Ship autopilot control method based on input end and parameter updating synchronous triggering

Abstract

The invention discloses a ship autopilot control method based on input end and parameter updating synchronous triggering. The ship autopilot control method based on input end and parameter updating synchronous triggering comprises the following steps: determining a real-time course error based on a reference course and a current course of a ship; judging whether the real-time course error meets the self-adjustment triggering rule or not based on the real-time course error and the self-adjustment triggering rule; responding to the condition that the real-time course error meets the self-adjustment triggering rule, and updating a triggering course error in the self-adjustment triggering rule to form an updated self-adjustment triggering rule; updating a control parameter based on the updated self-adjusting trigger rule to form an updated control parameter; and controlling the course of the ship based on the updated control parameters. An event triggering mechanism with a self-adjusting mechanism is established, so that the ship can autonomously determine the steering opportunity according to the course condition, the calculation load is greatly reduced, and communication resources are saved.

Description

Technical Field

[0001] The present application relates to the field of ship autopilot control, and in particular to a ship autopilot control method based on synchronous triggering of input end and parameter update. Background Art

[0002] Ship heading control is an important research topic in ship motion control, and its performance directly affects the economy and safety of navigation. In the field of ship motion control, the guidance algorithm is one of the important key technologies to solve the ship track keeping control. Among them, the control method can be divided into two categories: indirect track control and direct track control. At present, the existing guidance algorithm is introduced from the research field of missile shooting guidance to the field of ship navigation, which is what we usually call the line of sight (LOS) algorithm. The LOS algorithm solves the problem of using track deviation and heading deviation to calculate the ship's guidance heading in indirect track keeping control, and is also a widely used algorithm in shipborne automatic steering instruments. The following is a brief introduction to the specific technical features of the LOS algorithm.

[0003] The variable LOS radius and the waypoint switching boundary ring are two important concepts or variables in the LOS algorithm. The purpose of the LOS algorithm is to deduce the heading reference command required to complete the control task in track keeping control, that is, Ψ los The ship heading control technology uses the existing ship heading keeping controller to drive the steering actuator to make the ship heading track the reference command. Ψ los , reducing track deviation and ultimately enabling the ship to navigate automatically along the planned route.

[0004] Figure 1 The figure shows the basic guidance principle diagram of the LOS algorithm. In navigation practice, the planned route is usually designed by the pilot by setting waypoints, such as Figure 1 The coordinates in are ( x i-1 , y i-1 )、( x i , y i )and( x i+1 , y i+1 ) point. x, y ) as the center, with LOS radius R Draw an arc. Under the premise of selecting an appropriate LOS radius, the arc drawn can intersect the planned route. P i-1 P i At pointA B and A F . Starts at the current ship position (x, y) and ends at point A F The line segment is defined as the LOS line, and the corresponding azimuth is Ψ los ,in, Ψ los It can be calculated by formula (1), and Ψ los ∈(-π, π).

[0005] (1); among which, For point A F The vertical coordinate of y is the ordinate of the ship’s position, For point A F The horizontal axis of x is the horizontal coordinate of the ship's position.

[0006] Generally, there are three ways to obtain the LOS radius R: 1. Traditional LOS algorithm: R = αL PP ,in, α is the preset coefficient, L PP The length between the two columns of the ship, in this case, must be required α >1, otherwise the ship will fluctuate frequently around the planned route; 2. Improve LOS algorithm: R = d + Lp ,in, d The projected distance from the current ship position to the planned course, i.e., the track deviation. This selection can ensure R > d Always holds true, ensuring that the LOS line always exists; Third, the exponential convergence LOS algorithm, as shown in formula (2), where, lambertw is a function f ( x ) = x x The inverse function of R min = 1.7 L PP ,coefficient b is the exponential convergence factor, b = 0.05.

[0007] (2).

[0008] The LOS guidance algorithm can achieve the navigation guidance of the ship on a straight line and ultimately achieve the track keeping control task. However, when the ship is near a waypoint, that is, Figure 1 middle P i At the position, waypoint conversion is required, which involves the concept of waypoint switching boundary ring, that is, ( x i , y i ) is centered on δ i A circular area with a radius of . However, when a ship enters this area, the reference planned route is composed of route segments {( x i-1 , y i-1 ), ( x i , y i )}Switch to route segment{( x i , y i ), ( x i+1 , y i+1 )}, the switching condition is formula (3).

[0009] (3).

[0010] The current ship autopilot heading keeping control algorithm has some problems. For example, the current steering command causes the steering gear to brake frequently, and the computing pressure and communication load are large. Therefore, an optimized ship autopilot control method is needed. Summary of the invention

[0011] One advantage of the present application is that it provides a ship automatic rudder control method based on synchronous triggering of input terminals and parameter updates, wherein the ship automatic rudder control method based on synchronous triggering of input terminals and parameter updates reduces the transmission frequency of control commands, can reduce the braking frequency of the rudder to a certain extent, and reduce computing pressure and communication load.

[0012] Another advantage of the present application is that it provides a ship automatic rudder control method based on synchronous triggering of input terminals and parameter updates, wherein the ship automatic rudder control method based on synchronous triggering of input terminals and parameter updates autonomously issues steering commands based on the ship's heading deviation, which is in line with the steering habits of the ship's duty officer.

[0013] According to one aspect of the present application, a ship autopilot control method based on synchronous triggering of input terminal and parameter update is provided, which comprises the steps of: determining a real-time heading error based on a reference heading and a current heading of the vessel; Based on the real-time heading error and the self-adjustment trigger rule, it is determined whether the real-time heading error satisfies the self-adjustment trigger rule; In response to the real-time heading error satisfying the self-adjustment trigger rule, updating the trigger heading error in the self-adjustment trigger rule to form an updated self-adjustment trigger rule; updating the control parameters based on the updated self-adjusting triggering rules to form updated control parameters; and controlling the heading of the vessel based on the updated control parameters; The self-adjustment triggering rule is: ; in, t Indicates the triggering moment; t k Indicates k Trigger moment; t k+1 Indicates the first k+ 1) Triggering moment; k is a positive integer; Indicates the trigger heading error; represents the function of the trigger heading error with respect to time; ѱ e Indicates the real-time heading error; ѱ e ( t ) represents the function of real-time heading error with respect to time; Indicates trigger error; represents the trigger error as a function of time; represents the first trigger threshold parameter; represents the second trigger threshold parameter; ; In the updated self-adjustment trigger rule, the value of the trigger heading error is ѱ e ( t k ) is updated to ѱ e ( t k+1 ); ѱ e ( t k )express t k Real-time heading error at the moment; ѱ e ( t k+1 )express t k+1Real-time heading error at the moment; Among them, the update law of the first trigger threshold parameter is: ; The update law of the second trigger threshold parameter is: ;in, represents the updated first trigger threshold parameter; represents the updated second trigger threshold parameter; C 1 represents the first preset constant; C 2 represents the second preset constant; D Indicates the third preset constant.

[0014] In one embodiment of the ship autopilot control method based on synchronous triggering of input terminal and parameter update according to the present application, the control parameters are updated based on the updated self-adjusting trigger rule, including the steps of: obtaining a heading keeping virtual control law based on the updated self-adjusting trigger rule, wherein the heading keeping virtual control law is: ;in, α k represents the controlled state variable of the heading keeping virtual control law, wherein the controlled state variable of the heading keeping virtual control law is the angular velocity; α k ( t ) represents the function of the controlled state variables of the heading keeping virtual control law with respect to time; λ is a constant in [-1,1]; k ѱ represents the control parameters of the virtual control law; represents the time first derivative of the reference heading; express t k The time first derivative of the reference heading at time instant.

[0015] In one embodiment of the ship automatic pilot control method based on synchronous triggering of input terminal and parameter update according to the present application, the control parameters are updated based on the updated self-regulating trigger rule, and the step of obtaining dynamic reference information based on the updated self-regulating trigger rule is also included, wherein the dynamic reference information includes the controlled state variables of the heading keeping virtual control law after first-order filtering, through The controlled state variables of the heading keeping virtual control law after first-order filtering are obtained; wherein, represents the time constant; β k represents the controlled state variable of the heading keeping virtual control law after first-order filtering; represents the time first-order derivative of the controlled state variable of the heading keeping virtual control law after first-order filtering; ,in, β k(0) represents the yaw angular velocity at time 0; α k (0) represents the heading keeping virtual control law at time 0.

[0016] In one embodiment of the ship autopilot control method based on synchronous triggering of input terminal and parameter update according to the present application, the dynamic reference information also includes the dynamic error of the ship's bow pitch, wherein The dynamic error of the ship's bow motion is calculated; represents the dynamic error, r k Indicates that the ship is t k The actual yaw angular velocity at the moment.

[0017] In one embodiment of the ship automatic pilot control method based on the synchronous triggering of the input terminal and the parameter update according to the present application, the heading of the ship is controlled based on the updated control parameters, including the steps of: obtaining the control command and the steering command of the ship automatic pilot based on the updated control parameters, wherein, by Calculate the control command of the ship's automatic rudder, through Calculate and obtain the steering order; among them, ο k Indicates the control command of the ship's automatic pilot; k r Indicates the control parameters of the autopilot heading hold controller; δ k Indicates rudder orders; m r Indicates the ship's bow displacement; represents the dynamic nonlinear compensation parameter; Indicates the servo gain adaptive compensation parameter; θ k represents the activation function; represents a small positive quantity; the update law of the dynamic nonlinear compensation parameter is: ; The update law of the servo gain adaptive compensation parameters is: ;in, Represents the updated dynamic nonlinear compensation parameters; Indicates the updated servo gain adaptive compensation parameters; represents the learning rate of the update law for the dynamics nonlinear compensation parameters; Represents the learning rate of the update law of the servo gain adaptive compensation parameters; and are all constants and positive numbers; represents the initial dynamic nonlinear compensation parameter; Indicates the initial servo gain adaptive compensation parameter.

[0018] In one embodiment of the ship autopilot control method based on synchronous triggering of input terminal and parameter update according to the present application, the mathematical model of ship bow rolling motion is: ;in, ѱ Indicates the current heading of the ship; Represents the time first derivative of the current heading of the ship; u Indicates the ship's surge speed; v Indicates the ship's sway speed; r Indicates the actual yaw angular velocity; It represents the time first-order derivative of the actual yaw angular velocity; f(v) represents the nonlinear term of ship dynamics; Indicates the servo gain; d w Indicates the disturbance of the marine environment on the hull; δ Indicates the rudder angle indication value of the servo; m u Indicates the ship's longitudinal displacement; m v Indicates the ship's bow roll and sway displacement; m r Indicates the ship's bow displacement; d 1 represents the first ship hydrodynamic coefficient; d 2 represents the second ship hydrodynamic coefficient; d 3 represents the third ship hydrodynamic coefficient; λ R represents the rudder aspect ratio; α H represents the rudder blade attack angle; x R Indicates the coordinate value of the ship's center of gravity on the x-axis in the attached coordinate system; x H Indicates the coordinate value of the ship center on the x-axis in the attached coordinate system; ρ w Indicates the density of seawater; A R represents the rudder blade area; U R Indicates rudder apparent speed.

[0019] In one embodiment of the ship automatic steering control method based on synchronous triggering of input terminal and parameter update according to the present application, the rudder angle indication value of the steering gear satisfies the following conditions: ;in, δ max Indicates the maximum rudder angle indication value of the servo; δ 0 indicates the current rudder angle value.

[0020] In one embodiment of the ship autopilot control method based on synchronous triggering of input terminal and parameter update according to the present application, by Get the reference heading, where ѱ r represents the reference heading, represents the time first derivative of the reference heading; r r represents the reference bow angular velocity; Calculate the real-time heading error, where: ѱ e Indicates the real-time heading error.

[0021] In one embodiment of the ship automatic rudder control method based on synchronous triggering of input end and parameter update described in the present application, in the process of updating the control parameters based on the updated self-adjusting trigger rules, all control parameters are synchronously updated at the triggering moment based on the updated self-adjusting trigger rules.

[0022] Further objectives and advantages of the present application will be fully reflected through understanding of the following description and drawings.

[0023] These and other objects, features and advantages of the present application are fully reflected in the following detailed description, drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the drawings, the same reference numerals generally represent the same components or.

[0025] Figure 1 The figure shows a schematic diagram of the basic guidance principle of the LOS algorithm.

[0026] Figure 2 The figure shows a control logic diagram of a ship autopilot control method based on synchronous triggering of input terminals and parameter updates according to an embodiment of the present application.

[0027] Figure 3 The figure shows a flowchart schematic diagram of a ship autopilot control method based on synchronous triggering of input terminal and parameter update according to an embodiment of the present application.

[0028] Figure 4 A flowchart schematic diagram of a specific example of a ship autopilot control method based on synchronous triggering of input terminals and parameter updates according to an embodiment of the present application is illustrated.

[0029] Figure 5 The figure shows a schematic diagram of a comparison of a curve of a reference heading change with respect to time in a simulation situation and a curve of a real heading change with respect to time.

[0030] Figure 6 The figure shows a schematic diagram of a comparison between a curve of a trigger heading error changing over time under a simulation condition and a curve of a real-time heading error changing over time.

[0031] Figure 7 The figure shows a schematic diagram of a curve of a change in a steering command indication value with respect to time and a curve of a change in a control command with respect to time under a simulation situation.

[0032] Figure 8 The figure shows a schematic diagram of a curve diagram of the change of dynamic nonlinear compensation parameters with respect to time under simulation conditions.

[0033] Fig. 9 The figure shows a schematic diagram of a curve diagram of the change of the servo gain adaptive compensation parameters with respect to time under simulation conditions.

[0034] Fig.10 The figure shows a schematic diagram of a variation curve of the first trigger threshold parameter with respect to time and a variation curve of the second trigger threshold parameter with respect to time under simulation conditions.

[0035] Fig.11 The figure shows a schematic diagram of the change of the trigger interval under simulation conditions. DETAILED DESCRIPTION

[0036] Below, the exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the exemplary embodiments described here.

[0037] It is understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "one" cannot be understood as a limitation on the number. "Multiple" means greater than or equal to two.

[0038] Although ordinals such as "first," "second," and the like will be used to describe various components, those components are not limited herein. The term is used only to distinguish one component from another. For example, a first component may be referred to as a second component, and likewise, a second component may be referred to as a first component without departing from the teachings of the present application. The term "and / or" as used herein includes any and all combinations of one or more associated listed items.

[0039] The terms used herein are only used for the purpose of describing various embodiments and are not intended to be limiting. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates an exception. It will also be understood that the terms "including" and / or "having" when used in this specification specify the presence of the described features, numbers, operations, components, elements, or combinations thereof, without excluding the presence or addition of one or more other features, numbers, operations, components, elements, or combinations thereof.

[0040] Application Overview As mentioned above, there are some problems with the current ship autopilot heading keeping control algorithm. For example, the current steering command causes the steering gear to brake frequently, and the computing pressure and communication load are large. Therefore, an optimized ship autopilot control method is needed.

[0041] Specifically, in navigation practice, in the context of heading determination, the ship's duty officer's steering habit is to judge the timing of steering based on the heading error, which means that the ship's duty officer will only give new steering orders to correct the ship's heading when it deviates from his or her psychological expectations.

[0042] Accordingly, the current ship automatic steering heading keeping control algorithm mainly has two ideas: first, the ship sensor currently sends the ship heading information to the controller, and the controller currently generates a steering command to the steering gear; second, considering that the former control algorithm will cause frequent braking of the steering gear, which is not in line with the intermittent steering behavior of the ship's duty officer, the steering command signal is triggered, and a new steering command is sent to the steering gear when the steering command changes significantly, and when the steering command changes within a small range, it is chosen not to send a new steering command to the steering gear.

[0043] Based on the above analysis, it is found that the current ship autopilot heading keeping control algorithm has the following two main defects: First, it does not solve the problem of frequent execution of steering commands by the steering gear, causing steering gear wear; although it can trigger multiple steering commands, the algorithm is not intelligent enough, and it is difficult to give steering commands by judging the current heading of the ship similar to the steering habits of the ship's duty officer; Second, there are a large number of signal calculations and frequent communication frequencies in the communication links from the sensor to the controller and from the controller to the actuator of the ship's autopilot. The current heading keeping control algorithm has a large computing pressure and communication load in the communication link.

[0044] This application takes into account the fact that "the ship's duty officer gives the steering order based on the deviation of the ship's heading" in the practice of ship control engineering, and proposes a ship autopilot control method based on synchronous triggering of the input end and parameter update to solve the problem of ship autopilot heading maintenance. Specifically, this application establishes an event trigger mechanism with a self-adjusting mechanism, so that the ship can autonomously determine the timing of steering according to the heading situation; and all signals and parameters in the control closed loop are synchronously triggered, and are only transmitted and calculated at the triggering moment, which can greatly reduce the computing load and save communication resources.

[0045] Glossary Real-time heading error: The difference between the reference heading and the current heading of the ship.

[0046] Trigger heading error: The heading error that needs to be reached when the event is triggered in the self-adjusting trigger rule.

[0047] Trigger error: The difference between the trigger heading error and the real-time heading error.

[0048] Update law: The functional relationship between the updated controlled state variables and the system input signal.

[0049] Virtual control law: the functional relationship between the virtual controlled state variables and the system input signal.

[0050] Surge: The translational movement of a ship in the forward (bow) and aft (stern) directions.

[0051] Sway: The translation of a ship to the left (port side) or right (starboard side).

[0052] Yaw pitch: The left-right swaying of the bow of a ship.

[0053] Surge speed: the translational speed of a ship in the fore-and-aft direction.

[0054] Surge displacement: the displacement of a ship in the fore and aft translation direction.

[0055] Sway speed: the translation speed of the ship in the left and right directions.

[0056] Sway displacement: the displacement of a ship in the left and right translation direction.

[0057] Yaw angular velocity: the angular velocity of the ship in the left and right directions.

[0058] Bow displacement: the displacement in the left and right rotation direction of the ship.

[0059] Rudder blade angle of attack: the angle of elevation of the ship in the up and down directions.

[0060] Bow rate: The rate at which the bow of a ship turns.

[0061] Schematic diagram of a ship autopilot control method based on synchronous triggering of input and parameter update like Figures 2 to 11 As shown, the ship autopilot control method based on synchronous triggering of input terminal and parameter update according to the embodiment of the present application is explained. Figure 2 As shown, the input end and parameter update synchronization trigger strategy proposed in the present application is a communication link triggering method from sensor to controller and controller to actuator. The real-time heading error can be calculated based on the current heading and reference heading of the ship input to the sensor; then it is determined whether the real-time heading error meets the trigger rule, wherein when the real-time heading error meets the trigger rule, the parameters in the trigger rule are updated, for example, the trigger threshold parameter, and then the trigger rule is updated; and when the real-time heading error meets the trigger rule, the control parameters are updated, for example, the virtual control law, the dynamic reference information; then the controller generates a control command based on the updated control parameters, so that the steering gear servo mechanism, that is, the actuator changes the heading of the ship based on the control command.

[0062] Accordingly, if Figure 3 As shown, according to an embodiment of the present application, the ship automatic rudder control method based on synchronous triggering of input terminal and parameter update includes the following steps: S110, determining a real-time heading error based on a reference heading and a current heading of the ship; S120, judging whether the real-time heading error satisfies a self-adjusting trigger rule based on the real-time heading error and the self-adjusting trigger rule; S130, in response to the real-time heading error satisfying the self-adjusting trigger rule, updating the triggering heading error in the self-adjusting trigger rule to form an updated self-adjusting trigger rule; and, S140, updating the control parameters based on the updated self-adjusting trigger rule to form an updated control parameter; and S150, controlling the heading of the ship based on the updated control parameter.

[0063] In step S110, a real-time heading error is determined based on the reference heading and the current heading of the ship. The real-time heading error is equal to the difference between the reference heading and the current heading of the ship. Calculate the real-time heading error, where: ѱ e Indicates the real-time heading error; ѱ r Indicates the reference heading; ѱ Indicates the current heading of the ship.

[0064] In one example of the present application, the value of the time first-order derivative of the current heading of the ship is equal to the value of the actual yaw angular velocity. The value of the time first-order derivative of the reference heading is equal to the value of the reference yaw angular velocity. Accordingly, ,in, Represents the time first derivative of the current heading of the ship; rIndicates the actual yaw angular velocity; ,in, represents the time first derivative of the reference heading; r r Indicates the reference heading angular velocity. The reference heading angular velocity refers to the heading angular rate of the reference heading.

[0065] In the embodiment of the present application, the mathematical model of the ship's bow rolling motion is: ; in, ѱ Indicates the current heading of the ship; Represents the time first derivative of the current heading of the ship; u Indicates the ship's surge speed; v Indicates the ship's sway speed; r Indicates the actual yaw angular velocity; It represents the time first-order derivative of the actual yaw angular velocity; f(v) represents the nonlinear term of ship dynamics; Indicates the servo gain; d w Indicates the disturbance of the marine environment on the hull; δ Indicates the rudder angle indication value of the servo; m u Indicates the ship's longitudinal displacement; m v Indicates the ship's bow roll and sway displacement; m r Indicates the ship's bow displacement; d 1 represents the first ship hydrodynamic coefficient; d 2 represents the second ship hydrodynamic coefficient; d 3 represents the third ship hydrodynamic coefficient; λ R represents the rudder aspect ratio; α H represents the rudder blade attack angle; x R Indicates the coordinate value of the ship's center of gravity on the x-axis in the attached coordinate system; x H Indicates the coordinate value of the ship center on the x-axis in the attached coordinate system; ρ w Indicates the density of seawater; A R represents the rudder blade area; U R Indicates the apparent rudder speed. The apparent rudder speed refers to the speed of the rudder relative to the ocean current.

[0066] Surge refers to the translation of a ship in the forward (bow) and aft (stern) directions. Surge refers to the translation of a ship in the left (port) and right (starboard) directions. Bow roll refers to the swinging of the bow of a ship in the left and right directions. Surge speed refers to the translation speed of a ship in the front-to-back direction. Surge displacement refers to the displacement of a ship in the front-to-back translation direction. Surge speed refers to the translation speed of a ship in the left-to-right direction. Surge displacement refers to the displacement of a ship in the left-to-right translation direction. Bow roll angular velocity refers to the angular velocity of rotation of a ship in the left-to-right direction. Bow roll displacement refers to the displacement of a ship in the left-to-right rotation direction. In the embodiment of the present application, the mass of water displaced is recorded as displacement.

[0067] Rudder angle indication value of the servo δ The following conditions are met: ; in, δ max Indicates the maximum rudder angle indication value of the servo; δ 0 indicates the current rudder angle value; Indicates the current rudder angle value δ The absolute value of 0; is the current rudder angle value δ 0 sign function, when δ When 0 is greater than 0, is equal to 1, when δ When 0 is equal to 0, Equal to 0, when δ When 0 is less than 0, Equal to -1. Accordingly, when the current rudder angle value δ When the absolute value of 0 is less than the maximum rudder angle indication value of the servo, the rudder angle indication value of the servo δ Equal to the current rudder angle value δ 0; when the current rudder angle value δ The absolute value of 0 is greater than or equal to the maximum rudder angle indication value of the servo δ max When the rudder angle indication value of the servo is δ Equal to the maximum rudder angle indication value of the servo δ max With the current rudder angle value δ The product of the return value of 0.

[0068] In step S120, it is determined whether the real-time heading error satisfies the self-adjustment triggering rule based on the real-time heading error and the self-adjustment triggering rule. Specifically, assuming that the triggering time of the event is t 1, t 2, ..., t k , t k+1 ,k is a positive integer, for example, 1, 2, 3…; t 1, t 2, ..., t k , t k+1 can be respectively referred to as the first triggering moment, the second triggering moment, ..., the k Trigger moment, t k+1 Indicates the first k+ 1) Trigger moment.

[0069] In the embodiment of the present application, the present application establishes an event trigger mechanism with a self-adjusting mechanism, so that the ship can autonomously determine the timing of steering according to the heading conditions. This can not only reduce the transmission frequency of control commands, reduce the braking frequency of the steering mechanism to a certain extent, reduce the computing pressure and communication load, but also be more in line with the steering habits of the ship's duty officers, and improve the consistency between the automatic rudder control method and the steering habits of the ship's duty officers, which is of great significance to the intelligent driving of large ships.

[0070] The self-adjustment triggering rule is: ; in, t Indicates the triggering moment; t k Indicates k Trigger moment; t k+1 Indicates the first k+ 1) Triggering moment; k is a positive integer; Indicates the trigger heading error; wherein the value of the trigger heading error is equal to the value of the real-time heading error; represents the function of the trigger heading error with respect to time; ѱ e Indicates the real-time heading error; ѱ e ( t ) represents the function of real-time heading error with respect to time; Indicates trigger error; represents the trigger error as a function of time; represents the first trigger threshold parameter; Indicates the second trigger threshold parameter. Indicates that when the trigger time is met Update to the next moment, that is, from t k Updated to t k+1 .

[0071] In step S130, in response to the real-time heading error satisfying the self-adjustment triggering rule, the triggering heading error in the self-adjustment triggering rule is updated to form an updated self-adjustment triggering rule. Specifically, in the updated self-adjustment triggering rule, the value of the triggering heading error is ѱ e ( t k ) is updated to ѱ e ( t k+1 ),like Figure 4 As shown; ѱ e ( t k+1 )express t k+1 The real-time heading error at the moment. The trigger heading error refers to the heading error that needs to be reached when the event is triggered in the self-adjusting trigger rule. The trigger error is the difference between the trigger heading error and the real-time heading error. .

[0072] The update law of the first trigger threshold parameter is: ; The update law of the second trigger threshold parameter is: ;in, represents the updated first trigger threshold parameter; represents the updated second trigger threshold parameter; in the present application, the value of the time first-order derivative of the first trigger threshold parameter is the updated first trigger threshold parameter; the value of the time first-order derivative of the second trigger threshold parameter is the updated second trigger threshold parameter; C 1 represents the first preset constant; C 2 represents the second preset constant; D Indicates the third preset constant.

[0073] In step S140, the control parameters are updated based on the updated self-adjustment triggering rule to form updated control parameters. Specifically, the control parameters include heading keeping virtual control law and dynamic reference information.

[0074] Accordingly, step S140, updating the control parameters based on the updated self-regulating triggering rule, includes the steps of: acquiring a heading keeping virtual control law based on the updated self-regulating triggering rule and acquiring dynamic reference information based on the updated self-regulating triggering rule.

[0075] The virtual control law for heading keeping is: ;in, α k represents the controlled state variable of the heading keeping virtual control law, wherein the controlled state variable of the heading keeping virtual control law is the angular velocity;α k ( t ) represents the function of the controlled state variables of the heading keeping virtual control law with respect to time; λ is a constant in [-1,1]; k ѱ represents the control parameters of the virtual control law; represents the time first derivative of the reference heading; express t k The time first derivative of the reference heading at time instant.

[0076] The dynamic reference information includes the controlled state variables of the heading keeping virtual control law after first-order filtering and the dynamic error of the ship's bow pitch. The controlled state variables of the heading keeping virtual control law after first-order filtering are obtained; wherein, represents the time constant; β k represents the controlled state variable of the heading keeping virtual control law after the first order filtering, that is, the angular velocity of the heading keeping virtual control law after the first order filtering; represents the controlled state variable of the updated first-order filtered heading keeping virtual control law; ,in, β k (0) represents the yaw angular velocity at time 0, i.e., the initial yaw angular velocity; α k (0) represents the heading keeping virtual control law at time 0, that is, the initial heading keeping virtual control law. The dynamic error of the ship's bow motion is calculated; represents the dynamic error, r k Indicates that the ship is t k The actual yaw angular velocity at the moment.

[0077] The input terminal and parameter update synchronization trigger strategy proposed in this application is a communication link triggering method from sensor to controller and controller to actuator, so that all signals are transmitted and calculated only at the triggering moment, which greatly reduces the calculation load and saves communication resources. Accordingly, in the process of updating the control parameters based on the updated self-adjusting triggering rules, all control parameters are synchronously updated at the triggering moment based on the updated self-adjusting triggering rules.

[0078] In step S150, the heading of the ship is controlled based on the updated control parameters. Specifically, the control command and steering command of the ship's automatic rudder are obtained based on the updated control parameters, wherein Calculate the control command of the ship's automatic rudder, through Calculate and obtain steering orders.

[0079] ο k Indicates the control command of the ship's automatic pilot; k r Indicates the control parameters of the autopilot heading hold controller; δ k Indicates rudder orders; m r Indicates the ship's bow displacement; represents the dynamic nonlinear compensation parameter; Indicates the servo gain adaptive compensation parameter; θ k represents the activation function; represents a small positive quantity; the update law of the dynamic nonlinear compensation parameter is: ; The update law of the servo gain adaptive compensation parameters is: ;in, Represents the updated dynamic nonlinear compensation parameters; Indicates the updated servo gain adaptive compensation parameters; represents the learning rate of the update law for the dynamics nonlinear compensation parameters; Represents the learning rate of the update law of the servo gain adaptive compensation parameters; and are all constants and positive numbers; represents the dynamic nonlinear compensation parameter at time 0, that is, the initial dynamic nonlinear compensation parameter; It represents the servo gain adaptive compensation parameter at time 0, that is, the initial servo gain adaptive compensation parameter.

[0080] In order to verify the effectiveness of the ship autopilot control method based on synchronous triggering of input terminal and parameter update in the embodiment of the present application, a computer simulation experiment was carried out using Matrix&laboratory software (matlab). ѱ r =90deg, reference bow angular velocity r r =0deg / s, current heading of the ship ѱ = 0deg, actual bow angular velocity r =0deg / s, it is expected that the ship automatic rudder control method based on the synchronous triggering of the input end and parameter update in the embodiment of the present application can keep the heading of the ship on the reference heading.

[0081] Figures 5 to 11The simulation results of ship automatic rudder heading keeping under level 4 sea conditions simulated on the MATLAB simulation platform are shown. Figure 5 The diagram shows the curve of the reference heading changing with time and the curve of the actual heading changing with time in the simulation. Figure 5 It can be seen that the autopilot can keep the actual heading of the ship close to the preset reference heading. Figure 6 The figure shows the variation curve of the triggered heading error over time and the variation curve of the real-time heading error over time in the simulation. The triggered heading error is obtained after the real-time heading error has been self-adjusted through the triggering rules. It can be seen that when the real-time heading error changes within a small range, the triggered heading error remains unchanged. When the change of the real-time heading error reaches the triggering rule, the triggered heading error will be updated. At the same time, the ship control command and various parameters are also triggered based on the above self-adjusting triggering rules, such as Figures 7 to 10 The triggering time interval eventually stabilizes at around 5 to 10 seconds, as shown in Fig.11 shown.

[0082] Combined with the above verification experiments, the ship automatic rudder control method based on the synchronous triggering of the input end and parameter update in the embodiment of the present application solves the defect that the traditional heading keeping control algorithm cannot simulate the ship duty officer's steering habit to update the rudder order, and can realize the ship to autonomously determine the timing of steering according to the heading situation, which is of great significance to the intelligent driving of large ships. It also makes all signals transmitted and calculated only at the triggering moment, which greatly reduces the computing load and saves communication resources.

[0083] The present application and its implementation methods are described above, and such description is not restrictive. The drawings show only one implementation method of the present application, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design structural methods and embodiments similar to the technical solution without creative design without departing from the inventive purpose of the present application, they should all fall within the protection scope of the present application.

Claims

1. A ship autopilot control method based on synchronous triggering of input terminal and parameter update, characterized in that: Includes steps: determining a real-time heading error based on a reference heading and a current heading of the vessel; Based on the real-time heading error and the self-adjustment trigger rule, it is determined whether the real-time heading error satisfies the self-adjustment trigger rule; In response to the real-time heading error satisfying the self-adjustment trigger rule, updating the trigger heading error in the self-adjustment trigger rule to form an updated self-adjustment trigger rule; updating the control parameters based on the updated self-adjusting triggering rules to form updated control parameters; as well as controlling the heading of the vessel based on the updated control parameters; The self-adjustment triggering rule is: ； in, t Indicates the triggering moment; t k Indicates k Trigger moment; t k+1 Indicates the first k+ 1) Triggering moment; k is a positive integer; Indicates the trigger heading error; represents the function of the trigger heading error with respect to time; ѱ e Indicates the real-time heading error; ѱ e ( t ) represents the function of real-time heading error with respect to time; Indicates trigger error; represents the trigger error as a function of time; represents the first trigger threshold parameter; represents the second trigger threshold parameter; ; In the updated self-adjustment trigger rule, the value of the trigger heading error is ѱ e ( t k ) is updated to ѱ e ( t k+1 ); ѱ e ( t k )express t k Real-time heading error at the moment; ѱ e ( t k+1 )express t k+1 Real-time heading error at the moment; Among them, the update law of the first trigger threshold parameter is: ; The update law of the second trigger threshold parameter is: ;in, represents the updated first trigger threshold parameter; represents the updated second trigger threshold parameter; C 1 represents the first preset constant; C 2 represents the second preset constant; D Indicates the third preset constant.

2. The ship automatic pilot control method based on synchronous triggering of input terminal and parameter update according to claim 1 is characterized in that: Updating control parameters based on the updated self-adjusting triggering rules comprises the steps of: Based on the updated self-adjustment trigger rule, a heading keeping virtual control law is obtained, wherein the heading keeping virtual control law is: ; in, α k represents the controlled state variable of the heading keeping virtual control law, wherein the controlled state variable of the heading keeping virtual control law is the angular velocity; α k ( t ) represents the function of the controlled state variables of the heading keeping virtual control law with respect to time; λ is a constant in [-1,1]; k ѱ represents the control parameters of the virtual control law; represents the time first derivative of the reference heading; express t k The time first derivative of the reference heading at time instant.

3. The ship automatic pilot control method based on synchronous triggering of input terminal and parameter update according to claim 2 is characterized in that: The control parameters are updated based on the updated self-adjusting triggering rules, further comprising the steps of: Based on the updated self-regulating triggering rule, dynamic reference information is obtained, wherein the dynamic reference information includes the controlled state variables of the heading keeping virtual control law after first-order filtering, through Obtaining the controlled state variables of the heading keeping virtual control law after first-order filtering; in, represents the time constant; β k represents the controlled state variable of the heading keeping virtual control law after first-order filtering; represents the time first-order derivative of the controlled state variable of the heading keeping virtual control law after first-order filtering; ,in, β k (0) represents the controlled state variable of the heading keeping virtual control law after first-order filtering at time 0; α k (0) represents the heading keeping virtual control law at time 0.

4. The ship automatic pilot control method based on synchronous triggering of input terminal and parameter update according to claim 3 is characterized in that: The dynamic reference information also includes the dynamic error of the ship's bow pitch, wherein Calculate and obtain the dynamic error of the ship's bow rolling motion; in, represents the dynamic error, r k Indicates that the ship is t k The actual yaw angular velocity at the moment.

5. The ship automatic pilot control method based on synchronous triggering of input terminal and parameter update according to claim 4, characterized in that: The method controls the heading of a ship based on the updated control parameters, comprising the steps of: obtaining a control command and a steering command of the ship's automatic rudder based on the updated control parameters, wherein: Calculate the control command of the ship's automatic rudder, through Calculate and obtain steering orders; in, ο k Indicates the control command of the ship's automatic pilot; k r Indicates the control parameters of the autopilot heading hold controller; δ k Indicates rudder orders; m r Indicates the ship's bow displacement; represents the dynamic nonlinear compensation parameter; Indicates the servo gain adaptive compensation parameter; θ k represents the activation function; represents a small positive quantity; the update law of the dynamic nonlinear compensation parameter is: ; The update law of the servo gain adaptive compensation parameters is: ;in, Represents the updated dynamic nonlinear compensation parameters; Indicates the updated servo gain adaptive compensation parameters; represents the learning rate of the update law for the dynamics nonlinear compensation parameters; Represents the learning rate of the update law of the servo gain adaptive compensation parameters; and are all constants and positive numbers; represents the initial dynamic nonlinear compensation parameter; Indicates the initial servo gain adaptive compensation parameter.

6. The ship automatic pilot control method based on synchronous triggering of input terminal and parameter update according to claim 1, characterized in that: The mathematical model of ship bow rolling motion is: ； in, ѱ Indicates the current heading of the ship; Represents the time first derivative of the current heading of the ship; u Indicates the ship's surge speed; v Indicates the ship's sway speed; r Indicates the actual yaw angular velocity; It represents the time first-order derivative of the actual yaw angular velocity; f(v) represents the nonlinear term of ship dynamics; Indicates the servo gain; d w Indicates the disturbance of the marine environment on the hull; δ Indicates the rudder angle indication value of the servo; m u Indicates the ship's longitudinal displacement; m v Indicates the ship's bow roll and sway displacement; m r Indicates the ship's bow displacement; d 1 represents the first ship hydrodynamic coefficient; d 2 represents the second ship hydrodynamic coefficient; d 3 represents the third ship hydrodynamic coefficient; λ R represents the rudder aspect ratio; α H represents the rudder blade attack angle; x R Indicates the coordinate value of the ship's center of gravity on the x-axis in the attached coordinate system; x H Indicates the coordinate value of the ship center on the x-axis in the attached coordinate system; ρ w Indicates the density of seawater; A R represents the rudder blade area; U R Indicates rudder apparent speed.

7. The ship automatic pilot control method based on synchronous triggering of input terminal and parameter update according to claim 6, characterized in that: The rudder angle indication value of the servo meets the following conditions: ； in, δ max Indicates the maximum rudder angle indication value of the servo; δ 0 indicates the current rudder angle value.

8. The ship automatic pilot control method based on synchronous triggering of input terminal and parameter update according to claim 7, characterized in that: pass Get the reference heading, where ѱ r represents the reference heading, represents the time first derivative of the reference heading; r r represents the reference bow angular velocity; Calculate the real-time heading error, where: ѱ e Indicates the real-time heading error.

9. The ship autopilot control method based on synchronous triggering of input terminal and parameter update according to claim 1, characterized in that: In the process of updating the control parameters based on the updated self-adjusting triggering rule, all the control parameters are synchronously updated at the triggering moment based on the updated self-adjusting triggering rule.

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