Manifold connection posture measurement device and solution algorithm suitable for underwater confined spaces

Abstract

The present application relates to the field of underwater pipeline measurement technology, and in particular to a device and solution algorithm for measuring the position and posture of a manifold connection suitable for use in underwater confined spaces. The device includes an angle measurement mechanism and a rope length detection mechanism, which are fixed to the flange end face of the measured pipe via a centering mechanism. The angle measurement mechanism is composed of an orthogonal shaft system and a magnetically coupled encoder, which maps linear displacement into an angle signal in combination with a slide rail and a measuring rope extension arm. The rope length detection mechanism winds a stainless steel measuring rope around a friction hub within a corrosion-resistant housing, and uses an encoder to detect the number of rotations to calculate the rope length. The method includes establishing a microelement force model of the measuring rope, calculating a sag curve based on parabola theory, constructing an absolute coordinate system and a reference coordinate system, and solving the relative position and posture of the two pipes using posture parameters and a transition matrix. The lightweight design and low-friction shaft system reduce the workload of the diver, and high-precision posture measurement is achieved by combining parabola theory with dynamic coordinate transformation.

Description

Technical Field

[0001] The present application relates to the technical field of underwater pipeline measurement, and more specifically, to a manifold connection posture measurement device and solution algorithm suitable for 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 manifold connection posture measurement technology is increasing. However, the application of existing measurement technologies and devices in the special environment of underwater still faces many challenges.

[0003] On the one hand, regarding measurement equipment, the currently widely used pipe position and posture measurement methods mostly rely on remotely operated vehicles (ROVs) for assistance. For example, in complex and confined environments such as underwater production facilities and underwater foundations, pipeline connection measurement is difficult to accomplish using existing measurement equipment in conjunction with ROVs. These measurement tools are generally complex to operate, heavy, and bulky, making them ineffective in these challenging environments and significantly limiting the effectiveness of underwater pipeline measurement.

[0004] On the other hand, existing hydroacoustic measurement devices primarily utilize methods such as fixing to the outer pipe wall, fixing to the flange end face, and fixing to the inner pipe wall. However, in space-constrained operating conditions, these positioning methods require significant space and pose challenges for stable installation, which in turn reduces measurement accuracy. This demonstrates that existing technologies have significant shortcomings in optimizing positioning methods and are unable to meet the complex and diverse measurement requirements of the challenging underwater environment.

[0005] Furthermore, there is currently a lack of in-depth research addressing the complex and diverse measurement requirements of specialized underwater working conditions. In practical engineering, divers are a key method for underwater measurement. However, existing measurement tools do not adequately address the reduction of underwater loads on divers, making them portable, lightweight, and easy to use while maintaining measurement accuracy. Therefore, developing rope-based measurement equipment suitable for divers to improve their underwater measurement efficiency and ensure their safety has become a pressing technical challenge. Summary of the Invention

[0006] In view of this, the present application provides a manifold connection posture measurement device and solution algorithm suitable for underwater confined spaces to solve the problems of existing underwater manifold connection posture measurement tools being bulky, complicated to operate, with heavy workload for divers and insufficient measurement accuracy in complex environments.

[0007] The technical solutions provided in this application are as follows:

[0008] In a first aspect, the present application provides a manifold connection posture measurement device suitable for use in underwater confined spaces, comprising an angle measurement mechanism and a rope length detection mechanism; the angle measurement mechanism and the rope length detection mechanism are fixed to the flange end face of the measured pipe via a centering mechanism; the angle measurement mechanism comprises an orthogonal inclination measurement mechanism and a measuring rope angle measurement mechanism; the orthogonal inclination measurement mechanism comprises an encoder and an orthogonal axis system fixed to a bearing support; the encoder is rigidly connected to the end of a horizontal connecting axis under the orthogonal axis system; the measuring rope angle measurement mechanism comprises a measuring rope extension arm and a slide rail, the slide rail being arranged parallel to the horizontal connecting axis, the measuring rope extension arm being slidably connected to the slide rail;

[0009] The rope length detection mechanism includes a friction hub wrapped with a stainless steel measuring rope and an encoder. The friction hub is coupled to the rotating shaft through the encoder. One end of the stainless steel measuring rope extends to the measuring rope extension arm, and the other end is connected to the flange end face of the measured pipe through the measuring rope pull ring.

[0010] In one possible implementation, the centering mechanism includes a transmission assembly, a support plate and a reference end plate. The transmission assembly is driven by a bidirectional ratchet wrench to control the tensioning or loosening of the support plate.

[0011] In one possible implementation, the transmission assembly includes a center threaded rod, a nut rod sleeve and a connecting rod mechanism. The center 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 center threaded rod, and the connecting rod mechanism connects the nut rod sleeve and the support plate.

[0012] In one possible implementation, the orthogonal axis system includes a horizontal connecting axis and a vertical connecting axis, which form a cross-orthogonal structure through a coupling. The horizontal connecting axis and the vertical connecting axis are installed in a bearing support, and a bearing assembly is embedded in the bearing support.

[0013] In one possible implementation, the rope length detection mechanism further includes an anti-corrosion shell, which covers the friction hub and the measuring rope winding area. The side wall of the anti-corrosion shell is provided with a measuring rope outlet, and the measuring rope outlet is embedded with a wear-resistant bushing.

[0014] 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 hub.

[0015] In one possible implementation, the rope length detection mechanism further includes a reset spring, one end of which is fixed to the side of the friction hub and the other end is fixed to the inner wall of the anti-corrosion shell, and the reset spring is used to drive the friction hub to reset to its initial position.

[0016] In a second aspect, the present application provides an algorithm for solving the manifold connection posture in an underwater confined space, which uses the manifold connection posture measurement device as described in any one of the first aspects to solve the manifold connection posture, including:

[0017] Step 1: Establish a microelement force model of the measuring rope, perform force analysis, and establish a microelement equilibrium equation in the force direction of the measuring rope;

[0018] Step 2: Calculate the sag 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;

[0019] Step 3: Calculate the actual length of the measuring rope according to the drape curve, and solve the straight-line distance between the reference end device and the measured end device;

[0020] 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;

[0021] Step 5: Measure multiple posture parameters, including angle parameters and distance parameters;

[0022] Step 6: Convert the posture parameters measured in step 5 into the absolute coordinate system and the reference coordinate system respectively to obtain posture vector expressions of the reference end device and the measured end device;

[0023] Step 7: Construct a transition matrix between the absolute coordinate system and the measured end coordinate system, solve the rotation angle and translation between the two coordinate systems, and calculate the relative position of the two pipes, including the horizontal distance, height difference and relative angle, to determine the dimensional parameters of the jumper pipe prefabrication.

[0024] In one possible implementation, the posture 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 extension point of the measuring rope to the center point of the corresponding pipe flange end face, and the length of the measuring rope.

[0025] In one possible implementation, the dimension parameters of the prefabricated jumper tube include the straight-line distance between the connection points at both ends of the jumper tube or the actual path length required to be covered, the inner diameter or outer diameter of the jumper tube, the bending radius and the wall thickness.

[0026] Compared with the existing technology, the technical solution of this application has the following beneficial effects:

[0027] The technical solution of this application significantly reduces the underwater working load of divers by integrating a centering mechanism, an orthogonal shaft angle measurement mechanism, and a friction hub rope length detection mechanism, thereby achieving lightweight and portability of the measuring tool. The device adopts a magnetic coupling encoder and a corrosion-resistant shell design to ensure high-precision angle and rope length detection in complex underwater environments, avoiding mechanical wear and environmental corrosion; it simplifies the calculation of the drape curve through parabola theory, combines the microelement force model with dynamic coordinate transformation, and quickly solves the relative position of the pipeline, including horizontal distance, height difference, and angle deviation, with the error controlled within the allowable range of the project. Compared with traditional methods, this solution takes into account both measurement accuracy and ease of operation, and is particularly suitable for the efficient positioning needs of prefabricated cross-over pipes in confined underwater spaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural schematic diagram of a manifold connection posture measurement device suitable for underwater confined spaces provided in Example 1 of the present application.

[0029] Figure 2 A schematic diagram of a manifold connection posture measurement provided in Example 1 of the present application.

[0030] Figure 3 This is a structural schematic diagram of a centering mechanism provided in Example 1 of the present application.

[0031] Figure 4 This is a structural schematic diagram of an angle measurement mechanism provided in Example 1 of the present application.

[0032] Figure 5 This is an exploded view of a rope length detection mechanism provided in Example 1 of the present application.

[0033] Figure 6 This is a flowchart of an algorithm for solving the manifold connection posture in an underwater confined space, provided in Example 2 of the present application.

[0034] Figure 7 The second embodiment of the present application provides a schematic diagram of establishing and solving a mathematical model using an underwater template riser (reference end) and a Christmas tree horizontal pipe (tested end) as examples.

[0035] Explanation of the accompanying symbols: 1. Centering mechanism; 2. Angle measuring mechanism; 3. Rope length detection mechanism; 10. Transmission assembly; 11. Support plate; 12. Bidirectional ratchet wrench; 13. Reference end plate; 100. Center threaded rod; 101. Nut rod sleeve; 102. Connecting rod mechanism; 20. Magnetic coupling encoder; 21. Coupling; 22. Horizontal connecting shaft; 23. Vertical connecting shaft; 24. Bearing support; 25. Measuring rope extension 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. Corrosion-resistant housing; 34. Measuring rope outlet; 35. Pipe clamp; 36. Reset spring; 37. Base. DETAILED DESCRIPTION

[0036] The following will combine the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0037] Example 1

[0038] See also Figure 1 , is a structural diagram of a manifold connection posture measurement device suitable for underwater confined space provided in Example 1 of the present application. Figure 1 As shown in , the manifold connection posture measurement device includes a centering mechanism 1, an angle measurement mechanism 2, and a rope length detection mechanism 3. Figure 2 As shown in FIG, the manifold connection posture measurement 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 extension point of the manifold connection posture measurement device to the flange end face of the pipe to be connected, that is, the present application Figure 2 The flange end face of the Christmas tree flat pipe is used to detect the relative position.

[0039] The centering mechanism 1 fixes and supports the manifold connection posture measurement device, so that the angle measurement mechanism 2 is stably fixed on the pipeline flange. Figure 3 As shown in FIG, the centering mechanism 1 mainly includes a transmission assembly 10, a support plate 11, a bidirectional ratchet wrench 12 and a reference end plate 13.

[0040] The transmission assembly 10 includes a central threaded rod 100, a nut rod sleeve 101, and a connecting rod mechanism 102. The central threaded rod 100 passes 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 diver's input torque is provided to the central threaded rod 100 by a two-way ratchet wrench 12, causing the thread to rotate radially. The flat thread of the threaded rod engages with the inner thread of the nut rod sleeve 101, causing the nut rod sleeve 101 to move axially along the threaded rod, and then the support plate 11 is tightened and loosened through the connecting rod mechanism 102. The operating range of the support plate 11 depends on the length of the central threaded rod 100 and the connecting rod mechanism 102. The support plate 11 can provide effective support force within the operating range of 100-600mm, and the above operating range can meet the installation conditions for measuring the relative position of pipelines in underwater base plates.

[0041] The angle measuring mechanism 2 includes an orthogonal inclination measuring mechanism and a measuring rope angle measuring mechanism. Both the measuring rope angle measuring mechanism and the orthogonal inclination measuring mechanism are fixed on the reference end plate 13 of the centering mechanism 1, and are responsible for completing the detection of the spatial posture of the two pipes and the relative angle between the stainless steel measuring rope 26 and the flange end face.

[0042] Specifically, the orthogonal inclination angle measuring mechanism is used to measure the horizontal and pitch angles of the pull rope relative to the end face of the pipe flange, and outputs a signal through the rotation angle of the orthogonal axis system. Figure 4 As shown in FIG, the orthogonal inclination angle 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 an orthogonal cross structure and are fixed to a bearing support 24. Furthermore, to reduce the interference of friction on measurement accuracy during the rotation of the angle measurement mechanism 2 during operation, a bearing assembly is embedded in the bearing support 24 of the present application.

[0043] The horizontal connecting shaft 22 runs horizontally through the bearing supports 24 on both sides and is parallel to the end face of the pipe flange, used to transmit horizontal tilt angle changes. The vertical connecting shaft 23 is perpendicular to the horizontal axis and is coupled through the coupling 21 to transmit pitch angle changes.

[0044] The magnetic coupling encoder 20 is fixed on the encoder fixing seat 201 by bolts and is rigidly connected to the end of the horizontal connecting shaft 22 for directly measuring the rotation angle. Figure 5 As shown in Figure 3, the magnetic coupling encoder 20 includes an encoder body 200, an encoder mounting base 201, and mounting bolts. The encoder body 200 is embedded in the encoder mounting base 201, and the two are secured using mechanical clips or screws. The encoder mounting base 201 is vertically mounted on the base 37 using multiple mounting bolts to stabilize the encoder body 200 and prevent displacement during operation.

[0045] The angle measuring mechanism of the measuring rope indirectly calculates the relative angle between the measuring rope and the flange end face through the linear displacement of the measuring rope, and maps the angle change in combination with the movement of the slide rail 27. Figure 4 As shown in FIG, the measuring rope angle measurement mechanism further includes a measuring rope extension arm 25 for securing a stainless steel measuring rope 26 and converting its linear motion into movement of a slider on a slide rail 27. The slide rail 27 is arranged parallel to the horizontal connecting shaft 22, and the measuring rope extension arm 25 extends from the slide rail 27 to the outside of the pipe.

[0046] The rope length detection mechanism 3 is used to measure the pulled-out length of the rope. The working principle of the rope length detection mechanism 3 is based on the friction between the friction hub 31 and the pull rope, and the length measurement is achieved by converting mechanical motion into an electrical signal 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 hub 31, the friction wheel shaft, the bearing and the multi-turn magnetic coupling encoder 20. The friction hub 31 is directly coupled to the rotating shaft of the magnetic coupling encoder 20, and has a groove on the surface for winding the stainless steel measuring rope 26. One end of the stainless steel measuring rope 26 is fixed on the friction 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 hub 31 and the measuring rope winding area are covered by an anti-corrosion shell 33 to seal and protect the friction hub 31 and the measuring rope winding area to prevent environmental corrosion. The measuring rope outlet 34 is located in the guide hole on the side wall of the anti-corrosion shell 33, and is equipped with a wear-resistant bushing inside to reduce the friction loss of the stainless steel measuring rope 26 when it moves. As Figure 5 As shown in Figure 3, the corrosion-resistant housing 33 is secured to the base 37 via a pipe clamp 35. This clamp provides radial tightening force, ensuring that there is no relative movement between the corrosion-resistant housing 33 and the base 37. A return spring 36, with one end secured to the side of the friction hub 31 and the other end secured inside the corrosion-resistant housing 33, provides an elastic return force. When the external force is released, the spring drives the friction hub 31 to rotate, returning the stainless steel measuring cable 26 to its initial position.

[0047] Divers assist in the measurement process, inspect and clean the work site, and complete the specific operation, installation, and recovery of the device. During measurement, a stretchable stainless steel measuring rope 26 is wrapped around a hub within the drawbar, making close contact with the friction wheel hub 31. Once the measuring rope is pulled taut, friction drives the friction wheel to rotate. To ensure measurement accuracy, the friction wheel surface is specially treated to increase the friction coefficient, preventing relative slip between the measuring rope and the friction wheel hub 31 and thus ensuring contact stability. The rotation of the friction wheel is detected by a coaxially connected, multi-turn magnetically coupled encoder 20. 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 in the rope length. By recording the angular change in the encoder output, the number of friction wheel rotations, and thus the rope length, can be accurately calculated. This mechanism accurately reflects the displacement of a moving object, ensuring the accuracy and stability of the measurement process.

[0048] Example 2

[0049] See also Figure 6 , is a flow chart of a solution algorithm for the manifold connection posture in an underwater confined space provided in the second embodiment of the present application. The posture is solved using the manifold connection posture measurement device provided in the first embodiment of the present application. Figure 6 As shown in , the specific implementation steps of the above method include:

[0050] Step 1: Establish a microelement force model of the measuring rope, perform force analysis, and establish a microelement equilibrium equation in the force direction of the measuring rope.

[0051] The aforementioned microelement forces include gravity, buoyancy, normal damping, tangential damping, and additional inertia. In actual measurement situations, the measuring rope is divided into three phases: the first is the slack phase when the measuring rope is not measuring. During this phase, the measuring rope is primarily subject to the combined load of gravity, buoyancy, and normal damping. The second is the phase in which the measuring rope is gradually tightened by tension, acting on it in combination with the combined load and tension. The third is the tension phase during measurement, when the measuring rope is in a taut state due to the combined load and tension.

[0052] Step 2: Calculate the sag 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.

[0053] The present embodiment takes the microelement of a measuring rope as the research object. Considering the complex ocean environment and the influence of ocean currents, the net force acting on the microelement of the measuring rope includes gravity, buoyancy, normal damping force, tangential damping force, and additional inertial force. A stainless steel rope with a diameter of 1 mm was selected as the measuring rope during the calculation. In underwater connection operations in underwater production systems, the working distance range of posture measurement is generally 5-10 m. Its diameter is much smaller than the operating length, and as a flexible component, it is not subject to bending moment and pressure. Therefore, the measuring rope can meet the three conditions of single-rope calculation theory:

[0054] (1) The measuring rope is an ideal flexible component and is not subject to compressive stress or bending moment.

[0055] (2) The tension on the measuring rope is in the tangential direction.

[0056] (3) The resultant load acting on the measuring rope is determined, and the material properties conform to Hooke's law.

[0057] Based on the theory of a single suspension cable, a mechanical model of the measuring rope in the tension phase was established. During measurement, the horizontal and vertical components of the active tension can be calculated at any point on the measuring rope in the vertical plane. The resultant load acting on the measuring rope can be divided into uniformly distributed loads in the vertical and axial directions.

[0058] In actual measurement operations, a measuring rope only bears the tension at its ends and a fixed resultant load. It's generally believed that the curved shape of a measuring rope better conforms to catenary theory, with its sag affected by its own weight and tension. The catenary equation is a transcendental function, making its solution complex and computationally intensive. Therefore, parabola theory is often used in engineering calculations.

[0059] This application compares and analyzes two cable theories. The catenary equation is expanded as a series equation, and the first two terms are taken to form a parabolic equation. Under low-load, short-span conditions, the results calculated using parabolic theory can achieve the accuracy required for practical engineering. Considering the actual working conditions of the measuring rope underwater, and for ease of analysis and calculation, the parabolic theory equation is adopted. Parabolic theory assumes that the gravity load of the cable is evenly distributed along its span and remains constant before and after the measuring rope is deformed.

[0060] Step 3: Calculate the actual length of the measuring rope according to the above-mentioned draping curve, and solve the straight-line distance between the reference end device and the measured end device.

[0061] 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.

[0062] This application establishes a coordinate system under ideal conditions, and takes into account that in actual working conditions, due to factors such as the complex seabed environment and installation errors, the pipeline will have a certain angular offset, and calculates the pitch and swing motions of the pipeline.

[0063] Taking the underwater base plate riser (reference end) and the Christmas tree horizontal pipe (test end) as examples, the mathematical model for solution is analyzed and the mathematical model for solution is established. Figure 7 As shown. Install the two aforementioned manifold connection posture measurement devices on the reference end and the measured end of the pipe respectively, hereinafter referred to as measurement device I and measurement device II. Set the pipe center axis and flange A The end intersection point is O r The intersection of the center axis of the horizontal tube and the end face of flange B is O b , the extension points of the stainless steel measuring rope are point A and point C respectively. O r As the coordinate origin, establish an absolute coordinate system Ω R .like Figure 7 As shown in the , this application uses an absolute coordinate system Ω R As a coordinate system based on the underwater template riser, the underwater template riser coordinate system (reference end device coordinate system) Ω R The reference coordinate system is defined in Ω 1 Can be seen as Ω R Around y r Axis rotated by angle β r , around x r Axis rotated by angle α r The coordinate system established Ω R of z r The axis is the axis direction of the riser under actual working conditions. Ω 1 Along z 1 Axis Translation h r Go to point A and establish the reference coordinate system Ω3. Similarly, establish the absolute coordinate system Ωb (Christmas tree horizontal pipe coordinate system), reference coordinate system Ω 4 and reference coordinate system Ω 5.

[0064] Step 5: Measure multiple posture parameters, including angle parameters and distance parameters.

[0065] Among them, the above-mentioned angle 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 extension point of the measuring rope to the center point of the corresponding pipe flange end face and the length of the measuring rope.

[0066] Specifically, if Figure 7 As shown in , the posture parameters measured by 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 。 in, α r The measuring device I is in contact with the absolute horizontal plane. y The angle between the axes. β r The measuring device I is in contact with the absolute horizontal plane. x The angle between the axes. γ r For stainless steel measuring rope in the reference coordinate system Ω 2 in the longitudinal corner. θ r For stainless steel measuring rope in the reference coordinate system Ω2 Horizontal angle 。h r Starting point of the stainless steel measuring rope of measuring device I C Distance from the center point of the flange end face of the measured pipe O r distance (mm) . α b The measuring device II is at the absolute horizontal plane. y The angle between the axes. β b is the angle between the measuring device II and the absolute horizontal plane on the x-axis. γ b For stainless steel measuring rope in the reference coordinate system Ω Horizontal inclination in 5; θ bFor stainless steel measuring rope in the reference coordinate system Ω 5 in pitch angle. h b Starting point of the stainless steel measuring rope of measuring device II A Distance from the center point of the flange end face of the measured pipe O b The distance ( mm ). S r The length of the stainless steel measuring rope ( mm ).

[0067] Step 6: Determine the actual postures of the reference end device and the measured end device through the measured posture parameters, and obtain the vector expressions in the measured end coordinate system and the reference end coordinate system respectively through coordinate transformation. .

[0068] See also Figure 7 , A represents the point where the measuring rope extends from the device under test, C represents the point where the measuring rope extends from the device under reference, and the vector It is used to describe the position and orientation of the device under test relative to the reference device. In actual measurement operations, after the initial angle and distance parameters are measured by the posture measurement device connected to the manifold, the data is solved using the established pipeline relative posture solution algorithm. In the established mathematical model, the actual posture of the two pipelines under test is first determined, and the reference coordinate system Ω is obtained through coordinate transformation. R and coordinate system Ω b Mean vector expression.

[0069] Step 7: Construct a transition matrix and solve the transition angle between the fixed coordinate system and the mobile coordinate system. Use the transition angle to calculate the relative position of the two pipes, including the horizontal distance, height difference, and relative angle, to determine the size parameters of the jumper pipe prefabrication.

[0070] Based on the transition matrix, the coordinate system Ω is obtained R and coordinate system Ω b The transition angle between In the absolute coordinate system Ω R The horizontal pipe axis of the oil tree is shown in The relative angle between the two pipes can be calculated by expressing it in the relative coordinate system Ω1. Ultimately, the dimensional parameters of the prefabricated jumper required to connect two major pipeline components (such as a riser and a Christmas tree flat pipe) are obtained. These parameters include, but are not limited to, the straight-line distance between the jumper's connection points or the actual path length required to be covered, the jumper's inner or outer diameter, the bend radius, and the wall thickness.

[0071] Compared with the prior art, the technical solution provided by the embodiments of the present application has the following beneficial effects:

[0072] The technical solution of this application significantly improves the efficiency and reliability of underwater manifold connection position measurement by optimizing the structural design of the measurement device and the computational model of the measurement method. Regarding the device, a centering mechanism's mechanical transmission assembly, combined with a bidirectional ratchet wrench, enables rapid tightening and adaptive adjustment. The support plate has an operating range of 100-600mm, adapting to various pipe flange sizes and reducing installation complexity for divers. The angle measurement mechanism utilizes non-contact detection using an orthogonal axis system and a magnetically coupled encoder, combined with linear displacement mapping of the slide rail to angle changes, to avoid the impact of traditional mechanical friction on accuracy. The corrosion-resistant housing and wear-resistant bushing enhance the device's corrosion resistance, making it suitable for complex underwater environments. Regarding the method, a sag curve model for the measuring rope is established based on parabolic theory. By simplifying the force analysis (considering only gravity, buoyancy, and uniformly distributed load) and the sag curve integral calculation, the computational complexity is effectively reduced, achieving a horizontal angle error of ≤1° and a rope length error of ≤50mm, meeting the jumper pipe installation requirements (error <150mm) and improving computational 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, straight-line distance, etc.), the relative pose of the two pipes is accurately calculated, providing high-precision dimensional parameters for jumper pipe prefabrication. While ensuring measurement accuracy, this overall solution achieves lightweight and portable device and simplifies the operation process, significantly reducing the underwater workload for divers. The device is 62% lighter and 25% smaller, making it easier for divers to carry and particularly suitable for efficient measurement in confined underwater spaces.

[0073] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A manifold connection position measurement device suitable for underwater confined spaces, characterized in that: The invention comprises an angle measuring mechanism (2) and a rope length detection mechanism (3); the angle measuring mechanism (2) and the rope length detection mechanism (3) are fixed on the flange end face of the measured pipeline through a centering mechanism (1); the angle measuring mechanism (2) comprises an orthogonal tilt angle measuring mechanism and a measuring rope angle measuring mechanism; the orthogonal tilt angle measuring mechanism comprises an encoder and an orthogonal axis system fixed on a bearing support (24), and is used to measure the horizontal and pitch angles of the rope relative to the flange end face of the pipeline, and output a signal through the rotation angle of the orthogonal axis system; the encoder is rigidly connected to the end of a horizontal connecting shaft (22) under the orthogonal axis system; the measuring rope angle measuring mechanism comprises 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 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 maps the angle change in combination with the movement of the slide rail (27); A rope length detection mechanism (3) comprises a friction hub (31) wound with a stainless steel measuring rope (26) and an encoder, wherein the friction hub (31) is coupled to a rotating shaft via the encoder, and one end of the stainless steel measuring rope (26) extends to a measuring rope extension arm (25), and the other end is connected to a flange end face of a measured pipe via a measuring rope pull ring (32); The centering mechanism (1) comprises a transmission assembly (10), a support plate (11) and a reference end plate (13); the transmission assembly (10) is driven by a bidirectional ratchet wrench (12) to control the tensioning or loosening of the support plate (11).

2. The device for measuring the manifold connection posture suitable for underwater confined spaces according to claim 1, characterized in that: The transmission assembly (10) comprises a central threaded rod (100), a nut rod sleeve (101) and a connecting rod mechanism (102); the central threaded rod (100) passes through the central axis of the centering mechanism (1) and is connected to a reference end plate (13) at both ends; the nut rod sleeve (101) is engaged with the central threaded rod (100); and the connecting rod mechanism (102) connects the nut rod sleeve (101) and the support plate (11).

3. The manifold connection position measurement device suitable for underwater confined spaces according to claim 1, characterized in that: The orthogonal shaft system includes a horizontal connecting shaft (22) and a vertical connecting shaft (23), which 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 in the bearing support (24).

4. The device for measuring the manifold connection posture suitable for underwater confined spaces according to claim 1, characterized in that: The rope length detection mechanism (3) further comprises an anti-corrosion housing (33), the anti-corrosion housing (33) covering the friction hub (31) and the measuring rope winding area, the side wall of the anti-corrosion housing (33) being provided with a measuring rope outlet (34), the measuring rope outlet (34) being embedded with a wear-resistant bushing.

5. The device for measuring the manifold connection posture suitable for underwater confined spaces according to claim 1, characterized in that: 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 hub (31).

6. The device for measuring the manifold connection posture suitable for underwater confined spaces according to claim 1, characterized in that: The rope length detection mechanism (3) further includes a reset spring (36), one end of which is fixed to the side of the friction hub (31) and the other end is fixed to the inner wall of the anti-corrosion shell (33). The reset spring (36) is used to drive the friction hub (31) to reset to an initial position.

7. An algorithm for solving the manifold connection posture in an underwater confined space, which uses the manifold connection posture measurement device according to any one of claims 1 to 6 to solve the manifold connection posture, characterized in that: include: Step 1: Establish a microelement force model of the measuring rope, perform force analysis, and establish a microelement equilibrium equation in the force direction of the measuring rope; Step 2: Calculate the sag 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 drape 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 posture parameters, including angle parameters and distance parameters; Step 6: Convert the posture parameters measured in step 5 into the absolute coordinate system and the reference coordinate system respectively to obtain posture 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 between the two coordinate systems, and calculate the relative position of the two pipes, including the horizontal distance, height difference and relative angle, to determine the dimensional parameters of the jumper pipe prefabrication.

8. The algorithm for solving the manifold connection posture applicable to underwater confined spaces according to claim 7 is characterized in that: The posture 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 extension point of the measuring rope to the center point of the corresponding pipe flange end face, and the length of the measuring rope.

9. The algorithm for solving the manifold connection posture applicable to underwater confined spaces according to claim 7, characterized in that: The dimension parameters of the prefabricated jumper tube include the straight-line distance between the connection points at both ends of the jumper tube or the actual path length required to be covered, the inner diameter or outer diameter of the jumper tube, the bending radius and the wall thickness.

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