Positioning method of active mooring system based on large yawing angle and related equipment

Abstract

The invention discloses a positioning method of an active mooring system based on a large yawing angle and related equipment. The method comprises the following steps: constructing a dynamic model considering the large yawing angle; acquiring a transfer function matrix according to the constructed kinetic model; and designing a feedforward compensator according to the transfer function matrix, and applying the feedforward compensator to the active mooring system to realize system decoupling. According to the method, the relation between the motion and stress of the platform is described through the transfer function matrix, the influence of the heading angle of the platform is counted, the motion of the platform can be described more accurately, meanwhile, the feed-forward compensator is connected in series in front of the transfer function matrix, coupling among surging, swaying and yawing can be eliminated, and the control effect is more accurate. The method can be widely applied to the technical field of mooring and positioning of offshore floating platforms.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore floating platform mooring positioning, and in particular to a positioning method and related equipment for an active mooring system based on a large bow roll angle. Background Art

[0002] Affected by the disturbances of the marine environment, such as wind, waves, and currents, semi-submersible platforms inevitably experience six degrees of freedom (DOF) of oscillation, including sway (left and right translation along the Y axis), surge (forward and backward translation along the X axis), heave (up and down translation along the Z axis), roll (rotation around the X axis), pitch (rotation around the Y axis), and yaw (rotation around the Z axis). Semi-submersible platforms lack a restoring force against horizontal surge, sway, and pitch, causing them to gradually deviate from their equilibrium position, threatening their operation and safety. To achieve the platform's positioning requirements, the platform controls the retraction and extension of anchor chains arranged in three directions, ensuring that the platform remains within the set target positions in all three directions, even under the influence of complex external loads from wind, waves, and currents. This ensures the normal operation and safety of the platform.

[0003] The dynamic model is a mathematical model used to describe the motion of a floating platform and the external disturbances of wind, waves and currents. The existing swell-surge-yaw dynamic model that describes the horizontal degrees of freedom of the platform is generally:

[0004]

[0005] Where M is the mass matrix, D(v) is the damping matrix, τ M represents the anchor chain tension, τ e Represents the resultant force of wind, wave and current environmental loads on the moored platform; is the coordinate transfer matrix, which is expressed as follows:

[0006]

[0007] In order to facilitate controller design and reduce the influence of coupling factors brought by the rotation matrix, it is usually assumed that the platform's bowing angle is not large, that is, have to:

[0008]

[0009] Based on the above small angle assumption, the model is linearized and x=[v T , η T ] as the state variable, v represents the velocity vector in the roll, surge and yaw directions, and η represents the displacement vector in the roll, surge and yaw directions. The formula of the swell-surge-yaw dynamic model can be transformed into:

[0010]

[0011] Where A is the state matrix, B is the input matrix, and C is the observation matrix.

[0012] When constructing the sway-surge-yaw three-degree-of-freedom dynamic model of a semi-submersible platform, in order to reduce the influence of the coupling factor brought by the rotation matrix, it is assumed that the yaw angle of the platform under the action of wind, waves and current is not much different from the target yaw angle, and the rotation matrix is ​​converted into It is regarded as the unit matrix I. However, in actual operation, the semi-submersible platform may have a large bow angle under the action of wind, waves and currents. At this time, using the small angle assumption to simplify the original model will lead to excessive errors in the final calculation results, affecting the final control effect. Summary of the Invention

[0013] In order to solve at least one of the technical problems existing in the prior art to a certain extent, the object of the present invention is to provide an active mooring system positioning method and related equipment based on a dynamic model constructed under large bow pitch angles.

[0014] The first technical solution adopted by the present invention is:

[0015] A positioning method for an active mooring system based on a large pitch angle comprises the following steps:

[0016] Construct a dynamic model considering large bow pitch angles;

[0017] Obtaining the transfer function matrix based on the constructed dynamic model;

[0018] A feedforward compensator is designed according to the transfer function matrix and applied to the active mooring system to achieve system decoupling.

[0019] Furthermore, the construction of the dynamic model considering a large bow pitch angle includes:

[0020] According to the existing swell-surge-yaw dynamic model that describes the horizontal freedom of the platform, it is obtained:

[0021]

[0022] Where M is the mass matrix and D is the damping matrix; is the coordinate transfer matrix, F is the heading angle; x 、F y , N represent the forces on the semi-submersible platform in the X direction, Y direction and around the Z axis respectively; x, y represent the displacements in the longitudinal and transverse directions respectively;

[0023] The expressions of mass matrix M and damping matrix D are:

[0024]

[0025] Expanding formula (1), the dynamic model considering large bow pitch angle is obtained as follows:

[0026]

[0027] Furthermore, the transfer function matrix G(s) is obtained according to the constructed dynamic model, including:

[0028] Assume the output is o(t) and the input is u(t):

[0029]

[0030] u(t)=(u1,u2,u3) T =(F x ,F y ,N) T

[0031] In the zero initial state, that is, the platform is located at the origin of the fixed coordinate system and the yaw angle is zero, then:

[0032]

[0033] Performing a Lapse transformation on formula (2) yields:

[0034]

[0035] Convert formula (3) into matrix form, namely:

[0036]

[0037] in:

[0038]

[0039] Invert the matrix of formula (4) to obtain the undecoupled transfer function matrix:

[0040]

[0041] Furthermore, the designing of a feedforward compensator according to the transfer function matrix and applying the feedforward compensator to the active mooring system includes:

[0042] The feedforward compensator is used to realize the decoupling of the active mooring system. The feedforward compensator is connected in series before the transfer function matrix of the original active mooring system, so that the structure of the overall system formed by the feedforward compensator and the transfer function matrix G(s) is diagonal.

[0043] Matrix; the transfer function matrix of the entire series system is:

[0044] W(s)=W d (s)G(s)

[0045] Where W d (s) is the transfer function matrix of the feedforward compensator.

[0046] Furthermore, the feedforward compensator is designed as follows:

[0047] The transfer function matrix W of the series feedforward compensator d (s), so that the entire system W(s) after series connection satisfies the form of a diagonal matrix; as long as the inverse matrix of G(s) exists, the transfer function of the feedforward compensator can be obtained:

[0048] W d (s)=G -1 (s)W(s)

[0049] Design the feedforward compensator as:

[0050]

[0051] Right now:

[0052]

[0053] At this point, the series connection system is:

[0054]

[0055] Where, I 3×3 is the identity matrix;

[0056] After series connection, the transfer function of the system is a diagonal matrix, and there is no coupling between the channels, thus achieving decoupling.

[0057] Furthermore, the positioning control method of the active mooring system is:

[0058] The target position and heading are measured by position sensors and attitude sensors, and compared with the actual position and heading. The high-frequency noise is filtered out by a low-pass filter to obtain the low-frequency position information of the platform. The low-frequency position information is compared with the target position to obtain the deviation. The control resultant force is calculated based on the deviation value, and the heading angle information is passed to the feedforward compensator and dynamic model to update the heading angle parameters in the model in real time. The control resultant force is distributed to each anchor chain windlass according to preset rules. Finally, the restoring force is generated by retracting and extending the anchor chain to resist the external wind, wave and current loads, thereby achieving the positioning of the platform.

[0059] The second technical solution adopted by the present invention is:

[0060] A positioning system for an active mooring system based on a large bow pitch angle, comprising:

[0061] Dynamic model building module, used to build a dynamic model considering large bow pitch angles;

[0062] A transfer function construction module is used to obtain a transfer function matrix according to the constructed dynamic model;

[0063] The compensator design module is used to design a feedforward compensator based on the transfer function matrix and apply the feedforward compensator to the active mooring system to achieve system decoupling.

[0064] The third technical solution adopted by the present invention is:

[0065] An electronic device comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, wherein the at least one instruction, at least one program, the code set, or the instruction set is loaded and executed by the processor to implement a positioning method for an active mooring system based on a large pitch angle as described above.

[0066] The fourth technical solution adopted by the present invention is:

[0067] A computer-readable storage medium stores at least one instruction, at least one program, a code set, or an instruction set, wherein the at least one instruction, at least one program, the code set, or the instruction set is loaded and executed by a processor to implement a positioning method for an active mooring system based on a large pitch angle as described above.

[0068] The fifth technical solution adopted by the present invention is:

[0069] A computer program product or computer program includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the aforementioned positioning method for an active mooring system based on a large pitch angle.

[0070] The beneficial effects of the present invention are as follows: the present invention describes the relationship between platform motion and force through a transfer function matrix, takes into account the influence of the platform's heading angle, and can more accurately describe the platform's motion. At the same time, a feedforward compensator is connected in series in front of the transfer function matrix, which can eliminate the coupling between longitudinal surge, lateral swing, and yaw pitch, making the control effect more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following introduction is made to the drawings of the embodiments of the present invention or the related technical solutions in the prior art. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0072] Figure 1 This is a flowchart of the steps of a positioning method for an active mooring system based on a large bow pitch angle in an embodiment of the present invention;

[0073] Figure 2 This is the positioning control principle diagram of the active mooring system;

[0074] Figure 3 Schematic diagram of the coupling of sway, surge and pitch motion in an embodiment of the present invention;

[0075] Figure 4 1 is a schematic diagram of a feedforward compensator decoupling according to an embodiment of the present invention;

[0076] Figure 5 1 is a schematic diagram of the positioning control principle of an active mooring system based on a large bow pitch angle in an embodiment of the present invention. DETAILED DESCRIPTION

[0077] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. For the step numbers in the following embodiments, they are provided only for the convenience of explanation and are not intended to limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0078] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. The singular forms of "a", "said", and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. In addition, unless otherwise clearly defined, words such as setting, installing, and connecting should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0079] In the description of this application, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0080] In the description of this application, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The terms "first" and "second" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly specifying the number or order of the technical features indicated.

[0081] In the description of this application, "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0082] In response to the existing technical problems, the present invention aims to invent a dynamic model construction solution when the bow pitch angle is large, solve the decoupling between the lateral swing, longitudinal swing and bow pitch motions when the bow pitch angle is large, and design a feedforward compensator for decoupling.

[0083] Example 1

[0084] like Figure 1 As shown, this embodiment provides a positioning method for an active mooring system based on a large pitch angle, comprising the following steps:

[0085] S1. Construct a dynamic model considering large bow pitch angles;

[0086] S2. Obtaining a transfer function matrix according to the constructed dynamic model;

[0087] S3. Design a feedforward compensator based on the transfer function matrix and apply the feedforward compensator to the active mooring system to achieve system decoupling.

[0088] The above method is explained in detail below with reference to the accompanying drawings and specific implementation methods.

[0089] (1) Dynamic model considering heading angle

[0090] See also Figure 2The control principle of active mooring positioning is as follows: first, the target position and heading are measured by position and attitude sensors, and the actual position and heading are measured. The low-frequency position information of the platform is obtained by filtering the high-frequency noise through a low-pass filter. The deviation is obtained after comparison with the target position. Then, the controller calculates the appropriate control force based on the deviation value, and distributes the control force to each anchor chain windlass according to appropriate rules. Finally, the restoring force is generated by retracting and extending the anchor chain to resist the external wind, wave and current loads, thereby realizing the positioning of the platform.

[0091] When constructing the sway-surge-yaw three-degree-of-freedom dynamic model of a semi-submersible platform, in order to reduce the influence of the coupling factor brought by the rotation matrix and facilitate the design of the controller, it is usually assumed that the platform's yaw angle under the action of wind, waves and currents is not much different from the target yaw angle, and the rotation matrix is ​​converted into The model is linearized by treating it as the unit matrix I. However, in actual semi-submersible platform operations, the bow angle may be too large. In this case, simplifying the original model by applying the small angle assumption will lead to large deviations, and the final output will deviate significantly from the actual result. The mass matrix M and damping matrix D are usually in the following form:

[0092]

[0093] When the platform's heading angle deviates too much from the target heading angle, the heading angle is too large and the small angle principle cannot be used. Based on the existing sway-surge-sway dynamic model that describes the horizontal freedom of the platform, according to and get:

[0094]

[0095] Expanding equation (2), the dynamic model considering the heading angle can be transformed into:

[0096]

[0097] The derivation of formula (2) is as follows:

[0098]

[0099] Will Substitution have to:

[0100]

[0101] Finally obtained

[0102] (2) Transfer function matrix

[0103] Assume the output is o(t) and the input is u(t):

[0104]

[0105] u(t)=(u1,u2,u3) T =(F x ,F y ,N) T

[0106] Among them, F x 、F y , N represent the force on the platform in the X direction, the Y direction and the Z axis respectively. They represent displacements in surge, sway and pitch directions respectively.

[0107] In the zero initial state, that is, the platform is located at the origin of the fixed coordinate system, and the yaw angle is zero, that is:

[0108]

[0109] Performing a pull-type transformation on equation (3) yields:

[0110]

[0111] Convert equation (6) into matrix form, namely:

[0112]

[0113] in:

[0114]

[0115] Invert the matrix of formula (7) to obtain the input-output transfer function matrix:

[0116]

[0117] (3) Feedforward compensation decoupling

[0118] From formula (6), we can see that when the yaw angle exists, the force in the pitch direction will not only cause the motion in the pitch direction, but also affect the motion in the sway direction; the force in the sway direction will not only cause the motion in the sway direction, but also affect the motion in the pitch and yaw directions; the moment in the yaw direction will not only cause the motion in the yaw direction, but also affect the motion in the pitch and sway directions. This shows that there is a coupling phenomenon between pitch, sway, and yaw, such as Figure 3 This will lead to problems such as reduced system control performance and system robustness, and the system needs to be decoupled. The purpose is to achieve that in the input-output coupled MIMO system, each output is controlled by only one corresponding input, and each input can only control one corresponding output.

[0119] This embodiment uses a feedforward compensator to achieve system decoupling. It only needs to connect the feedforward compensator in series before the transfer function matrix of the original system so that the structure of the overall system formed by the feedforward compensator and the transfer function matrix G(s) is a diagonal matrix. The principle of the feedforward compensation method is as follows: Figure 4 As shown, G(s) is the undecoupled transfer function matrix, W d (s) is the transfer function matrix of the feedforward compensator, then the transfer function matrix of the entire series system is:

[0120] W(s)=W d (s)G(s) (10)

[0121] That is, the transfer function matrix W of the series feedforward compensator d (s), so that the entire system W(s) after series connection satisfies the form of a diagonal matrix.

[0122] Obviously, as long as the inverse matrix of G(s) exists, the transfer function of the feedforward compensator can be obtained:

[0123] W d (s)=G -1 (s)W(s) (11)

[0124] Design the feedforward compensator as:

[0125]

[0126] At this point, the series connection system is:

[0127]

[0128] After series connection, the transfer function of the system is a diagonal matrix, and there is no coupling between the channels, thus achieving decoupling.

[0129] See also Figure 5 The control principle of the active mooring system in this embodiment is as follows: First, the target position and heading are measured by position and attitude sensors, compared to the actual position and heading. High-frequency noise is filtered through a low-pass filter to obtain the platform's low-frequency position information. This information is compared with the target position to obtain a deviation. The controller then calculates the appropriate control force based on the deviation. The heading angle information is then transmitted to the feedforward compensator and dynamic model, updating the model's heading angle parameters in real time. The control force is then distributed to the anchor chain windlasses according to appropriate rules. Finally, the anchor chain is retracted and extended to generate a restoring force to counteract external wind, wave, and current loads, thereby achieving platform positioning.

[0130] In general, in order to facilitate controller design and reduce the influence of coupling factors brought by the rotation matrix, the existing mooring positioning control uses a small-angle assumption to linearize the platform's dynamic model and then controls it. This treatment method is reasonable when the platform's bow angle is small, and the obtained control effect can also meet the requirements. However, when the platform's bow angle is too large, the simplified model based on the small-angle assumption cannot accurately reflect the relationship between the platform's motion and force, and does not consider the coupling between sway, surge, and bow motion.

[0131] The present invention describes the relationship between platform motion and force through a transfer function matrix, taking into account the influence of the platform's heading angle, and can more accurately describe the platform's motion. At the same time, connecting a feedforward compensator in series in front of the transfer function matrix can eliminate the coupling between pitch, roll and yaw, making the control effect more accurate.

[0132] In summary, compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0133] (1) Existing technical solutions all linearize the dynamic model based on the small-angle assumption, without considering the case of a large bow pitch angle. Considering that when the platform has a large bow pitch angle, it is not appropriate to linearize the dynamic model using the small-angle assumption. Based on this, the present invention expands the dynamic model into the form of a transfer function matrix and constructs a transfer function matrix between the input and output.

[0134] (2) Based on the constructed transfer function matrix, the present invention finds that under the condition of large bow pitch angle, there is a coupling phenomenon among surge, sway and bow pitch, and designs a feedforward compensator to achieve system decoupling.

[0135] (3) The present invention detects the heading angle of the platform in real time, filters it and feeds it back to the dynamic model, and changes the heading angle parameters in the dynamic model and the feedforward compensator in real time.

[0136] Example 2

[0137] This embodiment provides a positioning system for an active mooring system based on a large pitch angle, comprising:

[0138] Dynamic model building module, used to build a dynamic model considering large bow pitch angles;

[0139] A transfer function construction module is used to obtain a transfer function matrix according to the constructed dynamic model;

[0140] The compensator design module is used to design a feedforward compensator based on the transfer function matrix and apply the feedforward compensator to the active mooring system to achieve system decoupling.

[0141] Since the device is a positioning system of an active mooring system based on a large bow roll angle in an embodiment of the present invention, and the principle of solving the problem by the system is similar to that of the method, the implementation of the system can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0142] Example 3

[0143] An embodiment of the present invention further provides an electronic device, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the following Figure 1 A positioning method for an active mooring system based on a large bow roll angle is shown.

[0144] It is understood that the memory may include random access memory (RAM) or read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory may be used to store instructions, programs, codes, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function, instructions for implementing the various method embodiments described above, etc.; the data storage area may store data created based on the use of the server, etc.

[0145] The processor may include one or more processing cores. The processor utilizes various interfaces and circuits to connect various components within the server. It executes various server functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in memory, as well as accessing data stored in memory. Optionally, the processor may be implemented using at least one of the following hardware forms: digital signal processing (DSP), field-programmable gate array (FPGA), and programmable logic array (PLA). The processor may integrate one or a combination of a central processing unit (CPU) and a modem. The CPU primarily processes the operating system and application programs, while the modem handles wireless communications. It is understood that the modem may not be integrated into the processor and may be implemented separately via a single chip.

[0146] Since the electronic device is an electronic device corresponding to a positioning method for an active mooring system based on a large bow roll angle in an embodiment of the present invention, and the principle of solving the problem by the electronic device is similar to that of the method, the implementation of the electronic device can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0147] Example 4

[0148] An embodiment of the present invention further provides a computer-readable storage medium, wherein the storage medium stores at least one instruction, at least one program, code set or instruction set, and the at least one instruction, the at least one program, the code set or instruction set is loaded and executed by a processor to implement the following Figure 1 A positioning method for an active mooring system based on a large bow roll angle is shown.

[0149] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0150] Since the storage medium is the storage medium corresponding to the positioning method of an active mooring system based on a large bow roll angle in an embodiment of the present invention, and the principle of solving the problem by the storage medium is similar to that of the method, the implementation of the storage medium can refer to the implementation process of the above-mentioned method embodiment, and the repeated parts will not be repeated.

[0151] Example 5

[0152] In some possible implementations, various aspects of the methods of the embodiments of the present invention may also be implemented in the form of a program product, which includes program code. When the program product is executed on a computer device, the program code is used to cause the computer device to execute the steps of the positioning method for an active mooring system based on a large pitch angle according to various exemplary embodiments of the present application described above in this specification. The executable computer program code or "code" used to execute the various embodiments may be written in a high-level programming language such as C, C++, Python, Smalltalk, Java, JavaScript, Visual Basic, Structured Query Language (e.g., Transact-SQL), Perl, or in various other programming languages.

[0153] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0154] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0155] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the essence of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A positioning method for an active mooring system based on a large pitch angle, characterized in that: The following steps are involved: Construct a dynamic model considering large bow pitch angles; Obtaining the transfer function matrix based on the constructed dynamic model; A feedforward compensator is designed according to the transfer function matrix and applied to the active mooring system to achieve system decoupling.

2. The positioning method of the active mooring system based on a large pitch angle according to claim 1, characterized in that: The construction of the dynamic model considering a large bow pitch angle includes: According to the existing swell-surge-yaw dynamic model that describes the horizontal freedom of the platform, it is obtained: Where M is the mass matrix and D is the damping matrix; is the coordinate transfer matrix, F is the heading angle; x 、F y , N represent the forces on the semi-submersible platform in the X direction, Y direction and around the Z axis respectively; x, y represent the displacements in the longitudinal and transverse directions respectively; The expressions of mass matrix M and damping matrix D are: Expanding formula (1), the dynamic model considering large bow pitch angle is obtained as follows:

3. The positioning method of the active mooring system based on a large pitch angle according to claim 2, characterized in that: The step of obtaining the transfer function matrix G(s) according to the constructed dynamic model includes: Assume the output is o(t) and the input is u(t): u(t)=(u1,u2,u3) T =(F x ,F y ,N) T In the zero initial state, that is, the platform is located at the origin of the fixed coordinate system and the yaw angle is zero, then: Performing a Lapse transformation on formula (2) yields: Convert formula (3) into matrix form, namely: in: Invert the matrix of formula (4) to obtain the undecoupled transfer function matrix:

4. The positioning method of an active mooring system based on a large pitch angle according to claim 1, characterized in that: The method of designing a feedforward compensator according to a transfer function matrix and applying the feedforward compensator to an active mooring system includes: A feedforward compensator is used to realize the decoupling of the active mooring system. The feedforward compensator is connected in series before the transfer function matrix of the original active mooring system, so that the structure of the overall system formed by the feedforward compensator and the transfer function matrix G(s) is a diagonal matrix; the transfer function matrix of the entire series system is: W(s)=W d (s)G(s) Where W d (s) is the transfer function matrix of the feedforward compensator.

5. The positioning method of the active mooring system based on large pitch angle according to claim 4, characterized in that: The feedforward compensator is designed as follows: The transfer function matrix W of the series feedforward compensator d (s), so that the entire system W(s) after series connection satisfies the form of a diagonal matrix; as long as the inverse matrix of G(s) exists, the transfer function of the feedforward compensator can be obtained: W d (s)=G -1 (s)W(s) Design the feedforward compensator as: Right now: At this point, the series connection system is: Where, I 3×3 is the identity matrix; After series connection, the transfer function of the system is a diagonal matrix, and there is no coupling between the channels, thus achieving decoupling.

6. The positioning method of the active mooring system based on large pitch angle according to claim 1, characterized in that: The positioning control method of the active mooring system is: The target position and heading are measured by position sensors and attitude sensors, and compared with the actual position and heading. The high-frequency noise is filtered out by a low-pass filter to obtain the low-frequency position information of the platform. The low-frequency position information is compared with the target position to obtain the deviation. The control resultant force is calculated based on the deviation value, and the heading angle information is passed to the feedforward compensator and dynamic model to update the heading angle parameters in the model in real time. The control resultant force is distributed to each anchor chain windlass according to preset rules. Finally, the restoring force is generated by retracting and extending the anchor chain to resist the external wind, wave and current loads, thereby achieving the positioning of the platform.

7. A positioning system based on an active mooring system with a large bow pitch angle, characterized in that: include: Dynamic model building module, used to build a dynamic model considering large bow pitch angles; A transfer function construction module is used to obtain a transfer function matrix according to the constructed dynamic model; The compensator design module is used to design a feedforward compensator based on the transfer function matrix and apply the feedforward compensator to the active mooring system to achieve system decoupling.

8. An electronic device, characterized in that: The electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The computer program product comprises computer instructions, which are used to perform the method according to any one of claims 1 to 6 when executed by a processor.

Images