When the matching score is greater than or equal to the preset value, the current waveform data is marked as a component to be filtered and is not included in the underground damage detection.

[0017] When the matching score is less than a preset value, extract the waveform data that is different from the obstacle waveform data in the current waveform data corresponding to the marked point and mark it as the underground damage component to be verified, and retain the predicted underground damage point.

[0018] Damage assessment is performed based on the predicted underground damage location data to obtain the first detection result.

[0019] In some specific embodiments, after obtaining the predicted underground damage location data, the method further includes:

[0020] Based on the temperature and / or humidity information corresponding to the location of the predicted underground damage point in the first echo data, the environmental correction coefficient corresponding to the temperature and / or humidity information is called from the preset feature library;

[0021] The waveform data corresponding to the predicted underground damage location in the primary echo data is corrected using the environmental correction coefficient.

[0022] In some specific embodiments, the secondary detection of the point to be verified using an ultrasonic module to obtain the secondary detection result includes:

[0023] The target detection area is divided into multiple detection sub-areas, and data statistics are performed on each detection sub-area. The data statistics include the number and size of underground damage points in each detection sub-area.

[0024] The underground damage points in the detection sub-region where the number of underground damage points exceeds a preset threshold and / or the underground damage points whose size is greater than a preset size threshold are marked as the points to be verified.

[0025] The ultrasonic module emits ultrasonic waves of a preset frequency to each of the points to be verified, and obtains echo signals. Damage assessment is performed on each of the points to be verified based on the echo signals to obtain the secondary detection results.

[0026] In some specific embodiments, the ground-penetrating radar module includes a high-frequency transmitting unit and a low-frequency transmitting unit; the environmental feature data includes a temperature range and / or a humidity range; and determining the transmission frequency band of the ground-penetrating radar module based on the depth range of the target detection area and the environmental feature data includes:

[0027] The depth range of the target detection area is obtained. When the proportion of the depth range falling into the preset shallow range exceeds the preset ratio, the transmission frequency band of the high-frequency transmission unit is set first.

[0028] When the proportion of the depth range falling into the preset medium-deep range exceeds a preset ratio, the transmission frequency band of the low-frequency transmission unit is first set; wherein the preset ratio is greater than or equal to 50%;

[0029] The ratio of the transmission frequency band of the high-frequency transmitting unit to the transmission frequency band of the low-frequency transmitting unit is set to 2:1 to 4:1;

[0030] The temperature range and / or humidity range of the target detection area are obtained, and the transmission frequency band of the ground penetrating radar module is adjusted within a preset elastic range according to the temperature range and / or humidity range.

[0031] In some specific embodiments, the first echo data includes the first echo data of the high-frequency transmitting unit and the second echo data of the low-frequency transmitting unit; after obtaining the first echo data, the method further includes: performing data fusion processing on the first echo data, specifically including:

[0032] Preprocess the first echo data and the second echo data;

[0033] Spatial registration is performed on the first echo data and the second echo data to unify the number of scan channels and the sampling interval of the first echo data and the second echo data;

[0034] The waveform images of the registered first echo data and the second echo data are fused.

[0035] In some specific embodiments, fusing the waveform images of the registered first echo data and the second echo data includes:

[0036] Extract the first image features corresponding to the preset shallow region from the first echo data, and extract the second image features corresponding to the preset medium-deep region from the second echo data;

[0037] The first image feature and the second image feature are fused together; the first image feature and the second image feature include one or more of the following: contour features, image boundary features, waveform intensity features and image texture features.

[0038] In some specific embodiments, prior to triggering the ground-penetrating radar module via the encoder, the method further includes:

[0039] The encoder associates the signal transmission time, signal reception time, current coordinates, and environmental feature data of the current coordinates of the ground penetrating radar module.

[0040] In some specific embodiments, after obtaining the underground damage detection report, the method further includes:

[0041] Collect the latest obstacle information from the underground damage detection report; the latest obstacle information includes the medium type information, coordinate information, depth information, and waveform feature information of the obstacles in the target detection area;

[0042] The latest obstacle information is incorporated into the known obstacle information.

[0043] Secondly, an underground damage detection system is proposed, which is applicable to any of the underground damage detection methods based on ground penetrating radar in the aforementioned technical solutions. The system includes a moving mechanism and a main control module, a ground penetrating radar module, a positioning module, an environmental sensor module and an ultrasonic module disposed in the moving mechanism.

[0044] The main control module connects the ground-penetrating radar module, the positioning module, the environmental sensor module, and the ultrasonic module. It is used to determine the transmission frequency band of the ground-penetrating radar module based on the depth range and environmental feature data of the target detection area, trigger the ground-penetrating radar module through the encoder, and perform secondary detection on the point to be verified through the ultrasonic module.

[0045] The ground-penetrating radar module includes an air-coupled radar, which is used to detect underground damage in the target detection area. The ground-penetrating radar module, the environmental sensor, and the positioning module are interconnected through an encoder.

[0046] The positioning module is associated with the mileage data of the mobile mechanism to form a coordinate system parallel to the target detection area;

[0047] The environmental sensor module includes one or more of a temperature sensor, a humidity sensor, and a material sensor, and is used to obtain the environmental feature data of the target detection area.

[0048] The ultrasonic module is used to perform secondary detection on the point to be verified and obtain the secondary detection result.

[0049] The mobile mechanism is used to carry the ground-penetrating radar module, the positioning module, the environmental sensor module and the ultrasonic module to move within the target detection area, so as to realize the detection of underground damage in the target detection area.

[0050] Beneficial Effects: This application proposes a ground-penetrating radar (GPR)-based underground damage detection method and system. The detection method filters the GPR echo data by querying a pre-set map database or obtaining corresponding known obstacle information from external sources. When no known obstacle information is available, obstacle features are inferred from the current environment or obtained from external input to obtain a detection result. This method effectively utilizes known obstacle information and obstacle features to filter GPR data, eliminating possible misjudgments and avoiding misjudging planned underground pipelines and facilities as damage. By applying this detection method, the GPR-based underground damage detection system can effectively improve the accuracy and precision of interpreting underground damage results. Attached Figure Description

[0051] Figure 1 This is a detailed schematic diagram of the detection method in this application;

[0052] Figure 2 This is a schematic diagram of some steps of the detection method in this application;

[0053] Figure 3 This is a schematic diagram of another partial step of the detection method in this application;

[0054] Figure 4 This is a schematic diagram of another partial step of the detection method in this application;

[0055] Figure 5 This is a schematic diagram of another partial step of the detection method in this application;

[0056] Figure 6 This is a schematic diagram of another partial step of the detection method in this application;

[0057] Figure 7 This is a simplified schematic diagram of the module connection relationship of an underground damage detection system according to this application.

[0058] Reference numerals: 1-Main control module; 2-Ground penetrating radar module; 3-Positioning module; 4-Environmental sensor module; 5-Ultrasonic module; 6-Communication module; 7-Storage module; 8-Moving mechanism. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] Example 1

[0061] Embodiment 1 of this application discloses a method for detecting underground damage based on ground-penetrating radar, such as... Figure 1 As shown, the specific methods include:

[0062] S100. Determine the target detection area, and determine the transmission frequency band of the ground-penetrating radar module 2 based on the depth range and environmental characteristic data of the target detection area;

[0063] S200: The ground penetrating radar module 2 is triggered by the encoder, so that the ground penetrating radar module 2 detects the target detection area at a preset speed and obtains one echo data.

[0064] S300: Based on the coordinates of the target detection area, query the preset map library or obtain the known obstacle information of the corresponding target detection area from an external source;

[0065] S400. Filter the echo data based on the known obstacle information to obtain a detection result. When there is no known obstacle information, infer the obstacle features based on environmental characteristics and / or obtain them from external input. Filter the echo data based on the inferred obstacle features to obtain a detection result.

[0066] S500: Based on the results of the first test, mark the points to be verified in the target test area, and perform a second test on the points to be verified through the ultrasonic module 5 to obtain the second test results;

[0067] S600. The results of the first and second tests are combined to obtain an underground damage detection report.

[0068] In some specific embodiments, such as Figure 4As shown, in step S400, the echo data is filtered based on known obstacle information to obtain a detection result, including:

[0069] S410. Based on a single echo data, predict the location of underground damage points;

[0070] The known obstacle information includes at least one known obstacle, and each known obstacle corresponds to the type of obstacle medium, obstacle coordinates, and obstacle depth; each known obstacle corresponds to different obstacle waveform data characteristics;

[0071] S420. Predicted underground damage locations that overlap with known obstacles in terms of obstacle coordinates and obstacle depth are selected.

[0072] S430. Compare the current waveform data corresponding to the predicted underground damage point with the waveform data features of the corresponding obstacle to obtain a matching score.

[0073] S440. When the matching score is greater than or equal to the preset value, the current waveform data is marked as a component to be filtered and will not participate in the underground damage detection.

[0074] S450. When the matching score is less than the preset value, extract the waveform data that is different from the obstacle waveform data in the current waveform data corresponding to the marked point and mark it as the underground damage component to be verified, and retain the predicted underground damage point.

[0075] S460. Based on the data of each predicted underground damage point, a damage assessment is performed to obtain a test result.

[0076] In practical applications, known obstacle information, as basic road administration information, will be registered in external map databases or information databases. By determining the coordinates of the target detection area, the corresponding known obstacle information can be found in a pre-set map database. For example, in some specific embodiments, multiple known metal pipes, power grid modules, water pipes, and natural gas pipelines are located underground in the target detection area. Different pipes use different manufacturing materials and correspond to different media. Therefore, different underground obstacles have different attenuation effects on the electromagnetic waves emitted by the ground penetrating radar module 2, resulting in different waveform data characteristics in the echo data of the ground penetrating radar module 2 for different underground obstacles.

[0077] Therefore, known obstacle information can include information such as the medium type, distribution coordinates, size, and waveform data characteristics of various underground pipelines and municipal facilities in the target detection area. In step S400, the ground-penetrating radar module 2 detects all possible damage in the target detection area and marks these damages as predicted underground damage points. When it is found that there is known obstacle information in the target detection area, the distance between the obstacle coordinates of the known obstacle and the coordinates of the currently obtained predicted underground damage points can be calculated to determine whether there is a situation where a known obstacle is mistakenly identified as a predicted underground damage point. When there is a predicted underground damage point that overlaps with the obstacle coordinates and obstacle depth of a known obstacle, it is more likely that the predicted underground damage point is the known obstacle itself. In this case, steps S430~S450 can be used to compare the known obstacle information and the predicted underground damage point.

[0078] For example, given that the waveform data of a known metal pipe as an obstacle is characterized by a strong amplitude hyperbola, and the depth and coordinates of the metal pipe underground are known, a predicted underground damage point corresponding to this depth and coordinates is represented on the waveform as a strong amplitude hyperbola with local amplitude abrupt changes. In a specific embodiment, the preset range of the matching score is 85%~100%. Setting the preset value of the matching score to 90% and performing a matching score on the two, if the matching score between the known metal pipe and the predicted underground damage point in the waveform image of the strong amplitude hyperbola is greater than 90%, it can be considered that the part of the waveform image of the predicted underground damage point with respect to the strong amplitude hyperbola corresponds to the known metal pipe, and the strong amplitude hyperbola in the waveform image can be filtered out. On the other hand, the location in the waveform image of the predicted underground damage point that has an amplitude abrupt change relative to the waveform image of the metal pipe has a lower matching score with the metal pipe. Therefore, the part of the waveform image with an amplitude abrupt change relative to the known obstacle information can be marked as the underground damage component to be verified, and this predicted underground damage point can be retained. Therefore, it can help users perform preliminary filtering and screening of echo data based on known obstacle information, avoid the influence of normal underground pipeline laying on the judgment of underground damage, and further improve the ability to reuse known geographical information of the target detection area.

[0079] Therefore, in step S460, the underground damage point data that has been compared is further combined with the underground damage point data that has not been compared to obtain a relatively complete assessment of the underground damage points in the target detection area. Based on the coordinates, depths and waveform characteristics of each predicted underground damage point, a preliminary assessment of the underground damage can be obtained, i.e., a detection result.

[0080] In step S400, when no known obstacle information exists, the system infers obstacle features based on environmental characteristics and / or obtains inferred obstacle features from external input. These inferred obstacle features are then used to filter the echo data, resulting in a detection result. Specifically, this can be achieved by obtaining features such as surface material characteristics, humidity characteristics, and road signs in the target detection area through environmental sensors, or by using external input from the user regarding potential obstacles and inferred obstacle features in the target detection area to filter the echo data. Inferred obstacle features are generally relatively obvious obstacles, such as water pipelines. Based on the type of medium in the water pipeline, the image features of the water pipeline in the waveform data can be obtained. Therefore, by comparing the waveform data of the predicted underground damage point with the waveform data of the water pipeline, the possibility of a water pipeline at the predicted underground damage point can be confirmed or ruled out, thus achieving the filtering of the echo data. Since the features are inferred obstacles, their confidence level is lower than that of known obstacle information. Therefore, for predicted underground damage points with a matching score greater than a preset value, corresponding warning information can be added to prevent misjudgment of the underground damage point.

[0081] In one specific embodiment, step S400 further includes:

[0082] The predicted underground damage location data is compared with the waveform data features corresponding to the inferred obstacle features to obtain a matching score;

[0083] When the matching score is greater than or equal to the preset value, the current waveform data is marked as the component to be filtered, and a prompt message is displayed.

[0084] When the matching score is less than the preset value, the waveform data that is different from the waveform data of the inferred obstacle feature in the current waveform data corresponding to the marked point is marked as the underground damage component to be verified, and the predicted underground damage point is retained.

[0085] In some specific embodiments, such as Figure 5 As shown, after step S410, the following steps are also included:

[0086] S411. Based on the temperature and / or humidity information of the location of the predicted underground damage point in a single echo data, call the environmental correction coefficient corresponding to the temperature and / or humidity information from the preset feature library.

[0087] S412. The waveform data corresponding to the predicted underground damage location in the primary echo data is corrected using an environmental correction coefficient.

[0088] In practical applications, the detection results of the ground penetrating radar module 2 may be affected by the surrounding environment during the detection process. The detection results may differ under different temperatures and humidity levels. Therefore, by pre-storing the variation coefficients of the detection parameters of the ground penetrating radar module 2 under different external environmental parameters in a preset feature library, and generating corresponding environmental correction coefficients, the detection results of the ground penetrating radar module 2 in different environments can be corrected for practical applications, ensuring that the waveform data obtained by the ground penetrating radar module 2 approximates the actual situation as closely as possible.

[0089] In one specific embodiment, the calculation method for the environmental correction factor K further includes:

[0090] K= 1+0.01×(T-T0)+0.005×(H-H0)

[0091] Where T represents the current actual temperature of the target detection area, and H represents the current actual humidity of the target detection area. Based on the standard operating mode of the ground-penetrating radar module, the standard temperature T0 = 25℃, the standard humidity H0 = 50%RH, and the reference correction coefficient K0 = 1 are set accordingly. By simulating different external environmental parameters, the variation coefficients of temperature and humidity can be obtained. In practical applications, higher temperatures accelerate the attenuation of electromagnetic waves, resulting in a smaller original amplitude; higher humidity also enhances the conductivity of the medium, weakening the reflected electromagnetic wave signal. Therefore, amplification using correction coefficients is necessary to restore the intensity of the echo signal as much as possible.

[0092] In a specific application, for example, during a summer rainy season, when inspecting a section of road structure, for a predicted underground damage point in the target detection area, the environmental sensor module 4 provides the current temperature data as 35℃ and the current humidity data as 70%RH. Based on this, the environmental correction coefficient K is calculated as K = 1 + 0.01 × (35℃ - 25℃) + 0.005 × (70%RH - 50%RH) = 1.2. Furthermore, the waveform data of the predicted underground damage point location is corrected using the current environmental correction coefficient K = 1.2. For example, the amplitude A0 of the waveform data is corrected, and the corrected amplitude A = A0 × K = A0 × 1.2.

[0093] In some specific embodiments, such as Figure 6 As shown, in step S500, the ultrasonic module 5 performs a secondary detection on the point to be verified, and the secondary detection results include:

[0094] S510. Divide the target detection area into multiple detection sub-areas, and perform data statistics on each detection sub-area. The data statistics include the number and size of underground damage points in each detection sub-area.

[0095] S520. Mark the underground damage points in the detection sub-region where the number of underground damage points exceeds the preset number threshold and / or the underground damage points with a size greater than the preset size threshold as points to be verified.

[0096] S530: Ultrasonic waves of a preset frequency are emitted to each point to be verified through ultrasonic module 5 to obtain echo signals. Damage assessment is performed on each point to be verified based on the echo signals to obtain secondary detection results.

[0097] When conducting underground damage detection, a single detection using ground-penetrating radar yields a single result, enabling a comprehensive screening of the entire target detection area. In one specific embodiment, after completing the overall screening of the target detection area, multiple verification points are obtained, distributed across various locations within the target area with different depths and sizes. At this point, the detection scope is narrowed down from the entire target detection area to the locations of each verification point. By utilizing the high resolution and precision detection capabilities of ultrasonic waves, further inspection of each verification point can be conducted to verify the judgment in the initial detection result. Furthermore, the damage type, size, and depth at each verification point can be measured with higher accuracy to further confirm the next repair plan.

[0098] In practical applications, depending on the target of underground damage detection and the different repair and maintenance plans, users may only need to maintain some of the underground damage that meets the repair and maintenance requirements. In this case, the locations of underground damage that need further inspection and repair can be screened by marking the points to be verified in the target detection area.

[0099] In one specific embodiment, the target detection area can be divided into multiple equally sized sub-regions of 0.5m × 0.5m. By statistically analyzing the data of each sub-region, the number and size of the points to be verified in each sub-region can be obtained. Furthermore, the average and median number of points to be verified in each sub-region, and the average size and median size of the points to be verified in the target detection area can be calculated. It should be noted that this application does not specifically limit the specific values ​​of the quantity threshold and size threshold. These can be determined by referring to the actual detection target and the repair plan, and preset quantity and size thresholds can be manually set. Alternatively, the average or median of the points to be verified can be set as the preset quantity threshold, and the average size of the points to be verified can be automatically set as the preset size threshold.

[0100] In some specific embodiments, the ground-penetrating radar module 2 includes a high-frequency transmitting unit and a low-frequency transmitting unit; environmental characteristic data includes temperature range and / or humidity range; wherein, for example Figure 2As shown, in step S100, determining the transmission frequency band of the ground-penetrating radar module 2 based on the depth range and environmental feature data of the target detection area includes:

[0101] S110, Obtain the depth range of the target detection area;

[0102] S120. When the proportion of the depth range falling into the preset shallow range exceeds the preset ratio, first set the transmission frequency band of the high-frequency transmission unit.

[0103] S130. When the proportion of the depth range falling into the preset middle-deep range exceeds a preset ratio, first set the transmission frequency band of the low-frequency transmission unit; wherein, the preset ratio is greater than or equal to 50%;

[0104] S140. Set the ratio of the transmission frequency band of the high-frequency transmitting unit to the transmission frequency band of the low-frequency transmitting unit to be 2:1 to 4:1.

[0105] S150: Obtain the temperature range and / or humidity range of the target detection area, and adjust the transmission frequency band of the ground penetrating radar module 2 within a preset elastic range according to the temperature range and / or humidity range.

[0106] Because the detection accuracy varies across different depth ranges for transmitted signals of different frequencies, in a practical setup, the transmission frequency band of the high-frequency transmitting unit can be set higher to ensure detection accuracy; conversely, the transmission frequency band of the low-frequency transmitting unit can be set lower as the depth range increases to ensure detection depth. By setting a multiple relationship between the high-frequency and low-frequency transmitting units based on the detection range the target detection area falls into, mutual interference between their signals can be avoided. Since their frequency bands do not overlap, the echo signals returned by the two units can be more effectively distinguished, improving the overall resolution efficiency of a single echo data. Furthermore, by determining the proportion of objects falling into different depth ranges and adjusting the priority of the transmission frequency bands, the advantages and characteristics of both high-frequency and low-frequency transmitting units can be better utilized. In one specific embodiment, the preset value is 50%. When the depth range falls into the preset shallow range by more than 50%, priority is given to damage detection in the shallow range, and priority is given to ensuring the accuracy of damage detection in the shallow range. When the depth range falls into the preset medium-deep range by more than 50%, priority is given to damage detection in the medium-deep range, and priority is given to ensuring the accuracy of damage detection in the medium-deep range.

[0107] It should be noted that this application does not specifically limit the range of the shallow and medium-deep zones. In practical applications, users can limit the range of the shallow and medium-deep zones of the target detection area according to the specific application, the overall size of the target detection area, and the total detectable depth of the ground penetrating radar module 2.

[0108] In one specific embodiment, the high-frequency transmitting unit is configured with a transmission frequency band of 1GHz to 2GHz, suitable for detecting shallow layers with a depth of 0-1.5m; the low-frequency transmitting unit is configured with a transmission frequency band of 500MHz to 1GHz, suitable for detecting medium-deep layers with a depth of 1.5-5m. While using both the high-frequency and low-frequency transmitting units to transmit signals, maintaining a transmission frequency band ratio of 2:1 between the high-frequency and low-frequency transmitting units can effectively avoid signal interference between them, while achieving complementarity for both shallow and medium-deep layer detection.

[0109] Furthermore, by adjusting the transmission frequency band of the ground-penetrating radar module 2 within a preset elastic range based on the temperature and / or humidity range of the target detection area, the flexibility of the transmission frequency band of the ground-penetrating radar module 2 is preserved, which can offset the impact of temperature and humidity changes on the propagation of radar signals. It should be noted that this application does not specifically limit the specific data of the preset elastic range. In practical applications, the size of the preset elastic range can be set according to the specific situation of the current environmental characteristics data, such as ±15%.

[0110] Specifically, the transmission frequency band of the ground penetrating radar module 2 can be automatically adjusted by pre-storing the variation coefficients between the transmission frequency band and the detection results of the ground penetrating radar module 2 under different external environmental parameters in the preset feature library, or the user can manually adjust the transmission frequency band of the ground penetrating radar module 2 within a preset elastic range.

[0111] In some specific embodiments, a single echo data includes first echo data from the high-frequency transmitting unit and second echo data from the low-frequency transmitting unit; such as Figure 3 As shown, after step S200, the method further includes:

[0112] Data fusion processing of a single echo data stream specifically includes:

[0113] S210. Preprocess the first echo data and the second echo data; wherein, the preprocessing includes denoising the first echo data and the second echo data, and synchronizing the time of the first echo data and the second echo data by an encoder. Specifically, random noise in the data can be removed by algorithms such as wavelet denoising algorithms.

[0114] S220. Spatial registration is performed on the first echo data and the second echo data to unify the number of scan channels and the sampling interval of the first echo data and the second echo data;

[0115] By unifying the number of scanning channels for the first and second echo data, the sampling density of the first and second echo data with different frequencies can be kept consistent in the horizontal direction (parallel to the ground), ensuring that the number of detection points collected at fixed length units is the same. Unifying the sampling interval ensures that the first and second echo data maintain synchronous sampling accuracy in the vertical direction (underground depth), ensuring that data such as sampling time is consistent each time. Thus, a correspondence between the waveform images of the first and second echo data in the same spatial coordinate system is established, allowing the first and second echo data with different frequencies to be accurately aligned with the same underground location, resulting in more complete and accurate detection results.

[0116] S230. The waveform images of the first and second echo data after registration are fused.

[0117] In some specific embodiments, step S230 includes:

[0118] S231. Extract the first image features corresponding to the preset shallow region in the first echo data, and extract the second image features corresponding to the preset medium-deep region in the second echo data.

[0119] S232. The first image features and the second image features are fused together; wherein the first image features and the second image features include one or more of the following: contour features, image boundary features, waveform intensity features and image texture features.

[0120] Specifically, depending on the actual application, different weights can be assigned to the first image feature and the second image feature, and then the features of the two can be superimposed to obtain the waveform data of the final first echo data. In one specific embodiment, the weight of the first image feature can be set to 0.55 and the weight of the second image feature can be set to 0.45, thereby further realizing the fusion of various specific features. In some specific embodiments, different weights can also be assigned to contour features, and / or image boundary features, and / or waveform intensity features, and / or image texture features according to the resolution effect of each feature, etc., to achieve fusion.

[0121] In practical applications, although the high-frequency signal emitted by the high-frequency transmitting unit has high detection accuracy, it has a shallow detection depth, while the low-frequency signal emitted by the low-frequency transmitting unit has a deep detection depth, but low detection accuracy. Therefore, by combining the high-frequency and low-frequency transmitting units, their advantages can be complemented, increasing the total information content obtained in the target detection area, improving the quality of the final imaging of the ground penetrating radar module 2, improving the accuracy of the single echo data, and ultimately improving the overall reliability of underground damage detection.

[0122] In step S473, by extracting the first image features corresponding to the preset shallow layer region of the high-frequency signal and the second image features corresponding to the preset medium-deep layer region of the low-frequency signal, the detection advantages of the two can be combined to generate complete waveform data for the target detection area from shallow to medium-deep.

[0123] In some specific embodiments, before step S200, the following steps are also included:

[0124] The encoder correlates the signal transmission time, signal reception time, current coordinates, and environmental feature data of the current coordinate position of the ground penetrating radar module 2. Specifically, the encoder assigns a unique timestamp to each detection location, establishing a mapping table of timestamp, current coordinates, environmental feature data, and a single echo data point, thus enabling the correlation of this data.

[0125] It can realize one-to-one correspondence between the time, location, environmental characteristics and echo data of each detection point of the ground penetrating radar module 2, which facilitates the traceability of the detection process.

[0126] In one specific embodiment, step S600, which combines the primary and secondary detection results to obtain an underground damage detection report, specifically includes:

[0127] Taking each detection sub-region in the target detection area as a unit, the data of some or all predicted damage points in the secondary detection results are updated relative to the data of predicted damage points in the primary detection results to obtain the underground damage detection report.

[0128] In practical applications, underground damage detection reports can include a coordinate system for the target detection area in both horizontal and vertical directions. All predicted damage points and points requiring secondary manual verification are marked on both the horizontal and vertical coordinate systems according to their corresponding coordinate and depth information. Furthermore, known obstacles identified within the target detection area are clearly marked on both the horizontal and vertical coordinate systems. This allows users to intuitively obtain the specific locations of all predicted damage points within the target detection area through the underground damage detection report. It also helps users synthesize known obstacle data and warning points from primary and secondary detection results. Users only need to further confirm the known obstacle data and warning points, greatly improving the efficiency of underground damage detection.

[0129] In some specific embodiments, after step S600, the method further includes:

[0130] S700, Collect the latest obstacle information from the underground damage detection report; the latest obstacle information includes the medium type information, coordinate information, depth information and waveform feature information of the obstacles in the target detection area;

[0131] S800: Incorporate the latest obstacle information into the known obstacle information.

[0132] In one specific embodiment, after the underground damage detection report is completed, the underground damage detection report includes data on the locations of underground damage points in the target detection area, known obstacle data, and the latest obstacle data determined based on the inferred obstacle characteristics. By incorporating the latest obstacle data into the known obstacle information, it is possible to update and archive the known obstacle data in the target area, which helps to identify underground damage in the same target detection area in the next time.

[0133] This embodiment proposes a ground-penetrating radar (GPR)-based underground damage detection method. It filters the primary echo data of the GPR by querying a pre-set map database or obtaining corresponding known obstacle information from external sources. When no known obstacle information is available, obstacle features are inferred from the current environment or obtained from external input, yielding a primary detection result. This method effectively utilizes known obstacle information and features to filter GPR data, making full use of existing geographic information, eliminating potential misjudgments, improving the overall efficiency of underground damage identification, shortening manual interpretation time, and avoiding misjudging planned underground pipelines and facilities as damaged. Furthermore, a secondary detection is performed on the verification point using an ultrasonic module. Leveraging the high accuracy and point-to-point detection characteristics of ultrasonic technology, this effectively compensates for the insufficient detection accuracy of the GPR module, enabling effective identification of various types of surface and underground defects and significantly improving the reliability of underground damage detection.

[0134] Example 2

[0135] Embodiment 2 of this application discloses an underground damage detection system, which is applicable to any of the underground damage detection methods based on ground penetrating radar in the aforementioned technical solutions. Specifically, the system includes: a mobile mechanism 8 and a main control module 1, a ground penetrating radar module 2, a positioning module 3, an environmental sensor module 4, and an ultrasonic module 5 disposed in the mobile mechanism 8.

[0136] The main control module 1 connects to the ground penetrating radar module 2, the positioning module 3, the environmental sensor module 4, and the ultrasonic module 5. It is used to determine the transmission frequency band of the ground penetrating radar module 2 based on the depth range and environmental feature data of the target detection area, trigger the ground penetrating radar module 2 through the encoder, and perform secondary detection on the point to be verified through the ultrasonic module 5.

[0137] Ground penetrating radar module 2 includes an air-coupled radar, which is used to detect underground damage in the target detection area. Ground penetrating radar module 2, environmental sensors and positioning module 3 are interconnected through an encoder. Specifically, ground penetrating radar module 2 includes a high-frequency transmitting unit and a low-frequency transmitting unit, which are used to transmit radar signals in different frequency bands to perform multi-frequency detection of the target area.

[0138] The positioning module 3 is associated with the mileage data of the mobile mechanism 8 to form a coordinate system parallel to the target detection area, for positioning of the ground penetrating radar module 2 and the ultrasonic module 5; specifically, the positioning module 3 is a GPS module.

[0139] The environmental sensor module 4 includes one or more of a temperature sensor, a humidity sensor, and a material sensor, used to obtain environmental characteristic data of the target detection area. The environmental characteristic data of the target detection area includes current temperature data, current humidity data, and current ground material data. Obtaining the current ground material data is beneficial for inferring obstacle characteristics when no known obstacle data is available, by combining it with the current temperature data, current humidity data, etc.

[0140] Ultrasonic module 5 is used to perform secondary detection on the point to be verified and obtain the secondary detection results;

[0141] The moving mechanism 8 carries the ground-penetrating radar module 2, positioning module 3, environmental sensor module 4, and ultrasonic module 5 to move within the target detection area to detect underground damage. The ground-penetrating radar module 2 can quickly detect the thickness, voids, and water content of various underground structural layers, while the ultrasonic module 5 can accurately assess internal material defects and mechanical property degradation. Combining these two modules effectively improves the detection accuracy of the target detection area. The connections between the modules are as follows: Figure 7 As shown.

[0142] In one specific embodiment, the system further includes a communication module 6 and a storage module 7 connected to the main control module 1. The storage module 7 can be used to store one or more types of data, including a preset map library, environmental feature data of the target detection area, primary echo data, primary detection results, secondary detection results, and underground damage detection reports. The communication module 6 can be connected to the storage module 7 and, under the control of the main control module 1, can transmit the data stored in the storage module 7 to an external host computer, or obtain data from an external host computer and transmit it to the storage module 7.

[0143] This embodiment proposes an underground damage detection system. By applying the underground damage detection method based on ground-penetrating radar (GPR) in Embodiment 1, it utilizes known obstacle data to eliminate interference from underground damage, effectively reducing misjudgments caused by known obstacles and improving the efficiency of underground damage identification. Furthermore, by combining the GPR module and the ultrasonic module for detection, it can effectively compensate for the insufficient accuracy of GPR in underground detection, effectively improving the detection accuracy of the target detection area, resulting in higher overall system detection accuracy and more reliable detection results.

[0144] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of a preferred embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing this application. Those skilled in the art will understand that the modules in the apparatus of the embodiment can be distributed within the apparatus of the embodiment as described, or can be located in one or more apparatuses different from this embodiment, with corresponding changes. The modules of the above-described embodiment can be combined into one module, or further divided into multiple sub-modules. The serial numbers of this application mentioned above are merely descriptive and do not represent the superiority or inferiority of the embodiment. The above disclosures are only a few specific embodiments of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. A method for detecting underground damage based on ground-penetrating radar, characterized in that, The method includes: The target detection area is determined, and the transmission frequency band of the ground-penetrating radar module is determined based on the depth range and environmental feature data of the target detection area. The ground-penetrating radar module is triggered by the encoder, causing the ground-penetrating radar module to detect the target detection area at a preset speed and obtain one echo data. Based on the coordinates of the target detection area, known obstacle information corresponding to the target detection area is obtained from a preset map library or from external sources; The echo data is filtered based on the known obstacle information to obtain a detection result. When there is no known obstacle information, the obstacle features are inferred based on the environmental features and / or obtained from external input. The echo data is then filtered based on the inferred obstacle features to obtain the detection result. Based on the first detection result, mark the points to be verified in the target detection area, and perform a second detection on the points to be verified using an ultrasonic module to obtain the second detection result. The results of the first and second tests are combined to obtain an underground damage detection report; The step of filtering the echo data based on the known obstacle information to obtain a detection result includes: Based on the first echo data, the predicted underground damage location data is obtained; The known obstacle information includes at least one known obstacle, and each known obstacle corresponds to an obstacle medium type, obstacle coordinates, and obstacle depth; each known obstacle corresponds to different obstacle waveform data features; Predicted underground damage points that overlap with the known obstacle's coordinates and depth are selected; the current waveform data corresponding to the predicted underground damage points is compared with the obstacle waveform data features corresponding to the obstacle to obtain a matching score; When the matching score is greater than or equal to the preset value, the current waveform data is marked as a component to be filtered and is not included in the underground damage detection. When the matching score is less than a preset value, the waveform data that is different from the obstacle waveform data in the current waveform data corresponding to the predicted underground damage point is extracted and marked as the underground damage component to be verified, and the predicted underground damage point is retained. Damage assessment is performed based on the predicted underground damage location data to obtain the first detection result; The secondary detection of the point to be verified using an ultrasonic module yields the following results: The target detection area is divided into multiple detection sub-areas, and data statistics are performed on each detection sub-area. The data statistics include the number and size of underground damage points in each detection sub-area. The underground damage points in the detection sub-region where the number of underground damage points exceeds a preset threshold and / or the underground damage points whose size is greater than a preset size threshold are marked as the points to be verified. The ultrasonic module emits ultrasonic waves of a preset frequency to each of the points to be verified, and obtains echo signals. Damage assessment is performed on each of the points to be verified based on the echo signals to obtain the secondary detection results.

2. The method for detecting underground damage based on ground-penetrating radar according to claim 1, characterized in that, After obtaining the predicted underground damage location data, the method further includes: Based on the temperature and / or humidity information corresponding to the location of the predicted underground damage point in the first echo data, the environmental correction coefficient corresponding to the temperature and / or humidity information is called from the preset feature library; The waveform data corresponding to the predicted underground damage location in the primary echo data is corrected using the environmental correction coefficient.

3. The method for detecting underground damage based on ground-penetrating radar according to claim 1, characterized in that, The ground-penetrating radar module includes a high-frequency transmitting unit and a low-frequency transmitting unit; the environmental characteristic data includes a temperature range and / or a humidity range; determining the transmission frequency band of the ground-penetrating radar module based on the depth range of the target detection area and the environmental characteristic data includes: The depth range of the target detection area is obtained. When the proportion of the depth range falling into the preset shallow range exceeds a preset value, the transmission frequency band of the high-frequency transmission unit is set first. When the proportion of the depth range falling into the preset middle-deep range exceeds a preset value, the transmission frequency band of the low-frequency transmission unit is first set; the preset ratio is greater than or equal to 50%. The ratio of the transmission frequency band of the high-frequency transmitting unit to the transmission frequency band of the low-frequency transmitting unit is set to 2:1 to 4:1; The temperature range and / or humidity range of the target detection area are obtained, and the transmission frequency band of the ground penetrating radar module is adjusted within a preset elastic range according to the temperature range and / or humidity range.

4. The underground damage detection method based on ground-penetrating radar according to claim 3, characterized in that, The single echo data includes the first echo data of the high-frequency transmitting unit and the second echo data of the low-frequency transmitting unit; After obtaining the first echo data, the process further includes: performing data fusion processing on the first echo data, specifically including: Preprocess the first echo data and the second echo data; Spatial registration is performed on the first echo data and the second echo data to unify the number of scan channels and the sampling interval of the first echo data and the second echo data; The waveform images of the registered first echo data and the second echo data are fused.

5. The underground damage detection method based on ground-penetrating radar according to claim 4, characterized in that, The process of fusing the waveform images of the registered first echo data and the second echo data includes: Extract the first image features corresponding to the preset shallow region from the first echo data, and extract the second image features corresponding to the preset medium-deep region from the second echo data; The first image features and the second image features are fused together; The first image feature and the second image feature include one or more of the following: contour features, image boundary features, waveform intensity features, and image texture features.

6. The method for detecting underground damage based on ground-penetrating radar according to claim 1, characterized in that, Before triggering the ground-penetrating radar module via the encoder, the following is also included: The encoder associates the signal transmission time, signal reception time, current coordinates, and environmental feature data of the current coordinates of the ground penetrating radar module.

7. The method for detecting underground damage based on ground-penetrating radar according to claim 1, characterized in that, After obtaining the underground damage detection report, the following is also included: Collect the latest obstacle information from the underground damage detection report; the latest obstacle information includes the medium type information, coordinate information, depth information, and waveform feature information of the obstacles in the target detection area; The latest obstacle information is incorporated into the known obstacle information.

8. A subsurface damage detection system, applicable to any one of the ground-penetrating radar-based subsurface damage detection methods according to claims 1-7, characterized in that, The system includes a mobile mechanism and a main control module, a ground-penetrating radar module, a positioning module, an environmental sensor module, and an ultrasonic module disposed in the mobile mechanism; The main control module connects the ground-penetrating radar module, the positioning module, the environmental sensor module, and the ultrasonic module. It is used to determine the transmission frequency band of the ground-penetrating radar module based on the depth range and environmental feature data of the target detection area, trigger the ground-penetrating radar module through the encoder, and perform secondary detection on the point to be verified through the ultrasonic module. The ground-penetrating radar module includes an air-coupled radar, which is used to detect underground damage in the target detection area. The ground-penetrating radar module, the environmental sensor, and the positioning module are interconnected through an encoder. The positioning module is associated with the mileage data of the mobile mechanism to form a coordinate system parallel to the target detection area; The environmental sensor module includes one or more of a temperature sensor, a humidity sensor, and a material sensor, used to obtain the environmental feature data of the target detection area; The ultrasonic module is used to perform secondary detection on the point to be verified and obtain the secondary detection result. The mobile mechanism is used to carry the ground-penetrating radar module, the positioning module, the environmental sensor module and the ultrasonic module to move within the target detection area, so as to realize the detection of underground damage in the target detection area.

Images