Manhole sonar scanning system and manhole structure detection method

Abstract

The application relates to the technical field of underwater detection, and discloses a manhole sonar scanning system and a manhole structure detection method.The manhole sonar scanning system comprises a wellhead fixing support, an automatic lowering and depth control module, a sonar scanning module, a sensing module and a control and data processing module; the wellhead fixing support is installed at the wellhead of a target manhole; the automatic lowering and depth control module is connected with the sonar scanning module; and the control and data processing module is connected with the automatic lowering and depth control module, the sonar scanning module and the sensing module respectively.The application improves the stability and accuracy of information exploration and data modeling of the flow direction and topological relationship of the underwater space of a manhole under high water level sonar detection.

Description

Technical Field

[0001] This invention relates to the field of underwater inspection technology, specifically to a sonar scanning system for inspection wells and a method for inspecting the structure of inspection wells. Background Technology

[0002] In urban drainage systems, inspection wells play a crucial role in connecting, turning, and hydraulically regulating multiple pipelines. Their internal spatial form and pipeline connections are key indicators for assessing the operational status and structural safety of the pipe network. However, under actual operating conditions, many inspection wells are constantly at high water levels or even completely filled with water, making the internal environment invisible, inaccessible, and untouchable, resulting in a long-term lack of information about their underwater structures.

[0003] The detection of related inspection wells often uses fixed scanning parameters, without taking into account the complexity of the internal structure of the inspection well and the changes in the water flow environment. This can easily lead to insufficient sampling in key structural areas and redundant data in regular areas, affecting detection efficiency and modeling accuracy, and seriously restricting the stability and reliability of sonar detection results. Summary of the Invention

[0004] This invention provides a sonar scanning system for inspection wells and a method for detecting the structure of inspection wells, in order to solve the problem that related methods for detecting the structure of inspection wells severely restrict the stability and reliability of sonar detection results.

[0005] In a first aspect, the present invention provides a sonar scanning system for inspection wells, the system comprising: a wellhead fixing bracket, an automatic lowering and depth control module, a sonar scanning module, a sensing module, and a control and data processing module; the wellhead fixing bracket is installed at the wellhead of the target inspection well; the automatic lowering and depth control module is connected to the sonar scanning module; the control and data processing module is connected to the automatic lowering and depth control module, the sonar scanning module, and the sensing module respectively; The sonar scanning module is used to collect sonar echo information from angle to angle during the automatic descent and depth control module descent process; the sonar echo information includes echo distance and echo energy information; The sensing module is used to collect equipment posture information, telescopic rod lowering depth information, and water flow direction and velocity information during the automatic lowering and depth control module lowering process; The control and data processing module is used to adaptively control the automatic descent and depth control module and the sonar scanning module based on sonar echo information and equipment attitude information, until the sonar scanning module is lowered to the bottom of the well and the sonar scanning module stops scanning.

[0006] This invention provides a sonar scanning system for inspection wells. A wellhead fixing bracket is installed at the target inspection wellhead, enabling a stable connection and providing a robust and precise installation reference for the entire system. This avoids equipment misalignment caused by bracket loosening during the inspection process. An automatic lowering and depth control module is connected to the sonar scanning module, enabling smooth lowering and precise depth control of the sonar scanning module. It can adjust the lowering speed and control the lowering stroke according to preset rules, ensuring the sonar scanning module is gradually lowered along a preset trajectory until it reaches the bottom of the well, guaranteeing the orderly scanning process, reducing water flow interference, and ensuring scanning stability. Furthermore, a sensing module collects equipment attitude information, telescopic rod lowering depth information, and water flow direction and velocity information. Based on the sonar echo information, equipment attitude information, and water flow direction and velocity information, the control and data processing module adaptively controls the automatic lowering and depth control module and the sonar scanning module, enabling adaptive focusing on structurally complex areas and improving the stability and reliability of the inspection results.

[0007] Secondly, the present invention provides a method for detecting the structure of a manhole, applied to the control and data processing module of a manhole sonar scanning system of the first aspect or any corresponding embodiment described above, the method comprising: Acquire sonar echo information, equipment attitude information, and water flow direction and velocity information collected during the automatic lowering and depth control module inside the target inspection well; The scanning status is determined based on sonar echo information and equipment attitude information; Based on the scanning status and water flow direction and velocity information, the sonar scanning parameters of the automatic lowering and depth control module and the sonar scanning module are adaptively adjusted and anti-water flow disturbance control is performed until the sonar scanning module is lowered to the bottom of the well, and the sonar scanning module is controlled to stop scanning. Valid echo information is obtained by identifying continuous abnormal echoes based on sonar echo information. The lowering depth of the telescopic boom, the plane coordinates of the wellhead, and the absolute elevation of the wellhead are obtained. Based on the water flow direction and velocity information, effective echo information, lowering depth of the telescopic boom, plane coordinates of the wellhead, and absolute elevation of the wellhead, a three-dimensional model of the inspection well is established.

[0008] This invention provides a sonar scanning method for inspection wells, which simultaneously acquires sonar echo information and equipment attitude information. It can perceive changes in the internal structure and water flow disturbance in the inspection well in real time, overcoming the limitation of not being able to perceive structural complexity and changes in the water flow environment. Based on sonar echo and attitude information, the scanning state is determined, distinguishing between structurally stable regions, structurally changing regions, and water flow disturbance regions, achieving accurate identification of different detection environments. The scanning parameters are adaptively adjusted according to the scanning state, and anti-water flow disturbance control is implemented. It can dynamically adjust the detection accuracy according to the structural complexity, and simultaneously suppress disturbances based on water flow direction and velocity information. The attitude shift and data distortion caused by water flow disturbance directly improve the stability and data reliability of the detection process. By continuously identifying and eliminating abnormal echoes from sonar echo information, transient interference such as suspended matter and air bubbles can be removed, ensuring that the echo data used in modeling is true and effective, further improving the reliability of detection results. By combining effective echo information, lowering depth, wellhead plane coordinates and absolute elevation to establish a three-dimensional model, the detection results have a unified and accurate absolute spatial reference, avoiding model deviations caused by the lack of absolute positioning, ensuring the accuracy and consistency of the three-dimensional model, and improving the stability and reliability of the detection results. Attached Figure Description

[0009] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the structure of a manhole sonar scanning system according to an embodiment of the present invention; Figure 2 This is a structural block diagram of the automatic lowering and depth control module according to an embodiment of the present invention; Figure 3 This is a structural block diagram of a sonar scanning module according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the external shape of the wing-shaped outer shell body according to an embodiment of the present invention; Figure 5 This is a structural block diagram of the sensing module according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a three-dimensional structural scan of the space inside a manhole according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the first process of a manhole structure detection method according to an embodiment of the present invention; Figure 8This is a schematic diagram of the pipeline topology according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the second process of a manhole structure detection method according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the third process of a manhole structure inspection method according to an embodiment of the present invention. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0012] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0013] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0014] Structural inspection of manholes still relies primarily on manual visual inspection and optical equipment, including manual inspection down into the well, closed-circuit television (CCTV) inspection, quick-view (QV) inspection, and 3D laser scanning. These methods generally depend on low water levels or clear water environments and are ineffective under high water levels, turbid water, and continuous flow conditions. In particular, they cannot obtain effective information about the underwater structure of the well bottom and walls, as well as pipe interfaces, forcing the underwater components of manholes to be simplified or even completely ignored during operational assessments.

[0015] To overcome the limitations of manual and optical methods in underwater environments, sonar detection technology has been gradually introduced into the field of drainage pipe network inspection. However, related sonar detection equipment is mainly designed for horizontal pipes, and often uses towed sonar or sonar mounted on powered robots to obtain information on the cross-section or inner wall morphology of the pipe. The above technologies can achieve certain results in horizontal and regular pipe sections. When this type of technology is applied to the environment of inspection wells, which are mainly vertical spaces with multiple branch pipes and obvious geometric changes, it is difficult to establish a stable spatial reference in the inspection well. The scanning posture and position are subject to great uncertainty due to water flow and equipment movement, making it difficult to unify the data obtained at different depths and times into the same coordinate system.

[0016] On the other hand, most sonar systems focus on acquiring two-dimensional acoustic images at a single height or in a single profile, lacking an effective mechanism for unified registration and overlay of scanning results at different water depths. This makes it difficult for the results to truly reflect the overall spatial morphology of the inspection well, let alone accurately describe the spatial topological relationship between the inspection well and the connected pipeline. Secondly, multibeam or imaging sonar systems are complex in structure and expensive. Moreover, in an environment like an inspection well where the scale is limited and the geometric features of the target are relatively regular, their high complexity does not bring technical benefits commensurate with the cost.

[0017] Furthermore, in full-water inspection wells, hydraulic factors such as pipeline flow, vortices within the well, and shear flow are prevalent. The water flow exerts periodic or random impacts on the detection equipment, causing slight changes in the sonar transducer's attitude, which in turn leads to measurement errors in echo distance and direction. Related inspections of inspection wells often employ fixed scanning parameters, failing to consider the complexity of the well's internal structure and variations in the water flow environment. This easily results in insufficient sampling in critical structural areas and redundant data in regular areas, affecting detection efficiency and modeling accuracy. The lack of effective identification and compensation mechanisms severely restricts the stability and reliability of sonar detection results.

[0018] Therefore, there is an urgent need for a sonar detection system and method that is designed for full-water inspection wells, can achieve continuous scanning and 3D modeling under a stable spatial reference, and has the ability to adaptively adjust scanning parameters, resist water flow disturbance, and invert the direction of incoming flow, in order to solve the above problems.

[0019] This embodiment provides a sonar scanning system for inspection wells, such as Figure 1 As shown, it includes: a wellhead fixing bracket 101, an automatic lowering and depth control module 102, a sonar scanning module 103, a sensing module 104, and a control and data processing module 105; the wellhead fixing bracket 101 is installed at the wellhead of the target inspection well; the automatic lowering and depth control module 102 is connected to the sonar scanning module 103; the control and data processing module 105 is connected to the automatic lowering and depth control module 102, the sonar scanning module 103, and the sensing module 104 respectively.

[0020] Among them, such as Figure 1 As shown, the wellhead fixing bracket 101 adopts an adjustable tripod support structure, with anti-slip rubber pads installed at the top of the legs. It is firmly locked to the inner wall of the well shaft or the edge of the wellhead of various specifications by a tightening mechanism. The center positioning and locking mechanism in the wellhead fixing bracket 101 is located at the center of the bracket and is used to determine the vertical center axis of the inspection well. The center positioning and locking mechanism also includes a quick clamping device, which is used to rigidly lock the first section (or base) of the telescopic rod to the bracket at the start of the inspection, ensuring that the starting origin of the entire lowering system is strictly aligned with the wellhead fixing coordinate system.

[0021] The sonar scanning module 103 is used to collect sonar echo information from angle by angle during the automatic descent and depth control module 102 descent process; the sonar echo information includes echo distance and echo energy information.

[0022] The sensing module 104 is used to collect equipment posture information, telescopic rod lowering depth information, and water flow direction and velocity information during the automatic lowering and depth control module 102 lowering process.

[0023] The control and data processing module 105 is used to adaptively control the automatic lowering and depth control module 102 and the sonar scanning module 103 based on sonar echo information, equipment attitude information, and water flow direction and velocity information, until the sonar scanning module 103 is lowered to the bottom of the well and the sonar scanning module 103 stops scanning.

[0024] Specifically, the control and data processing module 105 includes a main control processor, a data interface, a storage unit, and a mobile power supply. It is connected to other units via wired communication and wirelessly connected to a host computer (tablet, mobile computer). It is used to collect raw data, perform simple processing, and transmit it to the host computer. It also provides adaptive control for the sonar scanning module 103 and the automatic lowering and depth control module 102, that is, to coordinate the lowering of the telescopic pole and the sonar scanning.

[0025] Furthermore, the coordinated control mechanism for the telescopic pole lowering and sonar scanning includes: "telescopic-circular scan" coupled scanning mode: the sonar scanning module 103 executes a continuous spiral scanning path, horizontally: single beam 360° circular scan, vertically: the telescopic pole extends continuously; segmented constant depth scanning mode: after each fixed length of extension, the telescopic pole stops extending, completes a full circle of circular scan, and then continues to extend and retract. This mode is suitable for scenarios requiring high-precision pipe opening identification.

[0026] Furthermore, based on the sonar echo distance change rate, echo energy change rate, and attitude disturbance intensity, the descent speed, ring sweep angular velocity, and sampling frequency are jointly adjusted using adaptive adjustment of scanning parameters and anti-water flow disturbance control strategies.

[0027] This embodiment provides a sonar scanning system for inspection wells. A wellhead fixing bracket is installed at the target inspection wellhead, enabling a stable connection and providing a robust and precise installation reference for the entire system. This avoids equipment misalignment caused by bracket loosening during the inspection process. An automatic lowering and depth control module is connected to the sonar scanning module, enabling smooth lowering and precise depth control. It adjusts the lowering speed and controls the lowering stroke according to preset rules, ensuring the sonar scanning module gradually descends along a preset trajectory until it reaches the bottom of the well. This ensures the orderly operation of the scanning process, reduces water flow interference, and guarantees scanning stability. Furthermore, a sensing module collects equipment attitude information, telescopic rod lowering depth information, and water flow direction and velocity information. Based on the sonar echo information, equipment attitude information, and water flow direction and velocity information, the control and data processing module adaptively controls the automatic lowering and depth control module and the sonar scanning module. This allows for adaptive focusing on structurally complex areas, improving the stability and reliability of the inspection results.

[0028] In some alternative implementations, such as Figure 2 As shown, the automatic lowering and depth control module 102 includes: a multi-segment telescopic rod 1021, an electric drive assembly 1022, a telescopic position detection assembly 1023, and an anti-rotation guide structure 1024.

[0029] Specifically, the multi-segment telescopic rod 1021 is coaxially rigidly set, each segment of the telescopic rod adopts a hollow round tube structure, the material is carbon fiber composite material, the adjacent segments are sleeve-type sliding fit, and the inner wall is provided with wear-resistant guide bushing to reduce friction and limit displacement.

[0030] Furthermore, the last telescopic section of the multi-segment telescopic rod 1021 integrates a rotational power and signal coupler, which transmits power and control signals to the rotary motor of the sonar scanning module 103, while simultaneously transmitting back sonar data, attitude sensing sensor data, and water depth probe data.

[0031] The electric drive assembly 1022 is used to drive the multi-segment telescopic rod 1021 to extend sequentially segment by segment.

[0032] Specifically, the electric drive assembly 1022 is a linear electric push rod integrated drive, with each telescopic rod segment corresponding to at least one independent drive channel, or a cascaded drive structure; the motor controller receives the speed command from the control and data processing module 105, and controls each rod segment to extend sequentially according to preset logic: the upper segment extends first, then the lower segment extends in sequence, and the retraction is performed in the reverse order; wherein, the sequential extension logic can be expressed as: (1) In the above formula, for The total length of the drop-off at any given moment. For the first The telescopic pole at any time The extension length, This represents the number of segments on the telescopic pole.

[0033] The telescopic position detection component 1023 is used to measure the relative displacement between adjacent telescopic rods 1021.

[0034] Specifically, the telescopic position detection component 1023 includes a linear displacement sensor, a magnetic coding tape or grating ruler, and a reading head; wherein, a linear displacement sensor is installed in each telescopic rod segment 1021, a magnetic coding tape or grating ruler is laid at a specific position (such as the outer wall) of each rod segment, and a reading head is installed at the corresponding position of the adjacent outer rod. Through the above components, the relative displacement between any two adjacent rod segments can be measured in real time and absolutely.

[0035] Furthermore, the vertical coordinates of the sonar scanning module 103 for: (2) The anti-rotation guide structure 1024 is used to control the extension and retraction of the multi-segment telescopic rod 1021 along a preset axial direction.

[0036] Specifically, the anti-rotation guide structure 1024 adopts an anti-rotation keyway structure. An anti-rotation keyway structure is set between adjacent rod segments to ensure that each rod segment only extends and contracts along the axial direction and does not rotate relative to each other, thus ensuring the consistency between the sonar ring scan angle and the azimuth sensor output.

[0037] This embodiment provides a sonar scanning system for inspection wells, which introduces a multi-segment telescopic rod sequential extension and retraction mechanism into the system. This enables the continuous and automatic lowering of the sonar probe under a fixed spatial reference, eliminating the need for manual intervention during the scanning process and ensuring spatial consistency of vertical data. This structure overcomes the limitations of traditional manual handheld or winch-type lowering in terms of accuracy and stability.

[0038] In some alternative implementations, such as Figure 3 As shown, the sonar scanning module 103 includes: an airfoil-shaped housing body 1031, and a single-beam sonar transducer 1032, a ring-scan rotary drive mechanism 1033, and a rotation angle sensor 1034 disposed inside the sealed chamber of the airfoil-shaped housing body 1031; the single-beam sonar transducer 1032 is arranged radially along the airfoil-shaped housing body 1031; the upper end of the ring-scan rotary drive mechanism 1033 is coaxially connected to the end telescopic rod of the multi-segment telescopic rod 1021 via a drive shaft, and the lower output shaft of the ring-scan rotary drive mechanism 1033 is connected to the single-beam sonar transducer 1032; the rotation angle sensor 1034 is coaxially mounted on the rotation shaft of the ring-scan rotary drive mechanism 1033.

[0039] Among them, such as Figure 4 As shown, the airfoil body 1031 is an axisymmetric spiral body, and its meridional plane (section through the axis) profile is an airfoil section. The airfoil body 1031 preferably adopts a symmetrical airfoil with good stability in low-speed fluids, providing good structural strength and flow characteristics. It is cast from high-strength, corrosion-resistant engineering plastics (such as polycarbonate), and the interior is a sealed chamber. Its streamlined shape can effectively guide the water flow smoothly and reduce the irregular shaking caused by non-impact turbulence. When there is a stable incoming flow impact, due to symmetry, the angle between the incoming flow direction and the shell axis (i.e., vertical) will be directly and linearly converted into a predictable lateral force, thereby generating a stable and measurable attitude deflection angle. High-polymer elastic anti-collision coating layers are set at the leading edge, lower edge and key circumferential parts of the airfoil, with built-in energy absorption buffer structures, which play a role in anti-collision and buffer design.

[0040] The ring sweep rotary drive mechanism 1033 uses a waterproof stepper motor to directly drive the transducer to rotate around the vertical axis, and the waterproof stepper motor is placed in a sealed chamber.

[0041] The single-beam sonar transducer 1032 is used to collect echo distance and echo energy information at each angle.

[0042] Specifically, the operating frequency of the single-beam sonar transducer 1032 is selected to be 1-2MHz to achieve a spatial resolution of about 10-30cm in turbid water. The beam opening angle is a narrow beam (e.g., 3°×15°, narrow horizontally and wide vertically) to obtain a higher azimuth resolution.

[0043] Furthermore, the sonar transducer completes a 360° circumferential scan under the action of the circumferential scanning rotary drive mechanism 1033, and collects echo distance and echo energy information from angle to angle.

[0044] The rotation angle sensor 1034 is used to collect the angular position information of the single-beam sonar transducer 1032.

[0045] Specifically, the rotation angle sensor 1034 adopts an absolute encoder, which is installed on the rotating shaft and outputs the current azimuth angle β (unit: degrees, 0°≤β<360°) of the single-beam sonar transducer 1032 in real time, that is, the angular position information of the single-beam sonar transducer 1032.

[0046] Furthermore, the specific data output by the sonar scanning module 103 should cover the following four dimensions: (1) Core acoustic measurement data (core data layer): The physical quantities directly acquired by the single-beam sonar transducer 1032 are the cornerstone of subsequent modeling. Specifically, they include: Echo distance: calculated by the time-to-flight (TOF) and underwater sound velocity, representing the spatial distance from the probe center to the well wall or obstacle; Echo amplitude / energy intensity: reflects the acoustic hardness of the reflecting surface; for example, the echo intensity of a concrete well wall is usually higher than that of silt, and the echo intensity of a metal ladder is the highest, which is used to identify the material of the structure inside the well; Angular position Φ: the current absolute or relative encoder angle of the ring sweep motor (0°~360°); Full echo waveform data: in advanced mode, the energy distribution on the entire time axis is recorded to distinguish "multiple echoes" or penetrating suspended objects.

[0047] (2) Spatial positioning and attitude data (spatial reference layer) Since the sonar is in the process of being lowered, the spatial coordinates of each frame of data must be recorded: angular position: the current absolute or relative encoder angle of the ring sweep motor (0°~360°); lowering depth: the real-time vertical displacement fed back by the electric telescopic rod encoder and measuring device; real-time attitude angle: the pitch, roll and heading angles obtained by the built-in IMU (attitude sensor), which is the key to correcting the echo distortion caused by water flow disturbance; geographical azimuth angle θ, used to align the scan point cloud with the real geographical location.

[0048] (3) System control and environmental parameters (state monitoring layer): background parameters used to support the execution of adaptive algorithms: real-time scanning parameters: record the angular velocity, descent speed and sampling frequency (or sampling time T) corresponding to the sampling point; water depth / pressure value: optional pressure sensor, used as depth verification in addition to the length of the telescopic rod.

[0049] (4) Derivative processing data (application output layer) after being processed by the algorithm generates structured information: polar coordinate point cloud, i.e., original three-dimensional points; structural feature markers: such as Boolean markers for “pipe opening area”, “bottom hole mutation” or “suspected obstacle” identified by the algorithm; continuity evaluation indicators: distance change rate and energy change rate.

[0050] This embodiment provides a sonar scanning system for inspection wells. The sonar scanning module adopts a symmetrical airfoil shell, which can automatically form torque balance under the action of incoming flow, reducing attitude deflection. The single-beam sonar transducer is radially arranged, which can accurately collect echo distance and energy information at each angle, ensuring the accuracy of structural detection. The circumferential scanning rotation drive mechanism is coaxially connected to the end telescopic rod, which ensures smooth transmission and no eccentricity, ensuring a regular 360° circumferential scanning trajectory. The rotation angle sensor is coaxially installed, which can accurately obtain the angular position in real time, avoid angle errors, and improve the consistency of point cloud data.

[0051] In some alternative implementations, such as Figure 1 and Figure 5As shown, the sensing module 104 includes: a pole posture sensing component 1041, a scanning head posture sensing component 1042, a water depth probe 1043, and a flow field measurement unit 1044. The pole posture sensing component 1041 is installed at the root of the first telescopic pole in the multi-segment telescopic pole 1021, and is used to collect the basic posture information of the pole body of the telescopic pole 1021.

[0052] Specifically, the rod attitude sensing component 1041 is installed at the root of the first telescopic rod 1021 to monitor the basic attitude of the rod system. It integrates a high-performance MEMS (Micro-Electro-Mechanical System) sensor with a three-axis gyroscope and a three-axis accelerometer to output the roll angle φ, pitch angle ω and angular velocities φ' and ω' (unit: degrees, degrees / second) of the telescopic rod 1021 in real time, which is the basic attitude information of the rod. The basic attitude information of the rod is used to correct the depth and orientation deviation caused by the overall tilt of the rod system, provide an overall reference for the scanning data, and ensure the consistency of the scanning trajectory with the center axis of the wellhead.

[0053] The scanning head attitude sensing component 1042 is located inside the sealed chamber of the airfoil body 1031 and is used to collect attitude information of the sonar scanning module 103.

[0054] Specifically, the scanning head attitude sensing component 1042 outputs the roll angle, pitch angle and angular velocity of the sonar scanning module 103 in real time, that is, the attitude information of the sonar scanning module 103. The attitude information of the sonar scanning module 103 is directly used to correct the attitude deviation of the sonar scanning module 103 (such as roll, pitch, etc.) and avoid the measurement error of echo distance and angular position caused by its own attitude change.

[0055] A depth probe 1043 is installed on the outer surface of the airfoil body 1031 and is used to collect information on the lowering depth of the telescopic rod 1021.

[0056] Specifically, the depth probe 1043 can be a pressure-type depth sensor integrated into the sonar scanning module 103 to measure the water depth at which the scanning head is located in real time. (Unit: meters) is used to verify depth and sense changes in water level.

[0057] The flow field measurement unit 1044 is set on the outer surface of the airfoil body and is used to collect information on the direction and velocity of water flow during sonar scanning.

[0058] Specifically, a flow field measurement unit 1044 is added to the airfoil sonar ring scanning structure. The flow field measurement unit 1044 includes: an orthogonal dual-axis rotor assembly: two sets of mutually orthogonal micro-mechanical rotors (such as X-axis rotors and Y-axis rotors arranged in a cross shape) are horizontally embedded on the top or bottom of the airfoil shell of the sonar scanning unit (avoiding the sonar beam coverage angle). The rotor blades adopt a symmetrical straight plate or bidirectional spiral design, so that they exhibit opposite rotation directions under forward and reverse flow; a Hall-encoded velocity measurement assembly: a bipolar magnetic ring is integrated on the shaft of each rotor, and a dual Hall sensor (AB phase) with a phase difference of 90° is assembled at the stator end. The dual Hall sensor can not only collect the rotation frequency (speed) of the rotor at high frequency, but also accurately output the absolute rotation direction (clockwise or counterclockwise) of the rotor under the impact of water flow by determining the pulse lead / lag relationship between phase A and phase B; and an anti-clogging guide shield: a streamlined shield with a grid is provided on the outside of the rotor assembly to filter large pieces of suspended debris and guide the water flow, preventing debris from entangled and causing the rotor to jam.

[0059] This embodiment provides a sonar scanning system for inspection wells. The rod attitude sensing component is located at the base of the first telescopic rod section, enabling it to acquire the overall attitude of the rod system. This effectively corrects depth and azimuth deviations caused by the overall tilt of the rod system, providing a stable overall reference for the scanning data and ensuring the scanning trajectory is consistent with the wellhead axis. The scanning head attitude sensing component is located inside the scanning unit, directly monitoring the attitude deviation of the sonar scanning module itself, correcting echo distance and angle measurement errors in real time, avoiding echo distortion caused by water flow disturbance, and improving detection accuracy. The water depth probe is located outside the scanning module, allowing real-time measurement of water depth and verification of the telescopic rod's lowering depth, accurately sensing water level changes and improving the reliability of depth measurement. The flow field measurement unit achieves high-precision synchronous measurement of two-dimensional water flow velocity and direction through an orthogonal dual-axis rotor and dual Hall encoder velocity measurement scheme. The bidirectional blade design and anti-clogging shield solve the problems of distinguishing between forward and reverse flows and preventing debris blockage. Furthermore, the installation position does not affect the sonar beam and can be seamlessly integrated with existing sonar ring scanning structures. Without increasing system complexity, it provides key flow field data support for sonar echo error correction, significantly improving measurement reliability and detection accuracy in complex downhole environments. The aforementioned structure can automatically stop scanning when the sonar scanning module reaches the bottom of the well, achieving fully automated control, improving detection accuracy, and reducing errors caused by manual intervention.

[0060] In some alternative implementations, it also includes: Measurement module 106 is installed on top of wellhead fixed support 101 and connected to control and data processing module 105. It is used to acquire the wellhead plane coordinate information and wellhead absolute elevation information of the target inspection well, and transmit the wellhead plane coordinate information and wellhead absolute elevation information to control and data processing module 105. The control and data processing module 105 establishes a three-dimensional model of the inspection well based on sonar echo information, telescopic rod 1021 lowering depth information, wellhead plane coordinate information and wellhead absolute elevation information.

[0061] Specifically, the measurement module 106 includes: an RTK (Real-time kinematic) GNSS (Global Navigation Satellite System) antenna, an RTK receiving unit, an elevation calculation unit, and an azimuth sensing unit; wherein, the RTK GNSS antenna is mounted on the top of the wellhead fixed support 101; the RTK receiving unit communicates with an external reference station or CORS (Continuous Operational Reference System); the elevation calculation unit is used to obtain the absolute elevation information of the wellhead; the azimuth sensing unit is used to obtain the azimuth information of the sonar scanning module 103, and the azimuth sensing unit is equipped with a magnetic direction sensor, which adopts an anti-geomagnetic interference design.

[0062] Furthermore, obtain the planar coordinate information of the wellhead location. Wellhead absolute elevation information and azimuth And serve as the absolute spatial starting point for the inspection well data; the absolute elevation information of the wellhead is the absolute elevation of the wellhead location relative to the reference horizontal plane within the geographic information system; azimuth angle It is used to map sonar scan results to a geographic true north reference direction, thereby achieving a true spatial orientation representation of structures and nozzles.

[0063] Furthermore, the absolute elevation of the sonar scanning module 103 at any given time for: (3) in, This refers to the lowering depth of the telescopic rod 1021.

[0064] This embodiment provides a sonar scanning system for inspection wells. Through a measurement module, it achieves spatial association between the 3D model of the inspection well and the geographic coordinate system, ensuring unified coordinate alignment between models of different inspection wells. Engineering measurements of parameters such as pipe head elevation, well depth, and sediment thickness are also performed. Therefore, the detection results can directly serve municipal pipeline network GIS systems, defect assessment, and construction decisions, demonstrating significant engineering practicality. Furthermore, by employing a wellhead benchmark and a multi-segment telescopic rod automatic lowering mechanism, after establishing a stable spatial benchmark at the wellhead, the sonar scanning module is continuously lowered at a predetermined speed via a motor-driven telescopic rod. Compared to manual handheld or intermittent positioning scanning methods: the sonar probe maintains a fixed spatial relationship with the wellhead benchmark throughout the entire lowering process; there is no human-induced jitter or repeated positioning errors between different water depth positions; horizontal and vertical sampling are synchronized, avoiding discrete discontinuities between slices; the spatial coverage integrity of the well wall, pipe head transition zone, and complex structures is improved; and the 3D model is reconstructed from continuous data rather than discrete interpolation, resulting in higher geometric realism. It significantly outperforms traditional methods in terms of vertical spatial consistency, slice splicing accuracy, and overall 3D model stability.

[0065] In some alternative implementations, it also includes: The visualization analysis module 107, connected to the control and data processing module 105, is used to display the three-dimensional model of the inspection well.

[0066] Specifically, the visualization analysis module 107 can be a tablet, mobile computer (workstation), etc., used as a host computer to display real-time two-dimensional scanning results and three-dimensional modeling calculation and analysis.

[0067] The following specific embodiment illustrates the workflow of a well inspection sonar scanning system.

[0068] Example 1: The workflow of a manhole sonar scanning system includes the following steps: S1: System Deployment and Wellhead Benchmark Establishment: Before conducting the inspection, the wellhead of the inspection well must be cleaned to ensure that the wellhead edges are unobstructed and the structure is intact.

[0069] The wellhead fixing bracket is installed at the wellhead of the inspection well. The fixing bracket adopts an adjustable three-jaw or four-jaw structure and forms a stable fixed connection with the inner wall or edge of the wellhead through mechanical locking. After fixing, the geometric center of the wellhead fixing bracket is used as the spatial reference origin for this inspection, and a reference coordinate system consistent with the plane of the wellhead is established.

[0070] Simultaneously, the integrated measurement module is activated to acquire the planar coordinates and elevation information of the manhole opening, which will then be used as the absolute spatial reference for the subsequent 3D model.

[0071] S2: Automatic lowering unit initialization: Connect the sonar scanning module to the automatic lowering and depth control module. The lowering unit includes multiple electric telescopic rods, and each telescopic rod extends in a preset order.

[0072] Before the descent begins, the system completes the following initialization operations: calibrating the zero point of the depth probe; calibrating the attitude sensor and heading sensor.

[0073] S3: Layered automatic lowering and scanning trigger: The control system controls the telescopic rod to extend segment by segment according to the preset lowering step length, so that the sonar scanning module moves vertically downward along the center axis of the wellhead.

[0074] When the sonar scanning module reaches the water surface, the depth probe touches the water and sends out an alert. The system records the distance between the water surface and the wellhead, automatically pauses the lowering operation, and enters the scanning preparation state.

[0075] S4: Water depth spiral circumferential scan: Starting from the water surface, the telescopic rod slowly descends according to the preset rules, driving the single-beam sonar transducer to perform a 360° circumferential scan around the vertical axis, collecting sonar echo data point by point in different azimuth directions, including echo distance and echo energy information.

[0076] During the scanning process, water depth and attitude information are collected simultaneously. During the circumferential scanning process, the control system analyzes the changes in echo distance and echo energy of adjacent azimuth angles in real time, and combines the attitude change data obtained by the attitude sensor to determine the current scanning status.

[0077] When a significant structural change is detected, the scanning speed and descent speed are automatically reduced, and the sampling density is increased. When water flow disturbance is detected, which causes an aggravation of attitude change, the scanning speed is automatically reduced, the sampling time is extended, and the descent action is paused if necessary until the device attitude returns to stability before continuing the scan.

[0078] For areas with obvious anomalies or areas of particular interest, you can switch to constant depth scanning mode for a more thorough scan.

[0079] S5: The sensing module monitors the attitude changes of the sonar scanning module in real time. When the attitude deviation or vibration intensity exceeds the threshold, the control and data processing module performs attitude compensation correction on the scanning data. At the same time, combined with the symmetrical airfoil structure of the sonar scanning module shell, the impact and deflection of water flow on the equipment are reduced, thereby ensuring the stability and repeatability of the spiral scanning trajectory.

[0080] S6: Identification and Removal of Continuous Abnormal Echoes: Based on the data continuity characteristics along the depth direction, echo points that appear only at a single scanning angle or a single spiral position and do not repeat at adjacent depth positions are identified as abnormal echoes. These abnormal echoes are usually caused by suspended objects, bubbles, or transient interference and are removed in the subsequent modeling process to improve the stability of the overall data.

[0081] S7: Scanning End and System Retrieval: When the sonar scanning module is lowered to the preset maximum depth or close to the bottom of the well, the control and data processing module stops the lowering action; then, the electric telescopic rod retracts in reverse order, retrieving the sonar scanning module to the wellhead position, completing the entire scanning process.

[0082] S8: 3D model generation of inspection well: For valid echo data that has passed the screening, spatial positioning is performed based on the following information: current scanning azimuth; echo distance; current lowering depth; system attitude information.

[0083] The polar coordinate data obtained by single-beam sonar is converted into three-dimensional rectangular coordinate data to generate a continuously distributed three-dimensional point cloud.

[0084] The three-dimensional point cloud data obtained by continuous spiral scanning is superimposed and processed to construct a complete three-dimensional model of the inspection well.

[0085] Three-dimensional structural scan images of the space inside the inspection well, such as Figure 6 As shown, the 3D model and topology analysis can be directly interfaced with the urban pipeline network GIS (Geographic Information System) coordinate system.

[0086] S9: Structure Recognition and Topology Establishment Module: Based on the characteristics of sonar echoes in circumferential continuity and consistency of multi-depth slices, it identifies the location of manhole walls and pipe openings, measures pipe diameter, pipe elevation and other information, and combines azimuth information to establish a spatial topology model between manholes and connecting pipes, including plan views and longitudinal sections, and can export CAD files.

[0087] According to an embodiment of the present invention, an embodiment of a method for detecting manhole structures is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0088] This embodiment provides a method for detecting the structure of a manhole, which can be used in the control and data processing module of the aforementioned manhole sonar scanning system. Figure 7This is a flowchart of a manhole structure inspection method according to an embodiment of the present invention, such as... Figure 7 As shown, the process includes the following steps: Step S701: Acquire sonar echo information, equipment attitude information, and water flow direction and velocity information collected during the automatic lowering and depth control module process inside the target inspection well.

[0089] Specifically, it synchronously collects sonar echo information, rotation angle, pitch angle, water depth and azimuth information, and provides engineering parameter settings to achieve control of sonar range, amplitude, ring scan rate and pitch angle.

[0090] Furthermore, the rotor rotation direction and speed are collected by a flow meter installed at the rotor in the flow field measurement unit. Combined with IMU attitude data, the absolute water flow direction inside the inspection well is inverted. The specific steps are as follows: Define a local Cartesian coordinate system fixed to the sonar scanning module: real-time acquisition of the rotational speeds of the X-axis and Y-axis rotors. and the direction of rotation (indicated by positive or negative signs), through a pre-calibrated hydrodynamic transmission coefficient. Calculate the positive alternating velocity components in the local coordinate system: (4) (5) In the above formula, This represents the water flow velocity component in the X direction. This represents the water flow velocity component in the Y direction.

[0091] For example: when water flows in the positive direction of the X-axis, the rotor rotates in the forward direction. During reverse impact, the rotor reverses direction. The same applies to the Y-axis.

[0092] The synthesis of local flow direction angles is based on positive alternating velocity components, synthesizing the relative water flow impact azimuth angle in the local coordinate system. (Unit: degrees) and merging velocity : (6) (7) Among them, atan2 is the arctangent function in the four quadrants, which can uniquely determine the relative flow direction within 0~360° based on the combination of forward and reverse rotation of the rotor.

[0093] Absolute geographic flow mapping and spatial topology fusion: Obtaining the absolute azimuth of the current sonar scan unit output by the measurement module. (i.e., the current angle between the equipment and true north), calculate the absolute flow direction angle of the water flow in the geographic coordinate system. : (8) Based on the absolute direction angle of water flow in the geographic coordinate system Determine the direction of water flow.

[0094] Step S702: Determine the scanning status based on sonar echo information and device attitude information.

[0095] Specifically, the echo distance change rate is calculated based on sonar echo information. The echo distance change rate is used to reflect structural changes or the degree of echo instability, and its calculation formula is as follows: (9) (10) In the above formula, Indicates the rate of change of echo distance. Indicates the rate of change of echo energy. Indicates the first At the first lowering height, the first The echo distance obtained in the sampling direction (current angle) at each angle. Indicates the first At the first lowering height, the first The echo distance obtained in the sampling direction (the previous adjacent scanning angle) at each angle. Indicates the first At the first lowering height, the first The echo amplitude or energy intensity corresponding to the sampling direction (current angle) at each angle. Indicates the first At the first lowering height, the first The echo amplitude or energy intensity corresponding to each angular sampling direction (the previous adjacent scanning angle), This indicates the interval between adjacent sampling angles.

[0096] Furthermore, calculate the comprehensive echo change index. The calculation formula is as follows: (11) In the above formula, and The distance and energy change rate weighting coefficients can be set to a range that can be set to... , And it must meet the normalization condition. .

[0097] Furthermore, the pitch and roll angles obtained from the scanning head attitude sensing component at continuous moments are used to calculate the changes in the device's attitude. Equipment attitude change Used to characterize the degree of equipment instability caused by water flow impact or structural inflow; equipment attitude change. The calculation formula is as follows: (12) In the above formula, and For pitch and roll angles, and The attitude angle at the previous moment.

[0098] Furthermore, based on the echo change index and equipment attitude change The scanning state is divided into three categories: if ,and If so, it is in a stable scanning state; if ,and If so, it is in a structural change scanning state; if Then it is in the water flow disturbance scanning state; among them, The threshold value for initiating structural change is 0.1 to 0.25. This means that when the rate of change of the composite echo between adjacent angles exceeds 10%-25%, the system determines that the system has deviated from the regular well wall and entered the structural change region. Threshold for drastic structural changes: The value ranges from 0.4 to 0.5; The threshold for slight attitude disturbance is 1 to 4, and the system allows the overall equipment tilt angle fluctuation to be within 1° to 2°. This represents the threshold for severe water flow disturbance, ranging from 9 to 25. It indicates that when the equipment encounters a strong shear flow or incoming flow impact, and the overall tilt angle fluctuation reaches 3° to 5°, the anti-disturbance mechanism must be triggered. .

[0099] Step S703: Based on the scanning status and water flow direction and velocity information, the sonar scanning parameters of the automatic lowering and depth control module and the sonar scanning module are adaptively adjusted and anti-water flow disturbance control is performed until the sonar scanning module is lowered to the bottom of the well, and the sonar scanning module is controlled to stop scanning.

[0100] Step S704: Based on the sonar echo information, perform continuous abnormal echo discrimination to obtain valid echo information.

[0101] Specifically, continuous abnormal echo discrimination is used in the process of sonar scanning of inspection wells to automatically identify and remove abnormal echo points or segments that appear only in a single scanning cycle or a single height slice, based on the echo continuity constraint in the depth (lowering height) direction. This is to eliminate the influence of the following interference factors on the three-dimensional reconstruction results: transient bubble or suspended object reflection, instantaneous echo enhancement caused by local turbulence in the water, electrical noise or occasional mechanical disturbance, and false reflections caused by single attitude disturbance.

[0102] Furthermore, by introducing a cross-altitude, multi-slice temporal-spatial consistency criterion, the stability, reliability, and interpretability of sonar data are improved.

[0103] Step S705: Obtain the lowering depth of the telescopic rod, the plane coordinates of the wellhead, and the absolute elevation of the wellhead. Based on the water flow direction and velocity information, effective echo information, lowering depth of the telescopic rod, plane coordinates of the wellhead, and absolute elevation of the wellhead, establish a three-dimensional model of the inspection well.

[0104] Specifically, the multi-depth sonar ring scan data obtained during the automatic lowering and scanning of the inspection well are uniformly registered and reconstructed to form a three-dimensional spatial model of the interior of the inspection well, and the spatial positional relationship of the well wall morphology, well bottom structure and pipeline interface is expressed in the model.

[0105] Furthermore, the single-beam sonar 360° ring scan echo distance data acquired at different water depth locations, the corresponding water depth information, the attitude and azimuth information of the sonar scanning module, and the valid echo data processed by the abnormal echo discrimination module are used as modeling input data. A complete ring scan data completed at the same water depth location constitutes a water depth slice. Each water depth slice records the echo distance corresponding to each azimuth angle and is accompanied by a corresponding water depth label. The echo data in the water depth slice is converted from polar coordinates to spatial coordinates and corrected according to the attitude and azimuth information. Then, multiple water depth slices are stacked in water depth order to form a three-dimensional point cloud model of the inside of the inspection well.

[0106] Furthermore, based on the 3D point cloud, geometric constraints of the manhole inner wall are introduced to fit the manhole wall profile, identify areas with significant local radial changes as pipe interface locations, and determine their azimuth and elevation information.

[0107] Furthermore, the absolute flow will be directed towards the angle Spatiotemporal binding is performed with the sonar 3D model at the same depth; that is, in the 3D modeling module, the absolute flow angles at each depth are... The topology map of the flow field of the well is formed by superimposing it on the three-dimensional model. If the flow direction inversion result shows that there is a continuous flow of water when scanning a certain branch pipe interface (the direction of the flow matches the azimuth of the branch pipe), then the pipe can be identified as an inlet pipe in operation; otherwise, it is an outlet pipe or an abandoned pipe.

[0108] Furthermore, key structures within inspection wells (such as concealed pipe interfaces) often possess specific hydraulic characteristics. Therefore, when identifying areas of structural abrupt change, the absolute flow direction angle is crucial. Rate of change of sonar echo distance The specific steps for performing spatial logical cross-validation are as follows: A. Detection of suspected features: When the sonar ring sweeps to a specific azimuth angle... At that time, the rate of change of sonar echo distance increased sharply ( Acoustically, it appears as a "suspected opening (cavity)".

[0109] B. Flow field verification and directional densification: retrieve the absolute flow direction angle from slices at the same height. and flow rate If the absolute flow direction angle The direction and the azimuth of the "hole" Highly collinear and possessing a certain flow velocity ( (For example, if water is being sprayed out or drawn in from that angle), then the location is confirmed as an active branch pipe interface with a very high degree of confidence.

[0110] C. Not only will it automatically trigger the segmented constant depth scanning mode ( Furthermore, it allocates scanning resources based on the intensity of the fluid vector: instructing the scanning unit to operate within this specific angular range. A high-frequency reciprocating local sector scan is performed inside (greatly increasing the sampling frequency of the local area) until the clearest morphology of the inner wall of the tube opening is obtained, and then a 360° circumferential scan is restored.

[0111] Furthermore, output one or a combination of the following results: a 3D point cloud model of the manhole interior, a structured 3D model containing information on the manhole wall, bottom, and pipe interfaces, and spatial model data that can be used for measurement and analysis.

[0112] Furthermore, it enables three-dimensional reconstruction of the internal structure of inspection wells under full water conditions; spatial consistency of scanning results at different water depths; accurate acquisition of the spatial location of pipe interfaces; and supports subsequent structural analysis and topological relationship determination.

[0113] Furthermore, based on the characteristics of sonar echoes in circumferential continuity and consistency across multiple depth slices, the location of the manhole wall and pipe opening is identified, and information such as pipe diameter and elevation is measured. Combined with azimuth information, a spatial topological model of the manhole and connecting pipes is established, including plan views and longitudinal sections, and CAD files can be exported. The pipeline topology analysis results are as follows: Figure 8 As shown.

[0114] This embodiment provides a method for inspecting manhole structures. It simultaneously acquires sonar echo information and equipment attitude information, enabling real-time perception of internal structural changes and water flow disturbances within the manhole. This overcomes the limitation of not being able to perceive structural complexity and changes in the water flow environment. Based on sonar echo and attitude information, the scanning state is determined, distinguishing between stable, changing, and disturbed areas, achieving accurate identification of different inspection environments. The scanning parameters are adaptively adjusted according to the scanning state, and anti-water flow disturbance control is implemented. This allows for dynamic adjustment of inspection accuracy based on structural complexity. Simultaneously, by using water flow direction and velocity information, the method suppresses attitude shifts and data distortions caused by water flow disturbances, directly improving the stability and data quality of the inspection process. Reliability is ensured by continuously identifying and eliminating abnormal echoes from sonar echo information, removing transient interference such as suspended objects and bubbles, and guaranteeing the authenticity and validity of the echo data used in modeling. This further improves the reliability of the detection results. By combining valid echo information, lowering depth, wellhead plane coordinates, and absolute elevation to establish a three-dimensional model, the detection results have a unified and accurate absolute spatial reference, avoiding model deviations caused by the lack of absolute positioning, ensuring the accuracy and consistency of the three-dimensional model, and improving the stability and reliability of the detection results. At the same time, the three-dimensional model of the inspection well is integrated with RTK positioning and elevation measurement information, giving the detection results clear spatial positioning capabilities, which can directly serve the digital management and analysis of municipal drainage pipe networks.

[0115] This embodiment provides a method for detecting the structure of a manhole, which can be used in the control and data processing module of the aforementioned manhole sonar scanning system. Figure 9 This is a flowchart of a manhole structure inspection method according to an embodiment of the present invention, such as... Figure 9 As shown, the process includes the following steps: Step S901: Acquire sonar echo information, equipment attitude information, and water flow direction and velocity information collected during the automatic lowering and depth control module process inside the target inspection well. For details, please refer to [link to relevant documentation]. Figure 7 Step S701 of the illustrated embodiment will not be described again here.

[0116] Step S902: Determine the scanning status based on sonar echo information and device attitude information. For details, please refer to [link to relevant documentation]. Figure 7 Step S702 of the illustrated embodiment will not be described again here.

[0117] Step S903: Based on the scanning status and water flow direction and velocity information, the sonar scanning parameters of the automatic lowering and depth control module and the sonar scanning module are adaptively adjusted and anti-water flow disturbance control is performed until the sonar scanning module is lowered to the bottom of the well, and the sonar scanning module is controlled to stop scanning.

[0118] Specifically, step S903 includes: Step S9031: Adjust the ring sweep angular velocity, sampling time and descent speed based on the scanning state.

[0119] Specifically, the adaptive scanning parameter adjustment steps are as follows: adjust the sonar scanning parameters according to the scanning status, that is, adjust the circumferential scanning angular velocity, sampling time and descent speed.

[0120] The adjustment of the ring sweep angular velocity can be expressed as: (13) Sampling time adjustment can be expressed as: (14) The descent speed adjustment can be expressed as: (15) in, , , These represent the maximum, intermediate, and minimum values ​​of the circumferential sweep angular velocity, respectively. , , These represent the maximum, intermediate, and minimum values ​​of the sonar sampling time (i.e., dwell time or the time interval between transmitted / received pulses), respectively. These represent the maximum, intermediate, and minimum values ​​of the descent speed (lowering speed) of the multi-segment electric telescopic pole, respectively.

[0121] Step S9032: Calculate the attitude disturbance intensity based on the device attitude information, and compare the attitude disturbance intensity with the first attitude disturbance threshold and the second attitude disturbance threshold respectively; wherein, the first attitude disturbance threshold is less than the second attitude disturbance threshold.

[0122] Specifically, the first attitude perturbation threshold is set as a slight attitude perturbation threshold. The second attitude disturbance threshold is set to the threshold for severe water flow disturbance. .

[0123] Step S9033: If the attitude disturbance intensity is greater than or equal to the second attitude disturbance threshold, the anti-flow disturbance control strategy is used to jointly adjust the ring sweep angular velocity, sampling time and descent speed until the attitude disturbance intensity is less than the first attitude disturbance threshold.

[0124] Specifically, when the condition is met multiple times during continuous scanning... Implement one or a combination of the following control measures: reduce the circumferential scanning speed; extend the sampling time; reduce the descent speed; pause the descent action and maintain the scanning height unchanged.

[0125] Furthermore, based on the sonar echo distance change rate, echo energy change rate, and attitude disturbance intensity, the descent speed is jointly adjusted. Circular sweep angular velocity ω and sampling frequency f s Its joint regulation is a closed-loop control process involving multi-sensor fusion feedback.

[0126] In a stable scanning state: if the environment is deemed safe and geometrically regular, the motor is instructed to output the maximum descent speed. With maximum circumferential sweep velocity At the same time, it matches extremely short sampling times. (i.e., increase the sampling frequency f) s This allows for highly efficient coarse scanning.

[0127] During structural scanning: When nozzle or sediment features are detected, in order to improve the spatial resolution of 3D reconstruction, the control unit simultaneously reduces the descent speed and circumferential scanning angular velocity to a moderate value. and To obtain a denser point cloud.

[0128] During water flow disturbance scanning: attitude disturbance is satisfied during continuous scanning. At this point, the anti-disturbance strategy is triggered: the circumferential sweep velocity is actively reduced to the minimum. The decentralization speed has decreased. Or directly suspend the transfer ( =0), to reduce the additional torque caused by fluid resistance, and at the same time, extend the sampling time to (i.e., reducing the sampling frequency fs) by trading time for the integral of the acoustic energy of a single measurement, in order to ensure that the pipe wall features are accurately captured under poor signal-to-noise ratio conditions.

[0129] Furthermore, when the attitude disturbance intensity recovers to After a preset time, it automatically resumes normal scanning and lowering. The preset time can be set to 5 to 10 seconds, which can effectively cover multiple complete 360° circumferential scan cycles of the sonar probe. This effectively prevents the device from generating unstable high-frequency start-stop actions in the edge area of ​​the water flow vortex, and ensures that the flow field has indeed calmed down and the attitude sensor data has completely converged before resuming normal kinematic scanning.

[0130] Step S9034: If the attitude disturbance intensity is less than the first attitude disturbance threshold, the water flow direction and water flow velocity information are compared with the safety threshold. If the water flow direction and water flow velocity information are greater than or equal to the safety threshold, the ring sweep angular velocity, sampling time and descent speed are jointly controlled until the water flow direction and water flow velocity information are less than the safety threshold.

[0131] Specifically, because there is a time lag between the impact of water flow and the resulting attitude deflection, relying solely on attitude will cause the sonar to collect distorted data at the instant of deflection. The addition of water flow direction and velocity information provides early warning coordination: during continuous scanning, when the flow field measurement module detects the confluence velocity... Its rate of change exceeds the safety threshold (e.g., a high-speed jet region is detected below the lowered area), but the attitude sensor indicates that the device is still in a stable state. At this point, there is no need to wait for the situation to worsen; proactive intervention can be implemented, namely, actively reducing the descent speed. The sonar scanning parameters were switched to a medium or conservative state. When the device actually passed through the high-speed jet zone, due to the advance deceleration and sufficient sampling time, the data distortion rate was suppressed to a minimum even if the attitude began to fluctuate afterward.

[0132] In step S9035, when the sonar scanning module is lowered to the bottom of the well, the sonar scanning module is controlled to stop scanning, and the sonar scanning module and the automatic lowering and depth control module are controlled to be retrieved to the wellhead position of the target inspection well.

[0133] Step S904: Based on the sonar echo information, perform continuous abnormal echo discrimination to obtain valid echo information. For details, please refer to [link to relevant documentation]. Figure 7 Step S704 of the illustrated embodiment will not be described again here.

[0134] Step S905: Obtain the lowering depth of the telescopic boom, the plane coordinates of the wellhead, and the absolute elevation of the wellhead. Based on the water flow direction and velocity information, effective echo information, the lowering depth of the telescopic boom, the plane coordinates of the wellhead, and the absolute elevation of the wellhead, establish a 3D model of the inspection well. For details, please refer to [link to details]. Figure 7 Step S705 of the illustrated embodiment will not be described again here.

[0135] This embodiment provides a method for detecting manhole structures. By analyzing the echo distance change rate, echo energy change rate, and attitude disturbance intensity in real time, it dynamically adjusts the ring scan angular velocity, lowering speed, and sampling time. Specifically, it introduces an adaptive adjustment mechanism for scanning parameters based on the echo distance change rate, echo energy change rate, and attitude disturbance intensity: in areas with straight well walls and slow structural changes, the scanning angular velocity is increased; in areas with pipe inlets, bottom sediments, or abrupt structural changes, the angular velocity is automatically reduced and the sampling density is increased; in areas with enhanced water flow disturbance, the lowering speed is reduced and the signal processing threshold is adjusted. This mechanism adaptively allocates limited scanning time and data bandwidth to areas with higher information content, improving the identification accuracy of key structures without significantly increasing operation time. It can adaptively focus on structurally complex areas, improving overall detection efficiency and accuracy.

[0136] This embodiment provides a method for detecting the structure of a manhole, which can be used in the control and data processing module of the aforementioned manhole sonar scanning system. Figure 10 This is a flowchart of a manhole structure inspection method according to an embodiment of the present invention, such as... Figure 10 As shown, the process includes the following steps: Step S1001: Acquire sonar echo information, equipment attitude information, and water flow direction and velocity information collected during the automatic lowering and depth control module process inside the target inspection well. For details, please refer to [link to relevant documentation]. Figure 9 Step S901 of the illustrated embodiment will not be described again here.

[0137] Step S1002: Determine the scanning status based on sonar echo information and device attitude information. For details, please refer to [link to relevant documentation]. Figure 9 Step S902 of the illustrated embodiment will not be described again here.

[0138] Step S1003: Based on the scanning status and water flow direction and velocity information, adaptive adjustment of sonar scanning parameters and anti-water flow disturbance control are performed on the automatic lowering and depth control module and the sonar scanning module until the sonar scanning module is lowered to the bottom of the well, at which point the sonar scanning module stops scanning. For details, please refer to [link to details]. Figure 9 Step S903 of the illustrated embodiment will not be described again here.

[0139] Step S1004: Based on the sonar echo information, perform continuous abnormal echo discrimination to obtain valid echo information.

[0140] Specifically, step S1004 includes: Step S10041: Define the depth neighborhood based on the lowering depth of the telescopic pole.

[0141] Specifically, during the automatic descent scanning process, at each stable height... A complete 360° single-beam loop scan is performed to generate a set of polar coordinate echo data. : (16) in, Indicates the drop-down height index. Indicates the first Each angle is sampled in the direction of the sampling.

[0142] Furthermore, regarding the current scan height Define deep neighborhood for: (17) in, The length of the depth direction continuity window (usually 1–3).

[0143] Step S10042: Calculate the echo consistency index within the depth neighborhood based on sonar echo information.

[0144] Specifically, the sonar echo information of slices at different altitudes is angularly aligned to ensure that the same data can be directly compared between different altitudes: .

[0145] Furthermore, the echo consistency index includes distance consistency index and amplitude consistency index; among them, the current drop height... echo point Calculate its distance consistency index in the deep neighborhood. Simultaneously calculate the amplitude consistency index The calculation formula is as follows: (18) (19) Step S10043: Compare the echo consistency index within the deep neighborhood with the continuity discrimination threshold.

[0146] Specifically, the continuity discrimination threshold includes a distance threshold and an amplitude threshold. The value range is 0.05m to 0.20m, and the amplitude threshold is... Set to 10%~25% of the full scale of the echo signal.

[0147] Step S10044: If the echo consistency index within the depth neighborhood is less than or equal to the continuity discrimination threshold, then the sonar echo information is taken as valid echo information.

[0148] Specifically, real structure echoes are continuous in the depth direction, while transient anomalous echoes appear only at a single height or at very few heights. Therefore, by comparing the sampling directions at the same angle... Echo stability in adjacent height slices can distinguish between real structure echoes and anomalous noise echoes.

[0149] Furthermore, if ,and If so, then the sonar echo information is valid echo information.

[0150] Furthermore, if the echo consistency index within the deep neighborhood is greater than the continuity discrimination threshold, the number of consecutive occurrences of the candidate abnormal echo point is obtained, and the number of consecutive occurrences of the candidate abnormal echo point is compared with the minimum continuity threshold; if the number of consecutive occurrences of the candidate abnormal echo point is greater than or equal to the minimum continuity threshold, the sonar echo information of the candidate abnormal echo point is taken as valid echo information.

[0151] Furthermore, if ,and If the echo point is identified as a candidate anomalous echo point, then to avoid misjudging the edge of the real structure, the consecutive occurrence count of the candidate anomalous echo points is further statistically analyzed, i.e., an echo presence indication function in the depth direction is defined. : (20) Calculate the length of the continuous existence of this echo in the depth direction: (twenty one) Set a minimum threshold for continuity (Usually 2 or 3), if If so, the echo is determined to be a transient abnormal echo; if If so, it will be retained as a valid structural echo.

[0152] Furthermore, echo points determined to be abnormal can be processed using any of the following methods: direct rejection method: Depth interpolation substitution method: Confidence-weighted weakening method: , .

[0153] Step S1005: Obtain the lowering depth of the telescopic boom, the plane coordinates of the wellhead, and the absolute elevation of the wellhead. Based on the water flow direction and velocity information, effective echo information, the lowering depth of the telescopic boom, the plane coordinates of the wellhead, and the absolute elevation of the wellhead, establish a three-dimensional model of the inspection well. For details, please refer to [link to details]. Figure 9 Step S905 of the illustrated embodiment will not be described again here.

[0154] This embodiment provides a method for detecting the structure of inspection wells. Addressing common issues such as incoming flow impact, backflow, and vortexes within inspection wells, the method suppresses these problems from three levels: structure, control, and algorithm. Specifically, the sonar scanning unit employs a symmetrical airfoil shell, which automatically achieves torque balance under the influence of incoming flow, reducing attitude deflection. The lowering and scanning parameters can be adaptively adjusted according to the disturbance intensity. A continuous abnormal echo discrimination algorithm eliminates transient anomalies occurring only within a single scanning cycle. These measures work synergistically to ensure the system obtains stable and reliable sonar data even under conditions of significant water flow. By employing multi-level collaborative suppression of water flow disturbances through airfoil structure design, motion control, and signal algorithms, the method significantly improves usability and stability under actual operating conditions.

[0155] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this application.

[0156] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0157] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0158] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0159] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0160] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application embodiment, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0161] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. An inspection well sonar scanning system characterized by, The system includes: a wellhead fixing bracket, an automatic lowering and depth control module, a sonar scanning module, a sensing module, and a control and data processing module; the wellhead fixing bracket is installed at the wellhead of the target inspection well; the automatic lowering and depth control module is connected to the sonar scanning module; the control and data processing module is connected to the automatic lowering and depth control module, the sonar scanning module, and the sensing module respectively; The sonar scanning module is used to collect sonar echo information from angle by angle during the automatic descent and depth control module descent process; the sonar echo information includes echo distance and echo energy information. The sensing module is used to collect equipment posture information, telescopic rod lowering depth information, and water flow direction and velocity information during the automatic lowering and depth control module lowering process; The control and data processing module is used to adaptively control the automatic lowering and depth control module and the sonar scanning module based on the sonar echo information, the equipment attitude information, and the water flow direction and velocity information, until the sonar scanning module is lowered to the bottom of the well and the sonar scanning module stops scanning.

2. The system of claim 1, wherein, The automatic lowering and depth control module includes: a multi-segment telescopic rod, an electric drive assembly, a telescopic position detection assembly, and an anti-rotation guide structure; The electric drive assembly is used to drive the multi-segment telescopic rod to extend sequentially segment by segment; The telescopic position detection component is used to measure the relative displacement between adjacent telescopic rods; The anti-rotation guide structure is used to control the extension and retraction of the multi-segment telescopic rod along a preset axis.

3. The system of claim 2, wherein, The sonar scanning module includes: an airfoil-shaped shell body, and a single-beam sonar transducer, a circumferential scanning rotary drive mechanism, and a rotation angle sensor disposed inside a sealed chamber of the airfoil-shaped shell body; the single-beam sonar transducer is arranged radially along the airfoil-shaped shell body; the upper end of the circumferential scanning rotary drive mechanism is coaxially connected to the end telescopic rod of the multi-segment telescopic rod via a drive shaft, and the lower output shaft of the circumferential scanning rotary drive mechanism is connected to the single-beam sonar transducer; the rotation angle sensor is coaxially mounted on the rotation shaft of the circumferential scanning rotary drive mechanism. The single-beam sonar transducer is used to collect the echo distance and echo energy information at each angle. The rotation angle sensor is used to collect the angular position information of the single-beam sonar transducer.

4. The system of claim 3, wherein, The sensing module includes: a pole attitude sensing component, a scanning head attitude sensing component, a water depth probe, and a flow field measurement unit; The pole posture sensing component is installed at the root of the first telescopic pole in the multi-segment telescopic pole, and is used to collect the basic posture information of the telescopic pole. The scanning head attitude sensing component is located inside the sealed chamber of the airfoil body and is used to collect the attitude information of the sonar scanning module. The depth probe is installed on the outer surface of the airfoil body and is used to collect information on the lowering depth of the telescopic rod. The flow field measurement unit is located on the outer surface of the airfoil body and is used to collect information on water flow direction and velocity during sonar scanning.

5. The system of claim 1, wherein, Also includes: A measurement module, mounted on top of the wellhead fixing bracket and connected to the control and data processing module, is used to acquire the wellhead plane coordinates and absolute elevation information of the target inspection well, and transmit the wellhead plane coordinates and absolute elevation information to the control and data processing module; wherein, the control and data processing module establishes a three-dimensional model of the inspection well based on the sonar echo information, the telescopic rod lowering depth information, the wellhead plane coordinates and absolute elevation information.

6. The system of claim 5, wherein, Also includes: The visualization analysis module, connected to the control and data processing module, is used to display the three-dimensional model of the inspection well.

7. A method of detecting a structure of a manhole, characterized by, The control and data processing module applied to the inspection well sonar scanning system as described in any one of claims 1 to 6, the method comprising: Acquire sonar echo information, equipment attitude information, and water flow direction and velocity information collected during the automatic lowering and depth control module inside the target inspection well; The scanning status is determined based on the sonar echo information and the device attitude information; Based on the scanning status and the water flow direction and velocity information, the sonar scanning parameters of the automatic lowering and depth control module and the sonar scanning module are adaptively adjusted and anti-water flow disturbance control is performed until the sonar scanning module is lowered to the bottom of the well, and the sonar scanning module is controlled to stop scanning. Based on the sonar echo information, continuous abnormal echoes are identified to obtain valid echo information; The lowering depth of the telescopic rod, the plane coordinates of the wellhead, and the absolute elevation of the wellhead are obtained. Based on the water flow direction and velocity information, the effective echo information, the lowering depth of the telescopic rod, the plane coordinates of the wellhead, and the absolute elevation of the wellhead, a three-dimensional model of the inspection well is established.

8. The method of claim 7, wherein, The process of adaptively adjusting the sonar scanning parameters and controlling the sonar scanning module based on the scanning status and the water flow direction and velocity information, until the sonar scanning module is lowered to the bottom of the well, and then controlling the sonar scanning module to stop scanning includes: Adjust the ring sweep angular velocity, sampling time, and descent speed based on the scanning state; The attitude disturbance intensity is calculated based on the device attitude information, and the attitude disturbance intensity is compared with a first attitude disturbance threshold and a second attitude disturbance threshold, respectively; wherein, the first attitude disturbance threshold is less than the second attitude disturbance threshold; If the attitude disturbance intensity is greater than or equal to the second attitude disturbance threshold, the anti-flow disturbance control strategy is used to jointly adjust the ring sweep angular velocity, the sampling time and the descent speed until the attitude disturbance intensity is less than the first attitude disturbance threshold. If the attitude disturbance intensity is less than the first attitude disturbance threshold, the water flow direction and water flow velocity information are compared with the safety threshold. If the water flow direction and water flow velocity information are greater than or equal to the safety threshold, the ring sweep angular velocity, the sampling time and the descent speed are jointly controlled until the water flow direction and water flow velocity information are less than the safety threshold. When the sonar scanning module is lowered to the bottom of the well, the sonar scanning module is controlled to stop scanning, and the sonar scanning module and the automatic lowering and depth control module are controlled to be retrieved to the wellhead position of the target inspection well.

9. The method of claim 7, wherein, The step of determining continuous abnormal echoes based on the sonar echo information to obtain valid echo information includes: A depth neighborhood is defined based on the lowering depth of the telescopic rod; Calculate the echo consistency index within the depth neighborhood based on the sonar echo information; The echo consistency index within the deep neighborhood is compared with the continuity discrimination threshold; If the echo consistency index within the depth neighborhood is less than or equal to the continuity discrimination threshold, then the sonar echo information is taken as the valid echo information.

10. The method of claim 9, wherein, The step of determining continuous abnormal echoes based on the sonar echo information to obtain valid echo information further includes: If the echo consistency index within the deep neighborhood is greater than the continuity discrimination threshold, then the number of consecutive occurrences of the candidate abnormal echo points is obtained, and the number of consecutive occurrences of the candidate abnormal echo points is compared with the minimum continuity threshold. If the number of consecutive occurrences of the candidate abnormal echo point is greater than or equal to the minimum continuity threshold, then the sonar echo information of the candidate abnormal echo point is taken as the valid echo information.

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