阅读说明：本技术 一种具有横摇约束的欠驱动船舶航向制导方法 (Under-actuated ship course guidance method with rolling constraint ) 是由 刘志全 秦毅峰 朱云浩 储瑞婷 刘嘉昊 田晓 于 2021-09-17 设计创作，主要内容包括：本发明提供一种具有横摇约束的欠驱动船舶航向制导方法,具体步骤包括：步骤S1、设定路径(x-(p)(ω),y-(p)(ω))和路径参数ω；步骤S2、根据步骤S1获取路径点坐标(x-(p),y-(p))信息和路径切向角α-(p)信息；步骤S3、通过测量获得船舶位置坐标(x,y)信息和船舶运动状态信息；步骤S4、根据步骤S3所获得的船舶位置坐标信息和船舶运动状态信息估计横向漂角；步骤S5、结合步骤S1～步骤S4所获取的船舶信息,计算指令航向角ψ-(d)。本发明有效提高了恶劣海况下的指令航向角的精度,实现了对船舶航向的准确控制。(The invention provides an under-actuated ship course guidance method with rolling constraint, which specifically comprises the following steps: step S1, setting Path (x) p (ω),y p (ω)) and a path parameter ω; step S2, obtaining the coordinates (x) of the path point according to the step S1 p ,y p ) Information and path tangent angle alpha p Information; step S3, obtaining ship position coordinate (x, y) information and ship motion state information through measurement; step S4, estimating a transverse drift angle according to the ship position coordinate information and the ship motion state information obtained in the step S3; step S5, combining the ship information acquired in the steps S1-S4, calculating the command heading angle psi d . The invention effectively improves the precision of the instruction course angle under the severe sea condition and realizes the accurate control of the ship course.)

1. An under-actuated ship course guidance method with rolling constraint is characterized by comprising the following steps:

step S1, setting Path (x)_p(ω),y_p(ω)) and a path parameter ω;

step S2, obtaining the coordinates (x) of the path point according to the step S1_p,y_p) Information and path tangent angle alpha_pInformation;

step S3, obtaining ship position coordinate (x, y) information and ship motion state information through measurement;

step S4, estimating a transverse drift angle according to the ship position coordinate information and the ship motion state information obtained in the step S3;

step S5, combining the ship information acquired in the steps S1-S4, calculating the command heading angle psi_d。

2. The under-actuated marine vessel heading guidance method with roll constraint as claimed in claim 1, wherein the marine vessel motion state information of step S3 includes a surge speed u, a roll angle Φ, a heading angle ψ, a roll angular velocity p and a heading angular velocity r at a certain same time t.

3. The under-actuated marine vessel heading guidance method with roll constraint as recited in claim 2, wherein the estimating the lateral drift angle in step S4 specifically comprises the steps of:

step S401, according to ship position coordinate (x, y) information of certain same t time, tangential tracking error x is calculated_eAnd vertical tracking error y_e；

Step S402, according to the tangential tracking error x in step S401_eAnd vertical tracking error y_eCalculating an estimate of lateral drift angle beta

4. An under-actuated marine vessel heading guidance method with roll restraint as claimed in claim 3 wherein the estimated value of the lateral drift angle β of step S402Calculated using the following formula:

wherein the content of the first and second substances,is an estimate of g.

5. The method for under-actuated vessel heading guidance with roll constraint as recited in claim 4 wherein the tangential tracking error x of step S401_eAnd vertical tracking error y_eThe calculation formula of (a) is as follows:

6. the under-actuated marine vessel heading guidance method with roll constraint as claimed in claim 2, wherein the path parameter ω of step S1 is a function of time t, and is calculated by the following update law formula:

wherein u is horizontal oscillation speed, psi is course angle, alpha_p(ω) is the path tangent angle, x_eIs the tangential tracking error, x'_p(ω) is x_pDerivative of (ω) to ω, y'_p(ω) is y_p(ω) the derivative of ω, k is a design normal,is the derivative of ω with time t; (x)_p(ω),y_p(ω)) is the coordinates of the points that make up the path.

7. The under-actuated marine vessel heading guidance method with roll restraint as claimed in claim 6, wherein the path tangential angle α in step S2_pCalculated by the following formula:

wherein, the coordinates (x) of the waypoints described in step S2_p,y_p) And path tangential angle alpha_pRespectively composed of paths (x)_p(ω),y_p(ω)) and path tangent angle α_pAnd (omega) is obtained by calculation at a certain same t time.

8. The under-actuated vessel heading guidance method with roll constraint according to claim 7, wherein the relationship between the vessel motion state and the vessel position in step S3 is described by a four-degree-of-freedom kinematic coupling model, which is expressed as follows:

wherein the content of the first and second substances,the derivatives of the vessel position coordinates (x, y) with respect to time t, v is the surging velocity, u is the oscillation velocity,is the derivative of the roll angle phi with respect to time t,is the derivative of the heading angle psi over time t.

9. The method of claim 5 wherein said under-actuated vessel heading guidance with roll restraint is providedThe method can be obtained by calculation of a reduced order observer, and the formula of the reduced order observer is as follows:

wherein, M is a virtual state,is derived from M versus time tNumber, k₁In order to be a normal number for the design,is alpha_pDerivative with respect to time t.

10. The method of claim 9 for under-actuated vessel heading guidance with roll restraint based on the derived path tangent angle α_pEstimate of the lateral drift angle betaAnd vertical tracking error y_eThe command heading angle ψ described in step S5_dCalculated using the following formula:

where Δ is the look-ahead distance.

Technical Field

The invention relates to the technical field of ship motion control, in particular to an under-actuated ship course guidance method with rolling restraint.

Background

The ship inevitably generates six-degree-of-freedom swinging motion in the navigation of stormy waves, wherein the rolling motion is the most violent, and the normal operation of electrical equipment, the safe navigation of the ship and the comfort of sailors are seriously influenced by the large-amplitude rolling motion. The motion control devices of an under-actuated vessel are typically a heading control device (rudder) and a propulsion control device (thruster), with no corresponding control devices for the heaving and rolling motions. The path tracking control of the under-actuated ship plays an important role in the technical field of ship motion control, and requires a course control system of the ship to track a pre-planned path or track at a constant speed according to an instruction course angle calculated by a course guidance rule, wherein a currently common course guidance method is an LOS (line of sight) method.

The course guidance law is an important part in a path tracking control system, and a ship path tracking horizontal plane coordinate system is shown in figure 1, wherein: XOY is the geodetic coordinate system, (x)_p(ω),y_p(ω)) is a parameterized path, ω is a path parameter, and omitting parameter ω for convenience will simplify the path point coordinates to (x)_p,y_p) (x, y) are ship position coordinates, x_eFor tangential tracking error, y_ePhi is the vertical tracking error, phi is the heading angle, beta is the transverse drift angle, alpha_pThe tangential angle of the path is v, the oscillation speed is v, the surging speed is U, the navigation speed is U, and the forward-looking distance is delta. The ship position information can be obtained by GPS measurement, and the ship motion state information (including the surging speed u, the roll angle phi and the course angle psi, etc.) can be obtained by gyroscope measurement. Aiming at the problem of parameterized path tracking control, the currently proposed LOS methods (such as proportional LOS, integral LOS, adaptive LOS and the like) basically consider the problems of transverse drift angle estimation and vertical tracking error convergence, less consider the convergence problem of tangential tracking error, and simultaneously do not consider the influence of large-amplitude rolling motion on a course angle and a course guidance law, so that the large-amplitude rolling motion in stormy waves is greatly influencedUnder-actuated vessel path tracking control of the pendulum is considered insufficient. Therefore, for an under-actuated ship without a roll stabilizing control device, the course guidance method considering the roll constraint is beneficial to improving the path tracking precision of the under-actuated ship.

Disclosure of Invention

The invention aims to provide an under-actuated ship course guidance method with rolling constraint, which solves the problem of tracking accuracy of under-actuated ship path control of large rolling under severe sea conditions.

In order to achieve the aim, the invention provides an under-actuated ship course guidance method with rolling constraint, which comprises the following specific steps: step S1, setting Path (x)_p(ω),y_p(ω)) and a path parameter ω; step S2, obtaining the coordinates (x) of the path point according to the step S1_p,y_p) Information and path tangent angle alpha_pInformation; step S3, obtaining ship position coordinate (x, y) information and ship motion state information through measurement; step S4, estimating a transverse drift angle according to the ship position coordinate information and the ship motion state information obtained in the step S3; step S5, combining the ship information acquired in the steps S1-S4, calculating the command heading angle psi_d。

Preferably, the ship motion state information of step S3 includes a surge speed u, a roll angle phi, a heading angle psi, a roll angular velocity p, and a heading angular velocity r for a certain time t.

Preferably, the estimating the lateral drift angle in step S4 specifically includes the following steps:

step S401, according to ship position coordinate (x, y) information of certain same t time, tangential tracking error x is calculated_eAnd vertical tracking error y_e；

Step S402, according to the tangential tracking error x in step S401_eAnd vertical tracking error y_eCalculating an estimate of lateral drift angle beta

Preferably, the estimated value of the transverse drift angle beta in step S402Calculated using the following formula:

wherein the content of the first and second substances,is an estimate of g.

Preferably, the tangential tracking error x described in step S401_eAnd vertical tracking error y_eThe calculation formula of (a) is as follows:

preferably, the path parameter ω of step S1 is a function of time t, and is calculated by an update rule formula:

wherein u is the horizontal oscillation speed, psi is the course angle, alpha_p(ω) is the path tangent angle, x_eIs the tangential tracking error, x'_p(ω) is x_pDerivative of (ω) to ω, y'_p(ω) is y_p(ω) the derivative of ω, k is a design normal,is the derivative of ω with time t; (x)_p(ω),y_p(ω)) is the coordinates of the points that make up the path.

Preferably, the path tangential angle α described in step S2_pCalculated by the following formula:

wherein, the coordinates (x) of the waypoints described in step S2_p,y_p) And path tangential angle alpha_pRespectively composed of paths (x)_p(ω),y_p(ω)) and path tangent angle α_pAnd (omega) is obtained by calculation at a certain same t time.

Preferably, the relationship between the ship motion state and the ship position in step S3 is described by a four-degree-of-freedom kinematic coupling model, which is expressed as follows:

wherein the content of the first and second substances,the derivatives of the vessel position coordinates (x, y) with respect to time t, v is the surging velocity, u is the oscillation velocity,is the derivative of the roll angle phi with respect to time t,is the derivative of the heading angle psi over time t.

Preferably, saidCan be obtained by calculation with a reduced order observerThe equation for the detector is as follows:

wherein, M is a virtual state,is the derivative of M with respect to time t, k₁In order to be a normal number for the design,is alpha_pDerivative with respect to time t.

Preferably, the tangential angle α is obtained according to the path_pEstimate of the lateral drift angle betaAnd vertical tracking error y_eThe command heading angle ψ described in step S5_dCalculated using the following formula:

where Δ is the look-ahead distance.

In summary, compared with the prior art, the under-actuated ship course guidance method with rolling constraint provided by the invention has the following beneficial effects: the influence of large-amplitude rolling motion of the under-actuated ship on the course angle and the course guidance law under the severe sea condition is considered, the transverse drift angle estimation is calculated and obtained through the measured ship motion state, the precision of the instruction course angle under the severe sea condition is effectively improved, and the accurate control of the ship course is realized.

Drawings

FIG. 1 is a schematic diagram of a path tracking coordinate system of an under-actuated ship course guidance method with roll constraint according to the present invention;

FIG. 2 is a schematic diagram of a calculation process of an instruction course angle of the under-actuated ship course guidance method with roll constraint.

Detailed Description

Technical solutions, structural features, achieved objects and effects in the embodiments of the present invention will be described in detail below with reference to fig. 1 to 2 of the drawings in the embodiments of the present invention.

It should be noted that the drawings are simplified in form and not to precise scale, and are only used for convenience and clarity to assist in describing the embodiments of the present invention, but not for limiting the conditions of the embodiments of the present invention, and therefore, the present invention is not limited by the technical spirit, and any structural modifications, changes in the proportional relationship, or adjustments in size, should fall within the scope of the technical content of the present invention without affecting the function and the achievable purpose of the present invention.

It should be noted that, in the present invention, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only the elements explicitly listed, but may include other elements not explicitly listed, or may include elements inherent to such process, method, article, or apparatus.

The invention provides an under-actuated ship course guidance method with rolling restriction, which comprises the following steps as shown in figures 1 and 2:

step S1, setting Path (x)_p(ω),y_p(ω)) and a path parameter ω.

The path parameter ω in step S1 is a function of time t, and is calculated by the following update rule formula:

in formula (1), u is the oscillation speed, psi is the course angle, alpha_p(ω) is the path tangent angle, x_eIs the tangential tracking error, x'_p(ω) is x_pDerivative of (ω) to ω, y'_p(ω) is y_p(ω) the derivative of ω, k is a design normal,is the derivative of ω with time t; (x)_p(ω),y_p(ω)) are the coordinates of the points that make up the path;

further, the path tangential angle α_p(ω) is calculated by the following formula:

step S2, obtaining the coordinates (x) of the path point at t time according to the step S1_p,y_p) Information and t time path tangent angle alpha_pAnd (4) information.

And step S3, obtaining ship position coordinate (x, y) information of t time according to GPS measurement, and obtaining ship motion state information of t time through a gyroscope installed on the ship.

The ship motion state information in step S3 includes a surge speed u, a roll angle phi, a heading angle psi, a roll angular velocity p, and a heading angular velocity r.

Further, the relation between the ship motion state and the ship position is described by a four-degree-of-freedom kinematic coupling model, which is specifically as follows:

in the formula (3), the reaction mixture is,the derivatives of the vessel position coordinates (x, y) with respect to time t, v is the surging velocity, u is the oscillation velocity,is the derivative of the roll angle phi with respect to time t,is the derivative of the heading angle psi over time t.

Step S4, estimating the transverse drift angle according to the ship position coordinate information and the ship motion state information obtained in the step S3, which comprises the following steps:

step S401, calculating a tangential tracking error x according to ship position coordinate (x, y) information_eAnd vertical tracking error y_eThe calculation formula is as follows:

step S402, according to the tangential tracking error x in step S401_eAnd vertical tracking error y_eCalculating an estimate of lateral drift angle beta

Wherein, the estimated value of the transverse drift angle beta in the step S402Calculated using the following formula:

in the formula (5), the reaction mixture is,is an estimate of g.

Further, theThe method can be obtained by calculation of a reduced order observer, and the formula of the reduced order observer is as follows:

in the formula (6), M is a virtual state,is the derivative of M with respect to time t, k₁In order to be a normal number for the design,is alpha_pDerivative with respect to time t.

Step S5, the path tangential angle alpha acquired according to the steps S1 to S4_pEstimate of the lateral drift angle betaAnd vertical tracking error y_eCalculating the commanded heading angle psi_d。

Wherein the command heading angle ψ described in step S5_dCalculated using the following formula:

in the formula (7), Δ is a forward looking distance, and is usually 2 to 3 times the length of the ship.

The command heading angle ψ obtained by calculation according to step S5_dTo make the ship course angle psi obtain the instruction course angle psi capable of tracking_dI.e. the ship can make the heading angle psi according to the instruction_dAnd adjusting the ship navigation direction, realizing the ship course control and finishing the ship course guidance.

In conclusion, compared with the existing under-actuated ship course guidance method, the under-actuated ship course guidance method with the rolling constraint provided by the invention has the advantages that the instruction course angle precision under the severe sea condition can be effectively improved due to the consideration of the influence of the large-amplitude rolling motion of the under-actuated ship on the course angle and the course guidance rule under the severe sea condition, and the like.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.