Experimental Platform for Flow-Induced Vibration of Variable-Direction and Different-Diameter Marine Cables Based on Real-Time Force Feedback

Abstract

This invention provides an experimental platform for the flow-induced vibration of a variable-diameter marine pipeline based on real-time force feedback. A rigid segmented model of the variable-diameter twin-tube system is connected to an incoming flow angle-of-attack adjustment mechanism, which is connected to a cross-flow vibration simulation system, and the cross-flow vibration simulation system is connected to a downstream vibration simulation system. A real-time force feedback control system controls the incoming flow angle-of-attack adjustment mechanism, the cross-flow vibration simulation system, and the downstream vibration simulation system. The incoming flow angle-of-attack adjustment mechanism includes a gear set, a rotary motion control motor, a connecting plate, a device support frame, and a bearing assembly. This invention achieves high-fidelity reproduction of the dual-degree-of-freedom coupled vibration of the variable-diameter twin-tube system at any angle of attack through an integrated virtual-real interactive system, enabling rapid software-based traversal of the system's dynamic parameters.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and more specifically, to an experimental platform for flow-induced vibration of marine cables with varying flow directions and diameters based on real-time force feedback. Background Technology

[0002] In modern marine engineering, pipeline systems are crucial for ensuring oil and gas transportation. A typical engineering configuration is a unequal-diameter pipeline assembly, where smaller-diameter functional pipelines are attached to larger-diameter main risers, forming a "back-mounted" structure. When this assembly is subjected to ocean currents, complex wake interference occurs between the large and small pipelines, inducing flow-induced vibrations throughout the structure. More importantly, real ocean currents are constantly changing, and different angles of attack can drastically alter the flow patterns between the pipelines, resulting in extremely complex dynamic responses. Accurately predicting and understanding these response patterns is a core prerequisite for structural fatigue assessment and optimized design.

[0003] However, the current research paradigm relying on traditional physical model experiments has a fundamental bottleneck in meeting the parametric research requirements of engineering design. For robust design, it is essential to systematically study the impact of changes in key parameters such as structural stiffness and damping on vibration response. But in traditional experiments, these parameters are determined by fixed physical springs and dampers; any adjustment requires cumbersome and time-consuming hardware replacement, making efficient parametric research virtually impossible. Secondly, simulating real-world environments is difficult; precisely and continuously changing the flow direction in a water tank is technically challenging.

[0004] Patent document CN105203298A discloses a test device for vortex-induced vibration of an ocean riser with locally increased inflow velocity at an inclined angle, including an ocean riser model, a transverse test support frame, a velocity amplification device, a trailer, a strain gauge, and a computer. Patent document CN113390596A discloses a collision test system for vortex-induced vibration of an ocean riser bundle, mainly including an ocean riser model, a double-layer support device, a dual-degree-of-freedom air-floating slide rail system, a circulating wave flume, and a data measurement and acquisition system. Patent document CN105300635A discloses a test device for vortex-parametric coupled vibration of a vertical stepped inflow ocean riser, including an ocean riser model, a transverse test support frame fixed to the bottom of a trailer, an axial force reciprocating device, a strain gauge, and a computer; a steel wire rope connects the ocean riser model and the axial force reciprocating device.

[0005] The aforementioned patent documents have the following drawbacks: a) Two-degree-of-freedom motion is difficult to simulate. Current flow-induced vibration experiments, due to technical limitations, often simplify the motion to a single-degree-of-freedom vibration with only the transverse direction. However, this dimensionality reduction does not match the physical reality of the coupled motion in the longitudinal and transverse directions of real marine pipelines, which will lead to a deviation in the understanding of the response mechanism and affect the accuracy of safety assessment; b) Physical parameters are difficult to traverse. Traditional pool model experiments use fixed physical components to give the model a predetermined structural performance. However, this method makes it impossible to adjust parameters in a timely manner, which does not meet the requirements of systematic parameter optimization in engineering design. The process of replacing components is time-consuming and laborious, which seriously restricts experimental efficiency and research depth; c) The incoming flow angle is difficult to change. Existing pool experiments are often carried out at a fixed incoming flow angle. However, this method cannot simulate continuously changing flow directions, which does not match the actual working conditions of variable flow directions in the real marine environment. It may miss the extreme response value at the most unfavorable angle of attack, which may bring safety hazards to engineering design. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide an experimental platform for flow-induced vibration of marine cables with varying flow directions and diameters based on real-time force feedback.

[0007] According to the present invention, a flow-induced vibration experimental platform for a variable-diameter marine cable based on real-time force feedback includes: a rigid segmented model of a double-pipe with different diameters, an incoming flow angle of attack adjustment mechanism, a cross-flow vibration simulation system, a downstream vibration simulation system, and a real-time force feedback control system.

[0008] The rigid segmented model of the two-pipe with different diameters is connected to the incoming flow angle of attack adjustment mechanism, the incoming flow angle of attack adjustment mechanism is connected to the crossflow vibration simulation system, and the crossflow vibration simulation system is connected to the downstream vibration simulation system; the real-time force feedback control system controls the incoming flow angle of attack adjustment mechanism, the crossflow vibration simulation system, and the downstream vibration simulation system;

[0009] The incoming flow angle of attack adjustment mechanism includes: a gear set, a rotary motion control motor, a connecting plate, a device support frame, and a bearing set;

[0010] The transverse vibration simulation system is connected to the device support frame; the device support frame is connected to the rotary motion control motor and the bearing assembly; the rotary motion control motor is connected to the connecting plate through the gear assembly and can drive the connecting plate to rotate; the gear in the gear assembly connected to the connecting plate is rotatably connected to the device support frame through the bearing assembly; the connecting plate is connected to the rigid segmented model of the two pipes with different diameters.

[0011] Preferably, the gear set includes a primary gear and a driven gear that mesh with each other;

[0012] The main gear is connected to the drive end of the rotary motion control motor;

[0013] The driven gear is rotatably mounted on the connecting plate via the bearing assembly and is connected to the connecting plate.

[0014] Preferably, the number of teeth of the primary gear is less than the number of teeth of the driven gear.

[0015] Preferably, the connecting plate is an aluminum plate.

[0016] Preferably, the rigid segmented model of the two-pipe system with different diameters includes: a main pipe column model, a secondary pipe column model, and two baffles, wherein the main pipe column model and the secondary pipe column model are arranged side by side with intervals.

[0017] A first force measurement module is provided at each end of the main column model, and a second force measurement module is provided at each end of the secondary column model.

[0018] One of the baffles is connected to the first force measurement module at one end of the main pipe column model and the second force measurement module at one end of the secondary pipe column model; the other baffle is connected to the first force measurement module at the other end of the main pipe column model and the second force measurement module at the other end of the secondary pipe column model.

[0019] Preferably, the diameter of the main tube column model is different from the diameter of the secondary tube column model.

[0020] Preferably, the real-time force feedback control system includes: a host computer control module, a physical quantity acquisition module, and a servo control module;

[0021] The physical quantity acquisition module includes a three-part force sensor module and a motor displacement encoder; the three-part force sensor module can measure the hydrodynamic load on the rigid segmented model of the two pipes with different diameters in real time; the motor displacement encoder can measure the motion displacement of the transverse vibration simulation system and the co-current vibration simulation system in real time.

[0022] The host computer control module has a built-in dynamic algorithm module, which can solve the response displacement of the rigid segmented model of the two-diameter tube in real time based on the sensing data of the three-part force sensor module.

[0023] The servo control module includes a transverse flow servo driver, a forward flow servo driver, and a rotary motion servo driver; the transverse flow servo driver and the forward flow servo driver generate control pulses after receiving displacement commands output by the host computer control module; the rotary motion servo driver generates control pulses after receiving rotation commands output by the host computer control module.

[0024] Preferably, the real-time force feedback control system further includes: a human-computer interaction module;

[0025] The human-computer interaction module is used to set the vibration parameters of the rigid segmented model of the two-pipe with different diameters in the transverse and longitudinal directions. The vibration parameters include virtual mass, virtual stiffness, and virtual damping.

[0026] Preferably, the real-time force feedback control system further includes: an EtherCAT communication bus;

[0027] The EtherCAT communication bus is used to connect the host computer control module, the physical quantity acquisition module, the servo control module, and the human-machine interaction module, and to realize communication and command transmission between the various modules.

[0028] Preferably, the specific process of conducting the experiment using a variable-direction, unequal-diameter marine cable flow-induced vibration experimental platform based on real-time force feedback is as follows:

[0029] The experimental platform is placed in a uniform flow. The hydrodynamic load on the rigid segmented model of the two-pipe with different diameters is measured in real time by the three-force sensor module. The displacement of the rigid segmented model of the two-pipe with different diameters in the cross-flow and downstream directions is measured by the motor displacement encoder. The hydrodynamic load data and displacement data are transmitted to the host computer control module through the physical quantity acquisition module.

[0030] The host computer control module solves the motion equations of the rigid segmented model of the two-pipe system with different diameters in real time based on the recursive form of the Duhamel integral algorithm, calculates the target position at the next moment, and transmits the target position data to the transverse servo driver and the co-current servo driver. The transverse servo driver and the co-current servo driver drive the transverse vibration simulation system and the co-current vibration simulation system to operate, thereby moving the rigid segmented model of the two-pipe system with different diameters to the target position.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. This invention breaks through the limitations of traditional experiments conducted at a few discrete angles, and realizes continuous and variable simulation of the incoming flow direction, making it possible to fully capture the envelope of the structural dynamic response and accurately identify the most unfavorable design conditions.

[0033] 2. This invention can simultaneously decouple and measure the hydrodynamic loads on the main and auxiliary pipe models, and is used to analyze the torsional effect caused by asynchronous lift, as well as complex interference phenomena such as downstream repulsion / attraction caused by asymmetric drag.

[0034] 3. The experimental platform of this invention systematically breaks through the limitations of traditional experiments, realizes the simulation of two-degree-of-freedom coupled motion of two tubes with different diameters under variable flow, and also supports efficient systematic traversal of key parameters, laying the foundation for in-depth mechanism research.

[0035] 4. The application of force feedback technology in this invention enables soft adjustment of parameters, greatly simplifies the working condition switching process, reduces experimental costs and shortens the R&D cycle, and comprehensively improves the efficiency and universality of the experimental platform.

[0036] 5. This invention replaces the complex physical constraint system with active force feedback technology, which can not only accurately reproduce the coupled dynamic behavior in the longitudinal and transverse directions, but also greatly simplify the device structure and improve the reliability and simplicity of the experiment.

[0037] 6. This invention decouples key parameters such as stiffness and damping from physical entities and defines them in software through a virtual model, realizing online precise control and efficient traversal of parameters, providing core technical support for systematic engineering design optimization. Attached Figure Description

[0038] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0039] Figure 1 This is a schematic diagram of the experimental platform for flow-induced vibration of marine cables with varying flow directions and diameters based on real-time force feedback.

[0040] Figure 2 A front view of an experimental platform for flow-induced vibration of a variable-direction, unequal-diameter marine cable based on real-time force feedback;

[0041] Figure 3 A side view of an experimental platform for flow-induced vibration of a variable-direction, unequal-diameter marine cable based on real-time force feedback;

[0042] Figure 4 This is a top view of an experimental platform for flow-induced vibration of a variable-direction, unequal-diameter marine cable based on real-time force feedback.

[0043] Figure 5 This is a schematic diagram of the rigid segmented model of a two-pipe system with different diameters.

[0044] Figure 6 A schematic diagram of the internal structure of the main column model;

[0045] Figure 7 This is a schematic diagram of the transverse vibration simulation system;

[0046] Figure 8 This is a schematic diagram of the downstream vibration simulation system.

[0047] Figure 9 This is a schematic diagram of the incoming flow angle of attack adjustment mechanism;

[0048] Figure 10 This is a schematic diagram of a real-time force feedback control system.

[0049] The diagram shows:

[0050] 1. Rigid segmented model of two pipes with different diameters; 101. Main pipe column model; 102. Secondary pipe column model; 2. Downstream vibration simulation system; 3. Crossstream vibration simulation system; 4. Baffle plate; 5. Incoming flow angle of attack adjustment mechanism; 6. First hydrodynamic shell; 7. First three-part force sensor; 8. First square inner frame; 9. First connecting component; 10. First load-bearing component; 11. First limiting component; 12. Slider connecting component; 13. Crossstream motion control motor; 14. Crossstream linear slide rail module; 15. First drive shaft; 16. First reducer; 17. Crossstream motion slider; 18. Downstream motion control motor; 19. Downstream... 20. Linear slide rail module; 21. Flow-direction motion slider; 22. Real-time force feedback control system; 23. EtherCAT communication bus; 24. Servo control module; 25. Flow-direction servo driver; 26. Cross-flow servo driver; 27. Human-machine interaction module; 28. Host computer control module; 29. ​​Dynamics algorithm module; 30. Physical quantity acquisition module; 31. Three-part force sensor module; 32. Motor displacement encoder; 33. Connecting plate; 34. Device support frame; 35. Gear set; 36. Rotary motion control motor; 37. Bearing set; 38. Rotary motion servo driver; 39. Second transmission shaft; 30. Second reducer. Detailed Implementation

[0051] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0052] Example 1

[0053] like Figures 1 to 10 As shown, this embodiment provides a flow-induced vibration experimental platform for variable-diameter marine pipelines based on real-time force feedback, including: a rigid segmented model of a double-pipe with different diameters 1, an incoming flow angle of attack adjustment mechanism 5, a cross-flow vibration simulation system 3, a downstream vibration simulation system 2, and a real-time force feedback control system 21.

[0054] The rigid segmented model 1 of the two pipes with different diameters is connected to the incoming flow angle of attack adjustment mechanism 5, the incoming flow angle of attack adjustment mechanism 5 is connected to the cross-flow vibration simulation system 3, and the cross-flow vibration simulation system 3 is connected to the downstream vibration simulation system 2; the real-time force feedback control system 21 controls the incoming flow angle of attack adjustment mechanism 5, the cross-flow vibration simulation system 3 and the downstream vibration simulation system 2.

[0055] The rigid segmented model 1 of the two-pipe system with different diameters includes: a main pipe column model 101, a secondary pipe column model 102, and two baffles 4. The main pipe column model 101 and the secondary pipe column model 102 are arranged side by side with intervals. A first force measurement module is installed at each end of the main pipe column model 101, and a second force measurement module is installed at each end of the secondary pipe column model 102. One baffle 4 is connected to the first force measurement module at one end of the main pipe column model 101 and the second force measurement module at one end of the secondary pipe column model 102; the other baffle 4 is connected to the first force measurement module at the other end of the main pipe column model 101 and the second force measurement module at the other end of the secondary pipe column model 102. The pipe diameter of the main pipe column model 101 is different from the pipe diameter of the secondary pipe column model 102.

[0056] The incoming flow angle of attack adjustment mechanism 5 includes: a gear set 34, a rotary motion control motor 35, a connecting plate 32, a device support frame 33, and a bearing assembly 36; the transverse flow vibration simulation system 3 is connected to the device support frame 33; the rotary motion control motor 35 and the bearing assembly 36 are connected to the device support frame 33; the rotary motion control motor 35 is connected to the connecting plate 32 through the gear set 34 and can drive the connecting plate 32 to rotate; the gear in the gear set 34 connected to the connecting plate 32 is rotatably connected to the device support frame 33 through the bearing assembly 36; the connecting plate 32 is connected to the rigid segmented model 1 of the double-pipe with different diameters. The gear set 34 includes: a main gear and a driven gear that mesh with each other; the main gear is connected to the drive end of the rotary motion control motor 35; the driven gear is rotatably mounted on the connecting plate 32 through the bearing assembly 36 and is connected to the connecting plate 32. The number of teeth of the main gear is less than the number of teeth of the driven gear. The connecting plate 32 is an aluminum plate.

[0057] The transverse flow vibration simulation system 3 includes a transverse flow motion control motor 13, a transverse flow linear slide rail module 14, a first drive shaft 15, a first reducer 16, and a transverse flow motion slider 17. The transverse flow motion control motor 13 is driven by the first drive shaft 15 via the first reducer 16. The first drive shaft 15 is connected to the transverse flow linear slide rail module 14, and the transverse flow motion slider 17 is connected to the transverse flow linear slide rail module 14. The first drive shaft 15 can drive the linear slide rail module 14 to rotate, and the linear slide rail module 14 can drive the transverse flow motion slider 17 to move. Two transverse flow linear slide rail modules 14 are configured, arranged side-by-side with intervals, and both are connected to the first drive shaft 15. The transverse flow motion slider 17 is connected to the device support frame 33 via a slider connecting member 12.

[0058] The transverse linear slide rail module 14 includes: a first outer shell, a first conveyor wheel, and a first annular conveyor chain; two first conveyor wheels are provided, and the two first conveyor wheels are respectively located at both ends of the first outer shell, and the first annular conveyor chain is wrapped around the two first conveyor wheels; a first drive shaft 15 is connected to one of the two first conveyor wheels and can drive the first conveyor wheel to rotate; the first conveyor wheel can drive the first annular conveyor chain to rotate; a first conveying groove is provided on the first outer shell along its length direction, and a connecting structure on the transverse motion slider 17 passes through the first conveying groove and is connected to the first annular conveyor chain; the first conveying groove allows the transverse motion slider 17 to move on the first outer shell.

[0059] The downstream vibration simulation system 2 includes a downstream motion control motor 18, a downstream linear slide rail module 19, a second drive shaft 38, a second reducer 39, and a downstream motion slider 20. The downstream motion control motor 18 is driven by the second drive shaft 38 via the second reducer 39. The second drive shaft 38 is connected to the downstream linear slide rail module 19, and the downstream motion slider 20 is connected to the downstream linear slide rail module 19. The second drive shaft 38 can drive the downstream linear slide rail module 19 to rotate, which in turn drives the downstream linear slide rail module 19 to move the downstream motion slider 20. Two downstream linear slide rail modules 19 are configured, arranged side-by-side with intervals, and both are connected to the second drive shaft 38. The downstream motion sliders 20 on the two downstream linear slide rail modules 19 are respectively connected to both ends of the transverse linear slide rail module 14.

[0060] The downstream linear slide rail module 19 includes: a second outer shell, a second conveyor wheel, and a second annular conveyor chain; two second conveyor wheels are provided, respectively located at both ends of the second outer shell, and the second annular conveyor chain is wrapped around the two second conveyor wheels; a second drive shaft 38 is connected to one of the two second conveyor wheels and can drive the second conveyor wheel to rotate; the second conveyor wheel can drive the second annular conveyor chain to rotate; a second conveying groove is provided on the second outer shell along its length direction, and a connecting structure on the downstream motion slider 20 passes through the second conveying groove and connects to the second annular conveyor chain; the second conveying groove allows the downstream motion slider 20 to move on the second outer shell.

[0061] The main column model 101 includes a first hydrodynamic shell 6, a first square inner frame 8, and two first force measurement modules. The first hydrodynamic shell 6 is concentrically fitted onto the outside of the first square inner frame 8; the two first force measurement modules are respectively located at both ends of the first square inner frame 8 and at both ends of the first hydrodynamic shell 6.

[0062] The first force measurement module includes a first three-part force sensor 7, a first connecting member 9, a first load-bearing member 10, and a first limiting member 11. The first connecting member 9 is connected to the end of the first square inner frame 8 by bolts, the first three-part force sensor 7 is connected to the first connecting member 9 by bolts, and the first load-bearing member 10 is connected to the first three-part force sensor 7 by bolts. The first limiting member 11 is disposed on the first load-bearing member 10 and can contact the end edge of the first hydrodynamic shell 6, restricting the relative movement of the first hydrodynamic shell 6 with respect to the first load-bearing member 10 along its axial direction.

[0063] One end of each of the two baffles 4 is connected to the first load-bearing component 10 of the first force measurement module located at both ends of the first square inner frame 8. The first three-part force sensor 7 and the first connecting component 9 are located inside the first hydrodynamic housing 6. The hydrodynamic force experienced by the first hydrodynamic housing 6 during the test can be transmitted to the first three-part force sensor 7 through the first load-bearing component 10.

[0064] The first hydrodynamic shell 6 is a cylindrical tube; the inner diameter of the first hydrodynamic shell 6 is the same as the outer diameter of the first load-bearing member 10, and the first load-bearing member 10 is located at the port of the first hydrodynamic shell 6.

[0065] The length of the first hydrodynamic shell 6 is equal to the vertical distance between the upper surfaces of the two first load-bearing members 10 located at its two ends; the upper surface of the first load-bearing member 10 is the surface connected to the baffle plate 4; the first hydrodynamic shell 6 is in close contact with the first load-bearing member 9.

[0066] The secondary pipe column model includes a second hydrodynamic shell, a second square inner frame, and two second force measurement modules. The second hydrodynamic shell is concentrically fitted onto the outside of the second square inner frame; the two second force measurement modules are respectively located at both ends of the second square inner frame and at both ends of the second hydrodynamic shell.

[0067] The second force measurement module includes a second three-part force sensor, a second connecting member, a second load-bearing member, and a second limiting member. The second connecting member is bolted to the end of the second square inner frame, the second three-part force sensor is bolted to the second connecting member, and the second load-bearing member is bolted to the second three-part force sensor. The second limiting member is disposed on the second load-bearing member and can contact the end edge of the second hydrodynamic shell, restricting the relative movement of the second hydrodynamic shell with respect to the second load-bearing member along its axial direction.

[0068] The other ends of the two baffles are respectively connected to the second load-bearing components of the second force measurement modules located at both ends of the second square inner frame. The second three-part force sensor and the second connecting component are located inside the second hydrodynamic housing. The hydrodynamic force experienced by the second hydrodynamic housing during the test can be transmitted to the second three-part force sensor through the second load-bearing components.

[0069] The second hydrodynamic shell is a cylindrical tube; the inner diameter of the second hydrodynamic shell is the same as the outer diameter of the second load-bearing member, and the second load-bearing member is located at the port of the second hydrodynamic shell.

[0070] The length of the second hydrodynamic shell is equal to the vertical distance between the upper surfaces of the two second load-bearing members located at its two ends; the upper surface of the second load-bearing member is the surface connected to the baffle plate; the second hydrodynamic shell is in close contact with the second load-bearing member.

[0071] The diameter of the first hydrodynamic shell is the same as the diameter of the second hydrodynamic shell.

[0072] The real-time force feedback control system 21 includes: a host computer control module 27, a physical quantity acquisition module 29, and a servo control module 23; the physical quantity acquisition module 29 includes a three-part force sensor module 30 and a motor displacement encoder 31; the three-part force sensor module 30 can measure the hydrodynamic load on the rigid segment model 1 of the unequal-diameter double pipe in real time; the motor displacement encoder 31 can measure the motion displacement of the transverse vibration simulation system 3 and the downstream vibration simulation system 2 in real time; the host computer control module 27 has a built-in dynamic algorithm module 28, which can solve the problem of the rigid segment model 1 of the unequal-diameter double pipe in real time based on the sensing data of the three-part force sensor module 30. The real-time force feedback control system 21 also includes a human-machine interface module 26. The human-machine interface module 26 is used to set the vibration parameters of the rigid segmented model 1 with different diameters in the transverse and longitudinal directions. The vibration parameters include virtual mass, virtual stiffness, and virtual damping. The real-time force feedback control system 21 also includes an EtherCAT communication bus 22. The EtherCAT communication bus 22 is used to connect the host computer control module 27, the physical quantity acquisition module 29, the servo control module, and the human-machine interface module 26, and to realize communication and command transmission between the various modules. The force sensor module 30 consists of a first force sensor 7 on the main column model 101 and a second force sensor on the secondary column model 102.

[0073] The specific process of conducting the experiment using the variable-diameter, variable-flow-direction marine pipe and cable flow-induced vibration experimental platform based on real-time force feedback is as follows: The experimental platform is placed in a uniform flow. The hydrodynamic load on the variable-diameter double-pipe rigid segment model 1 is measured in real time by the three-part force sensor module 30. The displacement of the variable-diameter double-pipe rigid segment model 1 in the transverse and downstream directions is measured by the motor displacement encoder 31. The hydrodynamic load data and displacement data are transmitted to the host computer control module 27 through the physical quantity acquisition module 29. The host computer control module 27 solves the motion equation of the variable-diameter double-pipe rigid segment model 1 in real time based on the recursive form of the Duhamel integral algorithm, calculates the target position at the next moment, and transmits the target position data to the transverse servo drive 25 and the downstream servo drive 24. The transverse servo drive 25 and the downstream servo drive 24 drive the transverse vibration simulation system 3 and the downstream vibration simulation system 2 to operate, driving the variable-diameter double-pipe rigid segment model 1 to move to the target position.

[0074] Example 2

[0075] Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1.

[0076] This embodiment provides an experimental platform for flow-induced vibration of marine cables with varying flow direction and diameter based on real-time force feedback, which relates to the fields of marine engineering, fluid-structure interaction, and vortex-induced vibration technology.

[0077] The experimental platform for flow-induced vibration of marine cables with different diameters and different flow directions based on real-time force feedback control in this embodiment consists of a rigid segmented model of two pipes with different diameters, an incoming flow angle of attack adjustment mechanism, a cross-flow vibration simulation system, a downstream vibration simulation system, and a real-time force feedback control system.

[0078] The rigid segmented model of the two pipes with different diameters is connected to the incoming flow angle of attack adjustment mechanism, which is connected to the transverse flow motion slider in the transverse flow vibration simulation system. The transverse flow vibration simulation system is further connected to the downstream flow motion slider in the downstream flow vibration simulation system. The real-time force feedback control system communicates with each drive motor through the servo controller and control circuit to achieve synchronous control.

[0079] The rigid segmented model of the two-pipe system with different diameters consists of a main pipe column model and a secondary pipe column model. Each column model comprises a hydrodynamic shell, sensor support components, a square inner frame, connecting components, three-part force sensors, load-bearing components, limiting components, slider connecting components, and baffles. The hydrodynamic shell is made of carbon fiber, and its outer diameter is determined according to the similarity criteria of physical model experiments. The sensor support components are distributed at both ends of the square inner frame and are fixed by bolts through the connecting components. Two sets of three-part force sensors are installed between the sensor support components and the square inner frame, and can independently measure hydrodynamic information during the experiment. The load-bearing components are fixed to the ends of the three-part force sensors by bolts, and the limiting components are installed on the load-bearing components to constrain the assembly position of the hydrodynamic shell. The two ends of the hydrodynamic shell are fitted to the load-bearing components through the limiting components and coaxially fitted onto the outside of the square inner frame. The baffles at the upper and lower ends can effectively reduce the influence of the free liquid surface on the experimental results.

[0080] The incoming flow angle of attack adjustment mechanism consists of a gear set, a rotary motion control motor, a connecting aluminum plate, a device support frame, and a bearing set. The bearing set, rotary motion control motor, and gear set are fixedly connected to the device support frame. The gear set is fixedly connected to the connecting aluminum plate, which is connected to the rigid segmented model with a double-tube design of varying diameters. The rotary motion control motor receives control commands from the servo controller to precisely adjust the spatial angle of the model, enabling attitude switching under different incoming flow angles.

[0081] The transverse flow vibration simulation system consists of a transverse flow motion control motor, a transverse flow motion slider, and two linear slide rail modules. The two linear slide rail modules are mounted on the transverse flow vibration simulation system with a fixed distance between them. The transverse flow motion control motor is connected to the linear slide rail modules via a reducer and a drive shaft, receives command signals from the real-time feedback system, and drives the rigid segmented model of the two pipes with different diameters to move laterally to the target position.

[0082] The downstream vibration simulation system consists of a downstream motion control motor, a downstream motion slider, and two linear slide rail modules. The two linear slide rail modules are mounted and fixed on the tank trailer frame; the downstream motion control motor is coupled to the drive shaft through a reducer, driving the rigid segmented model of the two pipes with different diameters to move precisely along the downstream direction, realizing two-dimensional motion control.

[0083] The real-time force feedback control system consists of a host computer control module, a physical quantity acquisition module, a servo control module, an EtherCAT communication bus, and a human-machine interface terminal. The physical quantity acquisition module includes a three-part force sensor and a motor displacement encoder, used to acquire hydrodynamic load and displacement signals in real time. The host computer control module has a built-in dynamic calculation algorithm that calculates the response displacement of the rigid segmented model of the two-pipe system with different diameters in real time based on the sensor data. The servo control module includes a transverse servo driver and a co-current servo driver, which mainly receive displacement commands output from the host computer and generate control pulses. The human-machine interface is used to set virtual mass, stiffness, and damping parameters, enabling customized configuration of the closed-loop control system.

[0084] During the experiment, the system operates in a closed loop based on the force feedback principle: the three-part force sensor inside the rigid segmented model of the unequal-diameter double-pipe measures the force in real time, the displacement encoder collects the transverse and longitudinal displacement data, and inputs them into the host computer control module via the signal acquisition module; the host computer control module solves the motion equation in real time based on the recursive Duhamel integral algorithm, calculates the target position at the next moment within 2 ms, and transmits the result to the servo controller; the servo controller drives the transverse and longitudinal servo motors to run synchronously, and drives the model to move through the slide rail module, thereby realizing the closed-loop force feedback control of the entire process, accurately reproducing the vortex-induced vibration response characteristics of the unequal-diameter double-pipe under two degrees of freedom in the transverse and longitudinal directions.

[0085] This embodiment addresses the challenges of unclear flow interference mechanisms in tube bundles of varying diameters under variable flow conditions and the inherent bottlenecks in simulating dynamic parameters in traditional physics experiments. It provides a novel experimental platform based on real-time force feedback. This embodiment aims to achieve high-fidelity reproduction of the two-degree-of-freedom coupled vibration of two tubes of varying diameters at arbitrary angles of attack through an integrated virtual-real interactive system, enabling rapid software-based traversal of system dynamic parameters. Ultimately, it provides an efficient and accurate solution for mechanism exploration and engineering design in this field.

[0086] Example 3

[0087] Those skilled in the art can understand this embodiment as a more specific description of Embodiment 1.

[0088] This embodiment provides an experimental platform for flow-induced vibration of marine cables with different diameters and different flow directions based on real-time force feedback control. It consists of a rigid segmented model of two pipes with different diameters 1, an incoming flow angle of attack adjustment mechanism 5, a cross-flow vibration simulation system 3, a downstream vibration simulation system 2, and a real-time force feedback control system 21.

[0089] The rigid segmented model 1 of the two pipes with different diameters is connected to the incoming flow angle of attack adjustment mechanism 5. The incoming flow angle of attack adjustment mechanism 5 is connected to the transverse flow motion slider 17 in the transverse flow vibration simulation system 3. The transverse flow vibration simulation system 3 is further connected to the downstream flow motion slider 20 in the downstream flow vibration simulation system 2. The real-time force feedback control system 21 communicates with each drive motor through the servo controller and control circuit to achieve synchronous control.

[0090] The rigid segmented model 1 with different diameter dual pipes consists of a main pipe column model 101 and a secondary pipe column model 102, each pipe adopting a rigid segmented structure. Each segment includes: a hydrodynamic shell, three-part force sensors, a square inner frame, connecting components, load-bearing components, limiting components, slider connecting components, and baffles. Specifically: the hydrodynamic shell is made of carbon fiber, and its geometric proportions and outer diameter are determined according to the similarity criterion of flow-induced vibration; the square inner frame is a hollow aluminum alloy frame, used to provide rigid support and bear the sensors and connecting components; the three-part force sensors are arranged between the hydrodynamic shell and the square inner frame, used to measure the hydrodynamic forces of the model under the influence of the fluid in real time; the connecting components and load-bearing components are fixed to both ends of the sensors with bolts to ensure accurate force transmission paths; the limiting components are used to constrain the assembly position of the shell to prevent radial or axial displacement; the slider connecting components are used to realize the assembly connection between the model and the motion system; the baffles are set on the upper and lower end faces of the model, which can effectively reduce the interference of free liquid surfaces on experimental results. After the above-mentioned structural assembly, the differential diameter dual-pipe model can perform high-precision dynamic response testing under the drive of a two-dimensional motion system, and measure the hydrodynamic load under different working conditions in real time.

[0091] The incoming flow angle adjustment mechanism 5 includes a gear set 34, a rotary motion control motor 35, a connecting plate 32, a bearing assembly 36, and a device support frame 33. The device support frame 33 is fixedly connected to the transverse flow vibration simulation system 3, and the rotary motion control motor 35 and bearing assembly 36 are mounted on it. The gear set 34 is fixedly connected to the connecting plate 32, which in turn is connected to the rigid segmented model 1 with different diameter double pipes. The rotary motion control motor 35 receives control commands from the servo control module 23 and drives the model to rotate through the gear set 34, achieving precise attitude adjustment under different incoming flow angles.

[0092] The transverse flow vibration simulation system 3 includes a transverse flow motion control motor 13, a transverse flow linear slide rail module 14, a first reducer 16, a first drive shaft 15, and a transverse flow motion slider 17. Two transverse flow linear slide rail modules 14 are mounted on the longitudinal flow vibration simulation system 2 at a fixed distance. The transverse flow motion control motor 13 drives the transverse flow motion slider 17 to move linearly along the slide rail via the first reducer 16 and the first drive shaft 15, thereby driving the model to achieve precise lateral displacement. The transverse flow motion control motor 13 communicates with the real-time force feedback control system through the servo control module 23 to achieve real-time closed-loop control of the transverse flow motion.

[0093] The downstream vibration simulation system 2 includes a downstream motion control motor 18, a downstream linear slide rail module 19, a second reducer, a second drive shaft, and a downstream motion slider 20. Two downstream linear slide rail modules 19 are fixedly mounted on the tank trailer frame. The downstream motion control motor 18 drives the downstream motion slider 20 to move along the downstream direction via the second reducer and the second drive shaft, achieving downstream displacement control of the model. The combination of the downstream and cross-flow motion systems constitutes a two-dimensional motion mechanism, realizing dual-degree-of-freedom dynamic control of the rigid segmented model with unequal diameter pipes.

[0094] The real-time force feedback control system consists of a host computer control module 27, a physical quantity acquisition module 29, a servo control module 23, an EtherCAT communication bus 22, and a human-machine interaction module 26. Specifically: the physical quantity acquisition module 29 includes a three-part force sensor module and a motor displacement encoder 31, used to acquire the force and displacement information of the model; the host computer control module 27 has a built-in dynamics algorithm module 28, which calculates the displacement response of the unequal-diameter double-pipe model in real time based on the data acquired by the sensors; the servo control module 23 includes a downstream servo driver 24 and a cross-flow servo driver 25, which receive the target displacement signal calculated by the host computer and output control pulses to the corresponding motors; the EtherCAT communication bus 22 is used to achieve high-speed real-time communication; and the human-machine interaction module 26 is used to set control parameters such as virtual mass, damping, and stiffness, enabling customized configuration of experimental parameters. This system constitutes a high-frequency closed-loop control structure, which can update the model response within a 2 ms time step, achieving real-time feedback of force and displacement.

[0095] Working principle:

[0096] Before the experiment, the operator inputs the virtual mass, stiffness, and damping parameters of the simulation model into the host computer control module 27 via the human-computer interaction module 26, and drives the rotary motion control motor 35 through the servo control module 23 to adjust the rigid segmented model 1 of the two-pipe with different diameters to the target inflow angle. During the experiment, the water tank trailer moves forward at a constant speed, forming a uniform flow field, causing the model to generate vortex-induced vibration under the action of the fluid.

[0097] During the experiment: the three-part force sensor module measures the hydrodynamic forces of the model under the influence of the fluid in real time; the motor displacement encoder 31 synchronously measures the displacement and velocity of the model along the downstream and cross-flow directions; the data is filtered and noise-reduced by the physical quantity acquisition module 29 and then input into the host computer control module 27; the dynamic algorithm module 28 recursively calculates the target displacement at the next moment based on the current force and displacement data; the servo control module 23 generates pulse signals to drive the downstream motor 18 and the cross-flow motor 13 respectively; the two motors drive the model to the target position via the downstream linear slide rail module 19 and the cross-flow linear slide rail module 14. This process is executed in real time with a cycle period of 2 ms, realizing full closed-loop force feedback control, thereby accurately reproducing the vortex-induced vibration response characteristics of the two-pipe with different diameters under two degrees of freedom conditions.

[0098] This invention achieves high-fidelity reproduction of the dual-degree-of-freedom coupled vibration of two tubes with different diameters at any angle of attack through an integrated virtual-real interaction system, enabling rapid software-based traversal of the system's dynamic parameters.

[0099] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "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.

[0100] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An experimental platform for flow-induced vibration of marine cables with varying current direction and diameter based on real-time force feedback, characterized in that, include: Rigid segmented model of two pipes with different diameters (1), incoming flow angle of attack adjustment mechanism (5), cross-flow vibration simulation system (3), downstream vibration simulation system (2) and real-time force feedback control system; The rigid segmented model (1) of the two pipes with different diameters is connected to the incoming flow angle of attack adjustment mechanism (5), the incoming flow angle of attack adjustment mechanism (5) is connected to the cross-flow vibration simulation system (3), and the cross-flow vibration simulation system (3) is connected to the downstream vibration simulation system (2); the real-time force feedback control system controls the incoming flow angle of attack adjustment mechanism (5), the cross-flow vibration simulation system (3), and the downstream vibration simulation system (2); The incoming flow angle of attack adjustment mechanism (5) includes: a gear set (34), a rotary motion control motor (35), a connecting plate (32), a device support frame (33), and a bearing set (36); The transverse vibration simulation system (3) is connected to the device support frame (33); the device support frame (33) is connected to the rotary motion control motor (35) and the bearing assembly (36); the rotary motion control motor (35) is connected to the connecting plate (32) through the gear set (34) and can drive the connecting plate (32) to rotate; the gear in the gear set (34) connected to the connecting plate (32) is rotatably connected to the device support frame (33) through the bearing assembly (36); the connecting plate (32) is connected to the rigid segmented model (1) of the different diameter double tubes; The rigid segmented model (1) of the two pipes with different diameters includes: a main pipe column model (101), a secondary pipe column model (102) and two baffles (4), wherein the main pipe column model (101) and the secondary pipe column model (102) are arranged side by side with intervals. A first force measurement module is provided at each end of the main column model (101), and a second force measurement module is provided at each end of the secondary column model (102). One of the baffles (4) is connected to the first force measurement module at one end of the main pipe column model (101) and the second force measurement module at one end of the secondary pipe column model (102); the other baffle (4) is connected to the first force measurement module at the other end of the main pipe column model (101) and the second force measurement module at the other end of the secondary pipe column model (102). The diameter of the main tube column model (101) is different from the diameter of the secondary tube column model (102); The real-time force feedback control system (21) includes: a host computer control module (27), a physical quantity acquisition module (29), and a servo control module (23). The physical quantity acquisition module (29) includes a three-part force sensor module (30) and a motor displacement encoder (31); the three-part force sensor module (30) can measure the hydrodynamic load on the rigid segmented model (1) of the different diameter double pipe in real time; the motor displacement encoder (31) can measure the motion displacement of the transverse vibration simulation system (3) and the co-current vibration simulation system (2) in real time. The host computer control module (27) has a built-in dynamic algorithm module (28), which can solve the response displacement of the rigid segmented model (1) of the different diameter double tube in real time based on the sensing data of the three-part force sensor module (30). The servo control module (23) includes a transverse flow servo driver (25), a forward flow servo driver (24), and a rotary motion servo driver (37); the transverse flow servo driver (25) and the forward flow servo driver (24) generate control pulses after receiving displacement commands output by the host computer control module (27); the rotary motion servo driver (37) generates control pulses after receiving rotation commands output by the host computer control module (27). The real-time force feedback control system (21) also includes: a human-computer interaction module (26). The human-computer interaction module (26) is used to set the vibration parameters of the rigid segmented model (1) of the different diameter double pipe in the transverse and longitudinal directions. The vibration parameters include virtual mass, virtual stiffness and virtual damping.

2. The experimental platform for flow-induced vibration of marine cables with varying current direction and diameter based on real-time force feedback as described in claim 1, characterized in that, The gear set (34) includes a master gear and a driven gear that mesh with each other; The main gear is connected to the drive end of the rotary motion control motor (35); The driven gear is rotatably mounted on the connecting plate (32) via the bearing assembly (36) and is connected to the connecting plate (32).

3. The experimental platform for flow-induced vibration of marine cables with varying flow direction and diameter based on real-time force feedback as described in claim 2, characterized in that, The number of teeth on the primary gear is less than the number of teeth on the driven gear.

4. The experimental platform for flow-induced vibration of marine cables with varying flow direction and diameter based on real-time force feedback as described in claim 1, characterized in that, The connecting plate (32) is an aluminum plate.

5. The experimental platform for flow-induced vibration of marine cables with varying flow direction and diameter based on real-time force feedback according to claim 1, characterized in that, The real-time force feedback control system (21) also includes: an EtherCAT communication bus (22); The EtherCAT communication bus (22) is used to connect the host computer control module (27), the physical quantity acquisition module (29), the servo control module (23), and the human-machine interaction module (26), and to realize communication and instruction transmission between the modules.

6. The experimental platform for flow-induced vibration of marine cables with varying flow direction and diameter based on real-time force feedback as described in claim 1, characterized in that, The specific process of conducting the experiment using a variable-direction, unequal-diameter marine cable flow-induced vibration experimental platform based on real-time force feedback is as follows: The experimental platform is placed in a uniform flow. The hydrodynamic load on the rigid segmented model (1) of the two-pipe with different diameters is measured in real time by the three-force sensor module (30). The displacement of the rigid segmented model (1) of the two-pipe with different diameters is measured in the transverse and downstream directions by the motor displacement encoder (31). The hydrodynamic load data and displacement data are transmitted to the host computer control module (27) through the physical quantity acquisition module (29). The host computer control module (27) solves the motion equation of the rigid segmented model (1) of the different diameter double pipe in real time based on the recursive form of the Duhamel integral algorithm, calculates the target position at the next moment, and transmits the target position data to the transverse servo drive (25) and the co-current servo drive (24); the transverse servo drive (25) and the co-current servo drive (24) drive the transverse vibration simulation system (3) and the co-current vibration simulation system (2) to run, and drive the rigid segmented model (1) of the different diameter double pipe to move to the target position.

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