A ship fault-tolerant control method, system, device and storage medium

Abstract

This invention discloses a fault-tolerant control method, system, device, and storage medium for ships. The method includes: acquiring state variable information of the target ship; obtaining a predicted waypoint through a state-space model based on the state variable information and rudder angle control input information; obtaining the steering angle through a variational method based on the predicted waypoint; comparing the deviation between the steering angle and the heading angle with a preset tolerance deviation; when the deviation between the steering angle and the heading angle exceeds the preset tolerance deviation, using the steering angle as the target steering, and determining the rudder angle control quantity through a PID control algorithm to obtain the control input for the target ship. This invention employs an event-triggered mechanism. When the error between the heading and steering angle of the target ship exceeds the preset tolerance deviation, a corresponding steering control action is performed. This reduces the operational delay caused by time latency and also reduces invalid actions of the controller, making it widely applicable in the field of ship data processing technology.

Description

Technical Field

[0001] This invention relates to the field of ship data processing technology, and in particular to a ship fault-tolerant control method, system, device and storage medium. Background Technology

[0002] Because the ship's power drive structure has nonholonomic constraints and typical underactuated characteristics, and because changes in navigation conditions, severe interference with environmental parameters, and measurement inaccuracies cause ship motion to exhibit characteristics such as large inertia, long time delay, and nonlinearity, traditional ship control methods can no longer meet the control requirements, and new ship control methods must be explored. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a ship fault-tolerant control method, system, device and storage medium, which can efficiently realize ship fault-tolerant control.

[0004] On one hand, embodiments of the present invention provide a ship fault-tolerant control method, including:

[0005] Obtain the state variable information of the target vessel; wherein, the state variables include the forward displacement coordinates, lateral drift coordinates, heading angle, forward velocity, and lateral drift velocity of the target vessel in the inertial coordinate system;

[0006] Based on the state variable information and the rudder angle control input information, the predicted waypoint is obtained through the state space model;

[0007] Among them, the state-space model is based on the ship dynamics model and is constructed by linearizing the ship's motion process;

[0008] The turning angle is obtained using a variational method based on predicted waypoints.

[0009] The deviation between the steering angle and the heading angle is compared with the preset tolerance deviation;

[0010] When the deviation between the steering angle and the heading angle exceeds the preset tolerance deviation, the steering angle is used as the target steering angle, and the rudder angle control quantity is determined by the PID control algorithm to obtain the control input of the target ship.

[0011] Optionally, the method further includes:

[0012] The movement of the target vessel is controlled by the control input, and the control output of the target vessel is obtained after a preset time; wherein, the control output includes the position and speed of the target vessel;

[0013] When the control output does not meet the navigation expectation, the rudder angle control input information is updated in response to the control command of the target object, and the process of obtaining the state variable information of the target ship is repeated until the control output meets the navigation expectation.

[0014] Optionally, the method further includes:

[0015] A ship dynamics model is established based on the ship's moment characteristics, turning index, bow roll rate, and rudder angle.

[0016] The expression for the ship dynamics model is as follows:

[0017]

[0018] In the formula, T represents the ship's torque characteristics; r represents the bow roll rate. The derivative of r is represented by K; the gyrometry index is represented by δ; and the rudder angle is represented by δ.

[0019] Based on state variable information, an auxiliary function for the target ship is established;

[0020] The expression for the auxiliary function is:

[0021]

[0022] In the formula, x represents the forward displacement coordinate; y represents the lateral drift displacement coordinate; ψ represents the heading angle; v represents the forward velocity; and u represents the lateral drift velocity. and The derivatives of x, y, ψ, v, and u are respectively; T represents the ship's moment characteristics; K represents the yaw rate index; δ represents the rudder angle; and t represents the time marker.

[0023] Based on the ship dynamics model, combined with auxiliary functions, and by linearizing the ship motion process, a state-space model is obtained;

[0024] The expression for the state-space model is:

[0025]

[0026]

[0027] In the formula, v x The longitudinal component of the forward displacement, v y This represents the lateral component of the forward displacement velocity.

[0028] Optionally, based on the state variable information and the rudder angle control input information, the predicted waypoint is obtained through a state-space model, including:

[0029] Based on the state variable information and the rudder angle control input information, the predicted state variable sequence is obtained through the state space model;

[0030] Based on the predicted state quantity sequence and combined with the rudder angle control input information, the predicted output quantity sequence is obtained through the state space model.

[0031] Obtain the forward displacement coordinates and lateral drift displacement coordinates from the predicted output sequence, and arrange them by time to obtain a predicted waypoint.

[0032] Optionally, the steering angle is obtained using a variational method based on the predicted waypoints, including:

[0033] Obtain the target point for the ship's turning and rendezvous from the predicted waypoints; and obtain the initial position of the target ship;

[0034] The variational values ​​of the target point and the initial position point on the horizontal axis and the vertical axis are obtained by using the variational method.

[0035] The steering angle is obtained by using trigonometric functions based on the ratio of the vertical axis target variation value to the horizontal axis target variation value.

[0036] Optionally, the method further includes:

[0037] When the deviation between the turning angle and the heading angle does not exceed the preset tolerance deviation, the heading angle is used as the target heading.

[0038] Optionally, the rudder angle control quantity is determined through a PID control algorithm to obtain the control input of the target ship, including:

[0039] Obtain the target vessel's real-time heading angle and, in conjunction with the target vessel's turning direction, determine the target vessel's deviation angle;

[0040] Based on the deviation angle and combined with the control coefficients, the rudder angle control quantity is determined by the PID control algorithm to obtain the control input of the target ship; among which, the control coefficients include proportional coefficient, integral coefficient and derivative coefficient.

[0041] On the other hand, embodiments of the present invention provide a ship fault-tolerant control system, including:

[0042] The first module is used to acquire the state variable information of the target ship; among which, the state variables include the forward displacement coordinates, lateral drift coordinates, heading angle, forward velocity, and lateral drift velocity of the target ship in the inertial coordinate system;

[0043] The second module is used to obtain the predicted waypoints through a state-space model based on state variable information and rudder angle control input information.

[0044] Among them, the state-space model is based on the ship dynamics model and is constructed by linearizing the ship's motion process;

[0045] The third module is used to obtain the steering angle based on the predicted waypoints using a variational method;

[0046] The fourth module is used to compare the deviation between the steering angle and the heading angle with the preset tolerance deviation;

[0047] The fifth module is used to determine the rudder angle control quantity and obtain the control input of the target ship when the deviation between the steering angle and the heading angle exceeds the preset tolerance deviation.

[0048] Optionally, the system also includes:

[0049] The sixth module is used to establish a ship dynamics model based on the ship's torque characteristics, turning index, bow roll rate, and rudder angle; to establish an auxiliary function for the target ship based on state variable information; and to obtain a state-space model based on the ship dynamics model, combined with the auxiliary function, and by linearizing the ship's motion process.

[0050] The seventh module is used to use the heading angle as the target heading when the deviation between the turning angle and the heading angle does not exceed the preset tolerance deviation.

[0051] The eighth module is used to control the motion of the target vessel through control inputs and, after a preset time, acquire the control output of the target vessel. The control output includes the position and speed of the target vessel. When the control output does not meet the navigation expectation, the module updates the rudder angle control input information in response to the control command of the target vessel and returns to the step of acquiring the state variable information of the target vessel until the control output meets the navigation expectation.

[0052] On the other hand, embodiments of the present invention provide a ship fault-tolerant control device, including a processor and a memory;

[0053] Memory is used to store programs;

[0054] The processor executes the program as described above.

[0055] On the other hand, embodiments of the present invention provide a computer-readable storage medium storing a program that is executed by a processor to implement the method described above.

[0056] This invention also discloses a computer program product or computer program, which 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 method.

[0057] This invention first acquires the state variable information of the target vessel. These state variables include the target vessel's forward displacement coordinates, lateral drift coordinates, heading angle, forward velocity, and lateral drift velocity in the inertial coordinate system. Based on the state variable information and combined with rudder angle control input information, a predicted waypoint is obtained through a state-space model. This state-space model is based on a ship dynamics model and is constructed by linearizing the ship's motion process. Based on the predicted waypoint, the steering angle is obtained using a variational method. The deviation between the steering angle and the heading angle is compared with a preset tolerance deviation. When the deviation exceeds the preset tolerance deviation, the steering angle is used as the target steering angle, and the rudder angle control quantity is determined using a PID control algorithm to obtain the control input for the target vessel. This invention employs an event-triggered mechanism. When the error between the target vessel's heading and steering angle exceeds the preset tolerance deviation, a corresponding steering control action is performed. This reduces the operational delay caused by time delays and minimizes invalid controller actions. Furthermore, this invention accurately obtains the steering angle based on the state-space model's prediction and the variational method, providing an accurate data foundation for event triggering and ensuring the precision of ship control. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 A schematic flowchart of a ship fault-tolerant control method provided in an embodiment of the present invention;

[0060] Figure 2 A schematic diagram illustrating the basic principle of steering control provided in an embodiment of the present invention;

[0061] Figure 3 This is a schematic diagram of the overall process of the ship fault-tolerant control method provided in the embodiments of the present invention;

[0062] Figure 4 This is a schematic diagram of the structure of a ship fault-tolerant control system provided in an embodiment of the present invention;

[0063] Figure 5 This is a schematic diagram of the frame of a ship fault-tolerant control device provided in an embodiment of the present invention. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0065] On the one hand, such as Figure 1 As shown, an embodiment of the present invention provides a ship fault-tolerant control method, including:

[0066] S100, Obtain the state variable information of the target vessel;

[0067] The state variables include the target ship's forward displacement coordinates, lateral drift displacement coordinates, heading angle, forward velocity, and lateral drift velocity in the inertial coordinate system.

[0068] S200. Based on the state variable information and the rudder angle control input information, the predicted waypoint is obtained through the state space model.

[0069] Among them, the state-space model is based on the ship dynamics model and is constructed by linearizing the ship's motion process;

[0070] In some embodiments, the method may further include: establishing a ship dynamics model based on the ship's moment characteristics, turning index, bow roll rate, and rudder angle; wherein the expression of the ship dynamics model is:

[0071]

[0072] In the formula, T represents the ship's torque characteristics; r represents the bow roll rate. The derivative of r is represented by K; the gyrometry index is represented by δ; and the rudder angle is represented by δ.

[0073] Based on the state variable information, an auxiliary function for the target ship is established; the expression of the auxiliary function is:

[0074]

[0075] In the formula, x represents the forward displacement coordinate; y represents the lateral drift displacement coordinate; ψ represents the heading angle; v represents the forward velocity; and u represents the lateral drift velocity. and The derivatives of x, y, ψ, v, and u are respectively; T represents the ship's moment characteristics; K represents the yaw rate index; δ represents the rudder angle; and t represents the time marker.

[0076] Based on the ship dynamics model, combined with auxiliary functions, and by linearizing the ship's motion process, a state-space model is obtained; the expression of the state-space model is:

[0077]

[0078]

[0079] In the formula, v x The longitudinal component of the forward displacement, v y This represents the lateral component of the forward displacement velocity.

[0080] In some embodiments, step S200 may include: obtaining a predicted state quantity sequence through a state space model based on state variable information and rudder angle control input information; obtaining a predicted output quantity sequence through a state space model based on the predicted state quantity sequence and rudder angle control input information; obtaining forward displacement coordinates and lateral drift displacement coordinates from the predicted output quantity sequence, and arranging them in time to obtain a predicted waypoint.

[0081] In some specific embodiments, a ship dynamics model is first established:

[0082]

[0083] T represents the ship's torque characteristics, K represents the gyrometry index; r represents the bow roll rate (bow roll refers to the rotational oscillation motion of an object immersed in water around the vertical axis of the hull. Generally, this bow roll motion of a ship can be regarded as the result of the following three factors in addition to poor steering: (1) static pressure imbalance on the hull; (2) the circular motion of water in the waves; (3) gyroscopic effect.); δ represents the rudder angle.

[0084] Therefore, the forward displacement coordinate x, the lateral drift coordinate y, the heading angle ψ, the forward velocity u, and the lateral drift velocity v in the inertial coordinate system are selected as the state variables, and the auxiliary functions are as follows:

[0085]

[0086] Combining equations (1) and (2), the motion process is linearized, resulting in the state-space model of the ship system as follows:

[0087]

[0088]

[0089] The state-space model of a ship can be simplified as follows:

[0090]

[0091] y(t)=Cz(t)+Du(t) (6)

[0092] z represents the state vector; y represents the position output vector; u represents the ship's rudder angle control input.

[0093] Based on the initial state vector x(0) and external input u(0), substitute into equation (5) to calculate the state quantity x(1) at the next moment.

[0094] x(1)=Ax(0)+Bu(0)

[0095] Substitute x(1) into the state equation and continue to calculate x(2), x(3), ... until the state quantity sequence x(0), x(1), x(2), x(3), ..., x(N) for a future period of time is predicted.

[0096] x(2)=Ax(1)+Bu(1)

[0097] x(3)=Ax(2)+Bu(2)

[0098] ...

[0099] x(N)=Ax(N-1)+Bu(N-1)

[0100] N represents the number of time steps in the prediction, and N is large enough. The relationship between the prediction duration T1 and N is as follows:

[0101] N = T1 / n (7)

[0102] Where T1 must satisfy T1>T, T is the delay time measured for each round of control signal transmission, or the time it takes for the ship to move from its initial position to its current position, and n represents the time step.

[0103] Substitute the obtained state sequence into the output equation, i.e., equation (6), to calculate the corresponding predicted output sequence:

[0104] y(0)=Cx(0)+Du(0)

[0105] y(1)=Cx(1)+Du(1)

[0106] y(N-1)=Cx(N-1)+Du(N-1)

[0107] y(0), y(1), y(2), y(3), ..., x(N-1) is a sequence of state prediction outputs. The forward displacement coordinates and lateral drift displacement coordinates in this sequence can be arranged in time to form a predicted waypoint. Due to the time delay, the initial state and control input vectors predicted above are the ship's information and control inputs observed by the operator at the remote control terminal before the time delay.

[0108] S300: Based on predicted waypoints, the steering angle is obtained through variational methods;

[0109] In some embodiments, step S300 may include: obtaining the target point for the ship's turning and meeting from the predicted waypoints; obtaining the initial position point of the target ship; obtaining the target variation values ​​on the horizontal axis and the vertical axis between the target point and the initial position point using a variational method; and obtaining the turning angle using trigonometric functions based on the ratio of the vertical axis target variation value to the horizontal axis target variation value.

[0110] In some specific embodiments, the optimal target point for the ship to turn to at this moment is found from the predicted waypoints, i.e. Figure 2 The point (x2, y2) in the basic principle diagram should be noted as follows: Figure 2 In the diagram, (x1, y1) represents the ship's current position.

[0111] (x0, y0) represents the initial position of the ship under remote control, i.e., the ship's position observed by the operator based on the data received from the remote control terminal. Due to network latency, the ship's position observed by the operator is somewhat delayed. (x2, y2) represents the ship's optimal turning target point, calculated based on the initial and current positions, to obtain the turning angle θ. External disturbances encountered during the ship's navigation can cause deviations in position and heading angle. Therefore, the heading angle ψ1 at the current position in the figure will deviate from the heading angle ψ0 at the initial position, requiring a re-evaluation and calculation of the turning angle at the current position. Due to latency, ignoring the predicted values ​​at previous moments, y(0), y(1), y(2), y(3), ..., x(N-1) are approximated as a continuous straight line 1 with an angle of ψ. This straight line passes through the ship's position before the latency, i.e., the initial position point (x0, y0), and can be represented as:

[0112] y-y0=tanψ·(x-x0) (8)

[0113] The problem of finding the optimal target point is transformed into finding the fastest path, which can be solved by the following method:

[0114] Assuming the ship moves in a straight line, the equation of motion of the ship can be expressed as:

[0115] x(t)=x1+v·t·cosθ (9)

[0116] y(t)=y1+v·t·sinθ (10)

[0117] Where x1 and y1 are the ship's current position, v is the ship's speed (moving in a straight line), θ is the ship's turning angle, and t is time.

[0118] Assuming the time required for the ship to travel from its current position to its target position is T2, then the following conditions are met:

[0119]

[0120] Where (x1, y1) and (x2, y2) represent the ship's current position and target position, respectively.

[0121] The target location must meet the following requirements:

[0122]

[0123] α is the ship's limit turning angle, which is determined by the ship's own maneuvering properties.

[0124] At this point, the shortest path problem can be transformed into a variational problem, namely, finding a function y(x) such that the following expression is minimized:

[0125]

[0126] y(x) can be obtained using the variational method, and finally the turning angle θ is obtained as follows:

[0127]

[0128] S400. Compare the deviation between the steering angle and the heading angle with the preset tolerance deviation;

[0129] S500: When the deviation between the steering angle and the heading angle exceeds the preset tolerance deviation, the steering angle is used as the target steering angle, and the rudder angle control quantity is determined by the PID control algorithm to obtain the control input of the target ship.

[0130] In some embodiments, the rudder angle control quantity is determined by a PID control algorithm to obtain the control input of the target vessel. This may include: acquiring the real-time heading angle of the target vessel and determining the deviation angle of the target vessel in combination with the target steering; based on the deviation angle and in combination with control coefficients, determining the rudder angle control quantity by a PID control algorithm to obtain the control input of the target vessel; wherein the control coefficients include proportional coefficients, integral coefficients and derivative coefficients.

[0131] In some embodiments, the method may further include: when the deviation between the steering angle and the heading angle does not exceed a preset tolerance deviation, using the heading angle as the target heading.

[0132] In some embodiments, the method may further include: controlling the motion of the target vessel through control inputs, and after a preset time, acquiring the control output of the target vessel; wherein the control output includes the position and speed of the target vessel; when the control output does not meet the navigation expectation, updating the rudder angle control input information in response to the control command of the target vessel, and returning to the step of acquiring the state variable information of the target vessel, until the control output meets the navigation expectation.

[0133] A turning angle θ is formed. If θ and ψ satisfy the maximum tolerance deviation ε, the ship continues to maintain its current course with ψ as the target course. The maximum tolerance deviation is determined by the following formula:

[0134] ε=|θ-ψ1| (15)

[0135] Where ε∈[0,5], ψ1 is the actual heading angle of the ship (e.g., Figure 2 (As shown).

[0136] If θ and ψ do not meet the maximum tolerance deviation ε, proceed to the next step. The ship turns with the target steering angle θ, and the ship's control input is obtained through the following steps:

[0137] The ship's deviation angle is:

[0138] e(t)=|θ(t)-ψ2(t)| (16)

[0139] Where θ(t) is the desired heading angle and ψ2(t) is the current heading angle of the ship.

[0140] The ship's propeller speed is not zero. The final rudder angle control value is obtained through a PID control algorithm. The steps are as follows:

[0141] P(t) = K p ·e(t) (17)

[0142]

[0143]

[0144] Among them, K p K is a proportionality coefficient used to adjust the strength of the control proportional effect. i K is the integral coefficient, used to adjust the strength of the integral action of the control; d These are the differential coefficients, used to adjust and control the strength of the differential action.

[0145] The final rudder angle control quantity τ(t) is obtained by a weighted combination of the above three parts:

[0146] τ(t)=P(t)+I(t)+D(t) (20)

[0147] To facilitate understanding of the technical solution of the present invention, the overall process of the present invention will be explained and described below with reference to some specific embodiments. The following description should not be regarded as a limitation of the present invention.

[0148] The steps for implementing ship fault-tolerant control are as follows:

[0149] Step 1: Establish the ship's state-space equations, predict the ship's state variables for a future period of time starting from its initial position, and obtain the predicted waypoints.

[0150] Step 2: Based on the state prediction, calculate the turning angle θ according to the current ship navigation information.

[0151] Step 3: If ψ and θ satisfy the maximum tolerance deviation, the ship continues to maintain the current course with ψ as the target course. If ψ and θ do not satisfy the maximum tolerance deviation, proceed to the next step.

[0152] Step 4: The ship turns θ(t) with the target turning angle θ, and the control input of the ship is obtained.

[0153] In some specific embodiments, such as Figure 3 As shown, the system control process based on the above-mentioned ship fault-tolerant control method is as follows:

[0154] Step 1: After receiving the pilot's command input, the ship control terminal, combined with the acquired real-time ship control output, calculates the steering angle θ using the method described above. The deviation between ψ and θ is then compared with the preset maximum allowable deviation ε (ε≧0). If the deviation is greater than ε, proceed to the next control step; if the deviation is less than ε, skip to Step 3 for further operation.

[0155] Step 2: When the ship's heading angle deviation reaches the trigger condition, select θ as the steering angle, send the control input τ to the controlled ship, and jump to Step 4.

[0156] Step 3: Set ψ as the target heading on the ship control terminal and send the control input τ to the controlled ship.

[0157] Step 4: After the ship moves, the output control output quantities Y, such as position and speed, are sent back to the ship control terminal.

[0158] Step 5: The ship control terminal sends the information to the remote control terminal, and the helmsman makes a judgment. If the helmsman determines that adjustments are needed, he returns the control command to the ship control terminal and then repeats the Step 1 operation. If the helmsman determines that the current control is satisfactory, the ship controller is in a waiting state.

[0159] In summary, the embodiments of the present invention employ an event-triggered mechanism. When the error between the controlled vessel's heading and turning angle does not meet the maximum tolerable deviation, the controller will initiate a turning control action. This reduces the operational delay caused by time latency and also minimizes invalid actions of the controller.

[0160] On the other hand, such as Figure 4As shown, an embodiment of the present invention provides a ship fault-tolerant control system 600, comprising: a first module 610 for acquiring state variable information of a target ship; wherein the state variables include the forward displacement coordinates, lateral drift coordinates, heading angle, forward velocity, and lateral drift velocity of the target ship in an inertial coordinate system; a second module 620 for obtaining a predicted waypoint through a state space model based on the state variable information and combined with rudder angle control input information; wherein the state space model is based on a ship dynamics model and is constructed by linearizing the ship's motion process; a third module 630 for obtaining the steering angle based on the predicted waypoint using a variational method; a fourth module 640 for comparing the deviation between the steering angle and the heading angle with a preset tolerance deviation; and a fifth module 650 for determining the rudder angle control quantity through a PID control algorithm when the deviation between the steering angle and the heading angle exceeds the preset tolerance deviation, thereby obtaining the control input of the target ship, using the steering angle as the target steering.

[0161] It should be noted that, in some embodiments, the system may further include:

[0162] The sixth module is used to establish a ship dynamics model based on the ship's torque characteristics, turning index, bow roll rate, and rudder angle; to establish an auxiliary function for the target ship based on state variable information; and to obtain a state-space model based on the ship dynamics model, combined with the auxiliary function, and by linearizing the ship's motion process.

[0163] The seventh module is used to use the heading angle as the target heading when the deviation between the turning angle and the heading angle does not exceed the preset tolerance deviation.

[0164] The eighth module is used to control the motion of the target vessel through control inputs and, after a preset time, acquire the control output of the target vessel. The control output includes the position and speed of the target vessel. When the control output does not meet the navigation expectation, the module updates the rudder angle control input information in response to the control command of the target vessel and returns to the step of acquiring the state variable information of the target vessel until the control output meets the navigation expectation.

[0165] The content of the method embodiments of the present invention is applicable to the system embodiments. The specific functions implemented in the system embodiments are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above methods.

[0166] like Figure 5 As shown, another aspect of the present invention provides a ship fault-tolerant control device 700, including a processor 710 and a memory 720;

[0167] Memory 720 is used to store programs;

[0168] The processor 710 executes the program as described above.

[0169] The content of the method embodiments of the present invention is applicable to the device embodiments. The specific functions implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above methods.

[0170] Another aspect of this invention provides a computer-readable storage medium storing a program that is executed by a processor to implement the method described above.

[0171] The content of the method embodiments of the present invention is applicable to the computer-readable storage medium embodiments. The specific functions implemented by the computer-readable storage medium embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above methods.

[0172] This invention also discloses a computer program product or computer program, which 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 method.

[0173] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0174] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0175] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0176] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution means, apparatus, or device (such as a computer-based device, a processor-including device, or other means that can fetch and execute instructions from, or in conjunction with, an instruction execution means, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution means, apparatus, or device.

[0177] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0178] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution device. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0179] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0180] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0181] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A ship fault-tolerant control method, characterized in that, include: Obtain the state variable information of the target vessel; wherein, the state variables include the forward displacement coordinates, lateral drift coordinates, heading angle, forward velocity, and lateral drift velocity of the target vessel in the inertial coordinate system; Based on the state variable information and the rudder angle control input information, the predicted waypoint is obtained through the state space model; The state-space model is based on the ship dynamics model and is constructed by linearizing the ship's motion process. Based on the predicted waypoints, the steering angle is obtained using a variational method; The deviation between the steering angle and the heading angle is compared with a preset tolerance deviation; When the deviation between the steering angle and the heading angle exceeds the preset tolerance deviation, the steering angle is used as the target steering, and the rudder angle control quantity is determined by the PID control algorithm to obtain the control input of the target ship; The methods also include: A ship dynamics model is established based on the ship's moment characteristics, turning index, bow roll rate, and rudder angle. The expression for the ship dynamics model is as follows: In the formula, Indicates the ship's torque characteristics; Indicates the bow roll angular velocity. express The derivative; Indicates the reversibility index; Represents the rudder angle; Based on the state variable information, an auxiliary function for the target ship is established; The expression for the auxiliary function is: In the formula, Indicates the forward displacement coordinates; Indicates the lateral displacement coordinates; Indicates the heading angle; Indicates forward velocity; Indicates the drift speed; , , , and In order , , , and The derivative; Indicates the ship's torque characteristics; Indicates the reversibility index; represents the rudder angle, Indicates time stamp; Based on the ship dynamics model, combined with the auxiliary function, and by linearizing the ship motion process, a state-space model is obtained. The expression for the state-space model is as follows: + wherein represents the longitudinal component of the forward displacement velocity, represents the transverse component of the forward displacement velocity.

2. A ship fault-tolerant control method according to claim 1, characterized in that, The method further includes: The movement of the target vessel is controlled by the control input, and after a preset time, the control output of the target vessel is obtained; wherein, the control output includes the position and speed of the target vessel; When the control output does not meet the navigation expectation, the rudder angle control input information is updated in response to the control command of the target object, and the process returns to the step of obtaining the state variable information of the target ship until the control output meets the navigation expectation.

3. A ship fault-tolerant control method according to claim 1, characterized in that, The step of obtaining the predicted waypoint through a state-space model based on the state variable information and the rudder angle control input information includes: Based on the state variable information and the rudder angle control input information, a predicted state quantity sequence is obtained through a state space model; Based on the predicted state quantity sequence and the rudder angle control input information, the predicted output quantity sequence is obtained through the state space model. The forward displacement coordinates and the lateral drift displacement coordinates are obtained from the predicted output sequence, and a predicted waypoint is obtained by arranging them in time.

4. The ship fault-tolerant control method according to claim 1, characterized in that, The step of obtaining the steering angle based on the predicted waypoint using a variational method includes: Obtain the target point for the ship's turning and rendezvous from the predicted waypoints; and obtain the initial position of the target ship; The target point and the initial position point are obtained by variational method in terms of target variational values ​​on the horizontal axis and target variational values ​​on the vertical axis. The steering angle is obtained using trigonometric functions based on the ratio of the target variation value on the vertical axis to the target variation value on the horizontal axis.

5. A ship fault-tolerant control method according to claim 1, characterized in that, The method further includes: When the deviation between the steering angle and the heading angle does not exceed the preset tolerance deviation, the heading angle is used as the target heading.

6. A ship fault-tolerant control method according to claim 1, characterized in that, The step of determining the rudder angle control quantity through a PID control algorithm to obtain the control input of the target ship includes: The real-time heading angle of the target vessel is obtained, and the deviation angle of the target vessel is determined in combination with the target turning angle. Based on the deviation angle and combined with the control coefficients, the rudder angle control quantity is determined by the PID control algorithm to obtain the control input of the target ship; wherein, the control coefficients include proportional coefficient, integral coefficient and derivative coefficient.

7. A ship fault-tolerant control system, characterized by The system, applied to the method of claim 1, comprises: The first module is used to acquire the state variable information of the target ship; wherein, the state variables include the forward displacement coordinates, lateral drift coordinates, heading angle, forward velocity, and lateral drift velocity of the target ship in the inertial coordinate system; The second module is used to obtain the predicted waypoints through a state-space model based on the state variable information and the rudder angle control input information. The state-space model is based on the ship dynamics model and is constructed by linearizing the ship's motion process. The third module is used to obtain the turning angle based on the predicted waypoints using a variational method; The fourth module is used to compare the deviation between the steering angle and the heading angle with a preset tolerance deviation; The fifth module is used to determine the rudder angle control quantity by using the steering angle as the target steering when the deviation between the steering angle and the heading angle exceeds the preset tolerance deviation, and to obtain the control input of the target ship by using the steering angle as the target steering and the PID control algorithm.

8. A ship fault-tolerant control apparatus, characterized by, Including the processor and memory; The memory is used to store programs; The processor executes the program to implement the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The storage medium stores a program that is executed by a processor to implement the method as described in any one of claims 1 to 6.

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