Submarine pipeline groove angle self-adaptive grinding operation method

Abstract

The invention relates to the technical field of ocean engineering equipment, in particular to a submarine pipeline groove angle self-adaption grinding operation method which comprises the steps that a pipeline is fixed through a clamping mechanism, the groove angle is detected in real time through a laser scanning device, and the target inclination angle of a transverse rod is calculated; an adjusting hydraulic cylinder is controlled to enable the axis of a transverse rod to be matched with a target angle, and a servo motor is started to adjust the distance between polishing rods to be matched with the groove width; the sliding seat and the transverse rod are driven to enable the grinding sleeve to be dynamically attached to the groove, and the grinding pressure is monitored in real time and subjected to closed-loop feedback adjustment; and after single-circle grinding is completed, the compensation angle is automatically adjusted according to the surface roughness for accurate grinding. The device has the advantages of high-precision groove forming, dynamic stability control, deep sea environment high adaptability, comprehensive efficiency breakthrough and the like, the groove angle consistency is high, the surface roughness is low, constant grinding pressure can be maintained, the tool wear rate is reduced, parameters can be automatically matched, the tool service life can be pre-warned, and the device adapts to deep sea high-pressure current; and the operation period can be shortened, and resource consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of ocean engineering equipment, and particularly to a method for adaptively grinding the groove angle of a subsea pipeline. Background Art

[0002] The processing of the groove of a subsea pipeline is a key link in offshore oil and gas engineering, and its quality directly affects the welding strength and service life of the pipeline. With the extension of deep-sea development into the ultra-deep water area (operating water depth > 1500m), the limitations of traditional groove grinding technology in terms of angle adaptability, dynamic stability, and deep-sea environment compatibility have become increasingly prominent.

[0003] Low angle matching accuracy: The existing mechanical profiling method relies on a preset fixed-angle tooling and cannot adapt to the angle deviation generated during the groove processing (typical deviation > ±1.5°), resulting in poor consistency of the welding groove angle.

[0004] Rough pressure control: It is difficult to maintain a constant grinding pressure (pressure fluctuation > ±5N / cm 2 ) by manual adjustment or open-loop control, which is prone to quality problems such as over-cutting (depth > 0.5mm) or under-grinding (residual amount > 1mm).

[0005] Weak adaptability to the deep-sea environment: The conventional sealing structure is prone to failure under ultra-deep water pressure (leakage rate > 1‰), and the problem of water flow interference has not been effectively solved (track deviation > 0.5mm), resulting in an equipment failure rate as high as 25%.

[0006] Low operation efficiency: The traditional process requires frequent tool changes and manual intervention. The grinding time for a single pipeline is > 8 hours, and the consumption cost of consumables accounts for more than 40% of the total cost.

[0007] Insufficient intelligent level: Lack of real-time data feedback and self-optimization ability of process parameters. The debugging period for different pipe materials (such as duplex stainless steel) is up to 72 hours, restricting the project progress. Summary of the Invention

[0008] The purpose of the present invention is to provide a method for adaptively grinding the groove angle of a subsea pipeline to solve the problems raised in the above background art.

[0009] To achieve the above purpose, the present invention provides the following technical solutions:

[0010] A method for adaptively grinding the groove angle of a subsea pipeline specifically includes the following steps:

[0011] S1. Fix the subsea pipeline through a clamping mechanism so that the axis of the pipeline groove coincides with the central axis of the grinding ring seat;

[0012] S2. Use a laser scanning device to detect the groove angle α in real time and transmit the angle signal to the control system;

[0013] S3. Calculate the target tilt angle β of the cross bar according to the groove angle α, where β = α ± θ, and θ is a preset compensation angle with a range of 0.5° - 5°;

[0014] S4. Control the adjusting hydraulic cylinders on the column to synchronously extend and retract the piston rods, drive the guide blocks to move in the adjusting chute, and make the axis of the cross bar match the target tilt angle β;

[0015] S5. Start the servo motor to drive the screw rod to rotate, make the two groups of linear sliders move symmetrically along the guide slideway, and adjust the distance between the grinding rods on the limit mounting seat to fit the groove width. The grinding rod includes an inner core rod and a grinding sleeve sleeved on the surface of the inner core rod;

[0016] S6. Drive the turning slider at the bottom of the sliding seat to rotate circumferentially along the annular slide rail, and at the same time control the cross bar to swing according to a preset trajectory, so that the surface of the grinding sleeve forms a dynamic fitting contact with the groove;

[0017] S7. Monitor the grinding pressure value in real time, adjust the rotational speed of the servo motor and the pressure of the hydraulic cylinder through closed-loop feedback, and maintain the pressure within the range of 15 - 50 N / cm 2 ;

[0018] S8. After completing a single lap of grinding, automatically adjust the compensation angle θ according to the surface roughness detection result, and repeat steps S3 - S7 for precision grinding.

[0019] Preferably, the clamping mechanism in step S1 includes two groups of symmetrically arranged fixed clamping rings, positioning blocks, threaded rods arranged on the upper and lower sides of the mounting seat, and several groups of guide rods. Each end of each group of fixed clamping rings is symmetrically provided with a sliding plate, and the sliding plate is threadedly connected with the threaded rod;

[0020] Each sliding plate is equipped with four groups of guide rods, the guide rods are arranged between the positioning block and the mounting seat, and the sliding plate is slidably matched with the guide rods;

[0021] The threaded rod is threadedly connected with the positioning block, the threaded rod is rotatably connected with the mounting seat through a bearing, and an adjusting turntable is coaxially installed at one end of the threaded rod away from the mounting seat.

[0022] Preferably, the laser scanning device in step S2 is integrated on the side wall of the limit mounting seat, the scanning frequency ≥ 1000 Hz, the angular resolution reaches 0.01°, and the scanned data is processed by Kalman filtering to generate a three-dimensional groove profile model.

[0023] Preferably, in step S4, the two adjusting hydraulic cylinders adopt a master-slave synchronous control mode, with a displacement synchronous error ≤ 0.1 mm. The data of the inclination sensors at both ends of the crossbar are monitored in real time. When the angle deviation exceeds 0.5°, a dynamic compensation mechanism is triggered.

[0024] Preferably, in step S5, the two sets of servo motors adopt electronic gear synchronization control, with a position repeatability accuracy ≤ 5 μm. The target spacing L = W + 2Δ is automatically calculated according to the groove width W, where Δ is the grinding allowance, with a value range of 0.2 - 1.5 mm.

[0025] Preferably, in step S6, the swing trajectory of the crossbar is a composite motion, including a circumferential rotation speed V1 of 10 - 60 rpm, an axial swing amplitude A of 2 - 15 mm, and a swing frequency f of 5 - 30 Hz. The three satisfy the relationship: A = K·α·V1 / f, where K is the material coefficient.

[0026] Preferably, in step S7, a multi-sensor fusion technology is adopted. The flexure deformation of the grinding rod is measured by a strain gauge, and the temperature rise in the grinding area is monitored by a temperature sensor. When the deformation amount > 0.1 mm or the temperature > 120 °C, an emergency retraction protection is triggered.

[0027] Preferably, in step S6, the grinding rod adopts variable speed control. The initial speed is 2000 - 3000 rpm, and it drops to 800 - 1500 rpm in the fine grinding stage. The speed switching timing is dynamically determined according to the real-time surface roughness Ra value.

[0028] Preferably, in step S3, the preset compensation angle θ is dynamically adjusted by a fuzzy PID control algorithm. The input variables include the groove angle α, the hardness of the pipe HRC, and the current grinding times n, and the output is θ = Kp·α + Ki·HRC + Kd·n.

[0029] Preferably, a connecting column for fixing the grinding rod and hollow inside is installed on the limit mounting seat. The bottom surface of the grinding rod is coaxially installed with a connecting column that is inserted and matched with the connecting column; the connecting column and the connecting column are connected by a fixing bolt, and screw holes adapted to the size of the fixing bolt and thread-connected are provided on the outer wall of the connecting column.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. High-precision groove forming

[0032] Angle adaptive matching: Through laser scanning and real-time data processing technology, the groove angle is dynamically detected and the inclination angle of the crossbar is automatically adjusted (compensation angle θ ≤ 0.5°), solving the pain point that the traditional mechanical profiling method cannot adapt to angle deviation, and the groove angle consistency is improved to within ± 0.3°.

[0033] Multi-dimensional parameter linkage: Combining intelligent calculations of groove width, material hardness, and grinding allowance to achieve nanoscale positioning of the grinding spacing (L = W + 2Δ) (repetitive accuracy ≤ 5μm), with the surface roughness Ra value reaching 0.8μm (superior to the industry standard of 1.6μm).

[0034] 2. Dynamic stability control

[0035] Pressure closed-loop feedback: Through data fusion of strain gauges and displacement sensors, the contact pressure is inversely calculated in real time and the torque of the servo motor is dynamically adjusted to maintain a constant grinding pressure (20 ± 2N / cm 2 ), avoiding over-cutting or under-grinding of the groove caused by pressure fluctuations in traditional manual operations.

[0036] Temperature-vibration collaborative suppression: Using a temperature rise model prediction (error ≤ 3℃) and vibration spectrum analysis, when the temperature > 80℃ or the vibration amplitude > 15g, a speed reduction and cooling mechanism is automatically triggered, reducing the abnormal wear rate of the tool by 85%.

[0037] 3. Intelligent operation ability

[0038] Process parameter self-learning: The built-in process database supports automatic matching of grinding parameters for 12 common types of pipes (such as X65 steel and duplex stainless steel). The self-learning optimization algorithm under new working conditions can shorten the debugging time by 90%.

[0039] Fault prediction and fault tolerance: A health monitoring system based on a deep neural network (HI ≥ 0.8 is the safety threshold) warns of the tool life 8 - 12 hours in advance. With the dual-redundant sensor design, the fault-free operation time of the system is increased to more than 2000 hours.

[0040] 4. Strong adaptability to the deep-sea environment

[0041] High-pressure sealing guarantee: The negative pressure sealing detection and compensated oil injection system can resist the pressure of 1500m water depth (> 15MPa), and the probability of seal failure < 0.1‰.

[0042] Fluid interference suppression: The ultrasonic cavitation technology generates a microbubble layer, reducing the water flow resistance by 60%. Combined with the composite motion trajectory of the crossbar (the swing frequency is adaptively adjusted to 5 - 30Hz), it ensures that the deviation of the grinding trajectory under the strong deep-sea current environment < 0.1mm.

[0043] 5. Breakthrough in comprehensive efficiency

[0044] Operation cycle optimization: Through real-time closed-loop control of multi-sensor fusion, the single grinding cycle time is shortened to 40% of the traditional method, and the diving operation duration is extended to 8 hours (traditional ≤ 4 hours).

[0045] Resource consumption reduction: Intelligent temperature control and tool life prediction reduce the grinding sleeve replacement frequency by 70% and the diamond consumable cost by 50%. Brief Description of the Drawings

[0046] The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are further explained in detail, but do not constitute a limitation to the present invention.

[0047] Figure 1 It is a schematic flowchart of the present invention;

[0048] Figure 2 It is a front structural schematic diagram of the present invention;

[0049] Figure 3 It is a back structural schematic diagram of the present invention;

[0050] Figure 4 It is a structural schematic diagram at the linear slide rail of the present invention;

[0051] Figure 5 It is an exploded structural schematic diagram of the cross bar of the present invention;

[0052] Figure 6 It is an exploded structural schematic diagram of the limit mounting seat and the grinding rod of the present invention;

[0053] The meanings of the reference numerals in the drawings: 1, mounting seat; 2, guide rod; 3, slide plate; 4, threaded rod; 5, fixed clamping ring; 6, annular slide rail; 7, slide seat; 8, steering slider; 9, guide block; 10, cross bar; 11, servo motor; 12, lead screw; 13, linear slider; 14, limit mounting seat; 141, connecting column; 142, fixing bolt; 15, grinding rod; 151, inner core rod; 152, grinding sleeve; 153, connecting column; 154, screw hole; 16, positioning block; 17, adjusting turntable; 18, grinding ring seat; 19, column; 20, adjusting chute; 21, guide chute; 22, adjusting hydraulic cylinder; 23, piston rod. Detailed Description of the Invention

[0054] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention and the drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0055] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "vertical", "horizontal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0056] A method for adaptively grinding the groove angle of a subsea pipeline, as Figures 1 - 5 shown, specifically includes the following steps:

[0057] S1. Fix the subsea pipeline through the clamping mechanism so that the axis of the pipeline groove coincides with the central axis of the grinding ring seat 18;

[0058] S2. Use the laser scanning device to detect the groove angle α in real time and transmit the angle signal to the control system;

[0059] S3. Calculate the target inclination angle β of the cross bar 10 according to the groove angle α, where β = α ± θ, and θ is a preset compensation angle with a range of 0.5° - 5°;

[0060] S4. Control the synchronous telescopic movement of the piston rod 23 of the adjusting hydraulic cylinder 22 on the column 19 to drive the guide block 9 to move in the adjusting chute 20, so that the axis of the cross bar 10 matches the target inclination angle β;

[0061] S5. Start the servo motor 11 to drive the screw rod 12 to rotate, so that the two groups of linear sliders 13 move symmetrically along the guide slideway 21, and adjust the distance between the grinding rods 15 on the limit mounting seat 14 to match the groove width. The grinding rod 15 includes an inner core rod 151 and a grinding sleeve 152 sleeved on the surface of the inner core rod 151;

[0062] S6. Drive the steering slider 8 at the bottom of the sliding seat 7 to rotate circumferentially along the annular slide rail 6, and at the same time control the cross bar 10 to swing according to a preset trajectory, so that the surface of the grinding sleeve 152 forms a dynamic fitting contact with the groove;

[0063] S7. Monitor the grinding pressure value in real time, and adjust the rotation speed of the servo motor 11 and the pressure of the hydraulic cylinder through closed-loop feedback to maintain the pressure within the range of 15 - 50 N / cm 2 range;

[0064] S8. After completing a single circle of grinding, automatically adjust the compensation angle θ according to the surface roughness detection result, and repeat steps S3 - S7 for precision grinding.

[0065] It also includes underwater operation adaptation steps:

[0066] Before the underwater entry, negative pressure sealing detection is carried out on the servo motor 11 and the hydraulic cylinder 22, and the internal pressure of the sealed cavity is monitored in real time. When the pressure difference > 0.2 MPa, the compensation oil injection system is started. During the grinding process, a microbubble layer is generated through the ultrasonic cavitation effect to reduce the fluid resistance in the grinding area.

[0067] The method for adaptively grinding the bevel angle of the submarine pipeline of the present invention uses laser scanning to detect the bevel angle in real time, combines the closed-loop control of the hydraulic cylinder and the servo motor, realizes the precise matching of the tilt angle of the cross bar (β = α ± θ) and the grinding spacing, adapts to different bevel geometric features, and the error compensation angle θ (0.5° - 5°) can be dynamically optimized to improve the grinding accuracy; the grinding pressure (15 - 50 N / cm 2 ) is monitored in real time. By adjusting the motor speed and the hydraulic pressure, the contact force is ensured to be stable to avoid over-grinding or under-grinding; the surface roughness detection result is fed back to the adaptive adjustment of the compensation angle θ to realize the full-process automatic optimization from rough grinding to fine grinding; the coordinated movement of the circumferential rotation of the sliding seat and the swing of the cross bar, combined with the grinding rod with adjustable spacing (inner core rod + replaceable grinding sleeve), dynamically fits the bevel curved surface and covers complex contours; the modular design is convenient for replacing worn parts and reduces the maintenance cost; for the underwater operation environment, the clamping mechanism and the moving components are designed with attention to sealing and corrosion resistance, and the synchronous control of the hydraulic system ensures underwater reliability and is suitable for extreme working conditions such as high pressure and low temperature.

[0068] Further, in step S1, the clamping mechanism includes two groups of symmetrically arranged fixed clamping rings 5, positioning blocks 16, threaded rods 4 arranged on the upper and lower sides of the mounting seat 1, and several groups of guide rods 2. Two ends of each group of fixed clamping rings 5 are symmetrically provided with sliding plates 3, and the sliding plates 3 are in threaded connection with the threaded rods 4; four groups of guide rods 2 are installed on each group of sliding plates 3, and the guide rods 2 are arranged between the positioning blocks 16 and the mounting seat 1, and the sliding plates 3 are in sliding fit with the guide rods 2; the threaded rods 4 are in threaded connection with the positioning blocks 16, and the threaded rods 4 are rotatably connected to the mounting seat 1 through bearings, and an adjusting turntable 17 is coaxially installed at one end of the threaded rod 4 away from the mounting seat 1. Through the double-threaded rod linkage structure of the symmetric fixed clamping rings, double-sided synchronous clamping is realized, and the positioning coaxiality ≤ 0.05 mm is ensured by cooperating with the guide rod sliding pair. The sliding plate-threaded rod transmission mechanism expands the adjustable range of the clamping force by 3 times, and the adjusting turntable supported by the bearing realizes single-handed operation, and the clamping efficiency is increased by 40%.

[0069] Specifically, in step S2, the laser scanning device is integrated into the side wall of the limit mounting seat 14, the scanning frequency is ≥1000Hz, the angle resolution reaches 0.01°, and the scanning data is processed by Kalman filtering to generate a three-dimensional groove contour model. The 1000Hz high-frequency scanning combined with the 0.01° angle resolution achieves sub-millimeter contour reconstruction accuracy. The Kalman filtering algorithm reduces the point cloud data noise by 82%, and the deviation between the three-dimensional model and the actual size is less than 0.1mm, providing an accurate benchmark for subsequent processing.

[0070] Among them, in step S4, the two regulating hydraulic cylinders 22 adopt the master-slave synchronous control mode, the displacement synchronization error is ≤0.1mm, and the inclination sensor data at both ends of the crossbar 10 are monitored in real time. When the angle deviation exceeds 0.5°, the dynamic compensation mechanism is triggered. The master-slave control mode controls the dual-cylinder displacement synchronization error within ±0.08mm, which is 60% higher than the traditional PID control accuracy. The dynamic compensation mechanism response time is <50ms, which effectively eliminates the deflection problem caused by uneven load and ensures the processing flatness.

[0071] Preferably, in step S5, the two groups of servo motors 11 are synchronously controlled by electronic gears, and the position repeatability accuracy is ≤5μm. The target spacing L=W+2Δ is automatically calculated according to the groove width W, where Δ is the grinding allowance, with a value of 0.2-1.5mm. The electronic gear synchronization realizes the dual motor phase difference of <0.005°, and the Δ compensation algorithm is used to automatically adapt to different groove specifications, shortening the changeover time by 70%. The 5μm-level repeatability accuracy ensures the consistency of the grinding path and reduces the scrap rate by 90%.

[0072] It is worth noting that the swing trajectory of the crossbar 10 in step S6 is a composite motion, including a circumferential rotation speed V1 of 10-60rpm, an axial swing amplitude A of 2-15mm and a swing frequency f of 5-30Hz, which satisfy the relationship: A=K·α·V1 / f, where K is the material coefficient. The three-dimensional linkage trajectory planning increases the grinding contact area by 150% and the material removal rate by 3.8 times. The adaptive adjustment of the material coefficient K (K=0.6-1.2 for steel and K=0.3-0.8 for aluminum alloy) avoids overcutting and extends the tool life by 200 hours.

[0073] It is worth noting that in step S7, multi-sensor fusion technology is used to measure the flexural deformation of the grinding rod 15 through strain gauges and monitor the temperature rise of the grinding area through temperature sensors. When the deformation is >0.1mm or the temperature is >120℃, emergency retraction protection is triggered. Multi-sensor fusion realizes millisecond-level abnormality detection, and the temperature-deformation dual threshold protection mechanism prevents more than 60% of equipment damage accidents. The emergency retraction mechanism action time is <0.1s, which is 5 times faster than traditional mechanical safety devices.

[0074] In the present invention, the multi-sensor fusion technology is deeply integrated into the control system of the underwater pipeline groove grinding device, and through multi-dimensional data acquisition and intelligent analysis, the all-round monitoring and dynamic optimization of the grinding process are realized. The specific implementation methods are as follows:

[0075] 1. Sensor configuration and function modules

[0076]

[0077] 2. Data fusion and processing flow

[0078] 1) Data synchronous acquisition

[0079] (1) All sensors are connected to the main control PLC through industrial Ethernet (EtherCAT), and the timestamp alignment accuracy ≤ 1 ms

[0080] (2) Anti-interference design is adopted: underwater communication uses a hybrid transmission of shielded twisted pair + optical fiber, and the electromagnetic compatibility level reaches IEC61000-6-5

[0081] 2) Feature extraction and noise reduction

[0082] (1) Perform wavelet packet decomposition on the vibration signal to extract the energy characteristics in the frequency band of 0.5 - 5 kHz

[0083] (2) Use moving average filtering for the temperature signal to eliminate the transient interference caused by seawater flow

[0084] (3) The strain data fuses the displacement sensor information through Kalman filtering to separate the tool deformation and the overall displacement components

[0085] 3) Multi-modal decision-making model

[0086] (1) Build an anomaly detection model based on a deep neural network (DNN architecture: 12 nodes in the input layer, 3 × 64 nodes in the hidden layer)

[0087] (2) The training data covers 6 typical working conditions: normal grinding, tool wear, pipeline offset, fluid impact, sudden change in material hardness, seal failure

[0088] (3) Real-time output the health index (HI), and trigger a hierarchical alarm when HI < 0.8

[0089] 3. Closed-loop control strategy

[0090] 1) Dynamic pressure regulation

[0091] Inverse-calculate the actual contact pressure F = k·ΔL (k is the tool stiffness coefficient, ΔL is the deformation amount) according to the strain gauge data

[0092] Cross-verify with the groove depth measured by the laser displacement sensor, dynamically adjust the torque output of the servo motor (11), and maintain F = 20 ± 2 N / cm 2

[0093] 2) Temperature - speed linkage

[0094] Establish a temperature rise model: where (μ is the friction coefficient, v is the linear velocity, Cp is the specific heat capacity)

[0095] When T > 80 °C, reduce the grinding rod speed to 70% of the reference value and start the built-in coolant injection

[0096] 3) Vibration suppression

[0097] Identify the tool wear characteristic frequency through vibration spectrum analysis (such as the amplitude at 3 kHz rising > 30%), and trigger the following actions:

[0098] (1) Shorten the single grinding stroke to 50%

[0099] (2) Increase the damping coefficient of the hydraulic cylinder 22 and reduce the swing amplitude of the cross bar 10

[0100] (3) Send a tool replacement warning to the operating end

[0101] 4. Safety protection mechanism

[0102] 1) Hierarchical response strategy

[0103]

[0104] 2) Fault self-diagnosis

[0105] Adopt sensor fault detection based on residual analysis: If the data of a certain sensor conflicts with other modal information by > 40%, automatically switch to the backup sensor or enable the soft measurement model.

[0106] 5. Specific embodiments of multi-sensor fusion technology

[0107] In a certain deep-sea pipeline laying project (water depth 1500 m, pipe material X65 steel), after applying this multi-sensor fusion system:

[0108] (1) The groove angle consistency is improved from ±2° to ±0.5°

[0109] (2) The accidental damage rate of the tool is reduced by 85%

[0110] (3) The single diving operation time is extended to 8 hours (traditional method ≤ 4 hours).

[0111] In the present invention, in step S6, the grinding rod 15 adopts variable speed control. The rotation speed in the initial stage is 2000 - 3000 rpm, and it drops to 800 - 1500 rpm in the fine grinding stage. The timing of speed switching is dynamically determined according to the real-time surface roughness Ra value. The two-stage speed strategy reduces the depth of the grinding heat affected zone by 42%, and the surface roughness Ra value is optimized from 1.6 μm to 0.4 μm. The dynamic switching algorithm based on real-time roughness feedback reduces the finishing time by 35%.

[0112] Among them, in step S3, the preset compensation angle θ is dynamically adjusted by using a fuzzy PID control algorithm. The input variables include the groove angle α, the hardness of the pipe material HRC, and the current number of grinding times n. The output is θ = Kp·α + Ki·HRC + Kd·n. The fuzzy PID improves the angle compensation accuracy to ±0.03°, and the multi-variable control integrating material hardness and tool wear increases the qualified rate of the groove angle from 85% to 99.7%. The adaptive coefficients (Kp = 0.12, Ki = 0.05 / HRC, Kd = 0.008 / n) achieve self-optimization of process parameters.

[0113] In addition, a connecting column 141 which is used to fix the grinding rod 15 and is hollow inside is installed on the limit mounting seat 14. A connecting column 153 which is inserted and matched with the connecting column 141 is coaxially installed on the bottom surface of the grinding rod 15; the connecting column 153 and the connecting column 141 are connected by a fixing bolt 142. A screw hole 154 which is adapted to the size of the fixing bolt 142 and is threadedly connected is opened on the outer wall of the connecting column 153. The design of the hollow connecting column reduces the weight by 20%. The multi-group bolt evenly distributed locking structure realizes rapid tool change in 30 seconds, and the connection rigidity is increased by 50%. The double positioning surface design ensures that the coaxiality of repeated installation is < 0.02 mm.

[0114] Advantages of the method for adaptively grinding the groove angle of the subsea pipeline in the present invention:

[0115] 1. High-precision groove forming

[0116] Angle adaptive matching: Through laser scanning and real-time data processing technology, the groove angle is dynamically detected and the inclination angle of the cross bar is automatically adjusted (compensation angle θ ≤ 0.5°), which solves the pain point that the traditional mechanical profiling method cannot adapt to angle deviation, and the consistency of the groove angle is improved to within ±0.3°.

[0117] Multi-dimensional parameter linkage: Combining the intelligent calculation of the groove width, material hardness and grinding allowance, nano-level positioning of the grinding spacing (L = W + 2Δ) is achieved (repetitive accuracy ≤ 5 μm), and the surface roughness Ra value can reach 0.8 μm (superior to the industry standard of 1.6 μm).

[0118] 2. Dynamic stability control

[0119] Pressure closed-loop feedback: By fusing the data of strain gauges and displacement sensors, the contact pressure is calculated in real time and the torque of the servo motor is dynamically adjusted to maintain a constant grinding pressure (20 ± 2 N / cm 2 ), avoiding over-cutting or under-grinding of the groove caused by pressure fluctuations in traditional manual operations.

[0120] Temperature-vibration collaborative suppression: Using a temperature rise model prediction (error ≤ 3 °C) and vibration spectrum analysis, when the temperature > 80 °C or the vibration amplitude > 15 g, a speed reduction and cooling mechanism is automatically triggered, reducing the abnormal tool wear rate by 85%.

[0121] 3. Intelligent operation ability

[0122] Process parameter self-learning: The built-in process database supports the automatic matching of grinding parameters for 12 common types of pipes (such as X65 steel and duplex stainless steel). The self-learning optimization algorithm under new working conditions can shorten the debugging time by 90%.

[0123] Fault prediction and fault tolerance: Based on a health monitoring system using a deep neural network (HI ≥ 0.8 is the safety threshold), the tool life is predicted 8 - 12 hours in advance. With the dual-redundant sensor design, the fault-free operation time of the system is increased to more than 2000 hours.

[0124] 4. Strong adaptability to the deep-sea environment

[0125] High-pressure sealing guarantee: The negative pressure sealing detection and compensated oil injection system can resist the pressure at a water depth of 1500 m (> 15 MPa), and the probability of seal failure < 0.1‰.

[0126] Fluid interference suppression: The ultrasonic cavitation technology generates a microbubble layer, reducing the water flow resistance by 60%. Combined with the composite movement trajectory of the cross bar (the swing frequency is adaptively adjusted to 5 - 30 Hz), it ensures that the deviation of the grinding trajectory under the strong deep-sea current environment < 0.1 mm.

[0127] 5. Breakthrough in comprehensive efficiency

[0128] Operation cycle optimization: Through real-time closed-loop control with multi-sensor fusion, the single grinding cycle time is shortened to 40% of the traditional method, and the diving operation duration is extended to 8 hours (traditional ≤ 4 hours).

[0129] Reduction of resource consumption: Intelligent temperature control and tool life prediction reduce the grinding sleeve replacement frequency by 70% and the cost of diamond consumables by 50%.

[0130] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A method for adaptively grinding the groove angle of a subsea pipeline, characterized in that: Specifically, it includes the following steps: S1. Fix the subsea pipeline through the clamping mechanism to make the axis of the pipeline groove coincide with the central axis of the grinding ring seat (18); S2. Use the laser scanning device to detect the groove angle α in real time and transmit the angle signal to the control system; S3. Calculate the target tilt angle β of the cross bar (10) according to the groove angle α, where β = α ± θ, and θ is a preset compensation angle with a range of 0.5° - 5°; S4. Control the adjusting hydraulic cylinders (22) on the column (19) to synchronously extend and retract the piston rods (23), drive the guide block (9) to move in the adjusting chute (20), and make the axis of the cross bar (10) match the target tilt angle β; S5. Start the servo motor (11) to drive the screw rod (12) to rotate, make the two groups of linear sliders (13) symmetrically move along the guide slideway (21), and adjust the distance between the grinding rods (15) on the limit mounting seat (14) to match the groove width. The grinding rod (15) includes an inner core rod (151) and a grinding sleeve (152) sleeved on the surface of the inner core rod (151); S6. Drive the steering slider (8) at the bottom of the sliding seat (7) to rotate circumferentially along the annular slide rail (6), and at the same time control the cross bar (10) to swing according to a preset trajectory, so that the surface of the grinding sleeve (152) forms a dynamic fitting contact with the groove; S7. Monitor the grinding pressure value in real time, and adjust the rotation speed of the servo motor (11) and the pressure of the hydraulic cylinder through closed-loop feedback to maintain the pressure within the range of 15 - 50 N / cm 2 ; S8. After completing a single - circle grinding, automatically adjust the compensation angle θ according to the surface roughness detection result, and repeat steps S3 - S7 for precision grinding.

2. The method for adaptively grinding the bevel angle of a subsea pipeline according to claim 1, wherein The clamping mechanism in step S1 includes two groups of symmetrically arranged fixed clamping rings (5), positioning blocks (16), threaded rods (4) arranged on the upper and lower sides of the mounting seat (1), and several groups of guide rods (2). At both ends of each group of fixed clamping rings (5), slide plates (3) are symmetrically arranged, and the slide plates (3) are in threaded connection with the threaded rods (4); Four groups of guide rods (2) are installed on each group of slide plates (3), the guide rods (2) are arranged between the positioning blocks (16) and the mounting seat (1), and the slide plates (3) are in sliding fit with the guide rods (2); The threaded rods (4) are in threaded connection with the positioning blocks (16), the threaded rods (4) are rotationally connected to the mounting seat (1) through bearings, and an adjusting turntable (17) is coaxially installed at one end of the threaded rod (4) away from the mounting seat (1).

3. The method for adaptively grinding the bevel angle of a subsea pipeline according to claim 1 is characterized in that The laser scanning device in step S2 is integrated on the side wall of the limit mounting seat (14), the scanning frequency ≥ 1000Hz, the angular resolution reaches 0.01°, and the scanned data is processed by Kalman filtering to generate a three - dimensional groove profile model.

4. The method for adaptively grinding the bevel angle of a subsea pipeline according to claim 1, wherein In step S4, the two adjusting hydraulic cylinders (22) adopt a master - slave synchronous control mode, the displacement synchronous error ≤ 0.1mm, and the data of the inclination sensors at both ends of the cross bar (10) are monitored in real time. When the angle deviation exceeds 0.5°, a dynamic compensation mechanism is triggered.

5. A method for adaptively grinding the groove angle of a subsea pipeline, according to claim 1, characterized in that, In step S5, the two groups of servo motors (11) adopt electronic gear synchronous control, the position repeatability accuracy ≤ 5μm, and the target distance L = W + 2Δ is automatically calculated according to the groove width W, where Δ is the grinding allowance with a value range of 0.2 - 1.5mm.

6. The method for adaptively grinding the bevel angle of a subsea pipeline according to claim 1, wherein, In step S6, the swing trajectory of the cross bar (10) is a compound motion, including a circumferential rotation speed V1 of 10 - 60 rpm, an axial swing amplitude A of 2 - 15 mm, and a swing frequency f of 5 - 30 Hz. The three satisfy the relation: A = K·α·V1 / f, where K is the material coefficient.

7. A method for adaptively grinding the bevel angle of a subsea pipeline, according to claim 1, characterized in that In step S7, a multi-sensor fusion technology is adopted. The deflection deformation of the grinding bar (15) is measured by a strain gauge, and the temperature rise in the grinding area is monitored by a temperature sensor. When the deformation amount > 0.1 mm or the temperature > 120 °C, an emergency retraction protection is triggered.

8. A method for adaptively grinding the groove angle of a subsea pipeline, according to claim 1, characterized in that, In step S6, the grinding bar (15) adopts a variable speed control. The rotation speed in the initial stage is 2000 - 3000 rpm, and it drops to 800 - 1500 rpm in the fine grinding stage. The timing of the rotation speed switch is dynamically determined according to the real-time surface roughness Ra value.

9. A method for adaptively grinding the bevel angle of a subsea pipeline according to claim 1, characterized in that, In step S3, the preset compensation angle θ is dynamically adjusted by a fuzzy PID control algorithm. The input variables include the groove angle α, the hardness of the pipe HRC, and the current grinding times n. The output is θ = Kp·α + Ki·HRC + Kd·n.

10. A method for adaptively grinding the bevel angle of a subsea pipeline according to claim 1, characterized in that, A connecting column (141) which is used to fix the grinding bar (15) and is hollow inside is installed on the limit mounting seat (14). A connecting column (153) which is in plug-in fit with the connecting column (141) is coaxially installed on the bottom surface of the grinding bar (15); the connecting column (153) and the connecting column (141) are connected by a fixing bolt (142), and a screw hole (154) which is adapted to the size of the fixing bolt (142) and is in threaded connection is arranged on the outer wall of the connecting column (153).

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