Manifold connection pose measuring device suitable for underwater confined space and solving algorithm

Abstract

The invention relates to the technical field of underwater pipeline measurement, in particular to a manifold connection pose measuring device suitable for an underwater limited space and a solving algorithm. The device comprises an angle measuring mechanism and a rope length detecting mechanism, and is fixed on a flange end face of a detected pipeline through a centering mechanism; the angle measuring mechanism is composed of an orthogonal shaft system and a magnetic coupling encoder, and the linear displacement is mapped into an angle signal by combining a sliding rail and a measuring rope extension arm; the rope length detection mechanism winds a stainless steel measuring rope through a friction hub in an anti-corrosion shell, and the number of rotation turns is detected through an encoder so as to calculate the rope length. The method comprises the steps of establishing a measuring rope infinitesimal stress model, calculating a suspension curve based on a parabola theory, constructing an absolute coordinate system and a reference coordinate system, and resolving the relative pose of the two pipelines through pose parameters and a transition matrix. The working load of a diver is reduced through lightweight design and a low-friction shaft system, and high-precision pose measurement is achieved by combining the parabola theory and dynamic coordinate transformation.

Description

Technical Field

[0001] The present application relates to the technical field of underwater pipeline measurement, and more specifically, to a pipe connection pose measurement device and a solution algorithm applicable to underwater confined spaces. Background Art

[0002] In the field of underwater pipeline measurement, with the continuous development of ocean development and underwater engineering construction, the demand for underwater pipe connection pose measurement technology is increasing day by day. However, the existing measurement technologies and devices still face many challenges in the application of underwater special environments.

[0003] On the one hand, in terms of measurement devices, the currently widely used pipeline pose wire measurement method mostly relies on the assistance of remotely operated underwater vehicles (ROVs). For example, in special environments with complex structures and narrow spaces such as underwater production facilities and underwater bases, it is difficult to complete the measurement work of pipeline connections through the existing measurement devices and ROVs in cooperation. These measurement tools generally have problems such as complex operation, large weight and volume, resulting in their inability to effectively intervene in the above special environment operations, greatly limiting the development of underwater pipeline measurement work.

[0004] On the other hand, in terms of fixing methods, the existing measurement devices using underwater acoustic measurement methods mainly have methods such as fixing on the outer wall of the pipeline, fixing on the flange end face, and fixing on the inner wall of the pipeline. However, in working conditions with limited space, these positioning methods have problems such as large occupied space and unstable installation of the device, thereby reducing the measurement accuracy. It can be seen that there are obvious deficiencies in the optimization of the existing technology in terms of positioning methods and it cannot meet the complex and diverse measurement requirements in underwater special environments.

[0005] In addition, there is still a lack of in-depth research on the complex and diverse measurement requirements under underwater special environment working conditions. In actual engineering, diver operation is one of the important ways of underwater measurement. However, the existing measurement tools do not fully consider reducing the underwater operation load of divers and cannot achieve the portability, lightweight and simple operation of the measurement tools on the premise of ensuring measurement accuracy. Therefore, developing a wire measurement equipment applicable to diver operation and improving the underwater measurement efficiency and safety of divers has become a technical problem that needs to be solved urgently. Summary of the Invention

[0006] In view of this, the present application provides a pipe connection pose measurement device and a solution algorithm applicable to underwater confined spaces, to solve the problems of the existing underwater pipe connection pose measurement tools being bulky, complex to operate, large diver operation load, and insufficient measurement accuracy in complex environments.

[0007] The technical solutions provided by the present application are as follows: In a first aspect, a pipe connection pose measurement device applicable to an underwater confined space according to the present application includes an angle measurement mechanism and a rope length detection mechanism; the angle measurement mechanism and the rope length detection mechanism are fixed on the flange end face of the pipeline to be measured through a centering mechanism, the angle measurement mechanism includes an orthogonal inclination measurement mechanism and a measurement rope angle measurement mechanism, and the orthogonal inclination measurement mechanism includes an encoder and an orthogonal axis system fixed on a bearing support; the encoder is rigidly connected to the end of a horizontal connecting shaft under the orthogonal axis system; the measurement rope angle measurement mechanism includes a measurement rope extension arm and a slide rail, the slide rail is arranged parallel to the horizontal connecting shaft, and the measurement rope extension arm is slidably connected to the slide rail; The rope length detection mechanism includes a friction wheel hub wound with a stainless steel measurement rope and an encoder, the friction wheel hub is coupled to a rotating shaft through the encoder, one end of the stainless steel measurement rope extends to the measurement rope extension arm, and the other end is connected to the flange end face of the pipeline to be measured through a measurement rope pull ring.

[0008] In one possible implementation, the centering mechanism includes a transmission component, a support plate and a reference end plate, the transmission component is driven by a two-way ratchet wrench to control the support plate to be tightened or loosened.

[0009] In one possible implementation, the transmission component includes a central threaded rod, a nut rod sleeve and a link mechanism, the central threaded rod passes through the central axis of the centering mechanism and is connected to the reference end plate at both ends, the nut rod sleeve is engaged with the central threaded rod, and the link mechanism connects the nut rod sleeve and the support plate.

[0010] In one possible implementation, the orthogonal axis system includes a horizontal connecting shaft and a vertical connecting shaft, and the two form a cross-orthogonal structure through a coupling, the horizontal connecting shaft and the vertical connecting shaft are installed in a bearing support, and a bearing assembly is embedded in the bearing support.

[0011] In one possible implementation, the rope length detection mechanism further includes an anti-corrosion housing, the anti-corrosion housing covers the friction wheel hub and the measurement rope winding area, a measurement rope outlet is provided on the side wall of the anti-corrosion housing, and a wear-resistant bushing is embedded in the measurement rope outlet.

[0012] In one possible implementation, the encoder is a magnetic coupling encoder, and the rotating shaft of the magnetic coupling encoder in the rope length detection mechanism is coaxially and rigidly connected to the friction wheel hub.

[0013] In one possible implementation, the rope length detection mechanism further includes a return spring, one end of the return spring is fixed to the side of the friction wheel hub, and the other end is fixed to the inner wall of the anti-corrosion housing, and the return spring is used to drive the friction wheel hub to return to the initial position.

[0014] In a second aspect, the present application provides a solution algorithm for the pipe connection pose applicable to underwater confined spaces, and uses the pipe connection pose measurement device described in any item of the first aspect to solve the pipe connection pose, including: Step 1: Establish a micro-element force model of the measuring rope, conduct a force analysis, and establish a micro-element balance equation in the force direction of the measuring rope; Step 2: Calculate the catenary curve of the measuring rope based on the parabola theory, assuming that the gravity load of the measuring rope is evenly distributed along its span and remains constant before and after deformation; Step 3: Calculate the actual length of the measuring rope according to the catenary curve, and solve the straight-line distance between the reference-end device and the measured-end device; Step 4: Establish an absolute coordinate system with the center point of the pipe flange end face of the reference-end device as the origin, and a reference coordinate system with the center point of the pipe flange end face of the measured-end device as the origin; Step 5: Measure multiple pose parameters, including angle parameters and distance parameters; Step 6: Convert the pose parameters measured in Step 5 into the absolute coordinate system and the reference coordinate system respectively to obtain the pose vector expressions of the reference-end device and the measured-end device; Step 7: Construct a transition matrix between the absolute coordinate system and the measured-end coordinate system, solve the rotation angle and translation amount between the two coordinate systems, and calculate the relative pose of the two pipes, including the horizontal distance, height difference and relative angle, for determining the size parameters of the prefabricated crossover pipe.

[0015] In one possible implementation, the pose parameters measured in Step 5 further include the angle between the measuring device and the absolute horizontal plane, the rotation angle of the measuring rope in the reference coordinate system, the distance from the extension point of the measuring rope to the center point of the corresponding pipe flange end face, and the length of the measuring rope.

[0016] In one possible implementation, the size parameters of the prefabricated crossover pipe include the straight-line distance between the connection points at both ends of the crossover pipe or the actual path length to be covered, the inner diameter or outer diameter of the crossover pipe, the bending radius and the wall thickness.

[0017] Compared with the prior art, the technical solution of the present application has the following beneficial effects: The technical solution of this application integrates a centering mechanism, an orthogonal axis system angle measurement mechanism, and a friction wheel hub rope length detection mechanism, significantly reducing the underwater operation load of divers and realizing the lightweight and portability of the measurement tool. The device adopts a magnetic coupling encoder and an anti-corrosion housing design to ensure high-precision angle and rope length detection in complex underwater environments, avoiding mechanical wear and environmental corrosion; by simplifying the catenary curve calculation through the parabola theory, combining the micro-element force model and dynamic coordinate transformation, the relative pose of the pipeline is quickly solved, including the horizontal distance, height difference, and angle deviation, with the error controlled within the engineering allowable range. Compared with traditional methods, this solution takes into account both measurement accuracy and operation convenience, and is especially suitable for the high-efficiency positioning requirements of prefabricating cross-connecting pipes in underwater confined spaces. Brief Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a pipe connection pose measurement device applicable to underwater confined spaces provided in the first embodiment of this application.

[0019] Figure 2 It is a schematic diagram of pipe connection pose measurement provided in the first embodiment of this application.

[0020] Figure 3 It is a schematic structural diagram of a centering mechanism provided in the first embodiment of this application.

[0021] Figure 4 It is a schematic structural diagram of an angle measurement mechanism provided in the first embodiment of this application.

[0022] Figure 5 It is an exploded view of a rope length detection mechanism provided in the first embodiment of this application.

[0023] Figure 6 It is a flowchart of a solution algorithm for the pipe connection pose applicable to underwater confined spaces provided in the second embodiment of this application.

[0024] Figure 7 It is a schematic diagram of establishing a solution mathematical model with the underwater base riser (reference end) and the production tree horizontal pipe (measured end) as examples provided in the second embodiment of this application.

[0025] Description of reference numerals: 1, centering mechanism; 2, angle measuring mechanism; 3, rope length detecting mechanism; 10, transmission assembly; 11, support plate; 12, double-direction ratchet wrench; 13, reference end plate; 100, central threaded rod; 101, nut rod sleeve; 102, linkage mechanism; 20, magnetic coupling encoder; 21, coupling; 22, horizontal connecting shaft; 23, vertical connecting shaft; 24, bearing support; 25, measuring rope extending arm; 26, stainless steel measuring rope; 27, slide rail; 200, encoder body; 201, encoder fixing seat; 31, friction hub; 32, measuring rope pull ring; 33, anti-corrosion housing; 34, measuring rope outlet; 35, pipe clamp; 36, return spring; 37, base. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0027] Embodiment 1 See Figure 1 , which is a schematic structural diagram of a pipe connection pose measuring device applicable to an underwater confined space provided in Embodiment 1 of the present application. As Figure 1 shown, the above-mentioned pipe connection pose measuring device includes a centering mechanism 1, an angle measuring mechanism 2, and a rope length detecting mechanism 3. As Figure 2 shown, the pipe connection pose measuring device is locked with the flange end face of the underwater base pipe riser through the centering mechanism 1. The measuring rope extends from the extending point of the pipe connection pose measuring device to the flange end face of the pipe to be connected, that is, the flange end face of the horizontal pipe of the Christmas tree in the present application Figure 2 for detecting the relative pose.

[0028] The centering mechanism 1 plays a role of fixing and supporting the pipe connection pose measuring device, so that the angle measuring mechanism 2 is stably fixed on the pipe flange. As Figure 3 shown, the centering mechanism 1 mainly includes a transmission assembly 10, a support plate 11, a double-direction ratchet wrench 12, and a reference end plate 13.

[0029] The transmission assembly 10 includes a central threaded rod 100, a nut rod sleeve 101, and a linkage mechanism 102. The central threaded rod 100 penetrates through the central axis of the centering mechanism 1, and both ends are connected to the reference end plate 13 through bearings or bushings. The torque input by the diver is provided to the central threaded rod 100 by the bidirectional ratchet wrench 12, causing the thread to rotate radially. The planar thread of the threaded rod meshes with the inner thread of the nut rod sleeve 101, causing the nut rod sleeve 101 to move axially along the threaded rod, and further realizing the tensioning and relaxation of the support plate 11 through the linkage mechanism 102. The working range of the support plate 11 depends on the lengths of the central threaded rod 100 and the linkage mechanism 102. The support plate 11 can provide an effective supporting force within a working range of 100 - 600 mm, and the above working range can meet the installation conditions for the relative pose measurement of the pipes in the underwater foundation tray.

[0030] The angle measurement mechanism 2 includes an orthogonal inclination measurement mechanism and a measurement rope angle measurement mechanism. The measurement rope angle measurement mechanism and the orthogonal inclination measurement mechanism are both fixed on the reference end plate 13 of the centering mechanism 1, and are responsible for detecting the spatial poses of the two pipes and the relative angle between the stainless steel measurement rope 26 and the flange end face.

[0031] Specifically, the orthogonal inclination measurement mechanism is used to measure the horizontal and pitch inclinations of the pulling rope relative to the pipe flange end face, and outputs signals through the rotation angles of the orthogonal axis system. As Figure 4 shown in, the orthogonal inclination measurement mechanism includes a magnetic coupling encoder 20, a coupling 21, a horizontal connecting shaft 22, and a vertical connecting shaft 23. The horizontal connecting shaft 22 and the vertical connecting shaft 23 form a cross-orthogonal structure and are fixed on the bearing support 24. Further, to reduce the interference of friction during the rotation of the angle measurement mechanism 2 during operation on the measurement accuracy, a bearing assembly is embedded inside the bearing support 24 of this application.

[0032] The horizontal connecting shaft 22 transversely penetrates both sides of the bearing support 24 and is parallel to the pipe flange end face, and is used to transmit the change in the horizontal inclination. The vertical connecting shaft 23 is perpendicular to the horizontal axis and is coupled through the coupling 21 to transmit the change in the pitch inclination.

[0033] The magnetic coupling encoder 20 is fixedly installed on the encoder fixing seat 201 through bolts and is rigidly connected to the end of the horizontal connecting shaft 22, and is used to directly measure the rotation angle. As Figure 5 shown in, the magnetic coupling encoder 20 includes an encoder body 200, an encoder fixing seat 201, and fixing bolts. The encoder body 200 is embedded in the encoder fixing seat 201, and the two are fixed through mechanical buckles or screws. The encoder fixing seat 201 is vertically installed on the base 37 through a plurality of fixing bolts to stably fix the encoder body 200 and prevent displacement during the working process.

[0034] The measuring rope angle measuring mechanism indirectly calculates the relative angle between the measuring rope and the flange end face through the linear displacement of the measuring rope, and combines the movement of the slide rail 27 to map the angle change. As Figure 4 shown in, the measuring rope angle measuring mechanism further includes a measuring rope extending arm 25 for fixing the stainless steel measuring rope 26 and converting its linear motion into the movement of the slider of the slide rail 27. Among them, the slide rail 27 is arranged parallel to the horizontal connecting shaft 22, and the measuring rope extending arm 25 extends from the slide rail 27 to the outside of the pipeline.

[0035] The rope length detection mechanism 3 is used to measure the pulling out length of the measuring rope. The working principle of the rope length detection mechanism 3 is based on the friction between the friction wheel hub 31 and the pulling rope, and realizes the length measurement by converting mechanical motion into electrical signals that can be measured, recorded and transmitted. The key component of the rope length detection mechanism 3 is the friction wheel assembly, including the friction wheel hub 31, the friction wheel shaft, the bearing and the multi-turn magnetic coupling encoder 20. The friction wheel hub 31 is directly coupled to the rotating shaft of the magnetic coupling encoder 20, and the surface is provided with grooves for winding the stainless steel measuring rope 26. One end of the stainless steel measuring rope 26 is fixed on the friction wheel hub 31, and the other end is connected to the object to be measured through the measuring rope pull ring 32. In the embodiment of the present application, the friction wheel hub 31 and the measuring rope winding area are covered by an anti-corrosion housing 33 to seal and protect the friction wheel hub 31 and the measuring rope winding area to prevent environmental corrosion. The measuring rope outlet 34 is located in the guiding hole on the side wall of the anti-corrosion housing 33, and is internally equipped with a wear-resistant bushing to reduce the friction loss when the stainless steel measuring rope 26 moves. As Figure 5 shown in, the anti-corrosion housing 33 is fixed on the base 37 through the pipe clamp 35, and the pipe clamp 35 provides a radial tightening force to ensure that there is no relative movement between the anti-corrosion housing 33 and the base 37. One end of the return spring 36 is fixed on the side of the friction wheel hub 31, and the other end is fixed inside the anti-corrosion housing 33 to provide an elastic return force. After the external force is released, the spring drives the friction wheel hub 31 to rotate back, so that the stainless steel measuring rope 26 returns to the initial position.

[0036] The diver is responsible for assisting in the measurement operation, inspecting and cleaning the operation site, and completing the specific operation, installation, and recovery of the device. During measurement, the stretchable stainless-steel measuring rope 26 is wound around the hub in the wire drawing box and is in close contact with the friction hub 31. After the measuring rope is tensioned by pulling, it drives the friction wheel to rotate through friction. To ensure measurement accuracy, the surface of the friction wheel is specially treated to increase the friction coefficient, avoiding relative sliding between the measuring rope and the friction hub 31, thus ensuring contact stability. The rotation of the friction wheel is detected by a multi-turn magnetic coupling encoder 20 connected coaxially. The encoder is connected to the friction wheel shaft, and its output shaft rotates with the hub, generating an electrical signal proportional to the linear displacement of the measuring rope. Each rotation of the friction wheel corresponds to a fixed increment of the pulling rope length. By recording the angular change output by the encoder, the number of rotations of the friction wheel can be accurately calculated, and then the length of the pulling rope can be calculated. Thus, this mechanism can accurately reflect the displacement of the moving object, ensuring the accuracy and stability of the measurement process.

[0037] Embodiment 2 See Figure 6 , which is a flowchart of a solution algorithm for the pipe connection pose applicable to the underwater confined space provided in Embodiment 2 of this application. The pose is solved using the pipe connection pose measurement device provided in Embodiment 1 of this application. As Figure 6 shown in, the specific implementation steps of the above method include: Step 1: Establish a micro-element force model of the measuring rope, conduct a force analysis, and establish a micro-element balance equation in the force direction of the measuring rope.

[0038] Among them, the above micro-element forces include gravity, buoyancy, normal damping force, tangential damping force, and additional inertial force. In the actual measurement situation, the measuring rope is divided into three stages. One is the relaxation stage when the measuring rope is not in the measurement work. At this time, the measuring rope is mainly affected by the resultant load of forces such as gravity, buoyancy, and normal damping force. The second is the stage when the measuring rope is gradually tensioned under the action of the pulling force, and it is affected by the resultant load and the pulling force together. The third is the tensioned stage when the measuring rope is in the measurement work. The measuring rope is affected by the resultant load and the pulling force together and is in a tensioned state.

[0039] Step 2: Calculate the catenary curve of the measuring rope based on the parabola theory, assuming that the gravity load of the measuring rope is evenly distributed along its span and remains constant before and after deformation.

[0040] In the embodiment of the present application, a micro-element of the measuring rope is taken as the research object. Considering the complex marine environment and the influence of ocean currents, the resultant force acting on the micro-element of the measuring rope includes gravity, buoyancy, normal damping force, tangential damping force, and additional inertial force. When calculating, a stainless steel rope with a diameter of 1 mm is selected as the measuring rope. In the underwater connection operation of the underwater production system, the working distance range of pose measurement is generally 5 - 10 m. Its diameter is much smaller than the operation length, and as a flexible component, it does not bear bending moment and pressure. Therefore, the measuring rope can meet the three conditions of the single-cable calculation theory: (1) The measuring rope is an ideal flexible component, without compressive stress and bending moment acting on itself.

[0041] (2) The tension force acting on the measuring rope is along the tangent direction.

[0042] (3) The resultant force load acting on the measuring rope is determined, and the material characteristics conform to Hooke's law.

[0043] Based on the single-cable theory, a mechanical model of the measuring rope in the taut stage is established. When the measuring device is performing measurement operations, in the vertical plane, the horizontal and vertical components of the active tension can be calculated for any point on the measuring rope. The resultant force load acting on the measuring rope can be divided into uniformly distributed loads in the vertical and axial directions.

[0044] In actual measurement operations, the measuring rope only bears the tension at both ends and a fixed resultant force load. Generally, it is considered that the curve shape of the measuring rope conforms more to the catenary theory, and its sag amplitude is affected by its own weight and tension. The functional equation of the catenary is a transcendental function, and the solution process is complex and computationally intensive. Therefore, the parabola theory is often selected for calculation and solution in engineering.

[0045] In the present application, through comparative analysis of the two cable theories, the catenary equation is expanded according to the series equation and the first two terms are taken as the parabola equation. Under the working conditions of low load and short span, the results calculated by the parabola theory can also meet the accuracy requirements of actual engineering. Considering the actual working conditions of the measuring rope underwater and for the convenience of analysis and calculation, the parabola theory equation is adopted. The parabola theory assumes that the gravity load of the cable is uniformly distributed along its span and remains constant before and after the deformation of the measuring rope.

[0046] Step 3: Calculate the actual length of the measuring rope according to the above catenary curve, and solve the straight-line distance between the reference end device and the measured end device.

[0047] Step 4: Establish an absolute coordinate system with the center point of the pipe flange end face of the reference end device as the origin, and a reference coordinate system with the center point of the pipe flange end face of the measured end device as the origin.

[0048] In an ideal situation, a coordinate system is established in this application. Considering factors such as the complex seabed environment and installation errors in actual working conditions, there will be a certain angular offset in the pipeline, and the pitching motion and swaying motion of the pipeline are calculated.

[0049] Taking the underwater base riser (reference end) and the production tree horizontal pipe (measured end) as examples, the solution mathematical model is analyzed, and the solution mathematical model is established as Figure 7 shown. Two of the above-mentioned pipe connection pose measurement devices are respectively installed on the pipelines at the reference end and the measured end, hereinafter referred to as measurement device I and measurement device II. Let the intersection point of the pipe center axis and the flange A end face be O r , the intersection point of the horizontal pipe center axis and the flange B end face be O b , and the extension points of the stainless steel measuring ropes be point A and point C respectively. Taking O r as the coordinate origin, an absolute coordinate system Ω R is established. As shown in Figure 7 , this application uses the absolute coordinate system Ω R as the coordinate system with the underwater base riser as the reference. The underwater base riser coordinate system (reference end device coordinate system) Ω R defines the pose of the reference end device. The reference coordinate system Ω 1 can be regarded as Ω R rotated by an angle y r around the β r axis and rotated by an angle x r around the α r axis to establish. The Ω R axis of the coordinate system z r is the axis direction of the riser under actual working conditions. The coordinate system Ω 1 is translated along the z 1 axis by h r to point A to establish the reference coordinate system Ω3. Similarly, an absolute coordinate system Ωb (production tree horizontal pipe coordinate system), a reference coordinate system Ω 4 and a reference coordinate system Ω 5 are established.

[0050] Step 5: Measure multiple pose parameters, including angle parameters and distance parameters.

[0051] Among them, the above-mentioned angular parameters include, but are not limited to, the angle between the measuring device and the absolute horizontal plane, and the rotation angle of the measuring rope in the reference coordinate system. The above-mentioned distance parameters include the distance from the extending point of the measuring rope to the center point of the corresponding pipe flange end face and the length of the measuring rope.

[0052] Specifically, as Figure 7 shown, the pose parameters measured in this application include: α r , β r , γ r , θ r , h r , α b , β b , γ b , θ b , h b , S r 。 Among them, α r is the angle between the measuring device I and the absolute horizontal plane on the y axis. β r is the angle between the measuring device I and the absolute horizontal plane on the x axis. γ r is the longitudinal rotation angle of the stainless steel measuring rope in the reference coordinate system Ω 2. θ r is the transverse rotation angle of the stainless steel measuring rope in the reference coordinate system In Ω2 . 。h r is the distance from the starting point of the stainless steel measuring rope of the measuring device I to the center point of the end face of the pipeline flange to be measured C at a distance of O r . (mm) . α b is the angle between the measuring device II and the absolute horizontal plane on the y axis. β b is the angle between the measuring device II and the absolute horizontal plane on the x-axis. γ b is the horizontal inclination angle of the stainless steel measuring rope in the reference coordinate system Ω 5; θ bFor the pitch angle of the stainless - steel measuring rope in the reference coordinate system Ω in 5. h b Is the starting point of the stainless - steel measuring rope of the measuring device Ⅱ A The distance from the center point of the flange end face of the pipeline to be measured O b ( mm ) S r Is the length of the stainless - steel measuring rope ( mm )

[0053] Step 6: Determine the actual poses of the reference - end device and the measured - end device through the pose parameters obtained by measurement, and obtain the vector expressions in the measured - end coordinate system and the reference - end coordinate system respectively through coordinate transformation .

[0054] See Figure 7 , A represents the measuring - rope extension point on the measured - end device, C represents the measuring - rope extension point on the reference - end device, and the vector is used to describe the position and direction of the measured - end device relative to the reference - end device. In actual measurement operations, after the pipe - assembly connection pose measuring device measures the initial angle and distance parameters, the data is solved through the established pipeline relative - pose solving algorithm. In the established mathematical model, first determine the actual poses of the two pipelines to be measured, and obtain the expressions of the vector R in the reference coordinate system Ω b and the coordinate system Ω respectively through coordinate transformation.

[0055] Step 7: Construct a transition matrix, solve for the transition angle between the above - mentioned fixed coordinate system and the moving coordinate system, and use the above - mentioned transition angle to calculate the relative pose of the two pipelines, including the horizontal distance, height difference, and relative angle, to determine the size parameters of the prefabricated crossover pipe.

[0056] Solve for the transition angle between the coordinate system Ω R and the coordinate system Ω b based on the transition matrix. Finally, the expression of in the absolute coordinate system Ω R can be obtained, and the expression of the horizontal pipe axis of the Christmas tree in the relative coordinate system Ω1 can be obtained, and then the relative angle between the two pipelines can be calculated. Finally, the size parameters of the prefabricated crossover pipe required to connect two main pipeline components (such as riser and Christmas tree horizontal pipe) are obtained, including but not limited to the straight - line distance between the connection points at both ends of the crossover pipe or the actual path length to be covered, the inner diameter or outer diameter of the crossover pipe, the bending radius, and the wall thickness, etc.

[0057] Compared with the prior art, the technical solution provided by the embodiment of the present application has the following beneficial effects: The technical solution of this application significantly improves the efficiency and reliability of underwater pipeline connection pose measurement by optimizing the structural design of the measuring device and the calculation model of the measuring method. In terms of the device, the mechanical transmission component of the centering mechanism is combined with a two-way ratchet wrench to achieve rapid locking and adaptive adjustment. The operating range of the support plate covers 100 - 600 mm, adapting to different pipeline flange sizes and reducing the installation complexity for divers. The angle measuring mechanism uses non-contact detection of the orthogonal axis system and the magnetic coupling encoder, combined with the linear displacement mapping of the slide rail to map the angle change, avoiding the influence of traditional mechanical friction on the accuracy. At the same time, the anti-corrosion housing and wear-resistant bushing design enhance the corrosion resistance of the device, making it suitable for complex underwater environments. In terms of the method, a catenary curve model of the measuring rope is established based on the parabola theory. By simplifying the force analysis (only considering gravity, buoyancy, and uniform load) and calculating the catenary curve integral, the amount of calculation is effectively reduced. The horizontal angle error is ≤1°, and the rope length error is ≤50 mm, meeting the installation requirements of the crossover pipe (error < 150 mm), thus improving the calculation efficiency. By establishing a conversion model between the absolute coordinate system and the reference coordinate system, combined with multi-parameter pose fusion (horizontal inclination angle, pitch angle, linear distance, etc.), the relative pose of the two pipelines is accurately solved, providing high-precision dimension parameters for the prefabrication of the crossover pipe. While ensuring the measurement accuracy, the overall solution realizes the lightweight, portability of the device and the simplification of the operation process, significantly reducing the underwater operation load of divers. The device weight is reduced by 62%, and the volume is reduced by 25%, making it convenient for divers to carry, especially suitable for the efficient measurement requirements in underwater confined spaces.

[0058] Although the embodiments of this application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this application. The scope of this application is defined by the appended claims and their equivalents.

Claims

1. A pipe connection pose measurement device applicable to an underwater confined space, characterized in that It includes an angle measurement mechanism (2) and a rope length detection mechanism (3); the angle measurement mechanism (2) and the rope length detection mechanism (3) are fixed on the flange end face of the pipeline to be measured through a centering mechanism (1). The angle measurement mechanism (2) includes an orthogonal inclination measurement mechanism and a measuring rope angle measurement mechanism. The orthogonal inclination measurement mechanism includes an encoder and an orthogonal axis system fixed on a bearing support (24); the encoder is rigidly connected to the end of a horizontal connecting shaft (22) under the orthogonal axis system; the measuring rope angle measurement mechanism includes a measuring rope extension arm (25) and a slide rail (27), the slide rail (27) is arranged parallel to the horizontal connecting shaft (22), and the measuring rope extension arm (25) is slidably connected to the slide rail (27). The rope length detection mechanism (3) includes a friction wheel hub (31) wound with a stainless steel measuring rope (26) and an encoder. The friction wheel hub (31) is coupled to a rotating shaft through the encoder. One end of the stainless steel measuring rope (26) extends to the measuring rope extension arm (25), and the other end is connected to the flange end face of the pipeline to be measured through a measuring rope pull ring (32).

2. The pipe connection pose measurement device applicable to an underwater confined space according to claim 1, characterized in that The centering mechanism (1) includes a transmission component (10), a support plate (11) and a reference end plate (13). The transmission component (10) is driven by a two-way ratchet wrench (12) to control the tension or relaxation of the support plate (11).

3. The pipe connection pose measurement device applicable to an underwater confined space according to claim 2, characterized in that, The transmission component (10) includes a central threaded rod (100), a nut rod sleeve (101) and a link mechanism (102). The central threaded rod (100) passes through the central axis of the centering mechanism (1) and is connected to the reference end plate (13) at both ends. The nut rod sleeve (101) meshes with the central threaded rod (100), and the link mechanism (102) connects the nut rod sleeve (101) and the support plate (11).

4. The pipe connection pose measurement device applicable to an underwater confined space according to claim 1, wherein The orthogonal axis system includes a horizontal connecting shaft (22) and a vertical connecting shaft (23), and the two form a cross-orthogonal structure through a coupling (21). The horizontal connecting shaft (22) and the vertical connecting shaft (23) are installed in a bearing support (24), and a bearing assembly is embedded inside the bearing support (24).

5. The pipe connection pose measuring device applicable to an underwater confined space according to claim 1, wherein, The rope length detection mechanism (3) further includes an anti-corrosion housing (33). The anti-corrosion housing (33) covers the friction wheel hub (31) and the measuring rope winding area. A measuring rope outlet (34) is provided on the side wall of the anti-corrosion housing (33), and a wear-resistant bushing is embedded in the measuring rope outlet (34).

6. The pipe connection pose measurement device applicable to underwater confined spaces according to claim 1, wherein The encoder is a magnetic coupling encoder (20), and the rotating shaft of the magnetic coupling encoder (20) in the rope length detection mechanism (3) is coaxially and rigidly connected to the friction wheel hub (31).

7. The pipe connection pose measurement device applicable to underwater confined spaces according to claim 1, characterized in that, The rope length detection mechanism (3) further includes a return spring (36). One end of the return spring (36) is fixed to the side of the friction wheel hub (31), and the other end is fixed to the inner wall of the anti-corrosion housing (33). The return spring (36) is used to drive the friction wheel hub (31) to reset to the initial position.

8. An algorithm for solving the pipe connection pose applicable to underwater confined spaces, which uses the pipe connection pose measurement device described in any one of claims 1 to 7 to solve the pipe connection pose, characterized in that It includes: Step 1: Establish a micro-element force model of the measuring rope, conduct a force analysis, and establish a micro-element balance equation in the force direction of the measuring rope. Step 2: Calculate the catenary curve of the measuring rope based on the parabola theory, assuming that the gravity load of the measuring rope is uniformly distributed along its span and remains constant before and after deformation; Step 3: Calculate the actual length of the measuring rope according to the catenary curve and solve the straight-line distance between the reference end device and the measured end device; Step 4: Establish an absolute coordinate system with the center point of the pipe flange end face of the reference end device as the origin, and a reference coordinate system with the center point of the pipe flange end face of the measured end device as the origin; Step 5: Measure multiple pose parameters, including angle parameters and distance parameters; Step 6: Convert the pose parameters measured in Step 5 into the absolute coordinate system and the reference coordinate system respectively to obtain the pose vector expressions of the reference end device and the measured end device; Step 7: Construct a transition matrix between the absolute coordinate system and the measured end coordinate system, solve the rotation angle and translation amount between the two coordinate systems, and calculate the relative pose of the two pipes, including the horizontal distance, height difference and relative angle, for determining the dimensional parameters of the prefabrication of the cross-connecting pipe.

9. The solution algorithm for the pipe connection pose applicable to underwater confined spaces according to claim 8, characterized in that, The pose parameters measured in Step 5 also include the angle between the measuring device and the absolute horizontal plane, the rotation angle of the measuring rope in the reference coordinate system, the distance from the extending point of the measuring rope to the center point of the corresponding pipe flange end face, and the length of the measuring rope.

10. The solution algorithm for the pipe connection pose applicable to underwater confined spaces according to claim 8, characterized in that The dimensional parameters of the prefabrication of the cross-connecting pipe include the straight-line distance between the connection points at both ends of the cross-connecting pipe or the actual path length to be covered, the inner diameter or outer diameter of the cross-connecting pipe, the bending radius and the wall thickness.

Images