A method for fast and accurate installation of a deep sea four-pile jacket

Abstract

This application relates to the field of marine engineering technology and discloses a rapid and precise installation method for a four-pile jacket in deep-sea applications. The method includes: high-frequency synchronous acquisition of the crane vessel's motion state, environmental flow field, low-frequency position of the jacket, and transient tension of the four hydraulic compensation cylinders; extraction of differential tension components by removing vertical common-mode interference from the tension, converting them into the horizontal overturning moment of the jacket; reconstruction of the high-frequency pose coordinates of the jacket by combining inverse dynamic calculation and low-frequency position measurement updates; inner-loop impedance control of the independent hydraulic compensation cylinders based on the tension change rate, actively dissipating the lateral sway kinetic energy of the jacket through asymmetric extension and retraction; extraction of the low-frequency position error vector after removing high-frequency fluctuations, used as an outer-loop command to drive the crane vessel to translate and lower the jacket after alignment. This invention overcomes the problems of secondary overshoot and trajectory deflection caused by low damping of long flexible slings and underwater positioning delays, improving the operational efficiency and absolute accuracy of jacket docking and positioning.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, specifically to a method for rapid and precise installation of a four-pile jacket in deep-sea environments. Background Technology

[0002] Offshore oil and gas resource development and wind power construction typically require the placement of jacket structures on seabed foundations. As marine engineering operations extend into deeper waters, the installation depth of jackets gradually increases. In deep-sea lifting operations, the crane vessel and the jacket are connected by main lifting cables that are tens or even hundreds of meters long.

[0003] The conventional procedure for installing and positioning the existing jacket is to obtain the three-dimensional position coordinates of the bottom of the jacket using an underwater acoustic positioning system. The control system or operators then issue commands to the dynamic positioning system of the crane vessel based on the spatial deviation between these coordinates and the target installation point on the seabed. This drives the crane vessel to perform translation on the sea surface, and then the underwater jacket is towed by the main slings to achieve relative displacement, thus completing the alignment operation before the pile insertion.

[0004] In practical operations, conventional methods face definite limitations and technical obstacles. Due to the limited propagation speed of sound waves in seawater, the position data output by underwater acoustic positioning systems has a low refresh rate and is accompanied by an inherent time delay. If the control system directly uses this low-frequency and delayed observation data to drive the massive crane vessel to translate, the generated control commands will lag behind the actual movement of the bottom of the jacket in time sequence.

[0005] Lateral scouring by deep-sea currents and surface heave of the crane vessel caused by waves transmit dynamic loads downwards along the main suspenders. The long, flexible main suspenders have weak lateral stiffness in the horizontal direction and lack effective damping. Under continuous disturbance from environmental loads, the suspended jacket structure will experience prolonged lateral swaying underwater. Traditional crane vessel heave compensation devices typically employ a single-dimensional mechanical structure, designed only to isolate or compensate for vertical movement along the direction of gravity. They cannot detect the spatial roll and pitch tendencies of the jacket structure caused by asymmetrical forces, and lack an active dissipation mechanism for horizontal lateral kinetic energy.

[0006] In the absence of boundary damping intervention, when delayed surface translation commands are transmitted underwater via flexible slings, they not only fail to quickly counteract the current inertia of the jacket structure but also easily trigger secondary overshoot and superimposed oscillations in the spatial position of the jacket structure. This delay in state transmission, combined with the system's inherent low-damping characteristics, causes the bottom of the jacket structure to exhibit a difficult-to-converge fly-around phenomenon when approaching the target reference origin. This results in repeated oscillations during the docking and positioning process, increasing the waiting time for construction operations and making it difficult to meet the engineering requirements for installation efficiency and positional accuracy in complex deep-sea conditions. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a rapid and precise installation method for a four-pile jacket foundation in deep-sea environments. This method solves the problems of long installation time and low docking accuracy caused by the lack of damping in long flexible slings leading to prolonged lateral swaying of the jacket foundation under ocean current disturbances, and the reliance on low-frequency and delayed underwater acoustic positioning data to directly drive the crane vessel's translation, which can easily lead to control lag, secondary position overshoot, and repeated trajectory detours.

[0008] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for rapid and precise installation of a four-pile jacket in deep-sea environments, comprising the following steps: Simultaneously collect the crane ship's heave acceleration, three-axis angular velocity, three-axis acceleration, environmental flow field matrix, low-frequency position of the jacket, and transient tension of four independent hydraulic compensation cylinders; The differential tension component is extracted based on the transient tension and the heave acceleration of the crane vessel, and the differential tension component is converted into the horizontal roll moment and pitch moment of the jacket. The roll moment, pitch moment, environmental flow field matrix, triaxial angular velocity and triaxial acceleration are input into the dynamic equation to obtain instantaneous lateral acceleration. The instantaneous lateral acceleration and the low-frequency position of the jacket are input into the filter to output the high-frequency pose coordinates of the jacket. Combining the differential tension component with the differential rate of change of the differential tension component, a stroke control command is generated and sent to the independent hydraulic compensation cylinder to drive the independent hydraulic compensation cylinder to asymmetrically extend and retract to change the suspension boundary impedance; The position error vector between the high-frequency pose coordinates of the jacket and the seabed reference coordinates is extracted, and the position error vector is converted into a translation command and sent to the dynamic positioning system to drive the crane vessel to translate. After centering, the jacket is lowered.

[0009] Preferably, the synchronous acquisition of the crane vessel's heave acceleration, triaxial angular velocity, triaxial acceleration, environmental flow field matrix, low-frequency position of the jacket, and transient tension of the four independent hydraulic compensation cylinders specifically includes: Establish a global timestamp synchronization mechanism covering the crane vessel and the jacket structure; The heave acceleration, the three-axis angular velocity, the three-axis acceleration, and the transient tension of the crane vessel are synchronously read at a sampling frequency of 50 Hz or greater. The low-frequency position of the catheter holder is read at a refresh rate of less than 50 Hz; The read data is aligned and packaged based on the global timestamp.

[0010] Preferably, extracting the differential tension component based on the transient tension and the heave acceleration of the crane vessel specifically includes: Obtain the static mass of the jacket, the equivalent buoyant mass of the seawater displaced by the jacket, and the gravitational acceleration; The mass difference is obtained by subtracting the equivalent buoyant mass of the seawater displaced by the jacket from the static mass of the jacket. The combined acceleration is obtained by adding the heave acceleration of the crane ship to the gravitational acceleration. Multiplying the mass difference by the mixed acceleration yields the total dynamic reference tension of the system; The differential tensile force component is obtained by subtracting one-quarter of the total dynamic reference tensile force of the system from the transient tensile force.

[0011] Preferably, converting the differential tension component into horizontal roll moment and pitch moment of the jacket specifically includes: Obtain the planar projection coordinates of the suspension points of the four independent hydraulic compensation cylinders in the guide frame body coordinate system; The differential tension components corresponding to the four independent hydraulic compensation cylinders are combined into a differential tension tensor; Construct a geometric mapping matrix based on the plane projection coordinates; The differential tension tensor is input into the geometric mapping matrix for matrix multiplication to output the horizontal roll moment and pitch moment of the jacket.

[0012] Preferably, inputting the roll moment, pitch moment, environmental flow field matrix, triaxial angular velocity, and triaxial acceleration into the dynamic equation to obtain instantaneous lateral acceleration specifically includes: The environmental fluid drag force is obtained by performing a cross-sectional integral operation based on the environmental flow field matrix. The roll moment, pitch moment, environmental fluid drag, triaxial angular velocity, and triaxial acceleration are substituted into the rigid-flexible cable coupling dynamic equation to perform inverse dynamic calculation and output the instantaneous lateral acceleration at the bottom docking point of the jacket.

[0013] Preferably, inputting the instantaneous lateral acceleration and the low-frequency position of the duct frame into the filter to output the high-frequency pose coordinates of the duct frame specifically includes: Construct a state transition vector that includes the pose coordinate prediction value and the velocity prediction value; The time-updated state quantity is obtained by performing a double integration on the state transition vector using the instantaneous lateral acceleration; The observation residual is obtained by subtracting the predicted pose coordinates from the low-frequency position of the guide frame and the position in the time-updated state quantity. The observation residual is multiplied by the Kalman gain and then added to the time update state quantity to perform measurement update and output the high-frequency pose coordinates of the guide frame.

[0014] Preferably, generating the stroke control command by combining the differential tension component and the derivative rate of change of the differential tension component specifically includes: Obtain the proportional impedance gain and the differential damping gain; The differential tension component is multiplied by the proportional impedance gain to obtain the proportional control term; The differential control term is obtained by multiplying the differential rate of change of the differential tension component with the differential damping gain. The proportional control term and the derivative control term are added together to obtain the stroke control command corresponding to the independent hydraulic compensation cylinder.

[0015] Preferably, driving the independent hydraulic compensation cylinder to asymmetrically extend and retract to change the suspension boundary impedance specifically includes: The unidirectional swing trend of the guide frame is determined based on the positive or negative value of the differential tension component. For the independent hydraulic compensation cylinder on the upstream side where the differential tension component value increases, a stroke control command is issued to control the retraction of the independent hydraulic compensation cylinder; For the independent hydraulic compensation cylinder on the back side where the differential tension component value decreases, a stroke control command is simultaneously issued to control the extension of the hydraulic cylinder; The suspension boundary impedance is changed by adjusting the elevation of the suspension point using the retraction and extension of the independent hydraulic compensation cylinder.

[0016] Preferably, extracting the position error vector between the high-frequency pose coordinates of the jacket and the seabed reference coordinates specifically includes: Obtain the seabed reference coordinates; The initial spatial position difference vector is obtained by subtracting the seabed reference coordinates from the high-frequency pose coordinates of the jacket structure. The initial spatial position difference vector is input into a low-pass filter for filtering to remove high-frequency fluctuation components and output a low-frequency spatial position difference vector. The low-frequency spatial position difference vector is used as the position error vector.

[0017] Preferably, converting the position error vector into a translation command and sending it to the dynamic positioning system to drive the crane vessel to translate, and lowering the jacket after centering, specifically includes: The position error vector is transformed by a coordinate system to obtain the crane ship displacement compensation vector in the global geographic coordinate system. The displacement compensation vector of the crane vessel is converted into the translation command and sent to the dynamic positioning system; The dynamic positioning system is used to drive the crane vessel to perform sea-level translation according to the translation command; Calculate the magnitude of the position error vector; When the magnitude of the position error vector is less than a preset alignment threshold, the alignment is determined to be complete, and a lowering command is generated and sent to the main winch to lower the guide frame.

[0018] This invention provides a rapid and precise installation method for a four-pile jacket structure in deep-sea environments. It offers the following advantages: 1. This invention extracts the transient tension on the surface of the crane vessel and removes heave common-mode interference to obtain differential tension components and convert them into torque parameters. It then combines forward dynamics calculation with low-frequency position data of the jacket for filtering and fusion, thereby transforming conventional low-frequency underwater position observation into inverse deduction based on high-frequency mechanical parameters of the water surface. Under the existing hardware conditions limited by the communication bandwidth of the water medium, it outputs high-frequency spatial pose data of the bottom of the jacket, reducing the time delay in the position feedback loop.

[0019] 2. This invention utilizes the differential tension component and its differential rate of change to generate stroke control commands, driving four independent hydraulic compensation cylinders at the end of the hook to perform asymmetrical extension and retraction actions. Furthermore, based on the force change trend of the jacket, it actively changes the absolute elevation boundaries of each suspension support point in the compound pendulum system, applying a mechanical restoring torque to the jacket to dissipate the lateral kinetic energy brought by the flow field impact, and directly suppressing the transient oscillation of the long flexible sling system at the structural execution end.

[0020] 3. This invention constructs execution closed loops in different dimensions. It uses the high-frequency asymmetric extension and retraction of the hydraulic compensation cylinder to suppress the lateral sway of the guide frame. At the same time, it extracts the position error vector between the high-frequency pose coordinates and the seabed reference coordinates, and drives the dynamic positioning system to perform low-frequency translation compensation of the crane vessel. This allows for the layered decoupling of transient sway suppression and steady-state position correction, avoiding the secondary overshoot phenomenon of flexible slings caused by relying solely on the translation of the crane vessel for position feedback correction, and reducing spatial wandering behavior during the insertion and alignment process. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the method flow of the present invention; Figure 2 This is a schematic diagram of the system architecture of the present invention; Figure 3 This is a comparative curve showing the change of the lateral swing amplitude of the bottom of the catheter holder of the present invention over time; Figure 4 This is a comparison diagram of the two-dimensional horizontal trajectory on the seabed during the centering and positioning process of the crane vessel driven jacket of the present invention. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Reference Figure 1 and Figure 2 This invention provides a method for rapid and precise installation of a four-pile jacket in deep-sea areas, comprising the following steps: Simultaneously collect the crane ship's heave acceleration, three-axis angular velocity, three-axis acceleration, environmental flow field matrix, low-frequency position of the jacket, and transient tension of four independent hydraulic compensation cylinders; The differential tension component is extracted based on the transient tension and the heave acceleration of the crane vessel, and then converted into the horizontal roll moment and pitch moment of the jacket. The instantaneous lateral acceleration is obtained by inputting the roll moment, pitch moment, environmental flow field matrix, triaxial angular velocity and triaxial acceleration into the dynamic equation. The instantaneous lateral acceleration and the low-frequency position of the jacket are input into the filter to output the high-frequency pose coordinates of the jacket. Combining the differential tension component with the differential rate of change of the differential tension component, a stroke control command is generated and sent to the independent hydraulic compensation cylinder, which drives the independent hydraulic compensation cylinder to asymmetrically extend and retract to change the suspension boundary impedance. The position error vector between the high-frequency pose coordinates of the jacket and the seabed reference coordinates is extracted. The position error vector is converted into a translation command and sent to the dynamic positioning system to drive the crane vessel to translate. After centering, the jacket is lowered.

[0024] The rapid and precise installation method for deep-sea four-pile jacket foundations is based on the operation of an engineering operation system. The engineering operation system includes a crane vessel, a dynamic positioning system, a main winch, a main sling, a hook assembly, a jacket foundation, and a sensor assembly. The crane vessel is equipped with a dynamic positioning system and a main winch. The hook assembly is connected to the main winch via the main sling. The hook assembly contains four independent hydraulic compensation cylinders. The bottom of the four independent hydraulic compensation cylinders is connected to four suspension points on the top of the jacket foundation via rigging.

[0025] The sensor assembly includes a high-frequency tension sensor, a shipborne motion reference unit, a high-frequency inertial measurement unit, a shipborne acoustic Doppler current profiler, and an underwater acoustic positioning system. The high-frequency tension sensor is installed at the end of four independent hydraulic compensation cylinders and is used to collect the transient tension of the four independent hydraulic compensation cylinders.

[0026] The shipborne motion reference unit is installed on the crane ship and is used to collect the crane ship's heave acceleration. The high-frequency inertial measurement unit is installed on the top of the jacket and is used to collect the jacket's triaxial angular velocity and triaxial acceleration. The shipborne acoustic Doppler current profiler is installed on the bottom of the crane ship and is used to collect the environmental flow field matrix.

[0027] The underwater acoustic positioning system includes an acoustic array installed on the crane vessel and an underwater acoustic positioning beacon installed at the bottom of the jacket. The underwater acoustic positioning system is used to collect the low-frequency position of the jacket. The control terminal of the engineering operation system establishes data communication connections with the dynamic positioning system, the main winch, the independent hydraulic compensation cylinder, and the sensor assembly through an industrial communication bus.

[0028] The control end establishes a global timestamp synchronization mechanism. The control end reads multi-source data through sensor components. The refresh frequency of the low-frequency position of the jacket obtained by the underwater acoustic positioning system is lower than the sampling frequency of the high-frequency tension sensor, the shipborne motion reference unit, and the high-frequency inertial measurement unit.

[0029] After receiving multi-source data, the control terminal uses the heave acceleration of the crane vessel to calculate and remove common-mode interference in the transient tension, and separates the differential tension component. The control terminal inputs the differential tension component into the geometric mapping matrix, and converts the differential tension component into the horizontal roll moment and pitch moment of the jacket.

[0030] The control unit inputs the roll moment, pitch moment, environmental fluid drag force obtained by integrating the environmental flow field matrix, triaxial angular velocity and triaxial acceleration into the dynamic equation, and calculates the instantaneous lateral acceleration at the bottom of the jacket in reverse. The control unit performs a second integration using the instantaneous lateral acceleration and performs measurement updates using the low-frequency position of the jacket, outputting the high-frequency pose coordinates of the jacket with a refresh frequency consistent with the sampling rate of the high-frequency tension sensor.

[0031] The control unit calculates the differential tension component and the differential rate of change of the differential tension component, and generates stroke control commands for the independent hydraulic compensation cylinders. After receiving the stroke control commands, the independent hydraulic compensation cylinders perform asymmetric extension and retraction actions. The independent hydraulic compensation cylinder on the upstream side performs a retraction action according to the stroke control commands, and the independent hydraulic compensation cylinder on the downstream side performs an extension action synchronously according to the stroke control commands. The extension and retraction actions of the four independent hydraulic compensation cylinders change the relative elevation boundaries of the four suspension points of the jacket.

[0032] The control unit performs vector subtraction between the high-frequency pose coordinates of the jacket and the seabed reference coordinates, and then performs low-pass filtering to output a position error vector. The control unit converts the position error vector into a translation command and sends it to the dynamic positioning system. The dynamic positioning system drives the crane vessel to perform sea-level translation according to the translation command. When the magnitude of the position error vector is less than a preset alignment threshold, the control unit generates a lowering command and sends it to the main winch. The main winch then performs the main sling lowering action to complete the insertion and positioning of the jacket.

[0033] Reference Figure 1 and Figure 2 The control end establishes a global timestamp synchronization mechanism covering the crane vessel and the jacket. The control end sends synchronization clock signals to the high-frequency tension sensor, the shipborne motion reference unit, the high-frequency inertial measurement unit, the shipborne acoustic Doppler current profiler, and the underwater acoustic positioning system through a precision time protocol, so that all hardware acquisition nodes in the engineering operation system operate based on the same time reference, eliminating the independent local clock offset of each hardware node.

[0034] The control terminal sets the system's basic sampling period to be The corresponding high-frequency sampling frequency is The control unit synchronously reads the crane ship's heave acceleration, three-axis angular velocity, three-axis acceleration, environmental flow field matrix, and transient tension at a sampling frequency of 50 Hz or higher.

[0035] High frequency timestamps The high-frequency data set read by the control terminal is represented by the following vector formula: ; In the formula, For a moment A high-frequency data set; , , , These are the transient tensions at the ends of four independent hydraulic compensation cylinders, collected by four high-frequency tension sensors. The direction of the crane ship's heave acceleration is along the vertical direction of the global geographic coordinate system; The angular velocity vector of the jacket structure is its three axes. Let be the three-axis acceleration vector of the guide frame; The environmental flow field matrix at the depth of the water body obtained by the shipborne acoustic Doppler current profiler; This is the mathematical transpose symbol, indicating that the row vector within the parentheses is subjected to matrix transpose.

[0036] The underwater acoustic positioning system transmits acoustic signals through the water medium. The speed of sound propagation in the water medium limits the signal update rate. The control unit reads the low-frequency position of the jacket structure output by the underwater acoustic positioning system at a refresh frequency below 50 Hz. The data sequence of the jacket structure's low-frequency position is expressed by the following formula: ; In the formula, The low-frequency position vector of the jacket structure output by the underwater acoustic positioning system; For discrete time series indexes with low-frequency refresh cycles; , , The underwater acoustic positioning system at the 1st The three spatial coordinate components of the bottom reference point of the jacket structure in the global geographic coordinate system calculated in each refresh cycle; This is the mathematical transpose symbol, indicating that the row vector within the parentheses is subjected to matrix transpose.

[0037] The control unit aligns and packages the read data based on the global timestamp. The control unit indexes the discrete low-frequency time series data. The arrival time is mapped to consecutive high-frequency timestamps. On the axis. When a certain high-frequency timestamp With the When the arrival times of several low-frequency refresh data coincide, the control terminal will... and Perform merged storage; when high-frequency timestamps If no new data is received from the underwater acoustic positioning system within the current data acquisition cycle, the control terminal will... The data field is subjected to a zero-order hold operation, and is assigned the value of the previously received low-frequency position data. The final output is a structured data array containing the states of multiple sensor sources and with a unified time base.

[0038] Reference Figure 1 and Figure 2 The control unit acquires the static mass of the jacket, the equivalent buoyant mass of the seawater displaced by the jacket, and the acceleration due to gravity. The static mass of the jacket is its inherent mass in air. The equivalent buoyant mass of the seawater displaced by the jacket is obtained by multiplying the volume of the jacket submerged in water by the density of the seawater in the operating area.

[0039] The control unit subtracts the equivalent buoyant mass of the seawater displaced by the jacket from the static mass of the jacket, obtaining the mass difference. This mass difference characterizes the equivalent static load of the jacket in the underwater environment.

[0040] The control unit extracts the heave acceleration of the crane vessel. The heave acceleration reflects the high-frequency inertia of the crane vessel's surface along the vertical direction caused by the action of ocean waves. The control unit adds the crane vessel's heave acceleration to the gravitational acceleration to obtain a mixed acceleration.

[0041] The control unit multiplies the mass difference with the mixed acceleration to calculate and output the total dynamic reference tension of the system. The calculation logic for the total dynamic reference tension of the system is expressed by the following formula: ; In the formula, High-frequency timestamp The total tensile force of the system dynamic reference is as follows; The static mass of the catheter stent; The equivalent buoyant mass of the seawater displaced by the jacket structure; It is the acceleration due to gravity; High-frequency timestamp The lifting vessel's heave acceleration. The total dynamic reference tension of the system includes the common mode force reference of the lifting system in the vertical direction.

[0042] The control unit subtracts one-quarter of the total dynamic reference tension from the transient tension at the ends of the four independent hydraulic compensation cylinders. Through this subtraction, the control unit separates the common-mode force component caused by the heave of the crane vessel from the total tension data, which includes complex environmental noise, and extracts the differential tension component that only characterizes the spatial asymmetric disturbance of the jacket.

[0043] The control unit reads the preset dimensions of the jacket model and obtains the planar projection coordinates of the suspension points of the four independent hydraulic compensating cylinders in the jacket body coordinate system. The jacket body coordinate system uses the geometric center or the vertical line of the centroid of the jacket as its origin. The control unit sequentially combines the differential tension components corresponding to the four independent hydraulic compensating cylinders to generate a differential tension tensor in the form of a column vector.

[0044] The control unit constructs a geometric mapping matrix based on the acquired planar projection coordinates. The geometric mapping matrix uses the vertical distances from the four suspension points to the horizontal and vertical axes of the jacket body coordinate system to convert the one-dimensional tension parameter into a two-dimensional torque parameter.

[0045] The control unit inputs the differential tension tensor into the geometric mapping matrix for matrix multiplication, outputting the horizontal roll and pitch moments of the jacket. The logic of this matrix multiplication operation is expressed by the following formula: ; In the formula, High-frequency timestamp Rolling moment of the lower guide frame about the transverse axis; High-frequency timestamp The pitching moment of the lower jacket about its longitudinal axis; the roll moment and pitching moment together constitute the equivalent overturning moment of the jacket in the horizontal direction. Elements in the first row of the matrix. , , , The elements in the second row of the matrix represent the planar projection coordinate components of the four suspension points on the vertical axis of the jacket body coordinate system. , , , These are the negative values ​​of the planar projection coordinate components of the four suspension points on the horizontal axis of the jacket body coordinate system; , , To correspond to the four independent hydraulic compensation cylinders at any time The differential tensile force component.

[0046] Reference Figure 1 and Figure 2 The control unit reads the environmental flow field matrix acquired by the shipborne acoustic Doppler current profiler. This matrix contains ocean current velocity vectors at different water depth levels. The control unit, combined with a pre-defined three-dimensional geometric model of the jacket, obtains the upstream cross-sectional area parameters corresponding to the jacket at different water depth levels. The control unit multiplies the velocity vectors at each water depth level with the corresponding upstream cross-sectional area parameters, accumulates the multiplications at each level, performs a cross-sectional area integral operation, and outputs the overall environmental fluid drag force on the jacket.

[0047] The control unit extracts the horizontal roll moment, pitch moment, ambient fluid drag force, and triaxial angular velocity and triaxial acceleration collected by the high-frequency inertial measurement unit from the jacket. The control unit substitutes these parameters into a preset rigid-cable coupled dynamic equation. By solving the rigid-cable coupled dynamic equation, the control unit performs inverse dynamic calculations and outputs the instantaneous lateral acceleration of the jacket bottom docking point in the global coordinate system.

[0048] The control unit constructs a state transition vector containing predicted pose coordinates and predicted velocity values. The control unit performs a quadratic integral time update of the state transition vector using instantaneous lateral acceleration. The continuous-time state differential logic of this time update process is expressed by the following formula: ; In the formula, High-frequency timestamp The differential of the next state transition vector; High-frequency timestamp The predicted vector of pose coordinates at the bottom of the lower guide frame; High-frequency timestamp Predicted velocity vector at the bottom of the lower jacket; and These are their corresponding time derivatives; This is the instantaneous lateral acceleration vector output from the inverse dynamics solution. During the high-frequency sampling period when the low-frequency position of the jacket is not received, the control unit continuously updates the vector through discretized integration. and .

[0049] The control unit continuously monitors the arrival status of data from the underwater acoustic positioning system. (When high-frequency timestamps...) Upon receiving the latest frame of the duct arch low-frequency position, the control unit performs a measurement update operation. The control unit performs a vector subtraction operation between the received duct arch low-frequency position and the pose coordinate prediction value in the current time update state quantity, and outputs the observation residual.

[0050] The control unit acquires the Kalman gain matrix based on the system noise and measurement noise. The control unit multiplies the observation residual by the Kalman gain matrix to obtain the state correction, and then adds the state correction to the time-updated state value to complete the filtering and fusion. The logic of the measurement update operation is expressed by the following formula: ; In the formula, These are the high-frequency pose coordinates of the guide frame after measurement and updating. Update the output of the pose coordinate prediction values ​​over time; The Kalman gain matrix; For the first The low-frequency position vector of the guide frame input in each refresh cycle; This is the observation residual term obtained for calculation.

[0051] After the control terminal completes the measurement update, it will The pose coordinate parameters in the original state transition vector are replaced with new values ​​to suppress cumulative numerical drift during time integration. The control unit continuously outputs the updated high-frequency pose coordinate data sequence of the guide frame at the sampling frequency of the high-frequency tension sensor.

[0052] Reference Figure 1 and Figure 2 The control unit extracts the differential tension component. It then performs time derivative calculations on the differential tension component to obtain its differential rate of change. The control unit reads the proportional impedance gain and differential damping gain pre-set by the engineering operation system. The proportional impedance gain is used to establish the stiffness mapping relationship between tension deviation and spatial displacement, while the differential damping gain is used to establish the dissipation mapping relationship between the rate of change of tension and spatial displacement.

[0053] The control terminal multiplies the differential tension component with the proportional impedance gain, outputting a proportional control term. The control terminal multiplies the differential rate of change of the differential tension component with the differential damping gain, outputting a differential control term. The control terminal adds the proportional control term and the differential control term to generate the stroke control command for the corresponding independent hydraulic compensating cylinder. The calculation logic of the stroke control command is expressed by the following formula: ; In the formula, For the first Each independent hydraulic compensation cylinder at any time The received stroke control command represents the target mechanical displacement. This is the proportional impedance gain; For the first The differential tension component corresponding to each independent hydraulic compensation cylinder; This is the differential damping gain; This is the time derivative of the differential rate of change of the differential tension component; This is the number of the independent hydraulic compensation cylinder, and its value range is a positive integer 1, 2, 3, 4.

[0054] The control unit continuously reads the numerical status of the differential tension component. Based on the positive and negative changes in the differential tension component, the control unit determines the unidirectional oscillation trend of the jacket. When subjected to lateral impact from the ambient fluid, the distribution of the jacket's weight at the four suspension points shifts, resulting in an increase in the tension borne by the independent hydraulic compensation cylinder on the upstream side and a decrease in the tension borne by the independent hydraulic compensation cylinder on the downstream side.

[0055] For the upstream independent hydraulic compensation cylinder where the differential tension component increases, the control terminal sends a stroke control command to the upstream independent hydraulic compensation cylinder to control the retraction of the hydraulic piston rod. For the downstream independent hydraulic compensation cylinder where the differential tension component decreases, the control terminal simultaneously sends a stroke control command to the downstream independent hydraulic compensation cylinder to control the extension of the hydraulic piston rod.

[0056] Upon receiving a stroke control command, the independent hydraulic compensation cylinder on the upstream side retracts, shortening its cylinder length. Upon receiving a stroke control command, the independent hydraulic compensation cylinder on the downstream side extends, increasing its cylinder length.

[0057] The retraction and extension of the independent hydraulic compensation cylinders directly adjust the absolute elevation of the four suspension points in the global coordinate system. The asymmetric changes in the suspension point elevation alter the boundary stress state at the top of the jacket. This boundary elevation change process reshapes the mechanical restoring torque exerted by the suspension system on the jacket. This mechanical restoring torque dissipates the lateral kinetic energy exerted on the jacket body by the ambient fluid through mechanical work.

[0058] Reference Figure 1 and Figure 2The control unit acquires the seabed reference coordinates. These seabed reference coordinates represent the pre-planned target installation position of the jacket on the seabed foundation. The control unit extracts the reconstructed high-frequency pose coordinates of the jacket. The control unit performs a vector subtraction operation between the seabed reference coordinates and the high-frequency pose coordinates of the jacket, outputting an initial spatial position difference vector. The calculation logic for the initial spatial position difference vector is expressed by the following formula: ; In the formula, For a moment The initial spatial position difference vector; A three-dimensional vector containing seabed reference coordinates; For a moment The high-frequency pose coordinates of the guide frame are a three-dimensional vector.

[0059] The initial spatial position difference vector includes a steady-state position offset component caused by the steady scouring of the environmental flow field, and a high-frequency oscillation component induced by the long flexible sling system. The control unit inputs the initial spatial position difference vector into a preset low-pass filter for filtering. Based on a set cutoff frequency, the low-pass filter numerically attenuates and filters out high-frequency fluctuation components above the cutoff frequency, extracting a low-frequency spatial position difference vector characterizing the steady-state deviation trend of the jacket. The control unit assigns this low-frequency spatial position difference vector as the position error vector for performing translation compensation.

[0060] The control unit extracts the current heading angle parameter of the crane vessel. Based on the heading angle parameter, the control unit constructs a geographic coordinate rotation matrix. The control unit multiplies the position error vector with the geographic coordinate rotation matrix, performs a coordinate system transformation, and outputs the crane vessel displacement compensation vector in the global geographic coordinate system. The calculation logic of the crane vessel displacement compensation vector is expressed by the following formula: ; In the formula, This is the displacement compensation vector for the crane vessel in the global geographic coordinate system. Based on the current heading angle of the crane vessel The constructed rotation matrix; This is the position error vector output after low-pass filtering.

[0061] The control unit converts the crane vessel's displacement compensation vector into translation commands. These commands are then transmitted to the crane vessel's dynamic positioning system via a communication bus. Upon receiving the translation commands, the dynamic positioning system distributes the thrust output of each propeller, driving the crane vessel to translate along the three-dimensional vector direction specified in the translation commands on the sea surface. This sea-level translation of the crane vessel is then transmitted spatially to the suspended jacket structure via the main slings.

[0062] During the translation of the crane vessel driven by the dynamic positioning system, the control terminal continuously calculates the mathematical modulus of the position error vector. This modulus represents the absolute spatial distance between the centering point at the bottom of the jacket and the seabed reference coordinates.

[0063] The control unit compares the calculated magnitude of the position error vector with the preset alignment threshold of the engineering operation system. When the magnitude of the position error vector is greater than or equal to the preset alignment threshold, the control unit maintains the issuance of translation commands. When the magnitude of the position error vector is less than the preset alignment threshold, the control system determines that alignment is complete. The control unit generates a lowering command and sends it to the main winch. Upon receiving the lowering command, the main winch performs a cable-laying operation, continuously releasing the main sling to lower the jacket until the bottom structure of the jacket contacts the ground surface corresponding to the seabed reference coordinates.

[0064] Specific application examples: Figure 3 This is a comparative curve of the change of the lateral swing amplitude of the bottom of the duct frame over time, plotted according to an embodiment of the present invention. The horizontal axis of the figure is time, and the vertical axis is the lateral displacement deviation. Figure 4 This is a comparison diagram of the two-dimensional horizontal trajectory of the seabed during the centering and positioning process of the crane vessel driven jacket according to an embodiment of the present invention. The horizontal and vertical coordinates in the diagram are the relative coordinates of the X-axis and Y-axis in the global geographic coordinate system, respectively.

[0065] A deep-water oil and gas field development project requires the installation of a four-pile jacket. The operating area is 150 meters deep, the sea state is level 4, the surface current velocity is constant at 1.2 m / s, and there are irregular wave disturbances. The static mass of the jacket in the air is 1200 tons, and the main sling of the crane vessel is 130 meters long.

[0066] To verify the effectiveness of the technology, two hoisting and docking simulation experiments were conducted under the same initial sea conditions and hardware boundary conditions, divided into a control group and an experimental group: Control group (traditional method): Relying solely on the underwater acoustic positioning system to provide low-frequency (e.g., refreshed every 2 seconds) position feedback, the dynamic positioning system directly controls the crane vessel to perform translational correction based on this low-frequency position error, and the four hydraulic compensation cylinders at the end of the hook are in a passively locked state.

[0067] Experimental Group (Method of this Invention): The rapid and accurate installation method proposed in this invention is employed. The system acquires multi-source sensor data at high frequency, and the control terminal performs differential tension decoupling and high-frequency pose reconstruction. This drives four independent hydraulic compensation cylinders to perform asymmetrical extension and retraction, implementing inner-loop impedance control. Simultaneously, the low-frequency position error after low-pass filtering is output to drive the crane vessel for outer-loop translation compensation.

[0068] Reference Figure 3When subjected to lateral impact from the environmental flow field and parametric resonance caused by the heave of the crane vessel, the bottom of the jacket will oscillate laterally.

[0069] The control group (shown by the dashed line in the figure) exhibited low damping due to the lack of an impedance compensation mechanism, resulting in a long flexible sling system. The maximum lateral swing amplitude at the bottom of the jacket reached approximately 2.8 meters, and the decay was extremely slow, with a periodic oscillation of approximately 1.0 meter still present after 200 seconds, making it impossible to safely carry out the insertion and alignment operation.

[0070] In the experimental group (shown by the solid line in the figure), due to the implementation of asymmetric boundary impedance active modulation in this invention, the control end sends stroke control commands to the independent hydraulic compensation cylinder based on the differential tension change rate. The mechanical work of the retraction on the upstream side and the extension on the downstream side directly dissipates the lateral kinetic energy of the system. Under the initial environmental impact, the maximum lateral swing amplitude is suppressed to within 1.2 meters. With the continuation of the damping effect, the swing amplitude rapidly decays to a stable and safe range of less than 0.2 meters within 60 seconds. The experimental results show that this invention reduces the peak dynamic swing amplitude by about 57% and suppresses the transient oscillation of the flexible cable system.

[0071] Reference Figure 4 At the initial moment, the horizontal deviation of the bottom of the jacket from the seabed reference point (0,0) was approximately 12.8 meters.

[0072] In the control group (shown by the dashed line in the figure), during the translation towards the target origin, the translation command from the crane vessel always lagged behind the actual position of the jacket due to the low-frequency delay of underwater positioning and the secondary overshoot characteristics of the flexible sling. This caused the jacket to exhibit severe circular fly-around phenomenon when approaching the reference origin, resulting in a long trajectory and requiring multiple overshoots before barely entering the set 0.5-meter centering threshold circle, which was extremely time-consuming.

[0073] In the experimental group (shown by the solid line in the figure), due to the implementation of high- and low-frequency decoupled collaborative control in this invention, the outer loop translation command is generated based on a low-frequency steady-state error vector that eliminates high-frequency oscillations. Therefore, the translation of the crane vessel does not trigger secondary oscillations in the slings, and the movement trajectory of the bottom of the jacket structure exhibits a highly convergent, smooth curve, directly approaching the reference origin without significant overshoot or drift. The overall alignment time into the threshold loop is reduced by approximately 65% ​​compared to the control group. Experimental results demonstrate that this invention avoids spatial wandering behavior and improves the operational efficiency and absolute accuracy of deep-sea docking and positioning.

Claims

1. A method for rapid and precise installation of a four-pile jacket structure in deep-sea applications, characterized in that, Includes the following steps: Simultaneously collect the crane ship's heave acceleration, three-axis angular velocity, three-axis acceleration, environmental flow field matrix, low-frequency position of the jacket, and transient tension of four independent hydraulic compensation cylinders; The differential tension component is extracted based on the transient tension and the heave acceleration of the crane vessel, and the differential tension component is converted into the horizontal roll moment and pitch moment of the jacket. The roll moment, pitch moment, environmental flow field matrix, triaxial angular velocity and triaxial acceleration are input into the dynamic equation to obtain instantaneous lateral acceleration. The instantaneous lateral acceleration and the low-frequency position of the jacket are input into the filter to output the high-frequency pose coordinates of the jacket. Combining the differential tension component with the differential rate of change of the differential tension component, a stroke control command is generated and sent to the independent hydraulic compensation cylinder to drive the independent hydraulic compensation cylinder to asymmetrically extend and retract to change the suspension boundary impedance; The position error vector between the high-frequency pose coordinates of the jacket and the seabed reference coordinates is extracted, and the position error vector is converted into a translation command and sent to the dynamic positioning system to drive the crane vessel to translate. After centering, the jacket is lowered.

2. The method for rapid and precise installation of a four-pile jacket in deep-sea areas according to claim 1, characterized in that, The synchronous acquisition of the crane vessel's heave acceleration, three-axis angular velocity, three-axis acceleration, environmental flow field matrix, low-frequency position of the jacket support, and transient tension of the four independent hydraulic compensation cylinders specifically includes: Establish a global timestamp synchronization mechanism covering the crane vessel and the jacket structure; The heave acceleration, the three-axis angular velocity, the three-axis acceleration, and the transient tension of the crane vessel are synchronously read at a sampling frequency of 50 Hz or greater. The low-frequency position of the catheter holder is read at a refresh rate of less than 50 Hz; The read data is aligned and packaged based on the global timestamp.

3. The method for rapid and precise installation of a four-pile jacket in deep-sea areas according to claim 1, characterized in that, Extracting the differential tension component based on the transient tension and the heave acceleration of the crane vessel specifically includes: Obtain the static mass of the jacket, the equivalent buoyant mass of the seawater displaced by the jacket, and the gravitational acceleration; The mass difference is obtained by subtracting the equivalent buoyant mass of the seawater displaced by the jacket from the static mass of the jacket. The combined acceleration is obtained by adding the heave acceleration of the crane ship to the gravitational acceleration. Multiplying the mass difference by the mixed acceleration yields the total dynamic reference tension of the system; The differential tensile force component is obtained by subtracting one-quarter of the total dynamic reference tensile force of the system from the transient tensile force.

4. The method for rapid and precise installation of a four-pile jacket in deep-sea areas according to claim 1, characterized in that, Converting the differential tension components into horizontal roll and pitch moments for the jacket specifically includes: Obtain the planar projection coordinates of the suspension points of the four independent hydraulic compensation cylinders in the guide frame body coordinate system; The differential tension components corresponding to the four independent hydraulic compensation cylinders are combined into a differential tension tensor; Construct a geometric mapping matrix based on the plane projection coordinates; The differential tension tensor is input into the geometric mapping matrix for matrix multiplication to output the horizontal roll moment and pitch moment of the jacket.

5. The method for rapid and precise installation of a four-pile jacket in deep-sea areas according to claim 1, characterized in that, The process of inputting the roll moment, pitch moment, environmental flow field matrix, triaxial angular velocity, and triaxial acceleration into the dynamic equation to obtain instantaneous lateral acceleration specifically includes: The environmental fluid drag force is obtained by performing a cross-sectional integral operation based on the environmental flow field matrix. The roll moment, pitch moment, environmental fluid drag, triaxial angular velocity, and triaxial acceleration are substituted into the rigid-flexible cable coupling dynamic equation to perform inverse dynamic calculation and output the instantaneous lateral acceleration at the bottom docking point of the jacket.

6. The method for rapid and precise installation of a four-pile jacket in deep-sea areas according to claim 1, characterized in that, The instantaneous lateral acceleration and the low-frequency position of the duct frame are input into the filter to output the high-frequency pose coordinates of the duct frame, specifically including: Construct a state transition vector that includes the pose coordinate prediction value and the velocity prediction value; The time-updated state quantity is obtained by performing a double integration on the state transition vector using the instantaneous lateral acceleration; The observation residual is obtained by subtracting the predicted pose coordinates from the low-frequency position of the guide frame and the position in the time-updated state quantity. The observation residual is multiplied by the Kalman gain and then added to the time update state quantity to perform measurement update and output the high-frequency pose coordinates of the guide frame.

7. The method for rapid and precise installation of a four-pile jacket foundation in deep-sea areas according to claim 1, characterized in that, The generation of stroke control commands by combining the differential tension component and the derivative rate of change of the differential tension component specifically includes: Obtain the proportional impedance gain and the differential damping gain; The differential tension component is multiplied by the proportional impedance gain to obtain the proportional control term; The differential control term is obtained by multiplying the differential rate of change of the differential tension component with the differential damping gain. The proportional control term and the derivative control term are added together to obtain the stroke control command corresponding to the independent hydraulic compensation cylinder.

8. The method for rapid and precise installation of a four-pile jacket in deep-sea areas according to claim 1, characterized in that, The asymmetric extension and retraction of the independent hydraulic compensation cylinder to change the suspension boundary impedance specifically includes: The unidirectional swing trend of the guide frame is determined based on the positive or negative value of the differential tension component. For the independent hydraulic compensation cylinder on the upstream side where the differential tension component value increases, a stroke control command is issued to control the retraction of the independent hydraulic compensation cylinder; For the independent hydraulic compensation cylinder on the back side where the differential tension component value decreases, a stroke control command is simultaneously issued to control the extension of the independent hydraulic compensation cylinder; The suspension boundary impedance is changed by adjusting the elevation of the suspension point using the retraction and extension of the independent hydraulic compensation cylinder.

9. A method for rapid and precise installation of a four-pile jacket in deep-sea areas according to claim 1, characterized in that, Extracting the position error vector between the high-frequency pose coordinates of the jacket and the seabed reference coordinates specifically includes: Obtain the seabed reference coordinates; The initial spatial position difference vector is obtained by subtracting the seabed reference coordinates from the high-frequency pose coordinates of the jacket structure. The initial spatial position difference vector is input into a low-pass filter for filtering to remove high-frequency fluctuation components and output a low-frequency spatial position difference vector. The low-frequency spatial position difference vector is used as the position error vector.

10. A method for rapid and precise installation of a four-pile jacket foundation in deep-sea areas according to claim 1, characterized in that, Converting the position error vector into a translation command and sending it to the dynamic positioning system to drive the crane vessel to translate, and then lowering the jacket after centering, specifically includes: The position error vector is transformed by a coordinate system to obtain the crane ship displacement compensation vector in the global geographic coordinate system. The displacement compensation vector of the crane vessel is converted into the translation command and sent to the dynamic positioning system; The dynamic positioning system is used to drive the crane vessel to perform sea-level translation according to the translation command; Calculate the magnitude of the position error vector; When the magnitude of the position error vector is less than a preset alignment threshold, the alignment is determined to be complete, and a lowering command is generated and sent to the main winch to lower the guide frame.

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