Immersed tube butt joint installation method and system based on laser ranging and visual identification

Abstract

The invention discloses an immersed tube butt joint installation method and system based on laser ranging and visual recognition, and belongs to the technical field of ocean engineering. The method comprises the steps that a laser target set is installed on the butt joint end face of an installed pipe joint, and a laser positioning set and a laser projector are installed on the butt joint end face of a to-be-installed pipe joint; after the to-be-installed pipe joint sinks, the laser positioning group is started to measure the distance to the target group in real time, meanwhile, parallel light beams are emitted to the other end face of the to-be-installed pipe joint through the laser projector, and the position of a light spot is collected through visual recognition to obtain posture deviation; the distance and deviation data are fused, the optimal pose of the pipe joint to be installed is calculated through an optimization algorithm, and then the offset of the end face center and the axis deflection angle are obtained; and according to the parameters, a regulation and control instruction is generated, and the ballast water system and the winch system are controlled to adjust the posture of the to-be-installed pipe joint till accurate butt joint is achieved. According to the invention, full-underwater, high-precision and automatic immersed tube butt joint is realized, and the dependence on an overwater measuring tower and a GPS (Global Positioning System) is eliminated.

Description

Technical Field

[0001] This invention relates to the field of marine engineering, specifically to a method and system for the docking and installation of immersed tubes based on laser ranging and visual recognition. Background Technology

[0002] With the continuous advancement of major infrastructure construction such as cross-sea channels and undersea tunnels, the immersed tube method has become one of the mainstream technologies for underwater tunnel construction. Immersed tube tunnels are constructed by sequentially connecting multiple prefabricated tube sections underwater, and the precision of this connection directly determines the overall tunnel alignment, watertightness, and structural safety. Especially in deep-sea environments, where factors such as currents, waves, and visibility are complex, ensuring high-precision connection of tube sections under deep-water conditions has become a key technical bottleneck restricting project quality and progress.

[0003] Currently, underwater docking of immersed tunnel sections mainly relies on a combination of a surveying tower (or surveying well) and a Global Positioning System (GPS) for positioning. The specific method involves setting up a surveying tower on top of both the installed and uninstalled tunnel sections, with a GPS receiver mounted on the top of the tower. The spatial position of the tunnel sections is obtained through surface surveying, and then the positioning information is transmitted to the underwater docking face via a rigid connection. This method is relatively mature in near-shore shallow water areas and can achieve centimeter-level positioning accuracy.

[0004] As the project gradually extends into deep-sea areas, the traditional method of positioning using survey towers has revealed the following prominent problems: 1. Large structure, difficult to manufacture and install: The height of the measuring tower usually needs to be several meters above the water surface. The structure is complex and needs to be able to resist wind and waves. The manufacturing and installation costs are high.

[0005] 2. Poor adaptability to deep-water environment: The open sea is deep, has fast currents and low visibility. The measurement tower is easily disturbed by the environment. There are multiple path errors and delays in the process of GPS signals being transmitted from the surface to the underwater, resulting in a decrease in positioning accuracy.

[0006] 3. The information transmission link is too long: The transmission from the surface GPS to the underwater docking surface relies on a rigid structure, which is subject to error accumulation due to mechanical deformation, thermal expansion and contraction, etc., making it difficult to achieve high-precision closed-loop control.

[0007] 4. Inability to achieve real-time closed-loop control: Traditional methods are mostly open-loop modes of "measurement-adjustment-remeasurement", which cannot achieve real-time, dynamic docking attitude feedback and automatic control underwater.

[0008] Therefore, there is an urgent need for a new technology that can perform high-precision relative positioning and attitude measurement directly underwater without the need for an above-water measurement tower, in order to meet the accuracy and efficiency requirements of deep-water immersed tube docking. Summary of the Invention

[0009] The purpose of this application is to address the shortcomings of the aforementioned background technology and provide a method and system for the installation of immersed tubes based on laser ranging and visual recognition.

[0010] The technical solution of this application is: a method for submerged tube docking and installation based on laser ranging and visual recognition, comprising: Install a laser target assembly on the first mating end face of the installed pipe section; A laser positioning assembly and a laser projector are installed on the second mating end face of the pipe section to be installed; the laser projector is used to emit a visible laser beam parallel to the axis of the installed pipe section toward the other end face of the pipe section to be installed, which is away from the second mating end face. The pipe sections to be installed are towed to the docking area by a floating transport vessel and then sunk. Start the laser positioning group and obtain the distance between the laser positioning group and the laser target group in real time; The position of the spot formed by the visible laser beam on the other end face of the pipe section to be installed is collected, and the deviation between the pipe section to be installed and the installed pipe section is obtained based on the spot position. The optimal pose of the pipe section to be installed is calculated based on distance and deviation. Based on the optimal pose, the offset of the center of the second docking end face relative to the center of the first docking end face and the axis deflection angle are obtained; The control commands are generated based on the offset and axis deviation angle to control the attitude adjustment of the pipe section to be installed until the docking is completed and the two pipe sections are locked.

[0011] According to the method for submerged pipe docking and installation based on laser ranging and visual recognition provided in this application, the laser target group includes at least two laser targets; the laser positioning group includes laser rangefinders corresponding one-to-one with the laser targets, the laser rangefinders are mounted on a two-degree-of-freedom servo gimbal and can automatically track the corresponding laser targets; wherein, the spatial coordinates of each laser target in the coordinate system of the installed pipe section are known, and the spatial coordinates of each laser rangefinder in the coordinate system of the pipe section to be installed are known.

[0012] According to the immersed tube docking and installation method based on laser ranging and visual recognition provided in this application, a checkerboard target surface is installed on the inner side of the sealing door on the other end face of the pipe section to be installed, which is away from the second docking end face, and a high-definition camera is installed on the end face. The high-definition camera is used to acquire the position of the imaging spot of the visible laser beam on the checkerboard target surface in real time.

[0013] According to the immersed tube docking and installation method based on laser ranging and visual recognition provided in this application, the method for obtaining the optimal pose based on distance and deviation calculation includes: Construct a first functional relationship, which is based on the spatial coordinates of the laser target in the coordinate system of the installed pipe section, the spatial coordinates of the laser rangefinder in the coordinate system of the pipe section to be installed, and the transformation matrix and translation vector between the coordinate systems of the installed pipe section and the pipe section to be installed. Based on the pixel and angular deviations of the light spot position relative to the center of the checkerboard target surface obtained by the high-definition camera, a second functional relationship is constructed. Construct an optimization objective function based on the first and second functional relationships; The optimal pose is obtained by solving the objective function.

[0014] According to the immersed tube docking and installation method based on laser ranging and visual recognition provided in this application, the optimization objective function is constructed according to the following formula.

[0015] in: R —Transformation matrix between the coordinate system of the installed pipe section and the coordinate system of the pipe section to be installed; t —Translation vector, the position coordinates of the center of the second mating end face in the coordinate system of the installed pipe section; —The spatial coordinates of the i-th laser rangefinder in the coordinate system of the pipe section to be installed; —The spatial coordinates of the i-th laser target in the coordinate system of the installed pipe section; d i —The distance from the i-th laser rangefinder to the corresponding i-th laser target; l —Weighting coefficients; i —The pitch angle of the pipe section to be installed relative to the axis of the already installed pipe section; ψ —The yaw angle of the axis of the pipe section to be installed relative to the axis of the installed pipe section; k θ —Pixel and pitch angle conversion coefficients obtained from high-definition camera calibration; k ψ —Pixel and yaw angle conversion coefficients obtained from high-definition camera calibration; D v —Horizontal pixel deviation of the light spot position on the checkerboard target surface; D u —Vertical pixel deviation of the light spot position on the checkerboard target surface.

[0016] According to the immersed tube docking and installation method based on laser ranging and visual recognition provided in this application, the method for obtaining the offset of the center of the second docking end face relative to the center of the first docking end face based on the optimal pose includes: obtaining the offset of the center of the second docking end face relative to the center of the first docking end face based on the translation vector in the optimal pose. Δy=t y ;Δz=t z in: Δy —The horizontal deviation of the center of the second docking end face from the center of the first docking end face; Δz —Vertical deviation of the center of the second docking end face from the center of the first docking end face; t y —The horizontal vector value in the translation vector; t z — The vertical vector value in the translation vector.

[0017] According to the immersed tube docking and installation method based on laser ranging and visual recognition provided in this application, the method for obtaining the axial deviation angle of the center of the second docking end face relative to the center of the first docking end face based on the optimal pose includes: obtaining the axial deviation angle of the axis of the pipe section to be installed relative to the axis of the installed pipe section based on the transformation matrix between the coordinate system of the installed pipe section and the coordinate system of the pipe section to be installed in the optimal pose.

[0018] in: α —The horizontal axial deflection angle of the pipe section to be installed relative to the axis of the already installed pipe section; β —The vertical deflection angle of the axis of the pipe section to be installed relative to the axis of the already installed pipe section; R 32 、R 22 、R 31 、R 11 — Elements of the transformation matrix between the coordinate system of the installed pipe section and the coordinate system of the pipe section to be installed.

[0019] According to the immersed tube docking installation method based on laser ranging and visual recognition provided in this application, the center of the checkerboard target surface coincides with the center of the other end face of the pipe section to be installed; the laser projector coincides with the center of the second docking end face.

[0020] According to the immersed tube docking installation method based on laser ranging and visual recognition provided in this application, control commands are sent to the ballast water system and winch system of the tube section to be installed, and the ballast water system and winch system adjust the attitude of the tube section to be installed according to the control commands.

[0021] This application also relates to a immersed tunnel docking and installation system based on laser ranging and visual recognition. The installation system operates according to the aforementioned immersed tunnel docking and installation method based on laser ranging and visual recognition, including: The laser target assembly is installed on the first mating end face of the installed pipe section; The laser positioning assembly is installed on the second mating end face of the pipe section to be installed. A laser projector, mounted on the second docking end face, is used to emit a visible laser beam parallel to the axis of the installed pipe section toward the other end face of the pipe section to be installed, which is away from the second docking end face; The distance acquisition module is used to acquire the distance between the laser positioning group and the laser target group in real time; The deviation acquisition module is used to acquire the position of the spot formed by the visible laser beam on the other end face of the pipe section to be installed, and to acquire the deviation between the pipe section to be installed and the installed pipe section based on the spot position; The calculation module is used to calculate the optimal pose of the pipe section to be installed based on distance and deviation; The instruction generation module is used to obtain the offset and axis deviation angle of the center of the second docking end face relative to the center of the first docking end face according to the optimal pose, and to generate control instructions based on the offset and axis deviation angle. The control module is used to control the attitude adjustment of the pipe section to be installed according to the control instructions.

[0022] The advantages of this application are as follows: 1. The docking and installation method of this application is carried out entirely underwater, using laser ranging and visual recognition to replace the traditional surface measurement tower and GPS system, thereby eliminating the dependence on surface structures. This makes the docking and installation method of this application particularly suitable for deep-sea environments, avoiding the difficulties and costs of setting up measurement towers in harsh sea conditions. By fusing laser ranging (real-time distance acquisition) and visual recognition (obtaining deviation based on spot position), the docking and installation method of this application can achieve millimeter-level offset and milliradian-level angle measurement. This multi-sensor data fusion ensures the centimeter-level accuracy requirement for immersed tube docking and reduces human error. All equipment involved in this application is integrated inside the tube section, eliminating the need for large surface support structures and significantly reducing manufacturing, installation, and maintenance costs. The method simplifies on-site deployment and improves economic efficiency. The laser and vision systems operate in a closed underwater environment, unaffected by wind, waves, currents, or GPS signal loss. This closed environment enhances the stability and reliability of the system, ensuring the smooth progress of the docking process under complex marine conditions. 2. This application utilizes multiple laser targets and a laser rangefinder, along with a servo gimbal for automatic tracking. This allows the system to continuously align with the target, reducing blind spots and errors. Known spatial coordinates provide a basis for coordinate system transformation, thereby improving the accuracy of distance and angle measurements and achieving milliradian-level control. The automatic tracking mechanism ensures the laser beam remains aligned with the target throughout the pipe section's movement, maintaining stable measurements even under water flow or slight vibration interference. The underwater enclosed environment further reduces the impact of external factors on tracking accuracy. The integrated design of the laser rangefinder and servo gimbal avoids complex external adjustment mechanisms, reducing equipment size and cost. The entire system is built into the pipe section, eliminating the need for an additional surface platform and saving resources. 3. The checkerboard target surface of this application provides a high-resolution reference grid, which, combined with a high-definition camera, can accurately capture the pixel position of the light spot, thereby calculating minute deviations. This visual recognition method complements laser ranging, realizes multi-dimensional data fusion, and improves the overall measurement accuracy to the millimeter level. Both the camera and the target surface are installed in an underwater sealed environment, unaffected by surface waves and light changes. The vision system operates stably underwater, reducing the interference of environmental noise on image acquisition. The checkerboard target surface and high-definition camera have a simple structure, are easy to install inside the pipe section, do not require external support equipment, and reduce the overall system complexity and cost. 4. This application fuses laser ranging data and visual deviation data through mathematical modeling, optimizes the objective function to minimize the overall error, and ensures the accuracy and reliability of pose calculation. This method achieves millimeter-level offset and milliradian-level angle estimation, meeting the stringent precision requirements of immersed tube docking. The optimization function can handle noise in sensor data and compensate for potential errors through algorithms, improving the robustness of the system in uncertain environments. Data processing in an underwater confined environment further reduces external interference. The calculation process is based on built-in sensor data, eliminating the need for external measurement equipment, reducing hardware dependence and cost. Automated optimization reduces manual intervention and improves efficiency. 5. The optimization objective function of this application ensures the repeatability and accuracy of the calculation process; by balancing distance and angle deviations with weighting coefficients and converting pixel deviations into angles with calibration coefficients, the method achieves high-precision pose estimation, reaching millimeter-level and milliradian-level measurements; the error minimization mechanism in the function can adapt to data fluctuations, enhancing the stability of the system in the underwater environment; mathematical optimization reduces the impact of random errors; the software implementation based on the mathematical model requires no additional hardware, reducing system complexity and cost; the explicitness of the formula facilitates integration into the control system, improving the level of automation. 6. This application directly extracts the offset through translation vectors, which simplifies the calculation process, reduces the accumulation of intermediate errors, and ensures the accuracy of millimeter-level offset measurements. This direct coordinate system transformation method improves the efficiency of data processing. The offset calculation is based on optimized pose data, which has strong anti-noise capabilities. Even if the sensor data fluctuates slightly in the underwater environment, it can maintain a stable output through the optimization function. The calculation process is integrated into the control system, eliminating the need for external measurement equipment and reducing hardware requirements and costs. 7. This application calculates the axis deflection angle by transforming matrix elements. The method is mathematically rigorous and provides high-precision angle estimation, achieving milliradian-level measurement. This calculation method ensures the alignment accuracy of the pipe section axis, meeting docking requirements. The matrix calculation is based on the optimized pose, which can resist slight fluctuations in sensor data and improve the reliability of angle measurement. In the underwater environment, this method reduces the influence of external factors on angle estimation. The angle calculation is entirely based on built-in sensor data, eliminating the need for additional angle measuring instruments, thus saving cost and space. 8. This application ensures the consistency of the measurement benchmark through the center coincidence design, reducing coordinate system transformation errors; the spot position directly reflects the overall deviation of the pipe section, improving the accuracy of visual recognition and supporting millimeter-level offset measurement; benchmark alignment reduces the difficulty of system calibration, and can maintain long-term stability even in complex underwater environments, reducing drift errors; the coincidence design simplifies the installation and commissioning process, reducing labor costs and equipment complexity; all equipment is built-in, eliminating the need for external adjustment mechanisms. 9. This application utilizes an automated control system for the ballast water system and winch system. The method enables rapid response to attitude calculation results, achieving precise attitude adjustments and ensuring docking accuracy down to the centimeter level. Closed-loop control reduces human error. The ballast water and winch systems operate stably in the underwater environment, unaffected by surface waves. Control commands are based on real-time data, adapting to dynamic changes and improving system reliability. Adjustments are made using the existing pipe section system (ballast water and winch), eliminating the need for additional actuators, thus reducing costs and system complexity. The entire adjustment process is completed underwater, requiring no surface support equipment, making it suitable for deep-water operations. 10. This application also provides an installation system, which is fully integrated into the underwater pipe section, enabling fully underwater operation and eliminating reliance on GPS and measurement towers, making it particularly suitable for deep-sea environments. The system, through multi-module collaboration (such as distance acquisition, deviation acquisition, and calculation modules), integrates laser ranging and visual recognition data to achieve millimeter-level offset and milliradian-level angle measurements, meeting the centimeter-level accuracy requirements for immersed tube docking. All modules and equipment are built into the pipe section, resulting in a compact structure that eliminates the need for large above-water structures, significantly reducing manufacturing, installation, and maintenance costs. The system operates in a closed underwater environment, minimizing external interference to the laser and vision modules, and the control module adjusts based on real-time commands, ensuring high reliability and stability.

[0023] The immersed tube docking installation method proposed in this application achieves high precision, low cost, high reliability, and deep-water adaptability in immersed tube docking installation. It not only improves construction efficiency and quality but also reduces engineering risks, meeting the development needs of modern marine engineering. Attached Figure Description

[0024] Figure 1 This application includes a schematic diagram of the immersed tube docking and installation method. Figure 2 This application includes a schematic diagram of the immersed tunnel connection and installation. Among them: 1—laser target; 2—laser rangefinder; 3—laser projector; 4—checkerboard target; 5—high-definition camera. Detailed Implementation

[0025] The embodiments of this application are described in detail below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0026] In the description of this application, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0027] Furthermore, 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 application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this application, unless otherwise stated, the following coordinate system is used: the direction of the pipe section axis is the X-axis, the direction perpendicular to the X-axis in the horizontal plane is the Y-axis (horizontal direction), and the direction perpendicular to the X-axis in the vertical plane is the Z-axis (vertical direction).

[0029] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] This application relates to a method for immersed tunnel docking and installation based on laser ranging and visual recognition. This method utilizes laser ranging and visual recognition to replace traditional surface surveying towers and GPS systems, eliminating reliance on surface structures and making it particularly suitable for deep-sea environments, avoiding the difficulties and costs associated with setting up surveying towers in harsh sea conditions. By fusing laser ranging and visual recognition, this method achieves millimeter-level offset and milliradian-level angle measurements. This multi-sensor data fusion ensures centimeter-level accuracy in tunnel docking, reducing human error. Furthermore, all equipment involved in this application is integrated inside the tunnel section, eliminating the need for large surface support structures, significantly reducing manufacturing, installation, and maintenance costs, simplifying on-site deployment, and improving economic efficiency. The laser and vision systems operate in a closed underwater environment, unaffected by wind, waves, currents, or GPS signal loss. This enclosed environment enhances the system's stability and reliability, ensuring the successful docking process under complex marine conditions.

[0031] Specifically, such as Figure 1 As shown, the immersed tube docking and installation method based on laser ranging and visual recognition of this application is carried out according to the following steps: S1, Installation of laser target group, laser positioning group and laser projector 3; like Figure 2 As shown, on the first mating end face of the installed pipe section (e.g.) Figure 2 A) shows the installation of a laser target assembly (which was installed on the first docking end face before the pipe section was lowered). On the second mating end face of the pipe section to be installed (e.g.) Figure 2 A laser positioning assembly and a laser projector 3 are installed on the surface shown in B); the laser projector 3 is used to project the laser onto the other end face of the pipe section to be installed, away from the second mating end face (e.g., Figure 2 As shown in C), a visible laser beam is emitted parallel to the axis of the installed pipe section; The laser target assembly, laser positioning assembly, and laser projector 3 were all installed before the pipe section was lowered. The first mating end face is the axial end face of the installed pipe section facing the pipe section to be installed, and the second mating end face is the axial end face of the pipe section to be installed facing the installed pipe section. After the pipe section to be installed and the installed pipe section are mated and installed, the first mating end face and the second mating end face overlap. This application constructs a coordinate system {O1} for the installed pipe segment based on the center of the first docking end face (e.g., ...). Figure 2 As shown), construct the coordinate system {O2} of the pipe section to be installed based on the center of the second mating end face (as shown). Figure 2 (as shown) S2. The pipe section to be installed is towed to the docking area by a floating transport vessel and then sunk. S3. During the sinking process, activate the laser positioning group and laser projector 3; The laser positioning group emits a laser towards the laser target group and obtains the distance between the laser positioning group and the laser target group in real time. This distance refers to the point-to-point distance between the laser positioning group and the laser target group. Laser projector 3 emits a visible laser beam parallel to the axis of the installed pipe section to the other end face of the pipe section to be installed, which is away from the second docking end face. The visible laser beam forms a spot on the other end face of the pipe section to be installed, and the deviation between the pipe section to be installed and the installed pipe section is obtained based on the position of the spot. S4. Calculate the optimal pose of the pipe section to be installed based on distance and deviation; S5. Based on the optimal pose, obtain the offset of the center of the second docking end face relative to the center of the first docking end face and the axis deflection angle; S6. Based on the offset and axis deviation angle, control commands are generated to control the attitude adjustment of the pipe section to be installed until docking is completed and the two pipe sections are locked. During the attitude adjustment of the pipe section to be installed, the deviation is monitored in real time. The deviation is compared with the set thresholds (such as 5mm for x-axis deviation, 5mm for y-axis deviation, 5mm for z-axis deviation, 0.05° for horizontal lateral angle, and 0.05° for vertical lateral angle; in actual application, the values ​​are not limited to the above and can be set according to requirements). When the deviation is less than the set threshold, it is considered that the pipe section to be installed has been connected and installed in place, and the pipe section to be installed can be connected with the installed pipe section.

[0032] The docking installation method in this application achieves accurate pose estimation through multi-sensor data fusion. Laser ranging provides real-time distance information, while visual recognition captures angle and position deviations through the spot position; the two are combined to construct a comprehensive measurement system. The visible laser beam emitted by the laser projector 3 is parallel to the axis of the installed pipe section, serving as a reference benchmark. Changes in the spot position directly reflect the relative attitude of the pipe section to be installed. When calculating the optimal pose, a mathematical optimization algorithm (such as the least squares method) is used to minimize distance and deviation errors, thereby outputting high-precision offset and axis deflection angle. Control commands are generated based on these parameters, and the pipe section attitude is adjusted through closed-loop control to ensure docking accuracy.

[0033] This application presents a method for immersed tube docking that is performed entirely underwater, eliminating the need for GPS or surface surveying towers. This adapts to deep-sea environments and reduces deployment difficulties in complex sea conditions. By integrating laser ranging and visual recognition, it achieves millimeter-level offset and milliradian-level angle measurements, meeting the centimeter-level accuracy requirements for immersed tube docking and minimizing human error. All equipment is integrated within the tube section, eliminating the need for large surface structures and significantly reducing manufacturing, installation, and maintenance costs. The laser and vision systems operate in a sealed underwater environment, unaffected by wind, waves, or GPS signal interference, thus improving system reliability and stability.

[0034] In some embodiments of this application, the above step S1 has been optimized. This embodiment limits the laser target group to include at least two laser targets 1, and in actual applications, two laser targets 1 are generally sufficient. The laser positioning group includes a laser rangefinder 2 that corresponds one-to-one with the laser target 1. The laser rangefinder 2 is mounted on a two-degree-of-freedom (adjustable along the Y and Z directions) servo gimbal and can automatically track the corresponding laser target 1. The spatial coordinates of each laser target 1 in the coordinate system of the installed pipe section (i.e., {O1} mentioned above) are known, and the spatial coordinates of each laser rangefinder 2 in the coordinate system of the pipe section to be installed (i.e., {O2} mentioned above) are known.

[0035] This embodiment enhances the redundancy and accuracy of the measurement system by combining multiple laser targets 1 and a laser rangefinder 2. The two-degree-of-freedom servo gimbal allows the laser rangefinder 2 to automatically adjust its angle in both horizontal and vertical directions, tracking the laser target 1 in real time to ensure the measurement beam is always aligned with the target. Known spatial coordinates provide the basis for coordinate system transformation, and relative pose is calculated using transformation matrices and translation vectors. The automatic tracking mechanism reduces measurement errors caused by pipe section movement and improves data continuity.

[0036] During installation, two laser targets 1 are set on the installed pipe section, and their spatial coordinates are accurately measured. A corresponding number of laser rangefinders 2 are installed on the pipe section to be installed, each rangefinder fixed to a two-degree-of-freedom servo gimbal. After system startup, the servo gimbal automatically adjusts the direction of the laser rangefinders 2 according to a preset program or real-time feedback to track the laser targets 1. Distance data is transmitted to the processing unit in real time, and coordinate system transformation calculations are performed using the known spatial coordinates. Operators can observe the tracking status through the monitoring system to ensure measurement stability.

[0037] This automatic tracking mechanism ensures the laser beam remains continuously aligned with the target, reducing blind spots and enabling milliradian-level angle measurements, thus improving docking accuracy. The servo gimbal adapts to the dynamic underwater environment, resisting water flow and vibration interference to maintain measurement stability. The multi-sensor integrated design avoids complex external mechanisms, reducing equipment size and cost.

[0038] In other embodiments of this application, step S1 described above has been further optimized, specifically, as follows: Figure 2 As shown, a checkerboard target surface 4 is installed on the inner side of the sealing door on the end face of the pipe section to be installed, which is away from the second docking end face. This other end face is the axial end face of the pipe section to be installed, and is the side end face away from the first docking end face of the already installed pipe section. The checkerboard target surface 4 is a flat plate structure with a checkerboard pattern on the side facing the second docking end face. The checkerboard pattern is uniform, and the interval between adjacent scale lines is known. In this embodiment, the center of the checkerboard target surface 4 coincides with the center of the other end face of the pipe section to be installed. In this embodiment, the laser projector 3 coincides with the center of the second docking end face. This center-coinciding design ensures the consistency of the measurement reference; the laser beam spot position directly reflects the overall deviation of the pipe section, reducing the complexity of coordinate system transformation. This alignment simplifies data interpretation and improves the accuracy and reliability of visual recognition.

[0039] A high-definition camera 5 is installed on the other end face of the pipe section to be installed. The high-definition camera 5 is used to acquire the position of the image spot of the visible laser beam on the checkerboard target surface 4 in real time. The high-definition camera 5 acquires the image spot of the visible laser beam on the checkerboard target surface 4, and then obtains the deviation based on the distance between the spot and the center of the checkerboard target surface 4.

[0040] In this embodiment, the checkerboard target surface 4 provides a high-resolution reference grid, and the high-definition camera 5 captures the image of the laser beam spot on the target surface. The pixel coordinates of the spot are extracted through image processing algorithms. The deviation of the spot position relative to the center of the target surface directly reflects the attitude error of the pipe section to be installed. Combined with laser ranging data, the vision system provides supplementary angle and position information, realizing multi-sensor data fusion and improving the overall measurement accuracy.

[0041] During actual installation, a checkerboard target surface 4 is installed inside the sealing door of the pipe section to be installed, ensuring that the center of the checkerboard target surface 4 is aligned with the center of the pipe section end face. A high-definition camera 5 is fixed to the same end face and aimed at the checkerboard target surface 4. After the system starts, the camera continuously acquires images of the checkerboard target surface 4. The image processing unit identifies the spot position and calculates pixel and angular deviations. The data and laser ranging results are synchronously transmitted to the calculation module for pose optimization.

[0042] The checkerboard target surface 4 and high-definition camera 5 in this embodiment provide high-resolution visual data, enabling millimeter-level offset measurement and supplementing the limitations of laser ranging. The underwater enclosed environment protects the visual system from surface waves and light changes, ensuring image acquisition stability. The checkerboard target surface 4 and camera have a simple structure, making them easy to integrate into the pipe section to be installed, reducing additional costs.

[0043] In a further embodiment of this application, step S4 described above has been optimized, specifically, as follows: Figure 2As shown, let the coordinate system of the installed pipe section be {O1}, with the origin O1 located at the center of the first mating end face, the x1 axis pointing along the pipe section axis towards the direction to be installed, and y1 and z1 forming a right-handed coordinate system. The coordinate system of the pipe section to be installed is {O2}, with the origin O2 located at the center of its own mating end face, and the x2 axis along its own axis.

[0044] The coordinates of two laser targets T1 and T2 in {O1} are known, and are denoted as:

[0045] in: —Coordinates of laser target T1 in the coordinate system of the installed pipe section; —Coordinates of laser target T2 in the coordinate system of the installed pipe section; y t1 —The y-coordinate of laser target T1 in the coordinate system of the installed pipe section; z t1 —The z-coordinate of the laser target T1 in the coordinate system of the installed pipe section; y t2 —The y-coordinate of laser target T2 in the coordinate system of the installed pipe section; z t2 —The z-coordinate of the laser target T2 in the coordinate system of the installed pipe section.

[0046] Laser rangefinder 2 obtains the relative distance between itself and the corresponding laser target 1. The coordinates of laser rangefinders L1 and L2 in {O2} are known installation parameters, denoted as:

[0047] in: —Coordinates of laser rangefinder L1 in the coordinate system of the pipe section to be installed; —Coordinates of laser rangefinder L2 in the coordinate system of the pipe section to be installed; x L1 —The x-coordinate of laser rangefinder L1 in the coordinate system of the pipe section to be installed; y L1 —The y-coordinate of laser rangefinder L1 in the coordinate system of the pipe section to be installed; z L1 —The z-coordinate of laser rangefinder L1 in the coordinate system of the pipe section to be installed; x L2 —The x-coordinate of laser rangefinder L2 in the coordinate system of the pipe section to be installed; y L2 —The y-coordinate of laser rangefinder L2 in the coordinate system of the pipe section to be installed; z L2—The z-coordinate of laser rangefinder L2 in the coordinate system of the pipe section to be installed.

[0048] The distance from the laser rangefinder L1 to the laser target T1 is obtained through laser ranging. d 1 The distance from laser rangefinder L2 to laser target T2 d 2 :

[0049] in: d 1 —The distance from laser rangefinder L1 to laser target T1; d 2 —The distance from laser rangefinder L2 to laser target T2; —Coordinates of laser target T1 in the coordinate system of the installed pipe section; —Coordinates of laser target T2 in the coordinate system of the installed pipe section; —Coordinates of laser rangefinder L1 in the coordinate system of the pipe section to be installed; — Coordinates of laser rangefinder L2 in the coordinate system of the pipe section to be installed.

[0050] in,

[0051] in: R —The rotation matrix between the coordinate system of the installed pipe section ({O1}) and the coordinate system of the pipe section to be installed ({O2}); t —Translation vector, the position coordinates of the center of the second mating end face in the coordinate system of the installed pipe section; ——No. i The coordinates of a laser rangefinder in the coordinate system of the pipe section to be installed; ——No. i The coordinates of a laser target in the coordinate system of the installed pipe section.

[0052] Therefore, based on the spatial coordinates of laser target 1 in the coordinate system of the installed pipe section, the spatial coordinates of laser rangefinder 2 in the coordinate system of the pipe section to be installed, and the transformation matrix and translation vector between the coordinate systems of the installed and pipe sections to be installed, the first functional relationship can be constructed as follows:

[0053] Taking the installation of two laser rangefinders 2 and two laser targets 1 as an example, the first functional relationship is as follows:

[0054] Since there are only two distance constraints, it is not possible to uniquely determine the 6-DOF pose (3 translations + 3 rotations). Therefore, laser projection and visual deviation measurement are introduced as supplementary constraints to construct a second functional relationship.

[0055] Based on the pixel and angular deviations of the light spot position relative to the center of the checkerboard target surface 4 obtained by the high-definition camera 5, a second functional relationship is constructed. It is assumed that the emission direction of the visible laser beam is always parallel to the coordinate system {O1} of the installed pipe section. x 1 Shaft (e.g.) Figure 2 As shown), that is, the direction vector is v=(1,0,0)T The visible laser beam is projected onto the checkerboard target surface 4 on the other end face of the pipe section to be installed, forming a light spot.

[0056] Let the coordinates of the center of the checkerboard target surface 4 in the coordinate system {O2} of the pipe section to be installed be:

[0057] The center of the checkerboard target surface 4 is located x 2 Shaft (e.g.) Figure 2 As shown in the figure, the high-definition camera 5 imaging model is a pinhole model.

[0058] The equation of the visible laser beam in the coordinate system {O1} of the installed pipe section is:

[0059] in, Let {O1} be the position of laser projector 3 in the coordinate system {O1} of the installed pipe section.

[0060] The visible laser beam forms a straight line that intersects with the checkerboard target surface plane 4 (located in...). x=xC The intersection of the points (where O1 and O2) is the position of the light spot in the coordinate system {O1} of the installed pipe section. Through coordinate transformation, its coordinates in the coordinate system {O2} of the pipe section to be installed can be obtained. Then, through imaging with the high-definition camera 5, the pixel coordinates are obtained. (u,v) .

[0061] Under ideal docking conditions, the light spot should be located at the center of the checkerboard target surface 4, with a pixel deviation. (Δu,Δv) Reflects the angular deviation (pitch angle) of the pipe section to be installed relative to the installed pipe section. i Yaw angle ψ ).

[0062] By approximating with a small angle, we can obtain:

[0063] in: i —The pitch angle of the pipe section to be installed relative to the axis of the already installed pipe section; ψ —The yaw angle of the axis of the pipe section to be installed relative to the axis of the installed pipe section; k θ —Pixel and pitch angle conversion coefficients obtained from the calibration of the high-definition camera 5; k ψ —Pixel and yaw angle conversion coefficients obtained from the calibration of the high-definition camera 5; D v —The horizontal pixel deviation of the light spot position on the checkerboard target surface 4, i.e. y Pixel deviation; D u —The vertical pixel deviation of the light spot position on the checkerboard target surface 4, i.e. z Pixel deviation.

[0064] The optimization objective function is constructed based on the first and second functional relationships, as follows:

[0065] in: R —Transformation matrix between the coordinate system of the installed pipe section and the coordinate system of the pipe section to be installed; t —Translation vector, the position coordinates of the center of the second mating end face in the coordinate system of the installed pipe section; —The spatial coordinates of the i-th laser rangefinder 2 in the coordinate system of the pipe section to be installed; —The spatial coordinates of the i-th laser target 1 in the coordinate system of the installed pipe section; d i —The distance from the i-th laser rangefinder 2 to the corresponding i-th laser target 1; l —Weighting coefficients; i —The pitch angle of the pipe section to be installed relative to the axis of the already installed pipe section; ψ —The yaw angle of the axis of the pipe section to be installed relative to the axis of the installed pipe section; k θ —Pixel and pitch angle conversion coefficients obtained from the calibration of the high-definition camera 5; k ψ —Pixel and yaw angle conversion coefficients obtained from the calibration of the high-definition camera 5; D v —Horizontal pixel deviation of the spot position on the checkerboard target surface 4; D u —Vertical pixel deviation of the light spot position on the checkerboard target surface 4.

[0066] The optimal pose is obtained by solving the problem using a nonlinear least squares method (such as the Levenberg-Marquardt algorithm). (R, t) .

[0067] In this embodiment, the first functional relationship describes the distance error under coordinate system transformation, and the second functional relationship describes the angle error under visual bias. The optimization objective function combines the two, and the optimal pose is solved by minimizing the comprehensive error (such as the least squares method). Mathematical modeling ensures the rigor of data fusion, and the transformation matrix and translation vector are directly related to the relative position and attitude between pipe segments.

[0068] In actual operation, the data processing unit acquires distance data from the laser rangefinder 2 and pixel deviation data from the high-definition camera 5 in real time. First, a first functional relationship is constructed based on the known spatial coordinates to calculate the error between the theoretical and actual distances. Second, a second functional relationship is constructed based on the pixel deviation and calibration coefficients to calculate the angle error. Then, the two are weighted and combined into an optimization objective function, and a numerical optimization algorithm is used to solve for the transformation matrix and translation vector, outputting the optimal pose. Operators can monitor the optimization process through the software interface.

[0069] This embodiment's optimal pose determination method achieves millimeter-level and milliradian-level accuracy by mathematically optimizing and fusing multi-sensor data, meeting the requirements for immersed tube docking. The optimization function handles data noise, improving the system's robustness in uncertain environments. Based on a software algorithm, no additional hardware is required, reducing system complexity.

[0070] In a preferred embodiment of this application, step S5 described above is optimized. Specifically, the offset of the center of the second docking end face relative to the center of the first docking end face is obtained based on the translation vector in the optimal pose. Δy=t y ;Δz=t z in: Δy —The horizontal deviation of the center of the second docking end face from the center of the first docking end face; Δz—Vertical deviation of the center of the second docking end face from the center of the first docking end face; t y —The horizontal vector value in the translation vector; t z — The vertical vector value in the translation vector.

[0071] Based on the transformation matrix between the coordinate system of the installed pipe segment and the coordinate system of the pipe segment to be installed in the optimal pose, the axis deviation angle of the pipe segment to be installed relative to the axis of the installed pipe segment is obtained.

[0072] in: α —The horizontal axial deflection angle of the pipe section to be installed relative to the axis of the already installed pipe section; β —The vertical deflection angle of the axis of the pipe section to be installed relative to the axis of the already installed pipe section; R 32 、R 22 、R 31 、R 11 — Elements of the transformation matrix between the coordinate system of the installed pipe section and the coordinate system of the pipe section to be installed.

[0073] Translation vector t This directly represents the position of the center of the second mating end face in the coordinate system of the installed pipe section; therefore, its horizontal and vertical components can be directly used as offsets. This method simplifies calculations, avoids intermediate transformation errors, and improves data extraction efficiency. Transformation matrix R It describes the rotational relationship between coordinate systems, and its elements can be used to calculate Euler angles. Formula α and β These represent the angles of deviation of the axis of the pipe section to be installed relative to the axis of the installed pipe section in the horizontal and vertical directions, respectively. The mathematical derivation ensures the accuracy of the angle calculation.

[0074] In practice, after calculating the optimal pose, t is directly extracted from the translation vector t. y and t z The values ​​are used as horizontal deviation Δy and vertical deviation Δz. These values ​​are displayed in real time on the control interface and used to generate control commands. After obtaining the transformation matrix R of the optimal pose, elements R are extracted. 32 R 22 R 31 R 11 Substitute into the formula to calculate α and βThese angle values ​​are used to assess the alignment of pipe sections and are integrated into the control commands.

[0075] In some embodiments of this application, step S6 above has been optimized. Specifically, control commands are sent to the ballast water system and winch system of the pipe section to be installed, and the ballast water system and winch system adjust the attitude of the pipe section to be installed according to the control commands.

[0076] The ballast water system adjusts the buoyancy and center of gravity of the pipe sections by changing the water volume in the tanks, while the winch system fine-tunes the position via cable traction. The combination of these two systems achieves precise attitude control. Control commands are based on real-time attitude data, forming a closed-loop control system to ensure rapid response and accurate alignment.

[0077] After the control command is generated, it is transmitted to the controllers of the ballast water system and the winch system via wired or wireless transmission. The ballast water system regulates the opening and closing of the water pump valves to control the water inlet and outlet of the water tanks; the winch system adjusts the cable tension and length. The operator monitors the adjustment process to ensure that the offset and axis deviation angle gradually decrease until docking is completed.

[0078] This automated control method for adjusting the pipe segment attitude achieves centimeter-level docking accuracy, reducing human error. The underwater execution system is unaffected by wind and waves, ensuring high reliability. It is suitable for deep-water operations. Utilizing existing systems, no additional actuators are required.

[0079] In addition, this application also relates to a immersed tube docking and installation system based on laser ranging and visual recognition, including a laser target group, a laser positioning group, a laser projector 3, a distance acquisition module, a deviation acquisition module, a calculation module, a command generation module, and a control module. The laser target group is installed on the first docking end face of the installed tube section; the laser positioning group is installed on the second docking end face of the tube section to be installed; the laser projector 3 is installed on the second docking end face and is used to emit a visible laser beam parallel to the axis of the installed tube section to the other end face of the tube section to be installed, which is away from the second docking end face; the distance acquisition module is used for... The system acquires the distance between the laser positioning group and the laser target group in real time; the deviation acquisition module collects the position of the spot formed by the visible laser beam on the other end face of the pipe section to be installed, and obtains the deviation between the pipe section to be installed and the installed pipe section based on the spot position; the calculation module calculates the optimal pose of the pipe section to be installed based on the distance and deviation; the command generation module obtains the offset and axial deviation angle of the center of the second docking end face relative to the center of the first docking end face based on the optimal pose, and generates control commands based on the offset and axial deviation angle; the control module controls the attitude adjustment of the pipe section to be installed according to the control commands.

[0080] The system in this application integrates data acquisition, processing, and control through a modular design. The laser target group and laser positioning group provide distance data, the laser projector 3 and deviation acquisition module provide visual data, the calculation module fuses the data and optimizes the pose, the command generation module derives control parameters, and the control module drives the actuators. The entire system operates in a sealed underwater environment, ensuring high precision and reliability.

[0081] In actual control, after the system starts, the modules work together: the distance acquisition module continuously measures the distance, the deviation acquisition module collects light spot images, the calculation module optimizes the pose in real time, the command generation module outputs the offset and axis deflection angle, and the control module sends commands to the ballast water system and winch system for adjustment. Operators observe the entire process through the central monitoring platform and can manually intervene.

[0082] The installation system described in this application is fully integrated underwater, eliminating reliance on GPS and measurement towers and adapting to deep-water environments. Multi-module collaboration enables millimeter-level offset and milliradian-level angle measurements, meeting centimeter-level docking requirements. All equipment is internally mounted, eliminating the need for large above-water structures and reducing manufacturing and installation costs. The underwater sealed environment protects the system from wind, waves, and signal interference, improving reliability.

[0083] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the appended claims and their equivalents.

Claims

1. A method for submerged tube docking and installation based on laser ranging and visual recognition, characterized in that, include: Install a laser target assembly on the first mating end face of the installed pipe section; A laser positioning assembly and a laser projector are installed on the second mating end face of the pipe section to be installed; the laser projector is used to emit a visible laser beam parallel to the axis of the installed pipe section toward the other end face of the pipe section to be installed, which is away from the second mating end face. The pipe sections to be installed are towed to the docking area by a floating transport vessel and then sunk. Start the laser positioning group and obtain the distance between the laser positioning group and the laser target group in real time; The position of the spot formed by the visible laser beam on the other end face of the pipe section to be installed is collected, and the deviation between the pipe section to be installed and the installed pipe section is obtained based on the spot position. The optimal pose of the pipe section to be installed is calculated based on distance and deviation. Based on the optimal pose, the offset of the center of the second docking end face relative to the center of the first docking end face and the axis deflection angle are obtained; The control commands are generated based on the offset and axis deviation angle to control the attitude adjustment of the pipe section to be installed until the docking is completed and the two pipe sections are locked.

2. The immersed tube docking and installation method based on laser ranging and visual recognition according to claim 1, characterized in that, The laser target group includes at least two laser targets; the laser positioning group includes laser rangefinders corresponding to the laser targets one by one, the laser rangefinders are mounted on a two-degree-of-freedom servo gimbal and can automatically track the corresponding laser targets; wherein, the spatial coordinates of each laser target in the coordinate system of the installed pipe section are known, and the spatial coordinates of each laser rangefinder in the coordinate system of the pipe section to be installed are known.

3. The method for submerged pipe docking and installation based on laser ranging and visual recognition according to claim 2, characterized in that, A checkerboard target is installed on the inside of the sealing door on the other end face of the pipe section to be installed, which is away from the second docking end face. A high-definition camera is installed on this end face. The high-definition camera is used to acquire the position of the imaging spot of the visible laser beam on the checkerboard target in real time.

4. The immersed tube docking and installation method based on laser ranging and visual recognition according to claim 3, characterized in that, The method for obtaining the optimal pose based on distance and deviation calculation includes: Construct a first functional relationship, which is based on the spatial coordinates of the laser target in the coordinate system of the installed pipe section, the spatial coordinates of the laser rangefinder in the coordinate system of the pipe section to be installed, and the transformation matrix and translation vector between the coordinate systems of the installed pipe section and the pipe section to be installed. Based on the pixel and angular deviations of the light spot position relative to the center of the checkerboard target surface obtained by the high-definition camera, a second functional relationship is constructed. Construct an optimization objective function based on the first and second functional relationships; The optimal pose is obtained by solving the objective function.

5. The method for submerged pipe docking and installation based on laser ranging and visual recognition according to claim 4, characterized in that, Construct the optimization objective function according to the following formula. in: R —Transformation matrix between the coordinate system of the installed pipe section and the coordinate system of the pipe section to be installed; t —Translation vector, the position coordinates of the center of the second mating end face in the coordinate system of the installed pipe section; —The spatial coordinates of the i-th laser rangefinder in the coordinate system of the pipe section to be installed; —The spatial coordinates of the i-th laser target in the coordinate system of the installed pipe section; d i —The distance from the i-th laser rangefinder to the corresponding i-th laser target; λ —Weighting coefficients; θ —The pitch angle of the pipe section to be installed relative to the axis of the already installed pipe section; ψ —The yaw angle of the axis of the pipe section to be installed relative to the axis of the installed pipe section; k θ —Pixel and pitch angle conversion coefficients obtained from high-definition camera calibration; k ψ —Pixel and yaw angle conversion coefficients obtained from high-definition camera calibration; Δ v —Horizontal pixel deviation of the light spot position on the checkerboard target surface; Δ u —Vertical pixel deviation of the light spot position on the checkerboard target surface.

6. The immersed tube docking and installation method based on laser ranging and visual recognition according to claim 5, characterized in that, The method for obtaining the offset of the center of the second docking end face relative to the center of the first docking end face based on the optimal pose includes: obtaining the offset of the center of the second docking end face relative to the center of the first docking end face based on the translation vector in the optimal pose. Δy=t y ; Δz=t z in: Δy —The horizontal deviation of the center of the second docking end face from the center of the first docking end face; Δz —Vertical deviation of the center of the second docking end face from the center of the first docking end face; t y —The horizontal vector value in the translation vector; t z — The vertical vector value in the translation vector.

7. The method for submerged pipe docking and installation based on laser ranging and visual recognition according to claim 5, characterized in that, The method for obtaining the axial deviation angle of the center of the second docking end face relative to the center of the first docking end face based on the optimal pose includes: obtaining the axial deviation angle of the axis of the pipe segment to be installed relative to the axis of the installed pipe segment based on the transformation matrix between the coordinate system of the installed pipe segment and the coordinate system of the pipe segment to be installed in the optimal pose. in: α —The horizontal axial deflection angle of the pipe section to be installed relative to the axis of the already installed pipe section; β —The vertical deflection angle of the axis of the pipe section to be installed relative to the axis of the already installed pipe section; R 32 、R 22 、R 31 、R 11 — Elements of the transformation matrix between the coordinate system of the installed pipe section and the coordinate system of the pipe section to be installed.

8. The immersed tube docking and installation method based on laser ranging and visual recognition according to claim 3, characterized in that, The center of the checkerboard target surface coincides with the center of the other end face of the pipe section to be installed; the center of the laser projector coincides with the center of the second docking end face.

9. The method for immersed tube docking and installation based on laser ranging and visual recognition according to claim 1, characterized in that, Control commands are sent to the ballast water system and winch system of the pipe section to be installed, and the ballast water system and winch system adjust the attitude of the pipe section to be installed according to the control commands.

10. A submerged tube docking and installation system based on laser ranging and visual recognition, characterized in that, The installation system is operated according to the immersed tube docking installation method based on laser ranging and visual recognition as described in any one of claims 1 to 9, including, The laser target assembly is installed on the first mating end face of the installed pipe section; The laser positioning assembly is installed on the second mating end face of the pipe section to be installed. A laser projector, mounted on the second docking end face, is used to emit a visible laser beam parallel to the axis of the installed pipe section toward the other end face of the pipe section to be installed, which is away from the second docking end face; The distance acquisition module is used to acquire the distance between the laser positioning group and the laser target group in real time; The deviation acquisition module is used to acquire the position of the spot formed by the visible laser beam on the other end face of the pipe section to be installed, and to acquire the deviation between the pipe section to be installed and the installed pipe section based on the spot position; The calculation module is used to calculate the optimal pose of the pipe section to be installed based on distance and deviation; The instruction generation module is used to obtain the offset and axis deviation angle of the center of the second docking end face relative to the center of the first docking end face according to the optimal pose, and to generate control instructions based on the offset and axis deviation angle. The control module is used to control the attitude adjustment of the pipe section to be installed according to the control instructions.

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