Method and system for detecting underwater pipe ditch and obstacle

Abstract

The invention discloses a method and system for detecting an underwater pipe trench and an obstacle, and the method comprises the steps: collecting point cloud information representing the depth distribution characteristics of the underwater pipe trench and the obstacle in real time through employing a first type of equipment, and collecting image information representing the reflection intensity response characteristics of the underwater pipe trench and the obstacle in real time through employing a second type of equipment; the point cloud information and the image information are combined, and pipe ditch state information including the position, the width, the depth, the flatness and internal obstacles of the pipe ditch is comprehensively analyzed. According to the invention, the forming condition of the underwater pipe trench and the obstacles can be comprehensively detected efficiently and quickly.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater pipeline trench detection, and in particular to a method and system for detecting underwater pipeline trenches and obstacles. Background Art

[0002] Traditional underwater trench inspection mainly uses a single-beam depth sounder to measure the water depth points inside the trench, thereby inspecting the underwater trench formation status; at the same time, frogmen are sent underwater to manually observe the trench formation status, and underwater obstacles are interpreted through manual video recording, thereby realizing underwater trench formation status and obstacle detection.

[0003] However, the measurement points of the underwater trench inspection in the prior art are relatively far apart, and cannot accurately reflect the quality of trench forming. In addition, underwater video recording cannot quantitatively assess the width and forming condition of the trench, and cannot detect obstacles formed in the trench. Summary of the invention

[0004] The purpose of the present invention is to provide a method that can solve the problem that the distance between measurement points in traditional underwater trench detection is large and cannot accurately reflect the quality of trench forming.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a method for detecting underwater trenches and obstacles, including: using a first type of equipment to collect point cloud information characterizing the depth distribution characteristics of underwater trenches and obstacles in real time, and using a second type of equipment to collect image information characterizing the reflection intensity response characteristics of underwater trenches and obstacles in real time; combining the point cloud information and the image information, and comprehensively analyzing the trench status information including the trench position, width, depth, flatness and internal obstacles.

[0006] Preferably, before combining the point cloud information and the image information, the method also includes: constructing a three-dimensional model using the point cloud information collected by the first type of equipment to preliminarily identify the overall condition of the trench forming and the location and shape of trench obstacles; extracting multiple longitudinal sections and multiple transverse sections from the three-dimensional model; and obtaining initial trench section information based on the point cloud according to the multiple longitudinal sections and multiple transverse sections.

[0007] Preferably, before combining the point cloud information and the image information, the method further includes: using the second type of equipment to scan along the direction of the trench, and based on the collected image information characterizing the strength distribution state of the recovery signal, preliminarily identifying the position of the trench formation and the upper width and shape of the trench, based on this, obtaining characteristic information of obstacles inside the trench based on the signal strength distribution state.

[0008] Preferably, in the step of combining the point cloud information and the image information to comprehensively analyze the trench status information including the trench position, width, depth, flatness and internal obstacles, it includes: superimposing the initial trench section information and the intensity characteristics of the obstacles inside the trench, analyzing the types of obstacles at different positions in the depth measurement point cloud by comparing the strength distribution characteristics of the echo signals of the sounding point cloud and the side scan image, thereby generating the trench status information.

[0009] Preferably, the first type of equipment is a multi-beam depth sounding equipment, and the second type of equipment is a sonar equipment.

[0010] Preferably, the method further comprises: comparing the plurality of longitudinal sections and the plurality of transverse sections with the trench design parameters, determining whether the current trench state meets the design requirements, and issuing an early warning for the determination result.

[0011] On the other hand, the present invention also provides a system for detecting underwater trenches and obstacles, the system is used to implement the method as described above, wherein the system includes: a first type of equipment, which is used to collect point cloud information characterizing the depth distribution characteristics of underwater trenches and obstacles in real time; a second type of equipment, which is used to collect image information characterizing the reflection intensity response characteristics of underwater trenches and obstacles in real time; a data processing device, which is used to combine the point cloud information and the image information to comprehensively analyze the trench status information including the trench position, width, depth, flatness and internal obstacles.

[0012] Preferably, the first type of equipment is a multi-beam depth sounding equipment, and the second type of equipment is a sonar equipment.

[0013] Preferably, the data processing equipment includes: a point cloud information processing module, wherein the point cloud information processing module is executed according to the following steps: constructing a three-dimensional model using the point cloud information to preliminarily identify the overall condition of the trench forming and the location and shape of the trench obstacles; extracting multiple longitudinal sections and multiple transverse sections from the three-dimensional model; and obtaining initial trench section information based on the point cloud according to the multiple longitudinal sections and multiple transverse sections.

[0014] Preferably, the data processing equipment includes: an image information processing module, wherein the image information processing module is executed according to the following steps: based on the collected image information characterizing the strength distribution state of the recovery signal, the position of the trench formation and the upper width and shape of the trench are preliminarily identified, and based on this, characteristic information of obstacles inside the trench based on the signal strength distribution state is obtained.

[0015] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0016] The present invention proposes a method and system for detecting underwater trenches and obstacles. The method and system are aimed at underwater trench detection, and comprehensively utilize multi-beam and side-scan sonar technology to identify the trench forming conditions through three-dimensional models, longitudinal and transverse sections, sonar images and other methods, breaking through the limitations of traditional single-beam depth sounding technology, and improving the accuracy, resolution and work efficiency of underwater terrain detection; and in view of the hazards of internal trench obstacles that may cause serious damage to pipelines, by comparing three-dimensional point clouds with sonar images, the characteristics of underwater obstacles are analyzed, the width and forming conditions of the trench are quantitatively evaluated, and the formed obstacles in the trench are efficiently and quickly detected. To this end, the present invention can efficiently and quickly perform comprehensive detection of the forming conditions and obstacles of underwater trenches, has strong intuitiveness, can be used for process monitoring, and can be used for final forming condition detection, has the advantages of high measurement accuracy, low operating cost, high safety factor, etc., and has good practical value.

[0017] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 Schematic diagram of the steps of a method for detecting underwater trenches and obstacles according to an embodiment of the present application.

[0020] Figure 2 This is a specific flow chart of the method for detecting underwater trenches and obstacles according to an embodiment of the present application.

[0021] Figure 3 It is a schematic diagram of the structure of a system for detecting underwater trenches and obstacles according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0023] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. Also, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described can be performed in a sequence different from that here.

[0024] The terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "one", "one" and "item" used herein are also intended to include plural numbers. It should also be understood that the terms "include" and / or "comprise" used herein specify the existence of stated features, integers, steps, operations, units and / or components, without excluding the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0025] Traditional underwater trench inspection mainly uses a single-beam depth sounder to measure the water depth points inside the trench, thereby inspecting the underwater trench formation status; at the same time, frogmen are sent underwater to manually observe the trench formation status, and underwater obstacles are interpreted through manual video recording, thereby realizing underwater trench formation status and obstacle detection.

[0026] However, the measurement points of the underwater trench inspection in the prior art are relatively far apart, and cannot accurately reflect the quality of trench forming. In addition, underwater video recording cannot quantitatively assess the width and forming condition of the trench, and cannot detect obstacles formed in the trench.

[0027] In order to solve the above technical problems, the embodiment of the present application proposes a method and system for detecting underwater trenches and obstacles. The method and system comprehensively utilize multi-beam depth sounding and side-scan sonar equipment to detect the forming conditions of the trenches through three-dimensional models, longitudinal and cross-sections, sonar images and other methods, and analyze the characteristics of underwater obstacles by comparing the stereo point cloud with the sonar image. The present invention solves the technical problems that the traditional underwater trench detection measurement points are too far apart to accurately reflect the trench forming quality, and that underwater video recording cannot quantitatively evaluate the width, forming and other conditions of the trenches and cannot detect formed obstacles in the trenches.

[0028] Figure 1 This is a schematic diagram of the steps of the method for detecting underwater trenches and obstacles in an embodiment of the present application. Figure 1 The steps of the method for detecting underwater trenches and obstacles (also referred to as "trench detection method") described in an embodiment of the present invention are described.

[0029] During the navigation of the ship, step S110 uses the first type of equipment installed at the bottom of the ship to collect point cloud information representing the depth distribution characteristics of underwater trenches and trench obstacles in real time. At the same time, the second type of equipment installed at the bottom of the ship is used to collect image information representing the lateral intensity response characteristics of underwater trenches and trench obstacles in real time.

[0030] Step S110 uses the first type of equipment to continuously measure the distribution characteristics of the sounding points of the underwater trench during the ship's travel to obtain corresponding point cloud information. At the same time, step S110 also uses the second type of equipment to send sound waves to the underwater trench along the trench line to detect the sound signals reflected by the trench and obstacles in the water in real time. Since the reflected sound signals at different positions can reflect the reflection intensity characteristics of the underwater trench and obstacles, corresponding image information can be obtained.

[0031] Then, step S120 combines the point cloud information measured in real time in step S110 with the detected image information to comprehensively analyze the trench status information including the trench position, width, depth, flatness and internal obstacles in real time.

[0032] In one embodiment, the first type of device is a multi-beam bathymetric device, and the second type of device is a sonar device.

[0033] In this way, the present invention can use the intensity information detected in real time by the sonar equipment to compensate for the depth information detected by the multi-beam depth sounding equipment, so as to solve the problem of large measurement point spacing faced by the single-beam depth sounding equipment involved in the existing underwater trench detection process, and can accurately reflect the real-time forming quality of the trench.

[0034] Figure 2 This is a specific flow chart of the method for detecting underwater trenches and obstacles in an embodiment of the present application. Figure 2 , the specific steps of the pipe trench detection method described in the embodiment of the present invention are described below.

[0035] Step S201 uses a multi-beam depth sounding device to perform real-time measurement of the underwater trench to obtain point cloud information including depth distribution characteristic information of the underwater trench and obstacles.

[0036] Multi-beam bathymetry is an echo sounding system that can obtain multiple (for example: 256) adjacent narrow beams at the same time. Compared with the traditional single-beam bathymetry system, which can only obtain one seabed depth value vertically below the survey ship in each measurement, multi-beam bathymetry can obtain the seabed depth values ​​of multiple measurement points in a strip coverage area, realizing the transition from "point-line" measurement to "line-surface" measurement, breaking through the limitations of traditional single-beam bathymetry technology, and greatly improving the accuracy, resolution and work efficiency of seabed topography surveys.

[0037] In step S202, a sonar device is used to perform dynamic scanning and measurement perpendicular to the trench along the trench direction, so as to obtain image information including two-dimensional intensity response distribution characteristics of the underwater trench and obstacles in real time.

[0038] Side-scan sonar technology is a technology that uses the principle of echo sounding to detect seabed topography and underwater objects. It uses a transducer to emit sound waves of a certain frequency to the seabed on both sides. After being reflected by the seabed, part of the sound waves return to the transducer. The transducer array is installed in the hull or towed body. When sailing, fan-shaped beams are emitted from the bottom of both sides and recovered for imaging. The sonar equipment can complete the reception and transmission operations according to the set time, and directly display the data received each time, and can obtain two-dimensional images of the seabed topography (i.e., image information). Then, by using computer technology to process the image data, it can accurately judge and identify the underwater topography and landform information.

[0039] Next, after obtaining the point cloud information and image information, the embodiment of the present invention enters step S203 to use the point cloud information collected in real time by the first type of equipment (multi-beam depth sounder equipment) to perform point cloud filtering processing, and then step S204 constructs a three-dimensional model based on the filtered point cloud information, so as to preliminarily identify the overall condition of the trench forming and the position and shape of the trench obstacles.

[0040] Step S205 extracts multiple longitudinal sections and multiple transverse sections from the three-dimensional model constructed in step S204, and in step S206, based on the multiple longitudinal sections and multiple transverse sections extracted in real time in step S205, continuously obtains initial trench section information based on the point cloud.

[0041] In this way, after the embodiment of the present invention uses a multi-beam bathymetric device to measure the underwater trench, the real-time bathymetric point cloud information is filtered to remove noise, and then a three-dimensional model is generated to identify the overall condition of the trench formation and the position and size of the trench obstacles. Then, the longitudinal and cross-sections are automatically extracted to obtain the trench position, width, depth, flatness and internal obstacles of the trench preliminarily identified based on the point cloud information measurement scale, thereby realizing the detection of the underwater trench formation condition.

[0042] In the embodiment of the present invention, while continuously executing steps S203 to S206, the following steps S207 and S208 are also continuously executed, so as to synchronously process the point cloud information and image information collected in real time.

[0043] After scanning along the trench direction using the second type of equipment (sonar equipment), step S207 obtains image information characterizing the strength distribution state of the echo signal in real time, thereby preliminarily identifying the position of the trench formation and the upper width and shape of the trench. Then, step S208 further obtains lateral feature information of obstacles inside the trench based on the signal strength distribution state according to the position of the trench formation and the upper width and shape of the trench preliminarily identified in step S207.

[0044] In this way, after using the sonar equipment to scan along the direction of the trench, the embodiment of the present invention uses image analysis to identify the position of the trench formation and the width and shape of the upper part of the trench. Therefore, the present invention realizes the detection of underwater trench obstacles by identifying the characteristics of obstacles inside the trench through image analysis.

[0045] After completing the synchronous processing of the point cloud information and the image information, step S209 superimposes the initial trench section information obtained in step S206 and the intensity characteristics of the obstacles inside the trench obtained in real time in step S208, and analyzes the types of obstacles at different positions in the depth measurement point cloud by comparing the strength distribution characteristics of the sounding point cloud and the side scan image echo signal at the same position, thereby generating the final trench state information. At this time, the obtained trench state information not only has more dense sounding points than the initial trench state information, but also can obtain the position distribution characteristics, width distribution characteristics, depth distribution characteristics, flatness distribution characteristics of the underwater trench at the bottom of the ship based on a more refined sounding point image, as well as the shape, size and type (for example: rocks, floating objects in the water, etc.) characteristics of obstacles at different positions inside the trench.

[0046] In this way, the embodiment of the present invention superimposes the bathymetric point cloud with the side-scan image, compares the strength of the echo signal of the bathymetric point cloud and the side-scan image, and analyzes the obstacle characteristics in the bathymetric point cloud, thereby achieving a refined analysis of the underwater trench obstacle characteristics.

[0047] In addition, the embodiment of the present invention can also compare the internal cross-sectional features in the point cloud information collected in real time with the preset trench design parameters to evaluate the difference between the real-time (use) state of the trench and the original design parameters in real time. Specifically, the multiple longitudinal sections and multiple transverse sections in the point cloud information obtained in real time in step S205 are compared with the trench design parameters to determine whether the current trench state meets the original design requirements, and the difference is detected in real time. When the difference between different design parameters is greater than the corresponding preset threshold, the trench state at the current position is warned to remind relevant personnel to make timely construction corrections to the trench at this position, thereby realizing early warning of trench defects. Therefore, the present invention realizes quantitative analysis of the real-time state of the trench while also timely ensuring early warning of defects during normal use of the trench, and realizes the dynamic association between state detection and maintenance prompts.

[0048] On the other hand, based on the above pipeline trench detection method, an embodiment of the present invention further provides a system for detecting underwater pipeline trenches and obstacles (also called "pipe trench detection system"). The pipeline trench detection system is used to implement the above pipeline trench detection method.

[0049] Figure 3 Schematic diagram of the structure of the system for detecting underwater pipe trenches and obstacles in the embodiment of the present application. Figure 3 As shown, the pipe trench detection system described in the embodiment of the present invention includes: a first type of equipment 31, a second type of equipment 32 and a data processing device 33.

[0050] The first type of equipment 31 is used to collect point cloud information representing the depth distribution characteristics of underwater trenches and obstacles in real time. The second type of equipment 32 is used to collect image information representing the reflection intensity response characteristics of underwater trenches and obstacles in real time. The data processing equipment 33 is connected to the first type of equipment 31 and the second type of equipment 32 respectively. The data processing equipment 33 is used to combine the point cloud information and the image information to comprehensively analyze the trench status information including the trench position, width, depth, flatness and internal obstacles.

[0051] In one embodiment, the first type of equipment 31 is a multi-beam bathymetric equipment, and the second type of equipment 32 is a sonar equipment.

[0052] Furthermore, the data processing device 33 includes: a point cloud information processing module 331 , an image information processing module 332 and an information fusion module 333 .

[0053] In one embodiment, the point cloud information processing module 331 is implemented according to the method described in steps S203 to S206 above, specifically including: using point cloud information to construct a three-dimensional model to preliminarily identify the overall condition of the trench forming and the location and shape of trench obstacles; extracting multiple longitudinal sections and multiple transverse sections from the three-dimensional model; and obtaining initial trench section information based on the point cloud according to the multiple longitudinal sections and multiple transverse sections.

[0054] In one embodiment, the image information processing module 332 is implemented according to the method described in the above steps S207 to S208, specifically including: preliminarily identifying the position of the trench formation and the upper width and shape of the trench based on the collected image information characterizing the strength distribution state of the recovery signal, and based on this, obtaining the intensity characteristics of the obstacles inside the trench based on the signal strength distribution state.

[0055] In one embodiment, the information fusion module 333 is implemented according to the method described in the above step S209, specifically including: superimposing the initial trench section information and the intensity characteristics of the obstacles inside the trench, analyzing the types of obstacles at different positions in the depth measurement point cloud by comparing the strength distribution characteristics of the sounding point cloud and the side scan image echo signal, thereby generating the trench status information.

[0056] The present invention discloses a method and system for detecting underwater trenches and obstacles. The method and system are aimed at underwater trench detection, and comprehensively utilize multi-beam and side-scan sonar technology to identify the trench forming conditions through three-dimensional models, longitudinal and transverse sections, sonar images and other methods, breaking through the limitations of traditional single-beam depth sounding technology, and improving the accuracy, resolution and work efficiency of underwater terrain detection; and for the hazards of obstacles inside the trench that may cause serious damage to the pipeline, by comparing the three-dimensional point cloud with the sonar image, the underwater obstacle characteristics are analyzed, the width and forming conditions of the trench are quantitatively evaluated, and the formed obstacles in the trench are efficiently and quickly detected. To this end, the present invention can efficiently and quickly perform comprehensive detection of the forming conditions and obstacles of underwater trenches, has strong intuitiveness, can be used for process monitoring, and can be used for final forming condition detection, has the advantages of high measurement accuracy, low operating cost, high safety factor, etc., and has good practical value.

[0057] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0058] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0059] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0061] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0062] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for detecting underwater pipe trenches and obstacles, characterized in that: include: The first type of equipment is used to collect point cloud information representing the depth distribution characteristics of underwater trenches and obstacles in real time, and the second type of equipment is used to collect image information representing the reflection intensity response characteristics of underwater trenches and obstacles in real time; The point cloud information and the image information are combined to comprehensively analyze the trench status information including the trench position, width, depth, flatness and internal obstacles.

2. The method according to claim 1, characterized in that: Before combining the point cloud information with the image information, the method further includes: Using the point cloud information collected by the first type of equipment to build a three-dimensional model, to preliminarily identify the overall condition of the trench and the location and shape of trench obstacles; extracting a plurality of longitudinal sections and a plurality of transverse sections from the three-dimensional model; Initial trench section information based on point clouds is obtained according to the multiple longitudinal sections and the multiple transverse sections.

3. The method according to claim 2, characterized in that Before combining the point cloud information with the image information, the method further includes: The second type of equipment is used to scan along the direction of the trench, and the image information characterizing the strength distribution of the rebound signal is collected to preliminarily identify the location of the trench and the width and shape of the upper part of the trench. Based on this, characteristic information of obstacles inside the trench based on the signal strength distribution is obtained.

4. The method according to claim 3, characterized in that The step of combining the point cloud information with the image information to comprehensively analyze the trench state information including the trench position, width, depth, flatness and internal obstacles includes: The initial trench section information and the intensity characteristics of the obstacles inside the trench are superimposed, and the types of obstacles at different positions in the depth measurement point cloud are analyzed by comparing the strength distribution characteristics of the echo signal of the sounding point cloud and the side scan image, so as to generate the trench status information.

5. The method according to any one of claims 1 to 4, characterized in that: The first type of equipment is multi-beam depth sounding equipment, and the second type of equipment is sonar equipment.

6. The method according to claim 2, characterized in that The method further comprises: The multiple longitudinal sections and multiple transverse sections are compared with the trench design parameters to determine whether the current trench state meets the design requirements, and an early warning is issued for the determination result.

7. A system for detecting underwater pipe trenches and obstacles, characterized in that: The system is used to implement the method according to any one of claims 1 to 6, wherein the system comprises: The first type of equipment is used to collect point cloud information representing the depth distribution characteristics of underwater trenches and obstacles in real time; The second type of equipment is used to collect real-time image information that characterizes the reflection intensity response characteristics of underwater trenches and obstacles; The data processing device is used to combine the point cloud information and the image information to comprehensively analyze the trench status information including the trench position, width, depth, flatness and internal obstacles.

8. The system according to claim 7, characterized in that The first type of equipment is multi-beam depth sounding equipment, and the second type of equipment is sonar equipment.

9. The system according to claim 7 or 8, characterized in that: The data processing device comprises: a point cloud information processing module, wherein the point cloud information processing module is executed according to the following steps: Using the point cloud information, a three-dimensional model is constructed to preliminarily identify the overall condition of the trench and the location and shape of trench obstacles; a plurality of longitudinal sections and a plurality of transverse sections extracted from the three-dimensional model; Initial trench section information based on point clouds is obtained according to the multiple longitudinal sections and the multiple transverse sections.

10. The system according to claim 9, characterized in that The data processing device comprises: an image information processing module, wherein the image information processing module is executed according to the following steps: Based on the collected image information characterizing the strength distribution of the rebound signal, the location of the trench and the width and shape of the upper part of the trench can be preliminarily identified. Based on this, the characteristic information of the obstacles inside the trench based on the signal strength distribution can be obtained.

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